Materials and Properties
DONG Youbang, ZHANG Zeqi, YANG Rongjie
Abstract (
652 )
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507
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Caged aminopropylsilsesquioxane (NH2-propyl-POSS) was synthesized through one-pot hydrolysis-condensation
under alkali-catalyzed conditions using 3-aminopropyltrimethoxysilane as a raw
material. The obtained products were characterized using infrared spectroscopy, nuclear magnetic
resonance,
and electrospray ionization-time of flight mass spectrometry. The results
indicated that the synthesized NH2-propyl-POSS was a cage-structured mixture with
different sizes,
and the contents of cage structured T8, T9 and T10 were relatively high. Acetylpropyl
POSS and propynoyl POSS were further synthesized through the amidation of NH2-propyl-POSS with acetic acid and propiolic acid,
respectively,
and their structures were characterized using infrared spectroscopy, 1H-NMR spectroscopy, and 13C-NMR spectroscopy. X-ray diffraction analysis
indicated that the three POSSs were all amorphous structures. According to the
thermal decomposition characteristics obtained from thermogravimetric analysis, NH2-propyl-POSS showed the highest thermal stability among the
three POSSs. NH2-propyl-POSS was used for epoxy resin (EP) to improve
its thermal stability. The EP/NH2-propyl-POSS blends exhibited a glass transition
temperature of 180.7 oC and a limiting oxygen index of 25.2 vol% with the
addition of 5 wt% POSS.
JIAO Zhiwei, WANG Kechen, ZHANG Yang, YANG Weimin
Abstract (
679 )
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467
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A carbon nano coating was deposited on the surface of talc powder using a high-temperature pyrolysis polymer method and then was incorporated into PVC/ABS composite with carbon black. The effects of contents of talc powder and carbon black on the electrical properties, mechanical performance, thermal stability, and flame retardancy of the composites were investigated. The experimental results indicated that when 3 parts of talc powder was added into the composites, the percolation value of carbon black was only 3 parts. The tensile strength increased by 14.4 % for the composite with this addition amount. This can be explained by the fact that talc powder and carbon black can form a network structure in the matrix, in which talc powder is distributed in random positions and directions as nodes and carbon black acts as a channel to connect the nodes with each other.
YU Jiuyang, WANG Zhonghao, CHEN Qi, XIA Yazhong
Abstract (
540 )
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358
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In this article, the effect of modification methods on the mechanical properties of phenolic bulk film plastics (BMC), phenolic sheet film plastics (SMC) and vinyl SMC materials were studied, and the interaction mechanism of modification for the resin matrix and fiber phase was analyzed quantitatively. The optimal mechanical properties were obtained for the composites, and the feasibility for manufacturing the valve body using different composites was verified by simulation analysis. The results indicated that the vinyl SMC material achieved optimal tensile properties, but the phenolic SMC showed the worst one. On the other hand, the phenolic BMC material showed the optimal bending mechanical properties, whereas the phenolic SMC showed the worst ones. In summary, the vinyl SMC exhibited the best comprehensive mechanical properties. The tensile strength, tensile modulus, flexural strength, and flexural modulus of the vinyl SMC reached 148.255 MPa, 4.50 GPa, 92.33 MPa, and 2.39 GPa respectively at a molding temperature of 160 ℃, a molding pressure of 9 MPa, and a holding time of 30 min. The valve body statics analysis results showed that both the vinyl SMC and the phenolic BMC could meet a requirement for the manufacture of the valve body.
LI Yafei, SUN Xiaojie, REN Yueqing, ZHANG Yinling
Abstract (
480 )
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295
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A flame⁃retarded anti⁃static polyolefin material was prepared using halogen⁃free retardant (MRP⁃1400), carbon black, and polyethylene elastomer (POE) as additives, and the effects of these three additives on the mechanical properties of the flame⁃retarded anti⁃static material were investigated. The results indicated that the addition of MRP⁃1400 enhanced the flame⁃retardant properties of the material significantly. When 20 wt% MRP⁃1400 (corresponding to 8 wt% phosphorus), the material reached a UL 94 V⁃0 classification in the vertical burning test and passed the alcohol blow lamp examination according to Standard MT 113⁃1995. Moreover, when 6 wt% carbon black was incorporated, the anti⁃static properties of the material fulfilled the requirements specified in Standard MT 113⁃1995. The mechanical properties of the material increased with the addition of POE. The material achieved optimal overall performance when 5 wt% POE was added, achieving notched Izod impact strength of 35 kJ/m2 and elongation at break of 315 %. The material exhibited good fatigue resistance with a dynamic fatigue life over 1.2 million times.
YANG Zhi, XI Wang, QIAN Lijun, HU Lishuang
Abstract (
372 )
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306
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A quaternary flame?retardant system was constructed using dimethyl methyl phosphonate (DMMP), 10?(2,5?two hydroxytoluene)?10?hydrogen?9?oxygen hetero?10?phosphoryl phenylene?10?oxide (DOPO?HQ), expandable graphi?te (EG), and aluminum hydroxide (ATH) as raw material, and its flame retardant behavior in rigid polyurethane foam (RPUF) was investigated using thermogravimetric analyzer, cone calorimeter, and limiting oxygen index analyzer. The results indicated that the quaternary flame retardant system exhibited a synergistic flame?retardant effect in a wide temperature range during combustion. DOPO?HQ could generate an additional flame?retardant effect with EG/DMMP/ATH ternary flame?retardant system for the RPUF composites, resulting in an increase in limiting oxygen index by 30.8%. Meanwhile, the peak heat release rate, the RPUF composites with the quaternary flame?retardant system showed a lower total heat release rate and a lower total smoke release rate than the RPUF composites with the EG/DMMP/ATH ternary flame?retardant system. Moreover, the char residue rate were further improved, indicating that a synergistic effect resulting from the quaternary flame retardant system based on DOPO?HQ and EG/DMMP/ATH. In addition, the residual char was characterized by scanning electron microscope. The quaternary flame retardant system could act as a barrier in the condensed phase to exert the progressive flame?retardant actions in the early, middle, and later stages of combustion.
ZHANG Taozhong, CHEN Xiaolong, HAO Xiaoyu, YU Fujia
Abstract (
784 )
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473
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Polypropylene (PP)?matrix composites were prepared through melt blending with three types of white mineral powders including granular calcium carbonate (CaCO3) and barium sulfate (BaSO4) and lamellar talc as fillers. The effects of three types of mineral powders on the mechanical properties, flow properties and fracture morphology of the resultant composites were investigated. In addition, Turcasanyi formula was used to calculate the interface interaction between the PP matrix and mineral fillers. The results indicated that the composites showed a decrease in tensile strength with the addition of mineral powders. The tensile strength of the PP/talc composite was significantly higher than those of the PP/CaCO3 and PP/BaSO4 composites. The addition of talc significantly enhanced the tensile and bending moduli of PP and also increased its bending strength. However, the addition of CaCO3 and BaSO4 reduced the bending strength of PP. CaCO3 exhibited the most obvious effect to improve the elongation at break of PP and the notch impact strength of cantilever beam. The addition of talc improved the fluidity of the composites, whereas the addition of granular CaCO3 and BaSO4 showed few effects on the process ability. CaCO3 and BaSO4 were agglomerated in PP due their poor compati?bility with PP and obvious interface defects. The interface between talc and PP was vague, and there was a strong bon?ding effect between talc and PP.
CHEN Baiquan, ZHENG Youming, TIAN Jibo, XHANG Lei, WANG Jinsong, LIN Xiajie, DUAN Yapeng
Abstract (
717 )
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560
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Three types of reinforced flame?retardant polyamide (PA) composites with a high content of glass fiber were prepared using a twin?screw extruder, which included PA6?, PA66? and PA 56?matrix composites with 50 wt% glass fiber. The mechanical properties, flame retardant properties and laser marking properties of the composites were studied comparatively under three flame retardant systems including red phosphorus, bromine, and phosphorus?nitrogen. The results indicated that the flame retardant systems had obvious effects on the mechanical properties of the composites. The PA66 composites obtained the highest retention of mechanical properties after water absorption equilibrium. The PA56 composites exhibited better flame?retardant performance the PA6 and PA66 composites. The laser marking effect of infrared laser and ultraviolet laser was obviously different, and however, it showed no obvious difference among PA6, PA66 and PA56 under the same flame?retardant systems and laser source.
DU Qing, HE Yi, YU Tanjing, LAN Yanjiao, ZHAO Yanzhi, ZHOU Juying
Abstract (
555 )
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182
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4 )
A series of polyacrylonitrile (PAN)/carbon nanotube (MWCNT) nanofiber membranes with different orientation degrees were prepared through electrospinning using a high?speed rotating roller and thermal post?treatment. This process resulted in an improvement in the crystallinity of PAN, thus improving the tensile strength and elastic modulus of the nanofiber membranes and decreasing their elongation at break. The PAN/MWCNT nanofiber membranes exhibited optimal mechanical properties at an MWCNT content of 0.5 wt%. A series of thermoplastic polyolefin (POE) composi?tes with the PAN/MWCNT nanofiber membranes at different orientation degrees were prepared using an immersion method. The POE/h?P2M composite with a high orientation degree showed an increase in tensile strength by 71% compared to the POE/u?PM composite without orientation, but its elongation at break decreased. The composites exhibited optimal mechanical performance at a nanofiber?membrane content of 6.7 wt%.
QU Yuting, WANG Limei, QI Bin
Abstract (
543 )
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311
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poly(lactic acid) (PLA)/starch nanocrystal (SNC) and PLA/SNC/poly(ethylene glycol) (PEG) composites were prepared through solvent evaporation using PLA and SNC as raw materials and PEG as a plasticizer. The effects of PEG on the crystallization behavior, mechanical properties, and interfacial compatibility of the composites were investigated using differential scanning calorimetry, hot?stage polarizing microscopy, X?ray diffractometry, and scanning electron microscopy. The results indicated that PEG could synergistically promote the crystallization of PLA together with SNC, resulting in a significant increase in the crystallization rate of PLA/SNC/PEG composites. The crystalline structure of PLA/SNC composites was not changed with the addition of PEG. The composite containing 4 wt% SNC showed an increase at first and then a decrease in tensile strength with an increase in the PEG content. However, its elongation at break kept an increasing trend. The composite containing 4 wt% SNC and 2 wt% PEG obtained optimal mechanical properties with tensile strength of 47.86 MPa and elongation at break of 10.20 %. The interfacial compatibility between PLA and SNC was improved.
WANG Qian, YANG Kangning, ZHAI Shaoxiong, YIN Likun, HE Shaojian, LIN Jun
Abstract (
537 )
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456
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3 )
A UiO?66?NH2/PAMPS hybrid filler was prepared through the in?situ polymerization of 2?acrylamide?2?methylpropanesulfonic acid in a porous metal organic framework (UiO?66?NH2). The resultant filler was then added to the sulfonated poly(ether ether ketone) (SPEEK) to fabricate nanocomposite membranes. The properties of the nanofillers and membranes were investigated. The ordered pore networks of metal organic framework components in UiO?66?NH2/PAMPS provided fast proton diffusion pathways, and the sulfonic acid groups in PAMPS offered additional sites for proton transfer. This resulted in a significant improvement in proton conductivity of the nanocomposite membranes. The experimental results indicated that there is a strong electrostatic interaction between the filler and matrix, preventing the swelling of the nanocomposite membranes. When the filler content was 6 wt%, the proton conductivity of the nanocomposite membrane containing 6 wt% filler increased from 0.040 S/cm to 0.057 S/cm in water, which was 42.5 % higher than that of SPEEK as a control. Its swelling ratio decreased from 29 % to 23 %.
XIONG Yiming, SONG Jiling, QIN Shuhao, LONG Xuebin, LU Xianrui
Abstract (
777 )
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715
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9 )
After coupling modification of starch with hexadecyltrimethoxysilane (HDTMS), thermoplastic starch (TPS) was obtained through coupling modification with hexadecyltrimethoxysilane (HDTMS) and melt extrusion. The resultant TPS were subjected to direct blowing process with poly(adipic acid?co?butylene terephthalate) (PBAT). The relationship between the HDTMS content and the heat resistance and rheological properties of TPS and the relationship between the hydrophobic property and mechanical performance of PBAT/TPS composite membranes were investigated. The results indicated that the processing properties of TPS were improved with the addition of HDTMS, resulting in better heat resistance but easier separation of the additive. The hydrophobic properties of composite membranes were improved with the addition of 1 phr HDTMS, and their contact angle increased to 113.2 °. The contact angle was kept basically at 104 °~106 ° with a continuous increase in the HDTMS content. The tensile strength of the composite membrane increased at first and then decreased with an increase in the HDTMS content. The tensile strength reached 10.29 MPa when 3 phr HDTMS was incorporated.
GUO Xiaolei, LUO Jingyun, DING Xin, WANG Yuchen, NIE Minghan, SONG Jiajie, ZHANG Yan’e, HU Jing
Abstract (
546 )
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267
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4 )
The chain⁃extended poly(3?hydroxybutyrate?co?3?hydroxyvalerate) (PHBV) compound were prepared through melt blending using ethylene?glycidyl methacrylate copolymer (CE) as chain extender. Then, a series of PHBV foams were prepared using a super critical CO2 foaming method at 160 oC and 20 MPa. The results indicated that the PHBV compounds exhibited a lower crystallization temperature and a lower melting temperature measured at high pressure using differential scanning calorimetry compared to that measured at normal pressure. The introduction of CE enhanced the complex viscosity and storage modulus of PHBV compounds. The PHBV foams showed a gradual increase in cell density and volume expansion ratio but a decrease in cell size with an increase in the CE content.
Processing and Application
OUYANG Yufei, WANG Huashan
Abstract (
588 )
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306
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The surface of acrylonitrile?butadiene?styrene (ABS) resin was etched through non?thermal plasma surface treatment. A palladium?free sensitization and activation solution composed of vinyltrimethoxysilane, (3?mercaptopropyl)trimethoxysilane, and 3?triethoxysilyl?1?propanamine was used for the surface nickel plating of ABS. The properties of electroplated ABS were investigated using Fourier?transform total reflectance infrared spectroscopy, contact angle measuring instrument, and scanning electron microscope. A 90° adhesive strength testing method was adopted to measure the adhesion between the plastic and metal layer according to the national standard GB/T 9286—2021. The results indicated that the optimal pretreatment effectiveness was achieved for ABS electroplating at a treatment time of 300 s and a power of 600 W. As a result, the substrate bonding strength reached 0.94 kN/m.
LING Yuanzhi, WANG Haixiong, LI Yajun, HE Jinhui, YAN Tianxiang
Abstract (
446 )
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204
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0 )
To explore the effect of ultrasonic vibration and hot bed on the mechanical properties of poly(ethylene terephthalate?co?1,4?cyclohexanedimethanol ester) specimens manufactured through melt deposition molding, an ultrasonic vibration device was installed on the current melt deposition molding equipment to prepare the tensile specimen and compression specimen through changing the ultrasonic power and hot bed temperature. The mechanical properties of the speci?mens were measured. The results indicated that the specimens exhibited an increase in tensile strength with an increase in ultrasonic power in the range of 0~30 W under the same condition of other forming parameters. However, the warping deformation of the specimen was easy to occur if the ultrasonic power was too large. Ultrasonic vibration could improve the compressive strength of specimen, and the maximum compressive strength was obtained at a power of 12 W. A good quality was obtained for the specimens at a hot bed temperature of 70 ℃. However, there was no significant effect on the mechanical properties of the specimens resulting from the change of hot bed temperature.
WEN Yuan, HUANG Ming, SHI Chuncai, YU Jianhai, LI Yanping, ZHANG Wei, MAO Xianpeng, XU Kejie, SUN Hongsuo
Abstract (
528 )
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491
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0 )
Based on the requirements of GB/T 40934—2021, the influencing factors for the powder flowability test of rotational molding materials were investigated, and the precision data and quality judgment criteria of powders for rotational molding were presented. The results indicated that the influencing factors for the sensitivity of powder fluidity test were obtained by an order of outlet diameter >> sample temperature = sampling amount ≈ moisture content > > state condition time. In these factors, the outlet diameter was the most important factor for the accuracy of test. The greater the value of powder fluidity, the stronger was the sensitivity to the change of test conditions, indicating an increase in the coefficient of variation. There was only a weak negative correlation between the apparent density and powder fluidity.
PAN Shenglin, YANG Guibin, YUAN Min, FENG Yahui, HOU Jianjun, ZHANG Zhang, DAI Dongqing, ZHU Haiou, JIANG Yixin
Abstract (
560 )
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761
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This paper introduced the utilization status of imported and domestic recycled plastics and reviewed the evolution direction of risk monitoring of cross?border recycled plastics under the green and low carbon backgrounds. The basic risk of rapid identification and screening, the high?value orientation of domestic recycled plastics industry, and the new direction of risk monitoring under the dual carbon strategy were analyzed. The environmental impact and use risk of abnormal risk of cross?border recycled plastics were discussed, the management situation in China was summarized, and the follow?up supervision suggestions were proposed.
ZHANG Bing
Abstract (
864 )
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560
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8 )
The oxidation induction time (OIT) of random copolymer polypropylene pipe was measured using a differential scanning calorimeter, and the effects of specimen site, diameter, thickness, and sampling method on the text results were studied. The results indicated that the OIT test results were relatively reliable when using the sample taken from the direction perpendicular to the pipe wall with a core layer diameter of 6 mm and a thickness of 650 μm.
ZHAO Hongjing, ZHU Jiang
Abstract (
408 )
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265
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4 )
Aiming to ensure the uniform thickness of natural rubber (NR)/polypropylene (PP) compounds extruded by micro/nano lamination, a three?dimensional model laminated flow channel was established. The material viscosity was fitted according to the rheological test results, and then the three?dimensional isothermal viscoelastic flow of NR/PP compounds was numerically simulated. The results showed that the two?phase velocity at the outlet has a drastic change at the same inlet flow rates of the two materials. The velocity difference between different flow channels was large, and the viscosity boundary of two?phase was not clear. Therefore, there was a certain degree of mutual infiltration at the interface. After adjusting the inlet rates of the two phases, the velocity transition tended to be stable with a reduction in the velocity difference between different channels. The viscosity boundary of two?phase was regular without the offset phenomenon.
Additive
LIU Yi, WANG Ye, SUN Wei, QU Guoxing, XU Xia, YANG Shaolin, YUAN Ning
Abstract (
629 )
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448
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8 )
In this work, a method for determining the content of sorbitol acetal?type transparent nucleating agent in polypropylene PP through infrared spectrometry was established on the basis of its characteristic absorption peak at 1 073 cm-1 using an injection?molded specimen for calibration and test. This method eliminated the influence of sheet thickness on test results. The results showed that there was a good linear relationship between the content of transparent nucleating agent and the absorbance of characteristic peak with a correlation coefficient of 0.999 4. The recovery of the content was between 98.59 % and 100.02 %. This method exhibited the advantages of high speed, high precision and environmental protection, and it was suitable for determining the content of transparent nucleating agent in PP.
Plastic and Environment
HU Chenguang, SU Hang, FENG Xiaoxin, DING Feng, LI Enshuo, FU Jiawei
Abstract (
569 )
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284
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To improve the utilization rate of waste glass?fiber?reinforced plastic (GFRP) pipe, the effects of particle size, dosage, and shear conditions, such as temperature, time and rate, of waste GFRP powders on the ductility, penetration, and softening point of modified asphalt were investigated. The microstructure of modified asphalt was analyzed using polarizing microscope and infrared spectroscopy. The results indicated that the thermosetting resin in waste GFRP could react with asphalt to produce naphthenic hydrocarbons and aliphatic hydrocarbons. The increase of aliphatic hydrocarbon content increased the ductility of asphalt, and the excessive content of waste GFRP increased the formation of naphthenic hydrocarbons. This was disadvantageous to the improvement of asphalt ductility. Meanwhile, glass fiber reduced the penetration of asphalt and improved its high?temperature stability. If the content of glass fiber was too high, more defects were formed at an over high content of glass fiber, resulting in a decrease in ductility. This was disadvantageous to the improvement of asphalt hardness. In addition, a too low or too high shear temperature resulted in an increase in the content of naphthenic hydrocarbons in the modified asphalt. This was disadvantageous to the improvement of asphalt ductility. However, the influence of shear temperature on the high temperature stability of the modified asphalt was not obvious. Moreover, when the shear rate reached a certain value, an increase in shear rate generated few effects on the performance of the modified asphalt, and the increase of shear time was beneficial to an improvement in its performance. The optimal modification system was determined to be a particle size smaller than 0.3 mm, a dosage of 4 %, a modification temperature of 150 °C, a shear time of 4 h, and a shear rate of 8 000 r/min.
MA Teng, LIU Qianqian, WEI Xiaoli, SONG Haitao, LI Mingfeng
Abstract (
753 )
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1134
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15 )
Chemical recycling of waste plastics is one of the effective methods to deal with white pollution and realize high?value recycling synchronously. In particular, the technical route of further producing fuel oil or chemical products from waste plastic pyrolysis oil has attracted a great deal of attention. However, there are many impurities and complex components in plastics wastes, in which the effects of silicon and chlorine impurities on the reactor, products, catalysis and its own reactions cannot be ignored. This paper analyzed the sources, forms, formation mechanism and catalytic conversion laws of silicon and chlorine impurities in plastic pyrolysis oil, and put forward some effective countermeasures according to the possible adverse effects of impurities.
Review
YU Darong, XIN Yong
Abstract (
1041 )
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1034
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31 )
This paper reviewed the latest research progress in the modification methods of ultrahigh molecular weight polyethylene in recent years. These methods included the modification of friction properties using irradiation cross?linking method, modifications through filling and blending, fiber surface modification through coating, and plasma modification. The paper also discussed the challenges in the study of the modification of friction and fiber surface properties.
TANG Xiaoming, CAO Ning, JIANG Yuehang, WANG Qian, WANG Zhiyan, LI Jianhua, WANG Yatao, LIAN Huiqin, WANG Xiaodong, CUI Xiuguo
Abstract (
994 )
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802
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29 )
This paper introduced the classification of proton?exchange membranes and reviewed the latest research progress in polysulfone fuel cell proton?exchange membranes, such as main chain polysulfone proton?exchange membranes, side chain polysulfone proton?exchange membranes, and inorganic doped composite polysulfone proton?exchange membranes. The influence of morphology and structure on the physical and chemical properties of sulfonated polysulfone was described comprehensively, and application prospect of polysulfone fuel cell proton?exchange membrane was analyzed.
YANG Yan, WANG Jie, LI Zongyu, WANG Yiming, WANG Yunnan, LI Shuijuan, LEI Liangcai, LI Haiying
Abstract (
586 )
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520
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10 )
This article reviewed the synthetic methods of hyperbranched ionic liquid polymers (HPILs) and emphasized the synthetic technologies for the HPILs with a core structure such as polyglycidol, polyester, polyethylene oxide, imidazole, poly(p?chloromethylstyrene), etc. Finally, the research prospects in the synthesis technologies of HPILs were discussed.
BAI Shuiquan, BIAN Jiacheng, WANG Leyuan, YANG Jiahua, DENG Yafeng
Abstract (
1342 )
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847
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77 )
This paper analyzed the harm and sources of microplastics as well as their distribution in water environment all over the world. Four types of microplastics removal technologies were summarized, which include physical removal, chemical removal, biological removal, and combined technologies. Finally, the future research direction in microplastics removal technologies in water environment was prospected.