Materials and Properties
ZHANG Ce, YANG Weimin, TAN Jing, DING Yumei, CHENG Lisheng
Abstract (
205 )
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82
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10 )
The microwave removing process of residual dimethyl sulfoxide （DMSO） from polyacrylonitrile （PAN） films was studied using X⁃ray diffraction， elemental analysis， and scanning electron microscopy. The effects of microwave power and processing time on the DMSO removal efficiency， microstructure， and mechanical properties of PAN films were analyzed. The experimental results indicated that the residual amount of DMSO in PAN continued to decrease with an increase in the microwave processing power and microwave processing time. The crystallinity of PAN film tended to decrease at first and then increased. Meanwhile， the grain size continued to increase， the micropore size of PAN film decreased significantly， the overall tensile strength increased， and the elongation at break decreased. After treated with 540 W microwave for 4 minutes， the tensile strength of the PAN film reached 21.36 MPa， which was 46.5 % higher than that of the initial film. The average pore size inside the PAN film decreased and the overall structure became denser.
2023, 37 (10):
1-7;
Abstract (
0 )
PDF (0 KB)(
0
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The microwave removing process of residual dimethyl sulfoxide （DMSO） from polyacrylonitrile （PAN） films was studied using X-ray diffraction， elemental analysis， and scanning electron microscopy. The effects of microwave power and processing time on the DMSO removal efficiency， microstructure， and mechanical properties of PAN films were analyzed. The experimental results indicated that the residual amount of DMSO in PAN continued to decrease with an increase in the microwave processing power and microwave processing time. The crystallinity of PAN film tended to decrease at first and then increased. Meanwhile， the grain size continued to increase， the micropore size of PAN film decreased significantly， the overall tensile strength increased， and the elongation at break decreased. After treated with 540 W microwave for 4 minutes， the tensile strength of the PAN film reached 21.36 MPa， which was 46.5 % higher than that of the initial film. The average pore size inside the PAN film decreased and the overall structure became denser.
Materials and Properties
YU Min
Abstract (
183 )
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78
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HTML (
5 )
Based on gas chromatography⁃tandem mass spectrometry （GC⁃MS/MS）， a detection method for 14 types of organic phosphate flame retardants in polyurethane foams was established through adopting ultrasonic extraction and concentration with acetone， filtering with a constant volume， determining with gas chromatography⁃tandem mass spectrometry， and quantifying with an external standard method. Through parameter optimization， the experimental results indicated that there was a good linear relationship at gradient concentrations of tris（2⁃chloroethyl） phosphate （TCEP） and Tri⁃m⁃cresylphosphate （TMCP） in the range of 0.02~0.2 mg/L， a gradient concentration of tris（2⁃butoxyethyl） phosphate （TBEP） in the range of 0.05~0.5 mg/L， and gradient concentrations of the remaining 11 organic phosphates in the range of 0.01~0.1 mg/L with a linear correlation coefficient greater than 0.995. In this case， the quantification limit of TCEP and TMCP was 0.33 mg/kg， and their limit of detection was 0.10 mg/kg. The quantification limit of TBEP was 0.83 mg/kg， and its limit of detection was 0.25 mg/kg. The quantification limit of the ester was 0.17 mg/kg， and its limit detection was 0.05 mg/kg. The recoveries of three gradient spiked parallel experiments ranged from 87.0 % to 108.1 %， and their relative standard deviations ranged from 2.5 % to 10.6 %.
2023, 37 (10):
8-14;
Abstract (
0 )
PDF (0 KB)(
0
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Based on gas chromatography-tandem mass spectrometry （GC-MS/MS）， a detection method for 14 types of organic phosphate flame retardants in polyurethane foams was established through adopting ultrasonic extraction and concentration with acetone， filtering with a constant volume， determining with gas chromatography-tandem mass spectrometry， and quantifying with an external standard method. Through parameter optimization， the experimental results indicated that there was a good linear relationship at gradient concentrations of tris（2-chloroethyl） phosphate （TCEP） and Tri-m-cresylphosphate （TMCP） in the range of 0.02~0.2 mg/L， a gradient concentration of tris（2-butoxyethyl） phosphate （TBEP） in the range of 0.05~0.5 mg/L， and gradient concentrations of the remaining 11 organic phosphates in the range of 0.01~0.1 mg/L with a linear correlation coefficient greater than 0.995. In this case， the quantification limit of TCEP and TMCP was 0.33 mg/kg， and their limit of detection was 0.10 mg/kg. The quantification limit of TBEP was 0.83 mg/kg， and its limit of detection was 0.25 mg/kg. The quantification limit of the ester was 0.17 mg/kg， and its limit detection was 0.05 mg/kg. The recoveries of three gradient spiked parallel experiments ranged from 87.0 % to 108.1 %， and their relative standard deviations ranged from 2.5 % to 10.6 %.
Materials and Properties
SHEN Haijuan, LI Chenggao, GUO Rui, XIN Meiyin, HUANG Xiangyu, ZHANG Zhonghui, XIAN Guijun
Abstract (
173 )
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81
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5 )
In this paper， the stress distribution and anchoring mechanism of three typical anchoring systems were studied for the anchoring failure of carbon/glass fiber reinforced polymer composite rods. The results indicated that the anchoring capacity of the carbon fiber layer anchoring system was low due to the interfacial debonding and cross⁃section weakening. The mechanical anchoring system easily generated an initial compressive damage and stress concentration for the rod. The adhesive type anchoring system produced a debonding failure due to the low bonding strength of the rod⁃adhesive interface. Aiming at the problems of section weakening， the stress concentration and interfacial debonding existing in the above three anchoring systems， this study proposed a wedge⁃bonded compound anchoring system considering of the wedge extrusion and resin bonding. The results from the finite element simulation and tensile test indicated that the stress distribution in the anchor of the wedge⁃bond compound anchor system was uniform， the rod underwent a burst failure， and there was no slippage in the anchor. The ultimate anchor bearing capacity of the anchor system was 360.1 kN. This effectively solves the anchor failure problem in the composite rods.
2023, 37 (10):
15-23;
Abstract (
0 )
PDF (0 KB)(
0
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In this paper， the stress distribution and anchoring mechanism of three typical anchoring systems were studied for the anchoring failure of carbon/glass fiber reinforced polymer composite rods. The results indicated that the anchoring capacity of the carbon fiber layer anchoring system was low due to the interfacial debonding and cross-section weakening. The mechanical anchoring system easily generated an initial compressive damage and stress concentration for the rod. The adhesive type anchoring system produced a debonding failure due to the low bonding strength of the rod-adhesive interface. Aiming at the problems of section weakening， the stress concentration and interfacial debonding existing in the above three anchoring systems， this study proposed a wedge-bonded compound anchoring system considering of the wedge extrusion and resin bonding. The results from the finite element simulation and tensile test indicated that the stress distribution in the anchor of the wedge-bond compound anchor system was uniform， the rod underwent a burst failure， and there was no slippage in the anchor. The ultimate anchor bearing capacity of the anchor system was 360.1 kN. This effectively solves the anchor failure problem in the composite rods.
Materials and Properties
MA Zhirui, YIN Tian, JIANG Zhikui, YANG Fan, ZHU Mengke, YANG Yang, HAN Yu, WENG Yunxuan, ZHANG Caili
Abstract (
274 )
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119
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23 )
The paper reviewed the research progress in the preparation and applications of poly（butylene succinate）（PBS） and its blends. The current main synthesis technologies of PBS at home and abroad include direct esterification， transesterification， and chain extension. PBS is a type of completely biodegradable aliphatic polyester with good heat resistance and excellent mechanical properties， and it is capable of fundamentally solving the plastic white pollution as one of the most important biodegradable materials. The PBS blends with other brittle degradable polyesters can improve its toughness and biodegradability. Through blending with other renewable resources， The PBS blends can obtain an increase in rigidity， melting point， and mechanical properties， but a decrease in the cost. Through blending with a small quantity of inorganic fillers such as calcium carbonate and silica， PBS obtained not only a decrease in price but also an improvement in performance. In the present， PBS is mainly used in packaging materials， agricultural and forestry supplies， household goods， textiles， and medical products. The mechanical and gas barrier properties of PBS are two important indicators for its thin films. This review focused on the research progress in improving the mechanical properties and gas barrier properties of PBS composite films. Finally， the future research and development direction of PBS was prospected. The future direction in the PBS production technology will be to develop PBS products with high comprehensive performance， low cost， and green environment protection.
2023, 37 (10):
24-33;
Abstract (
0 )
PDF (0 KB)(
0
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The paper reviewed the research progress in the preparation and applications of poly（butylene succinate）（PBS） and its blends. The current main synthesis technologies of PBS at home and abroad include direct esterification， transesterification， and chain extension. PBS is a type of completely biodegradable aliphatic polyester with good heat resistance and excellent mechanical properties， and it is capable of fundamentally solving the plastic white pollution as one of the most important biodegradable materials. The PBS blends with other brittle degradable polyesters can improve its toughness and biodegradability. Through blending with other renewable resources， The PBS blends can obtain an increase in rigidity， melting point， and mechanical properties， but a decrease in the cost. Through blending with a small quantity of inorganic fillers such as calcium carbonate and silica， PBS obtained not only a decrease in price but also an improvement in performance. In the present， PBS is mainly used in packaging materials， agricultural and forestry supplies， household goods， textiles， and medical products. The mechanical and gas barrier properties of PBS are two important indicators for its thin films. This review focused on the research progress in improving the mechanical properties and gas barrier properties of PBS composite films. Finally， the future research and development direction of PBS was prospected. The future direction in the PBS production technology will be to develop PBS products with high comprehensive performance， low cost， and green environment protection.
Materials and Properties
GU Hainan, YING Jie, QIU Qihao, CHEN Meng, WANG Chenye, TONG Qifeng
Abstract (
207 )
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189
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5 )
In this paper， a poly（ISB⁃co⁃CHDM carbonate）/bisphenol⁃A polycarbonate alloy was prepared at a mass ratio of 50/50， and the effect of refractive index differences of raw materials on the appearance of the alloy was investigated. The glass⁃transition temperature of the alloy was determined by DSC， and the compatibility between two phases was explored. The results indicated that the two phases of the alloy were partially compatible. The effect of antioxidant （AO300） content on the glass⁃transition temperature and transmittance of the alloy were studied. The results indicated that when 9 phr of AO300 was added， the transmittance of the alloy reached 82 %. This suggests that the alloy basically became a fully compatible system. The effects of flexibilizers （M577 and M732） on the mechanicals properties， heat deformation temperature， and melting flow rate of the alloy were investigated. The results indicated that M577 generated a better toughening effect than M732. The effect of different types of compatibilizers on the material properties of the alloy was compared. The results indicated that the GMA⁃type compatibilizers enhanced the compatibility of the alloy and generated a significant influence on its fluidity. Based on the use of compatibilizers and flexibilizers， the alloy can meet the requirement of practical use.
2023, 37 (10):
34-39;
Abstract (
0 )
PDF (0 KB)(
0
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In this paper， a poly（ISB-co-CHDM carbonate）/bisphenol-A polycarbonate alloy was prepared at a mass ratio of 50/50， and the effect of refractive index differences of raw materials on the appearance of the alloy was investigated. The glass-transition temperature of the alloy was determined by DSC， and the compatibility between two phases was explored. The results indicated that the two phases of the alloy were partially compatible. The effect of antioxidant （AO300） content on the glass-transition temperature and transmittance of the alloy were studied. The results indicated that when 9 phr of AO300 was added， the transmittance of the alloy reached 82 %. This suggests that the alloy basically became a fully compatible system. The effects of flexibilizers （M577 and M732） on the mechanicals properties， heat deformation temperature， and melting flow rate of the alloy were investigated. The results indicated that M577 generated a better toughening effect than M732. The effect of different types of compatibilizers on the material properties of the alloy was compared. The results indicated that the GMA-type compatibilizers enhanced the compatibility of the alloy and generated a significant influence on its fluidity. Based on the use of compatibilizers and flexibilizers， the alloy can meet the requirement of practical use.
Processing and Application
SUN Jing, XIONG Faqiang, DENG Ruhui, TAO Yaxian, CHEN Xinggang
Abstract (
206 )
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169
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4 )
Intelligent polymeric materials are a rapidly developing interdisciplinary discipline in modern times， and they have now become a cutting⁃edge interdisciplinary research direction involving materials science， chemistry， biology， and medicine. In the present， the preparation of intelligent polymeric materials has received widespread attention. Intelligent polymeric materials are becoming “feeling” and “perceiving” and have been used for medical monitoring to solve more problems. This paper reviewed the development of intelligent polymeric materials in recent years， introduced the intelligent polymeric materials in the field of medical monitoring in detail from the aspects of light， force， sound， electricity， and other disciplines， and introduced the applications of intelligent polymer materials for medical monitoring in intelligent biosensors， intelligent tissue repair materials， intelligent medical scaffolds， and intelligent drug delivery systems.
2023, 37 (10):
40-49;
Abstract (
0 )
PDF (0 KB)(
0
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Intelligent polymeric materials are a rapidly developing interdisciplinary discipline in modern times， and they have now become a cutting?edge interdisciplinary research direction involving materials science， chemistry， biology， and medicine. In the present， the preparation of intelligent polymeric materials has received widespread attention. Intelligent polymeric materials are becoming “feeling” and “perceiving” and have been used for medical monitoring to solve more problems. This paper reviewed the development of intelligent polymeric materials in recent years， introduced the intelligent polymeric materials in the field of medical monitoring in detail from the aspects of light， force， sound， electricity， and other disciplines， and introduced the applications of intelligent polymer materials for medical monitoring in intelligent biosensors， intelligent tissue repair materials， intelligent medical scaffolds， and intelligent drug delivery systems.
Processing and Application
ZHANG Hengyuan, LIU Tao, ZHANG Shijun, LIU Jianye
Abstract (
128 )
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61
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3 )
In this paper， the processability and mechanical properties of commercial polypropylene were systematically evaluated， and the differences between sinter laser sintering （SLS） and injection molding were compared. The results indicated that preheating temperature， laser power and energy density were three important process parameters for SLS to generate a great impact on the performance of final products. When the process parameters were selected， both mechanical properties and machining accuracy should be considered. This study exhibits uniqueness in the quantitative analysis of the crystal forms of the selective sintering strips under different technological conditions， and the relationship between technological conditions， crystalline properties， and mechanical properties was established. Through adjusting the process parameters of SLS， different crystal contents could be obtained for molded samples， and therefore then the mechanical properties of the sample could be regulated.
2023, 37 (10):
50-55;
Abstract (
0 )
PDF (0 KB)(
0
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In this paper， the processability and mechanical properties of commercial polypropylene were systematically evaluated， and the differences between sinter laser sintering （SLS） and injection molding were compared. The results indicated that preheating temperature， laser power and energy density were three important process parameters for SLS to generate a great impact on the performance of final products. When the process parameters were selected， both mechanical properties and machining accuracy should be considered. This study exhibits uniqueness in the quantitative analysis of the crystal forms of the selective sintering strips under different technological conditions， and the relationship between technological conditions， crystalline properties， and mechanical properties was established. Through adjusting the process parameters of SLS， different crystal contents could be obtained for molded samples， and therefore then the mechanical properties of the sample could be regulated.
Processing and Application
XIAO Weigen, LONG Chunguang, WANG Ke, MIN Jianxin
Abstract (
159 )
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37
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1 )
To address the poor thermal conduction issue of polyoxymethylene （POM）， copper fiber （COF） and basalt fiber （BF） were added to POM to prepare POM/COF and POM/COF/BF composites through an extrusion⁃injection molding process. The influence of COF on the thermal conductivity of POM was verified using the ABAQUS software. The results indicated that the addition of copper fiber increased the thermal conductivity of POM up to 0.39 W/mK. The mechanical test results indicated that the incorporation of COF increased the stiffness of POM slightly but reduced its tensile strength. The thermal conductivity of POM/COF composite increased with an increase in the BF content and reached a maximum of around 0.5 W/mK at a BF content of 15 wt%， which was approximately 50 % higher than that of pure POM. Meanwhile， the addition of BF increased the stiffness of POM significantly， resulting in a maximum increase by about 200 %. Through steady⁃state thermal conduction simulation using the ABAQUS software， the composite containing copper fiber was found to obtain a lower surface temperature. This may be because the heat flow was more easily transferred to the low⁃temperature area through the fibers.
2023, 37 (10):
56-62;
Abstract (
0 )
PDF (0 KB)(
0
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To address the poor thermal conduction issue of polyoxymethylene （POM）， copper fiber （COF） and basalt fiber （BF） were added to POM to prepare POM/COF and POM/COF/BF composites through an extrusion-injection molding process. The influence of COF on the thermal conductivity of POM was verified using the ABAQUS software. The results indicated that the addition of copper fiber increased the thermal conductivity of POM up to 0.39 W/mK. The mechanical test results indicated that the incorporation of COF increased the stiffness of POM slightly but reduced its tensile strength. The thermal conductivity of POM/COF composite increased with an increase in the BF content and reached a maximum of around 0.5 W/mK at a BF content of 15 wt%， which was approximately 50 % higher than that of pure POM. Meanwhile， the addition of BF increased the stiffness of POM significantly， resulting in a maximum increase by about 200 %. Through steady-state thermal conduction simulation using the ABAQUS software， the composite containing copper fiber was found to obtain a lower surface temperature. This may be because the heat flow was more easily transferred to the low-temperature area through the fibers.
Processing and Application
WANG Chen, ZHANG Jiayin, JIANG Minhan, XIA Lingran
Abstract (
220 )
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39
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2 )
To explore the connection performance between the hot melt nut inserts and plastics， the connection method of hot melt nut inserts was reasonably applied for 3D⁃printed plastic shells. This paper analyzed the influence of insert type， hot⁃melt temperature， and hole diameter on the connection performance of the hot⁃melt nut insert and plastics through a single⁃factor test， optimized the embedding parameters by the Taguchi methods， obtained the optimal combination of embedding parameters， and completed the practical application verification of the hot⁃melt nut inserts in a 3D⁃printed electronic product shell. The results indicated that the shape of the insert affected its connection performance with plastics. The order of anti pull⁃out performance of various inserts is as follows： twill > mesh > straight， and the order of their anti⁃torsion performance is as follows： twill > straight > mesh. The connection performance between the insert and the plastics increased with an increase in the hot melt temperature ranging from 180 to 220 ℃. Meanwhile， the connection performance between the insert and the plastics increased with a decrease in the hole diameter ranging from 6.0 to 5.8 mm. The order of the influence level of embedding parameters on the connection performance between the insert and plastics is as follows： insert type > hole diameter > hot melt temperature. The optimized embedding parameters were determined to be an insert type of twill， a hole diameter of 5.8 mm， and a hot melt temperature of 220 ℃. Under this parameter combination， the maximum pulling force of the hot melt nut insert was 1.22 kN， and the maximum torque was 3.04 N·m， achieving the best connection performance between the insert and plastics.
2023, 37 (10):
63-69;
Abstract (
0 )
PDF (0 KB)(
0
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To explore the connection performance between the hot melt nut inserts and plastics， the connection method of hot melt nut inserts was reasonably applied for 3D-printed plastic shells. This paper analyzed the influence of insert type， hot-melt temperature， and hole diameter on the connection performance of the hot-melt nut insert and plastics through a single-factor test， optimized the embedding parameters by the Taguchi methods， obtained the optimal combination of embedding parameters， and completed the practical application verification of the hot-melt nut inserts in a 3D-printed electronic product shell. The results indicated that the shape of the insert affected its connection performance with plastics. The order of anti pull-out performance of various inserts is as follows： twill > mesh > straight， and the order of their anti-torsion performance is as follows： twill > straight > mesh. The connection performance between the insert and the plastics increased with an increase in the hot melt temperature ranging from 180 to 220 ℃. Meanwhile， the connection performance between the insert and the plastics increased with a decrease in the hole diameter ranging from 6.0 to 5.8 mm. The order of the influence level of embedding parameters on the connection performance between the insert and plastics is as follows： insert type > hole diameter > hot melt temperature. The optimized embedding parameters were determined to be an insert type of twill， a hole diameter of 5.8 mm， and a hot melt temperature of 220 ℃. Under this parameter combination， the maximum pulling force of the hot melt nut insert was 1.22 kN， and the maximum torque was 3.04 N·m， achieving the best connection performance between the insert and plastics.
Additive
WANG Fang, HAO Jianwei
Abstract (
148 )
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51
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1 )
The flame retardancy and mechanism of bamboo⁃based porous carbon （PCM） and aluminum diethylphosphonate （AlPi） for epoxy resins （EP） were studied through using renewable resources as synergies. Combustion test results indicated that the flame⁃retardant EP obtained a significant increase in the LOI value when 3 wt% PCM and 4.4 wt% AlPi was introduced. A V⁃0 classification was also achieved for the flame⁃retardant EP， and its peak heat release rate decreased by 60.7 %. This means that there is a remarkable catalytic effect of PCM and AlPi on the flame⁃retardant EP. TG⁃FTIR， TG⁃MS， XPS， and Raman spectra indicated that owing to the catalysis of PCM， the diethyl phosphinic acid released by AlPi could capture free radicals in the gas phase to form alumina， aluminum phosphate， and aluminum pyrophosphate in the condensed phase. This improves the resistant thermal oxidation property of char and promotes the formation of graphite⁃like char.
2023, 37 (10):
70-76;
Abstract (
0 )
PDF (0 KB)(
0
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The flame retardancy and mechanism of bamboo-based porous carbon （PCM） and aluminum diethylphosphonate （AlPi） for epoxy resins （EP） were studied through using renewable resources as synergies. Combustion test results indicated that the flame-retardant EP obtained a significant increase in the LOI value when 3 wt% PCM and 4.4 wt% AlPi was introduced. A V-0 classification was also achieved for the flame-retardant EP， and its peak heat release rate decreased by 60.7 %. This means that there is a remarkable catalytic effect of PCM and AlPi on the flame-retardant EP. TG-FTIR， TG-MS， XPS， and Raman spectra indicated that owing to the catalysis of PCM， the diethyl phosphinic acid released by AlPi could capture free radicals in the gas phase to form alumina， aluminum phosphate， and aluminum pyrophosphate in the condensed phase. This improves the resistant thermal oxidation property of char and promotes the formation of graphite-like char.
Standard and Test
LI Zhao, JIA Yuanshan
Abstract (
206 )
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58
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2 )
Based on the error propagation formula， an error model was established for the determination of grafting ratio of PP⁃g⁃MAH through acid⁃base back titration. The effects of sampling amount， concentration of HCl⁃isopropanol solution， and content of grafted maleic anhydride on the determination error of grafting ratio were investigated. PP⁃g⁃MAH was prepared in the laboratory and analyzed by using infrared spectroscopy. The grafting ratio of samples was determined through acid⁃base back titration at different sample amounts and HCl⁃isopropanol solution concentrations. The determination errors of two different maleic anhydride contents of PP⁃g⁃MAH were compared. The results indicated that maleic anhydride was grafted onto the PP molecular chain. The precipitation of PP⁃g⁃MAH and the entrapment effect on KOH were considered as the main reasons for a large determination error and poor reproducibility of grafting ratio. The reduction of the concentrations of acid and base titration solutions and the increase of the sampling amount could reduce the determination error. The minimum determination error was achieved when the concentrations of acid and base titration solutions were 0.01 mol/L. The relative standard deviation of grafting ratio of the prepared PP⁃g⁃MAH was 32 % when the sampling amount was 0.2 g and the concentrations of acid and base titration solutions were 0.01 mol/L. The established error model can be used to optimize the test conditions for the grafting ratio PP⁃g⁃MAH and reduce the determination errors.
2023, 37 (10):
77-84;
Abstract (
0 )
PDF (0 KB)(
0
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Based on the error propagation formula， an error model was established for the determination of grafting ratio of PP-g-MAH through acid-base back titration. The effects of sampling amount， concentration of HCl-isopropanol solution， and content of grafted maleic anhydride on the determination error of grafting ratio were investigated. PP-g-MAH was prepared in the laboratory and analyzed by using infrared spectroscopy. The grafting ratio of samples was determined through acid-base back titration at different sample amounts and HCl-isopropanol solution concentrations. The determination errors of two different maleic anhydride contents of PP-g-MAH were compared. The results indicated that maleic anhydride was grafted onto the PP molecular chain. The precipitation of PP-g-MAH and the entrapment effect on KOH were considered as the main reasons for a large determination error and poor reproducibility of grafting ratio. The reduction of the concentrations of acid and base titration solutions and the increase of the sampling amount could reduce the determination error. The minimum determination error was achieved when the concentrations of acid and base titration solutions were 0.01 mol/L. The relative standard deviation of grafting ratio of the prepared PP-g-MAH was 32 % when the sampling amount was 0.2 g and the concentrations of acid and base titration solutions were 0.01 mol/L. The established error model can be used to optimize the test conditions for the grafting ratio PP-g-MAH and reduce the determination errors.
Plastic and Environment
YANG Xiying, ZHANG Wencai, ZHAO Zhixin
Abstract (
142 )
PDF (3672 KB)(
45
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0 )
To further modify the high cost and technical defects of asphalt separately modified with nano⁃calcium carbonate （nano⁃CaCO3） and waste polyethylene （WPE）， the nano⁃CaCO3/TTS/WPE composite modifier （CTW） and CTW⁃modified asphalt were prepared through melt extrusion using isopropyl triisostearyl phthalate （TTS） as a coupling agent. The influence of TTS content on the properties of CTW⁃modified asphalt was studied， and the modification mechanism was analyzed. The analysis of conventional indexes indicated that the softening point， elongation， and viscosity of the CTW⁃modified asphalt increased at first and then kept stable with an increase in the TTS content. However， the penetration degree exhibited an opposite change. According the investigation on the dynamic shear rheology and low temperature properties， a certain amount of TTS was conducive to improving the high⁃ and low⁃temperature properties of the CTW⁃modified asphalt. Meanwhile， microtopography and mechanism analysis was carried out for the above⁃mentioned changes in the properties， and the results indicated that the physical and chemical interactions between different contents of TTS and nano⁃CaCO3/WPE/asphalt led to the performance changes of the CTW⁃modified asphalt.
2023, 37 (10):
85-92;
Abstract (
0 )
PDF (0 KB)(
0
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To further modify the high cost and technical defects of asphalt separately modified with nano-calcium carbonate （nano-CaCO3） and waste polyethylene （WPE）， the nano-CaCO3/TTS/WPE composite modifier （CTW） and CTW-modified asphalt were prepared through melt extrusion using isopropyl triisostearyl phthalate （TTS） as a coupling agent. The influence of TTS content on the properties of CTW-modified asphalt was studied， and the modification mechanism was analyzed. The analysis of conventional indexes indicated that the softening point， elongation， and viscosity of the CTW-modified asphalt increased at first and then kept stable with an increase in the TTS content. However， the penetration degree exhibited an opposite change. According the investigation on the dynamic shear rheology and low temperature properties， a certain amount of TTS was conducive to improving the high- and low-temperature properties of the CTW-modified asphalt. Meanwhile， microtopography and mechanism analysis was carried out for the above-mentioned changes in the properties， and the results indicated that the physical and chemical interactions between different contents of TTS and nano-CaCO3/WPE/asphalt led to the performance changes of the CTW-modified asphalt.
Functional modification of polymers and their extreme service applications
SUN Ying, BAI Lin, LIU Minghao, WENG Yunxuan, CHEN Liping
Abstract (
150 )
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83
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2 )
Taking blueberry as a research object， a series of biodegradable composite films based on polyglycolic acid （PGA） and polybutylene terephthalate adipate （PBAT） were prepared by using a twin⁃screw extruder according the tape casting mechanism. The quality of cling film was characterized in terms of thermal weight loss， gas permeability， and gas composition. The results indicated that a mass ration of PGA to PBAT of 60∶40 could effectively inhibit an increase in the content of polyphenol oxidase （PPO） activity and delay a decrease in ascorbic acid peroxidase （APX）， superoxide dismutase （SOD）， and catalase （CAT） activity. The PGA group delayed the decrease of peroxidase （POD） activity and pH value. Therefore， the biodegradable preservation film composed of PGA and PBAT is more advantageous to the preservation for blueberries， especially for the preservation film containing 60 % PGA and 40 % PBAT. The CO2 volume fraction could be controlled within 2 %~3 %， whereas the O2 volume fraction continued to decrease with a variation of storage time to reach 10 %~12 %. After storage for six days， the enzyme activity was 3.42 U/g for PPO， 5.98 U/g for APX， 8.37 U/g for SOD， 81.12 U/g for POD， and 115.78 U/g for CAT.
2023, 37 (10):
93-100;
Abstract (
0 )
PDF (0 KB)(
0
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Taking blueberry as a research object， a series of biodegradable composite films based on polyglycolic acid （PGA） and polybutylene terephthalate adipate （PBAT） were prepared by using a twin-screw extruder according the tape casting mechanism. The quality of cling film was characterized in terms of thermal weight loss， gas permeability， and gas composition. The results indicated that a mass ration of PGA to PBAT of 60∶40 could effectively inhibit an increase in the content of polyphenol oxidase （PPO） activity and delay a decrease in ascorbic acid peroxidase （APX）， superoxide dismutase （SOD）， and catalase （CAT） activity. The PGA group delayed the decrease of peroxidase （POD） activity and pH value. Therefore， the biodegradable preservation film composed of PGA and PBAT is more advantageous to the preservation for blueberries， especially for the preservation film containing 60 % PGA and 40 % PBAT. The CO2 volume fraction could be controlled within 2 %~3 %， whereas the O2 volume fraction continued to decrease with a variation of storage time to reach 10 %~12 %. After storage for six days， the enzyme activity was 3.42 U/g for PPO， 5.98 U/g for APX， 8.37 U/g for SOD， 81.12 U/g for POD， and 115.78 U/g for CAT.
Functional modification of polymers and their extreme service applications
WANG Xiaonan, FU Jingao, CHEN Sisi, GAO Hainan, CAI Yudong
Abstract (
202 )
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85
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This paper reviewed the research progress in the high⁃performance hydrogels as filter materials for leak plugging， oil repelling， and oil⁃water separation in the field of oilfield development. The characteristics and applications of different types of hydrogels were summarized and analyzed， and the development direction was discussed.
2023, 37 (10):
101-110;
Abstract (
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This paper reviewed the research progress in the high-performance hydrogels as filter materials for leak plugging， oil repelling， and oil-water separation in the field of oilfield development. The characteristics and applications of different types of hydrogels were summarized and analyzed， and the development direction was discussed.
Functional modification of polymers and their extreme service applications
WANG Bin, WANG Zhenchao, HE Anqi, CHENG Debao, WANG Yaru, ZHAO Xiaoying, XIANG Aimin
Abstract (
172 )
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In this study， the polyethylene/carbon black composites for pipelines were prepared through melt blending carbon black with polyethylene. The resultant welding composites were further used to weld pipelines under different welding conditions including single⁃program welding and multi⁃program welding， and the welding properties， mechanical properties， crystallization properties， and microscopic morphology of the welded pipes were studied. The results indicated that the processing temperature of the extruder should not exceed 240 ºC， and the screw speed should not exceed 40 rpm. This can effectively avoid the defects of uneven dispersion of carbon black and bubble in the preparation process of pipeline. In the single⁃stage welding process， the temperature was found to rise sharply at the end of the experiment. However， the temperature of the melting zone could keep in a relatively stable range in the multi⁃stage welding procedure. The tensile stripping test results indicated that the welding performance of welded samples obtained from the multi⁃stage welding process was better than that from the single⁃stage welding process.
2023, 37 (10):
111-116;
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In this study， the polyethylene/carbon black composites for pipelines were prepared through melt blending carbon black with polyethylene. The resultant welding composites were further used to weld pipelines under different welding conditions including single-program welding and multi-program welding， and the welding properties， mechanical properties， crystallization properties， and microscopic morphology of the welded pipes were studied. The results indicated that the processing temperature of the extruder should not exceed 240 oC， and the screw speed should not exceed 40 rpm. This can effectively avoid the defects of uneven dispersion of carbon black and bubble in the preparation process of pipeline. In the single-stage welding process， the temperature was found to rise sharply at the end of the experiment. However， the temperature of the melting zone could keep in a relatively stable range in the multi-stage welding procedure. The tensile stripping test results indicated that the welding performance of welded samples obtained from the multi-stage welding process was better than that from the single-stage welding process.
Functional modification of polymers and their extreme service applications
LI Zhenyin, ZHANG Xiaolin, WEI Cong, SHI Zhiyong, SHAO Chunguang
Abstract (
134 )
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48
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The crystallization behavior of isotactic polypropylene （iPP）/multi⁃walled carbon nanotubes （MWCNTs） composites at different pressurization rates and temperatures was studied by using wide angle X⁃ray diffractometer （WAXD） and differential scanning calorimetry （DSC）. The results indicated that a lower temperature was advantageous to the formation of α⁃iPP under the condition of low pressurization rate （1 MPa/s）， but a higher temperature was more conducive to γ⁃iPP. MWCNTs could induce the crystallization of iPP. The formed γ⁃iPP has a stable structure and cannot recrystallize during the heating process. Pure γ⁃iPP could be prepared at a lower pressurization temperature under the condition of a high pressurization rate （200 MPa/s）. However， the presence of MWCNTs resulted in an increase in the viscosity of iPP melt and hindered the movement of its molecular chains， which was disadvantageous to crystal growth. The γ⁃iPP crystal was formed in a poor structural perfection， and it was unstable and tended to recrystallize during the heating process. Therefore， the metastable mesophase iPP can be prepared at a higher pressurization temperature. The crystalline structure of iPP was determined by the synergistic effect of pressurization rate and melt memory effectiveness. At a low pressurization rate， melt memory effect generated a greater impact on the crystallization structure of the composite， and this effect weakened with an increase in the pressurization rate.
2023, 37 (10):
117-124;
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The crystallization behavior of isotactic polypropylene （iPP）/multi-walled carbon nanotubes （MWCNTs） composites at different pressurization rates and temperatures was studied by using wide angle X-ray diffractometer （WAXD） and differential scanning calorimetry （DSC）. The results indicated that a lower temperature was advantageous to the formation of α-iPP under the condition of low pressurization rate （1 MPa/s）， but a higher temperature was more conducive to γ-iPP. MWCNTs could induce the crystallization of iPP. The formed γ-iPP has a stable structure and cannot recrystallize during the heating process. Pure γ-iPP could be prepared at a lower pressurization temperature under the condition of a high pressurization rate （200 MPa/s）. However， the presence of MWCNTs resulted in an increase in the viscosity of iPP melt and hindered the movement of its molecular chains， which was disadvantageous to crystal growth. The γ-iPP crystal was formed in a poor structural perfection， and it was unstable and tended to recrystallize during the heating process. Therefore， the metastable mesophase iPP can be prepared at a higher pressurization temperature. The crystalline structure of iPP was determined by the synergistic effect of pressurization rate and melt memory effectiveness. At a low pressurization rate， melt memory effect generated a greater impact on the crystallization structure of the composite， and this effect weakened with an increase in the pressurization rate.
Functional modification of polymers and their extreme service applications
WANG Linfeng, XIE Jikai, GUO Jiaxing, HAO Zhi, GUO Jianbing, LONG Xiaoqin, AO Qianlan, ZHU Yan, WU Mingmi
Abstract (
196 )
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80
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A type of master rubber was prepared using silicone rubber （SR） as a matrix and mullite fiber （MF）， hollow glass microbeads （GB）， 2，5⁃dimethyl⁃2，5⁃di（tert⁃butylperoxy）hexane， CaCO3， and Fe2O3 as additives. Then， ceramic⁃retardable flame⁃retardant silicone rubber composites were prepared by adding Al（OH）3 and Mg（OH）2 at different parts ratios through open mixing and vulcanization. The results indicated that GB played a role of bonding bridge at a high temperature and MF acted as a skeleton in the preparation of the ceramic⁃retardable flame⁃retardant silicone rubber composites. The rubber composite containing 30 parts of Mg（OH）2 obtained a tensile strength of up to 4.93 MPa， elongation at break of 1 450.73 %， and a limiting oxygen index of 31.8 vol%. The silicone rubber composite with a thickness of 6 mm could burn for 15min at a frequency of 50 Hz， 5 g acceleration， and a temperature of 1 050 °C without burning through.
2023, 37 (10):
125-130;
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A type of master rubber was prepared using silicone rubber （SR） as a matrix and mullite fiber （MF）， hollow glass microbeads （GB）， 2，5-dimethyl-2，5-di（tert-butylperoxy）hexane， CaCO3， and Fe2O3 as additives. Then， ceramic-retardable flame-retardant silicone rubber composites were prepared by adding Al（OH）3 and Mg（OH）2 at different parts ratios through open mixing and vulcanization. The results indicated that GB played a role of bonding bridge at a high temperature and MF acted as a skeleton in the preparation of the ceramic-retardable flame-retardant silicone rubber composites. The rubber composite containing 30 parts of Mg（OH）2 obtained a tensile strength of up to 4.93 MPa， elongation at break of 1 450.73 %， and a limiting oxygen index of 31.8 vol%. The silicone rubber composite with a thickness of 6 mm could burn for 15min at a frequency of 50 Hz， 5 g acceleration， and a temperature of 1 050 °C without burning through.
Machinery and Mould
ZHANG Yiming, HUANG Zhigang, XU Zhen, CHENG Yuanyuan
Abstract (
160 )
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222
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6 )
The flow channel distribution of three different screw configurations was discussed by taking polylactic acid （PLA） in a twin⁃screw extruder with different directions at ratios of screw heads to rotor of 2∶2， 3∶2， 4∶2. The 3D models for these three screw configurations were established by the SolidWorks software according to a theoretical end curve equation. The mesh models of the three screw configurations were established using the Workbench software， and the actual flow field was simulated using the Polyflow fluid simulation software to obtain the post⁃processing results. The final result was analyzed by using the FieldView post⁃processing analysis software. The pressure， shear rate， and viscosity of the PLA fluid were studied under different screw configurations. Meanwhile， the residence time distribution curve and distribution mixing characteristics were compared by using the Polystat statistical module. The results indicated that the pressure fluctuation decreased， the shear effect increased， the residence time increased， and the distribution effect increased with an increase in the number of screw heads of the negative rotor at a screw speed of 60 rpm with the certain number of screw heads of the positive rotor. There are advantageous to the output and mixing of materials.
2023, 37 (10):
131-138;
Abstract (
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The flow channel distribution of three different screw configurations was discussed by taking polylactic acid （PLA） in a twin-screw extruder with different directions at ratios of screw heads to rotor of 2∶2， 3∶2， 4∶2. The 3D models for these three screw configurations were established by the SolidWorks software according to a theoretical end curve equation. The mesh models of the three screw configurations were established using the Workbench software， and the actual flow field was simulated using the Polyflow fluid simulation software to obtain the post-processing results. The final result was analyzed by using the FieldView post-processing analysis software. The pressure， shear rate， and viscosity of the PLA fluid were studied under different screw configurations. Meanwhile， the residence time distribution curve and distribution mixing characteristics were compared by using the Polystat statistical module. The results indicated that the pressure fluctuation decreased， the shear effect increased， the residence time increased， and the distribution effect increased with an increase in the number of screw heads of the negative rotor at a screw speed of 60 rpm with the certain number of screw heads of the positive rotor. There are advantageous to the output and mixing of materials.
Machinery and Mould
ZHAO Liping, ZHANG Weihe, PENG Xinhua
Abstract (
208 )
PDF (3494 KB)(
38
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3 )
An interchanging structure design was adopted for the plastic parts of a car seat side guard plate（with and without a button hole） mold structure with a fixed mold and a moving mold. Such a design solved the problem that the same mold could produce two types of plastic parts with different structures， improve the use value of the mold， and reduce the cost of product research and development for products. Through the design of convenient interchanging structure of a mold insert， the removal of mold， mold installation time， and labor costs were greatly reduced. The abnormal⁃shaped inclined top core⁃pulling mechanism and the straight top core⁃pulling mechanism could cooperate to help the conventional inclined top core⁃pulling mechanism to complete the normal demolding of the plastic parts when the design position was insufficient.
2023, 37 (10):
139-143;
Abstract (
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An interchanging structure design was adopted for the plastic parts of a car seat side guard plate（with and without a button hole） mold structure with a fixed mold and a moving mold. Such a design solved the problem that the same mold could produce two types of plastic parts with different structures， improve the use value of the mold， and reduce the cost of product research and development for products. Through the design of convenient interchanging structure of a mold insert， the removal of mold， mold installation time， and labor costs were greatly reduced. The abnormal-shaped inclined top core-pulling mechanism and the straight top core-pulling mechanism could cooperate to help the conventional inclined top core-pulling mechanism to complete the normal demolding of the plastic parts when the design position was insufficient.
Review
YU Hongli, LIU Qian
Abstract (
218 )
PDF (4439 KB)(
190
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9 )
This paper briefly introduced the basic working principle of dielectric elastomer actuators， summarized the research progress in the different configurations of dielectric elastomer actuators in China and abroad， and elaborated the application progress of dielectric elastomer actuators in the field of soft robots. Finally， the challenges of dielectric elastomer actuators for practical applications were analyzed and their future research prospects were proposed.
2023, 37 (10):
144-152;
Abstract (
0 )
PDF (0 KB)(
0
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This paper briefly introduced the basic working principle of dielectric elastomer actuators， summarized the research progress in the different configurations of dielectric elastomer actuators in China and abroad， and elaborated the application progress of dielectric elastomer actuators in the field of soft robots. Finally， the challenges of dielectric elastomer actuators for practical applications were analyzed and their future research prospects were proposed.
