CHEN Yu, CUI Zheng, ZHANG Zhao-hui, ZHANG Sheng
Abstract (
2126 )
It was suggested in this paper that the formulation for plastics modification should be simplified. More attentions should be paid on the resin itself and functional additives. The employment of crystallization modifier and flame retardant were also discussed.
MIAO Ai-zhen
Abstract (
2133 )
The studies of phosphite applied in the synthesis, processing and modification of PLA in recent years were reported in this paper. Phosphite, as a secondary antioxidant and a chain extender, not only improved the antioxidation performance, but also the processing stability and mechanical properties of PLAn. The prospect of the application of phosphite in PLA was discussed as well in the paper.
XIAO Feng, WANG Ting-wei, DING Pei
Abstract (
2130 )
The effects of crystallinity, chain flexibility, and chemical composition on the degradation behavior of PBS were analyzed in this paper. It was found that the flexible segments promoted, the regular crystalline structure hindered the biodegradability. Aliphatic segments biodegraded easier than the aromatic ones. The degradation remained a challenging problem in the work of improving the performance of PBS-based copolyester.
WANG Zhen-hua, WANG Pei-zhang
Abstract (
2115 )
Rare earth luminescent material was modified with silane coupling agent, which was further encapsulated with a layer of poly（methyl methacrylate ）(PMMA) via in-situ emulsion polymerization. FTIR, TG and SEM showed that PMMA was uniformly grafted on the surface of rare earth luminescence materials forming a thin layer. Such PMMA coated rare earth luminescence materials maintained good fluorescence performance and their original luminescence centers.
GUO Jian-bing, ZHU Hong, HE Min, QIN Shu-hao
Abstract (
2222 )
PA6, ABS and their compatibilizer, styrene-co-maleic anhydride (SMA) was blended using a corotating twin-screw extruder with different blending procedure. The morphology of the blends was observed through TEM. The influence of blending procedure on the morphology, properties, and brittle-ductile transition was studied. The addition of SMA decreased the rubber particle size, and thus the matrix ligament thickness. with increasing content of SMA. As the content of SMA increased, the tensile strength of the blends increased, the brittle-ductile transition temperature of decreased firstly and then increased.
LAN Hao, WANG Bao-xu, LIU Fu-ping
Abstract (
2284 )
The effects of triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP), and PX on the flame retardancy of PC/ABS blends were studied．All the phosphate could improve the flame retardancy of PC/ABS blends effectively. Into a PC/ABS blend of weight ratio 7/3，11 wt% of TPP or 14 wt% of RDP or 12 wt% of PX was introduced, UL94 grade of V-0 could be obtained. In addition, the positive effect of a compatibilizer on the mechanical properties of PC/ABS alloy was also observed．
LI Peng-hui, WANG Cheng-yi, LI Guang, JIANG Jian-ming
Abstract (
1939 )
A novel fluorinated diamine monomer, 1,4-bis[4-amino-2-(trifluoromethyl)phenoxy]cyclohexane, was synthesized via two steps using 2-chloro-5-nitrobenzotri?uoride and 1,4-cyclohexanediol as the starting materials, which was subsequently employed to prepare a series of fluorinated aromatic polyamides with various aromatic acids, terephthalic acid, isophthalic acid, 4,4'-oxydibenzoic acid, and 2,2-bis(4-carboxy-phenyl)hexa?uoropropane. The inherent viscosities of the resulted polyamides were in range of 0.89~1.29 dL/g, and they exhibited excellent solubility and optical property. They could be readily dissolved in not only strong polar solvents such as N-methy-2-pyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide, but also in some low-boiling-point solvents such as tetrahydrofuran, chloroform, and dichloromethane. The film prepared from these polyamides was colorless and transparent, with a UV-vis absorption edge between 335 nm and 357 nm. Furthermore, the polyamides also showed good thermal properties. The temperature of 10 % weight loss was 330~364 °C under nitrogen atmosphere. The glass-transition temperatures (Tgs) were in the range of 202~223 °C.
CHENG Qing-min, DING Guo-fang, LUO Shi-kai
Abstract (
2321 )
Blends of siloxane and butyl rubbers were prepared via mechanical blending. The influence of butyl rubber content on the mechanical property, thermal stability, and damping properties of the composites were investigated. It was found that, with increasing content of butyl rubber, the mechanical property and thermal stability decreased, but the damping properties increased obviously. When the dosage of butyl rubber were 100 phr, the effective damping temperature range (tanδ>0.3) of the composites was broadened from 0 ℃ to 75 ℃, the maximum loss factor was increased from 0.11 to 0.80, and the glass transition temperature increased by 8 ℃, compared with neat silicone rubber.
ZHONG Liang, YANG Yan-juan
Abstract (
2251 )
In this paper, the dielectric property of PC and PE-LD melts were studied. For PC melt between 220 and 320 ℃, increasing temperature increased considerably the 10Hz dielectric constant, but marginally affect the values between 100 Hz and 1 000 Hz. For PE-LD melt between 120 and 300 ℃, the 10Hz dielectric constant first increased, then decreased and finally increased again, When the frequency was 1 000 Hz, the temperature had little influence on its dielectric constant. At low frequency zone, the dielectric constants of both melts decreased with increasing frequency.
GU Hong-yan, LU Qin
Abstract (
2232 )
The mechanical, friction and wear properties of polytetrafluoroethylene (PTFE) composites filled with nanometer AlN, Si3N4, and TiN were studied. It was found that the nano-particle increased the hardness and wear resistance of PTFE but decreased the tensile and impact strengths of the composites. The tensile fracture surface was observed using scanning electron microscope (SEM), which showed that nano-TiN was finely dispersed in the PTFE matrix, however, nano-AlN and Si3N4 could not be well dispersed.
MU Nan-qiang, YUE Qun, LIU Bing-xue, YUAN Mao-quan, HU Mei-hua, WU De-zhen
Abstract (
2252 )
Three kinds of chlorinated poly(vinyl chloride)(CPVC) resin with similar molecular weight and distribution were subjected to 13C-NMR analysis in order to determine their sequence structure. According to the formation mechanism of allyl chlorine, a method to calculate the allyl chlorine content of CPVC was established. Thermal stability of the CPVC resins was studied using Brabender rheometer. It was found that the thermal stability of CPVC increased with decreasing allyl chlorine content.
LIN Li-zong, GUO Xi-qiang, XING Dong-shi, HUANG Zhuan, SUN Li-juan
Abstract (
2472 )
Using moldflow simulating analysis software, the filling, flow, cooling, and warp processes of the automobile airbag cover were simulated. Through comparing various design schemes, the optimal designing was determined. The simulation demonstrated the importance of CAE technology in molding design on simplifying the design process, improving the design efficiency, and decreasing the rate of waste products.
WANG Huai-yuan, ZHU Yan-ji, FENG Xin, LU Xiao-hua
Abstract (
1551 )
The tribological behavior and corrosion resistance of glass fibers (GF) and carbon fibers (CF) filled PTFE in both dry condition and sulfuric acid were investigated. In sulfuric acid, the optimal content of fillers was 15 wt %, which resulted in the wear resistance of PTFE/GF and PTFE/CF composites increased 7.7 and 4.4 times based on neat PTFE, respectively. When the filler content was higher than 15 wt %, furrow and abrasive wear constituted the main mechanisms for PTFE composites. Owing to the cooling and lubricating effects of acid media, the friction coefficient of PTFE composites decreased more obvious than that in dry condition. However, the acid inhibited the formation of transfer film on the counterpart.
JI Yu-bi, XU Guo-min, ZHANG Min-min, HU Zhi, TAN Hong
Abstract (
2226 )
Viscosity and its stability over time of PVC plastisols were studied using compounds of a high- and a low-degree polymerization PVC paste resins, PSH-10 and CPM-31. When PSH-10/CPM-31=20/80, the plastisol provided the lowest viscosity. When PSH-10/CPM-31=50/50, the worst stability was observed. The viscosity and stability of PVC plastisols were more sensitive to the content of low-degree polymerization component.
ZHUANG Jian, ZHANG Ya-jun, WANG Xiao-na, ZHAO Zhong-li, WU Da-ming
Abstract (
2094 )
Based on the orthogonal experimental method, micro-injection molding processes of micro-connector with various processing parameters were studied. The weight of micro plastic part was selected as the experimental indicator. Six processing parameters, mold temperature, melt temperature, injection velocity, packing pressure, packing time, and cooling time were taken as influencing factors. The order in importance of the influencing factors was determined through range analysis (RS). The mold temperature was the most important process parameter, and the cooling time was the least important process parameter. According to the change trends of factors and levels, the optimized process parameter scheme was mold temperature 80 ℃, melt temperature 335 ℃, injection velocity 100 mm/s, packing pressure 20 MPa, packing time 1.5 s, and cooling time 3.0 s, which could be taken as a reference in the process design of micro plastic parts.
HU Xiao-ping, YANG Jun, LI Xiao-yan, LI Shao-xian, LI Hong-bo, ZHOU Yuan-lin
Abstract (
2371 )
A novel phosphorouse-nitrogen structure containing intumescent flame retardant poly(3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5.5] undecane-3,9-dioxide) hexamethylene diamine (SPHD) was prepared by 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5.5] undecane-3,9-dioxide ( SPDPC ) and hexamethylene diamine (HD) through melting ploymerization in N2. The effects of ratio of material and reaction temperature on relative molecular weight were studied by intrinsic viscosity test. The results showed that the highest yield was 84 %, and the optimal reaction conditions were as follows: polymerization time, the molar ratio of SPDPC to hexamethylene diamine, reaction temperature were about 4 hours, 1/1.1, 165 ℃, respectively. The molecular structure and thermal stability of SPHD were characterized by FT-IR，1H-NMR and TG, separately. Results showed that the products could be obtained successfully by melt polymerization, which had good thermal stability. The flame retardancy of SPHD was studied when used in PE-LD with addition of ammonium polyphosphate (APP), when the content of SPHD was 15 %, the limiting oxygen index(LOI) value was 27.2 %and V-0 rating of UL94 could be achieved.
MA Zhi-ling, TANG Hui-peng, LU Zheng-yu, WANG Yue-feng, ZHAI Wen-qing
Abstract (
2220 )
Ammonium polyphosphate (APP) was encapsulated with melamine formaldehyde resin (MF) forming capsules (MAPP). When the mass ratio of APP/MF was 3/1, the solubility of the capsules in water at 50 ℃ was 0.052 g/100 mL, reduced 78 ％ compared to APP; the intumescent degree reached 78.6 ㎝3/g. The MAPP capsules was introduced into polypropylene as an intumescent flame retardant. The thermal analysis indicated that the degradation of PP/MAPP was more rapidly with reduced heat release compared to neat APP. Due to the formation of porous carbon layers, the flame retardancy of MAPP/PP was better than that of PP/APP. When the mass ratio of PP/MAPP was 70/30, its oxygen index reached 30.6 %.
LIU Xian-Feng HONG Jian-cheng BU Hai-tao ZHANG Xiong-wei WU Shi-jian
Abstract (
1662 )
UG software was applied to formulate a three-dimensional model, based on which the tensile stress distribution in a polystyrene dumb-bell specimen was simulated using ANSYS finite element software. The factors causing stress concentration were analyzed in the different transitionary structures. The finite element analysis indicated that the maximal tensile stress occurred in domain of the transitionary circular arc 1～3 mm. The relationship between geometric parameter and stress concentration factor was formulated data fitting.
JING Jun-tao, XIE Lin-sheng, MA Yu-lu, ZHANG Xia
Abstract (
2103 )
Numerical simulation was performed on polymer melt in the mixing section of two-rotor continuous mixer using POLYFLOW software. The flow field characteristics experienced by the materials was statistically analyzed using particle tracking analysis (PTA) method. The average shear rate, resident time distribution (RTD), and cumulative max-stretch-rate distribution were obtained, which were used to describe the influences of structure of rotors and technological parameters on the mixing performance of the mixer. It was found that the shearing and stretching actions that materials subjected to increased with increasing rotor speed; the specific shear rate in unit resident time of the materials in the mixing section decreased with increasing feeding rate; the shearing action increased with decreasing length of rotor convergence section. The length of rotor convergence section and the angle of rotor had little influence on resident time distribution. The results of numerical simulation agreed well with the data.
SHAO Zhu-na, ZHOU Hua, XIE Peng-cheng, LIU Yan-xiu, YANG Wei-min
Abstract (
2532 )
A mathematical model and related concepts of mould design optimization techniques were introduced. An example of first order optimization analysis was given, in which the width of tendons and the thickness of mould board were taken as design variables, the allowable stress and deformation amount of mould board were taken as state variables, and the minimum volume value of mould board was taken as objective function, the optimum geometric parameters were determined. The optimization based on the finite element method was proven reliable and was useful in practical engineering design.
