SI Mingming, HAO Jianwei, XU Lishi, DU Jianxin
Abstract (
397 )
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On the basis of structure and characteristics of nano-Sb2O3, research development in the surface modification of nano-Sb2O3 and its dispersion method in resin matrix were reviewed in this paper, including the using of masterbatch, surfactants and coupling agents, in situ polymerization. The dimension effect of Sb2O3 was explored. The synergistic effect between nano-Sb2O3 and halogen-containing and halogen-free flame retardants in polymeric materials was introduced. The development significance and direction about nano-Sb2O3 were finally summarized
XU Bo, ZHU Guangming, ZHU Meng
Abstract (
373 )
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The latest progress of expanded polytetrafluoroethylence aircraft sealant was reviewed, including Gore method and poreforming agent foaming method. The effect of raw materials, lubricant, stretching condition, and sintering temperature on porosity and pore size was summarized. The future research trend on expanded polytetrafluoroethylence was also prospected.
NIU Ping, YAN Jiaan, XU Haiyun, LIU Cai, TIAN Huafeng, XIANG Aimin
Abstract (
497 )
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The progress in polyvinyl alcohol/starch blends in recent years was reviewed in this paper. The processing methods include solution casting, extrusion and compression molding. The influence of plasticizers, crosslinkers, modified starch, and nanoparticles on the properties of biodegradable ecofriendly blends was discussed. A number of potential applications for this novel material were also introduced.
ZHANG Yu, QI Zhiguo, LIU Zunhao, TANG Yiren, ZENG Yiming, XU Jun, GUO Baohua
Abstract (
420 )
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Branched poly(butylene succinate) copolymers (PBS-bge) with different ratios of branch units were synthesized via polycondensation of succinic acid(SA), 1,4-butanediol(BDO), and butyl glycidyl ether(BGE) as the branch monomer. The compositions and crystallization properties of the resulted branched PBS were investigated by 1H-NMR, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and polarizing optical microscope (POM). The results suggested that the crystal structure of the branched PBS copolymers hardly changed, but the thermodynamic properties were significantly changed from PBS. The melting temperature(Tm) and the degree of crystallinity(Xc) both decreased with the increase of the BGE units. Isothermal crystallization results showed that Avrami exponents (n) of the PBS-bge reduced to some extent compared with PBS. And the spherulitic morphologies, especially the banded spherulites were greatly affected when the BGE unit ratio was high.
YIN Guoqiang, LI Yang, SHEN Kaihua, ZHANG Feng, ZHANG Dongmei, SHI Jinghong, WANG Yurong
Abstract (
464 )
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In this article, styrene-isoprene-butadiene copolymer was synthesized via free radical initiated emulsion polymerization. Acrylonitrile-styrene-butadiene copolymer was toughened by styrene-isoprene-butadiene copolymer latex instead of high cost butadiene latex. To achieve this goal, four steps were taken, synthesis of styrene-isoprene-butadiene copolymer, the agglomeration of styrene-isoprene-butadiene copolymer, emulsion grafting polymerization, and the melt blending of SAN and high rubber content ABS power. Studying the effect of monomer ratio on SIBL kinetics, diameter, polydispersity, gel content and Tg. At the same time, we study the effect of monomer ratio on the grafting efficiency and the performance of ABS resin. The result shows that the method of synthesis of SIBL by free radical initiated emulsion polymerization is possible, the comprehensive properties of ABS resin were improved greatly, Izod from139J/m up to 233J/m.
LUO Xing, LUO Bing, XIAO Yuxing
Abstract (
228 )
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Influence of different corotating twin screw extruder elements including kneading block，hexagonal prism and variable gap rotor on the length of glass fiber polypropylene composite was studied by numerical simulation and experiment. It showed that with increasing shear effect of screw elements, the average length of glass fiber in products decreased, both the tensile and impact strengths of polypropylene composite decreased.
ZHAO Jing, YAO Xiuchao, LV Tong jian, CHEN Xin, WU Shuling
Abstract (
465 )
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The effect of a new dual-functional flexihilizer KT-30 on the properties of PC were studied. Izod impact strength，melt flow rate, tensile strength，bending strength and cracking time were test by impact tester, melt flow indexer，universal testing machine and electronic balance, respectively. It showed that with increasing KT-30，the impact strength of PC increased significantly, the melt flow properties and the flexural and melt flow properties decreased a little, and the stress cracking resistance was enhanced. KT-30 could he finely dispersed in PC matrix and the compounded system could he readily injection molded. When the mass fraction of KT-30 was 5 %，the impact strength of PC reached 40. 8 kJ/m2，about 5 times that of neat PC.
WANG Hongliang
Abstract (
428 )
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The friction and wear properties of basalt fiber (BF) reinforced polyphenylene sulfide composites were studied. It showed that the BF could effectively improve the friction and wear properties of composites, the friction coefficient decreased gradually, while wear rate increased with increasing fiber volume fraction.
WU Maoying, LIANG Ling
Abstract (
402 )
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Abstract, The performances of heat stabilization of several substituted diphenylureas on PVC were studied by oven discoloration method. It was shown that the substituted diphenylureas were initial- term effective type primary heat stabilizers showing characteristics of heat stabilization similar to zinc stearate and remarkable synergistic effects with calcium stearate and epoxidized soybean oil; the heat stabilizing performance of substituted diphenylureas improved with increasing electron-attracting ability of the groups linked to the urea moiety of the molecules. Based on this heat stabilizing behavior, it could he speculated that substituted diphenylureas stabilized PVC by electrophilic reaction with PVC using their carbonyl carbon atoms as a electrophilic atom. This meant that the traditional Frye and Horst‘s theory on mechanism of heat stabilization of heat stabilizers did not apply to，substituted diphenylureas，and therefore, the exact mechanism of heat stabilization of heat stabilizers needed to he clarified by further research.
LI Dan, CHANG Haibo, MA Conghe, YOU Qianqian, ZHANG Puyu
Abstract (
286 )
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With the surface repaired methyl nano-SiO2 (DNS-3) as initiator, polycaprolactone / DNS-3 (PCL/DNS-3) composite material were prepared by in situ polymerization. Thermogravimetry (TG) curves and Fourier transformed infrared spectrums (FT-IR) revealed that there had strong chemical bonds between PCL matrix and the DNS-3. In the same reaction conditions, with increasing DNS-3 content, the molecular weight (Mw) of nanocomposite material was reduced, but its thermal stability and crystallization rate were improved. The crystallization temperature of PCL/DNS-3 composite material was increased compared to pure PCL.
TAO Guoliang, ZHANU Tianqi, MA Wenzhong, XIA Yanping, JI Boyin
Abstract (
348 )
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PVDF/TiO2 composite film was prepared via casting，the thermostahility, mechanical property, crystalline form, thermal performance and weather resistance of the composites films were studied. It showed that when the mass ratio of PVDF/TiO2=98/2，the tensile strength of the composites films reached 59. 5 MPa. However，the initial decomposition temperature was lowered to 340 ℃，which was compared to neat PVDF film. The degree of crystallinity of PVDF was not changed so much by the incoporation of TiO2.The weather resistance of PVDF/TiO2 composites films was improved obviously according to ultraviolet radiation tests.
FANG Xiaofeng, HE Jimin, CHEN Yanfeng
Abstract (
286 )
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Employing single screw extrusion, by changing the quality content and the types of the ultra-high molecular weight polyethylene (PE-UHMW), prepared the activated carbon / PE-UHMW microporous tubing; what is more, using SEM and mercury porosimetry analyzed the microporous structure and parameters of the microporous tubing, also tested microporous tubing s density and compressive strength was introduced. As the results shows, PE-UHMW contributes to the extrusion of activated carbon, but it is easily wrap the active carbon and clog the micro porous when its content is too high；The microporous materials, prepared by single screw extrusion and sintering, have similar pore size and porosity；With the increase of PE-UHMW’s molecular weight, the density and compressive strength of the microporous materials increase; with the increase of PE-UHMW’s content, the density and compressive strength of the microporous materials decrease.
YANG Biao, WANG Sheng
Abstract (
58 )
ZHOU Guofa, CHAO Fangchao, YAN Li
Abstract (
428 )
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Polymer water-assisted co-injection molding is a new and innovative advanced molding technology of molding inner surface smooth, dense, high-performance multi-layer composite hollow plastic products, and may make up for the inner surface porosity defects of gas-assisted co-injection molding products which leads to decline in the mechanical strength of products. The melt shear –thinning effect characteristics is the key control parameters of controlling the penetration process of water or core melt, and the inner quality of water assisted co-injection molding products. Therefore, the influencing rules of the melt shear –thinning effect characteristics on the penetration process of water or core melt and the front moving interface flow stability for water-assisted co-injection molding process were systematic studied by means of the established the full three-dimensional unsteady and non-isothermal finite element numerical simulation algorithm and technology of water-assisted co-injection molding process, and the influencing mechanisms were finally revealed by theoretical analysis. Research results show that with the increase in the shear-thinning effect characteristics of core melt, the water and core melt penetration depth increase, which is conducive to water-assisted co-injection molding process of slender plastic products, but the increase in the shear-thinning effect characteristics of core melt make the front moving interface between water and core melt tend to be unstable, which affects seriously the inner surface quality of water-assisted co-injection molding products.
CHEN Xiaohua, XIAO Jianhua, OU Junfei
Abstract (
363 )
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Canna leaf was used as the template to prepare the super-hydrophobic materials of PVA/PS、PDMS/LDPE by double replication technology. Using the SEM to observe the morphology of these materials and the contact angle meter was employed to test the static angles(CA) and sliding angles(SA) of water droplets on these surface. The results show that the surface of polymers successfully replicated the micro-nano structure of canna leaf. The CA of PVA/PS is 156° and its SA is 47°, the CA of PDMS/LDPE is 140° and its SA is greater than 90°. The hydrophobicity of these two replicas are significantly enhanced than the flat materials.
BAI Junhong, LIU Youzhi, SHEN Yanhong
Abstract (
351 )
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Magnesium hydroxide retardant,smoke and fill at the same time,has become a growing concern inorganic environment-friendly flame retardant materials. Research of online modified was made on magnesium hydroxide flame retardant by sodium dodecyl benzene sulfonate or polyvinyl alcohol.Then contrast settling propertise、filter performance、activation、oil absorption value and viscosity before and after modification. The stirring speed under the conditions of 200-300rpm,the experimental results show that:the best optimal amount of sodium dodecyl benzene sulfonate was 2.5%,the magnesium hydroxide magnitude sedimentation rate achieve 1.111×10-4m/s,increase 11 times nearly,cake specific resistance was reduced to 21.835×10-10m/Kg, activation grade reach to97.62%,oil absorption value decreased to 28.5mL/100gMg(OH)2, viscosity reduced about 1/2 of unmodified;the best optimal amount of polyvinyl alcohol was 1.5%,the magnesium hydroxide magnitude sedimentation rate achieve 5.208×10-4m/s ,increase 50 times nearly,cake specific resistance was reduced to 20.779×10-10m/Kg,activation grade reach to97.73%,oil absorption value decreased to25mL/100gMg(OH)2 and viscosity reduced about 1/2 of unmodified.
CHEN Zhenzhen, HUANG Hanxiong, XU Linqiong
Abstract (
256 )
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Two kinds of polypropylene/waste ground rubber tire (PP/WGRT) blends with different viscosities of PP as the matrix were prepared by melt blending using a self-developed chaotic mixing extruder. Phase morphology, rheological properties, and mechanical properties of PP/WGRT blends taken from four positions along the extruder were investigated. The results showed that along the extruder the size of the WGRT agglomerates decreased and their dispersion became increasingly uniform in PP matrix due to the chaotic mixing provided by the extruder in this work. This led to higher values of both the complex viscosity (η*) and storage modulus () of the blend samples taken from four positions than those of the corresponding PP. The values of η* and of the blend samples in the low frequency increased gradually along the extruder. The introduction of the WGRT obviously improved the impact strength of the PP with higher viscosity but slightly increased that of the PP with lower viscosity.
WANG Kejian, GUO Bing
Abstract (
331 )
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Single conical screw extruder is easier than common extruder in solid-feeding with compression effect, which is capable of processing powder or thermal sensitive materials. On the basis of classic extrusion theory, the conical degree can be analyzed by the developed solid- and melt- transportion models as well as melting model in compression section. Conical geometry is favorable for increasing output while decreasing the length of melting zone.
ZHANG Weihe
Abstract (
409 )
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Double-shot molding technology is developed in recent 10 years, It′s one of the core technology of innovative significance in injection moulding field.it was invented and widely used, to write a new chapter for plastic products. This paper introduces the double-shot mold for mouse cover and the design experience and skills. There two feed system, One is pin point gate and other is submarine gate. The last channel of PC melt is molding by the auxiliary core. Mold side core-pulling mechanism is very complicated, which is composed of a slider in fixed mould and a angle ejector rod in movable mould. Water channel of mould layout equilibrium, guiding and positioning system is safe and reliable, It is a classic example of double-shot mold.
SONG Jianhui
Abstract (
290 )
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he theoretical and finite element models were established for the Lshape polymer profile gasassisted extrusion. The computer simulation was carried out with the aid of Polyflow software. The analysis showed that, during the gasassisted extrusion, a gas layer was established in the die and the frictional resistance was greatly reduced. The flow of polymer melt became the same，the die swell could be reduced effectively. So the shape and dimension precision of the extrudate could be improved which was helpful for the polymer extrusion processing with high speed and high quality.
