WANG Ping-ping, CfEN Xiao-yuan, WANG Gang, LU Ai, ZHANG Qing
Abstract (
2710 )
Main factors that influence the tribological properties of PPS are analyzed. The friction and wear properties of PPS can be affected by filling particles, relative sliding speed, load, temperature,frictional pairs, surface roughness, and friction/wear environments. The developing tendency of improving the tribological behavior of polymers and their composites is discussed.
GUO Yan-Bing, GUO Shao-hui, CHEN Jun, ZHENG De, HUANG Hgon-lin
Abstract (
2014 )
the nano-scale inorganic flame-retardants are well in characteristics of high efficiency, multi-functionalities, reduced fuming and low filling of additives, which may well be used in retardant polymeric composite. Research work is reviewed about nano-scale inorganic flame-retardants used in polypropylene (PP)，including PP/nano-scale metal hydroxide composite, PP/carbon nano-tube(PP/CNT's)composite, PP/nano-montmorillonite(PP/MM)and PP/nano-polyhedral oligomeric silsesquioxane (PP/POSS) composites.
LI Yin-huan, WANG Lian-shi, DAI Jing-Qi, WEN Shao-kun, ZHANG An-qiang
Abstract (
2161 )
Polyethylene-octene elastomer(POE)-graft- methyl methacrylate/acrylonitile/styrene (POE-g-MAS) was synthesized by grafting methyl methacrylate(MMA)，acrylonitrile(AN) and styrene (St) onto POE elastomer. }Che effect of weight ratios of POE to the three monomers and initiator concentration on the graft copolymerization were investigated. the graft copolymer was extracted with acetone from the system and was characterized using F}L}IR spectroscopy. It showed that MMA-An-St was grafted onto the POE chains. Introducing the POE-g-MAS into SAN resin by melt blending generated a novel high impact engineering plastics, POE-g-MAS/SAN.SEM analysis showed that POE-g-MAS had good compatibility with SAN resin.
JIANG Dong-sheng, WANG Yong-Zhong, LU Kang-Li, YANG Jin-tao, ZHONG Ming-qiang
Abstract (
3687 )
YAN Hong-Xia, NING Rong-chang, SONG Chang-wen, LEI Ping-sen
Abstract (
1900 )
A novel bismaleimide resin (5406 resin) and its composites with nanometer Si3N4 were prepared. the effect of the content of nanometer Si3N4 on the properties of 5406 resin and its composites was investigated. }Che resin 5406 had high modulus, good heat properties, especially a low viscosity allowing the fine dispersion of the nanoparticles and the casting of the composite precursors. the composite with nanometer Si3N4 exhibited considerably lower friction coefficient and wear rate than the neat 5406 resin. SEM indicated that the wear mechanism of the composites of 5406/Si3N4 was essentially adhesion wear, while that of the neat 5406 resin was mainly plastic deformation.
PANG Jian, ZHOU Zheng-fa, XU Wei-bing
Abstract (
2156 )
In this paper, Zrq was applied to modify polypropylene (PP).The tensile strength of PPdecreases when ZrO2 was added, while the notched Charpy impact strength and elongation at break of PP increased considerably. the notched Charpy impact strength of PP reached 13.7 kJ /m2 when the amount of ZrO2 was 0 .3%.the determination of differential scanning calorimeter (DSC) and polarizing optical microscope revealed that the crystallization temperature increased and spherulite sizes of PP decreased with increasing amount of ZrO2 .the (3-crystallite of PP was observed by X-ray diffractometer (XRD) when ZrO2 was added, and the content of (3-crystallite increased with increasing amount of ZrO2.
WANG Que, TAN Tou-wen
Abstract (
2956 )
A coating was applied on the surface of PS-HI samples and cured with ultraviolet irradiation.The changes in the mechanical properties of PS-HD were studied. Compared with the properties of neat PS-HD, the flexural strength and flexural modulus slightly increased, however, the tensile strength, impact strength, and elongation at break decreased by 8 .2%，11.0%，and 85.1%，respectively. Such deterioration in properties may be caused by stress cracking, degradation，crosslinking, and so on. the elongation at break was most sensible to the irradiation times.
LI Mei, GAo Shan
Abstract (
1975 )
Blends of poly ( 3-hydroxybutyrate-co-4-hydroxybutyrate)polylactic acid (PHB/PLA) were prepared via melt mixing, whose properites were investigated with the XDR, differential scanning oalorimetry (DSC)，Rheometer，and polarizing mioroscope(PLM).With increasing amount of PLA,the crystallization temperature decreased from 102. 09 C to 62. 33 C，melting point decreased from 156 .OS C to 130 .32 C，the glass temperature increased from一8.69℃to 3.42 C.
CHEN Kui, YANG Rui-cheng, YUE Gui-jie
Abstract (
4182 )
Thermogravimetric analysis was used to study the polypropylene(PP) and polypropylene/montmorillonite (PP/OMMT) composites. the thermal decomposition kinetics parameters of PP and PP/OMMT composites (4 wt% montmorillonite) was calculated by means of Qzawa method at different heating rates of 10，20，30 and 40 K/min in nitrogen atmosphere，thermal decomposition kinetics mechanism was studied by Coats-Redfern method. thermal decomposition of both PP and PP/OMMT composite were completed in one step. the activation energy of PP was lower than that of composites before 22 wt% mass loss, and higher after 22 wt% mass loss. the most probable kinetic function of the thermal decomposition of PP and PP/OMMT composites was the Valensi function with n=1/2 and Mampel Power theorem with n=1 /4.
DING Xing-yan, WU Yu-jiao, XIAO Xian-bin, WANG Jue, MENG Ri-liang
Abstract (
1864 )
Influence of blending procedure on the toughness of PP/POE/SiO2 composites was studied.The samples were obtained through injection molding after extrusion blending of different procedures:(i) PEE and Siq were blended first and the mixture blended with PP; (ii) PP and SiO2 were blended first and the mixture blended with PEE;(iii) PEE and PP were blended first and the mixture was blended with Siq;(iv) the three components were blended at the same time. the toughness of the composites was in the order(i)>(ii>(iii) >(iv).If a composite was extrusion blended one more time, better toughness was obtained.
MA Yu-chunMENGQing-rong, ZHANGLiucheng
Abstract (
175 )
Abstract:Composites of epoxy resin and liquid crystalline bismaleimide(IA)were prepared and charac terized using impacterSEMHDT,and TGA.The impact strength of the composites was improved based on neat epoxy resin. When the content of IA was 0.8 wt%，the impact strength reached 5.3kj/m.When the content of IA was 1.5%，the heat deformation temperatureT5,and Tso were12℃，57 ℃，and 45 ℃higher than neat epoxyresinrespectively.
ZHOU Run-heng, HUANG Han-xiong, LIU Xu-hui, HE Jian-min
Abstract (
2414 )
this paper describes the design of a self-locked pin for water-assisted inj ection molded polypropylene curved pipes, which meets the demand of high flow rate and preventing being stuck by melt. the wall thickness of parts molded using both self-locked and orifice pins were compared under the same processing parameters. the parts molded using the self-locked pin resulted in more uniform and thinner wall thickness. the effects of the water pressure and injection delay time on the wall thickness and water penetration length of parts were investigated using the self-locked pin.
ZHENG Jin-yang, ZHU Yan-cong, LI Xiang, GAO Yong-jian, LI Ya-xian
Abstract (
2680 )
the short-term buckling critical pressure and long-term buckling creep pressure were measated according to previously proposed methods. In order to understand the mechanisms of the buckling of PSP, a model was formulated to predict the buckling critical pressure. PSP was simplified as orthotropic laminated cylinder shell, and elastic parameters of single layers were estimated based on rectangle model. Short-term buckling critical pressure was deduced from Donnell shell theory. theoretical prediction on short-term buckling critical pressure agreed well with experimental data. Relationship between structure parameters and critical pressure were analyzed and measures to improve the critical pressure were proposed.
MENG Jun, CHENG Min-lian, LUAN Fu-jin
Abstract (
2349 )
Barrier pipe was made via extrusion from a blend of PE-HD, polyethylene-co-vinyl alcohol)(EVOH)，and PE-g-MAH.the effects of dosages of PE-g-MAH and processing conditions on barrier,rheological, and mechanical properties of the materials were investigated. the laminar structure of the pipe section was observed by scanning electron microscope (SEM).the barrier and mechanical property of PE-HD/EVOH pipe were better than those of PE-HD/PA6 pipe. the processing conditions for the former were easily controlled. the optimal set of recipe and processing parameters was as follows:EVOH 16一18 wt，PE-g-MAH 1一3 wt，extrusion temperature 225 C，screw rotating speed 20 r/min，and drawing ratio 1 .5一1 .6 m/min.
ZHENG Guo-qiang, YANG Wei, YANG Ming-bo, LI Qiang, CHEN Jing-bo
Abstract (
1931 )
the influence of processing parameters(delay time, gas pressure, melt temperature, short-shot size) of gas-assisted injection molding on the gas penetration behavior (residual wall thickness, penetration length) was studied. It showed that the shorter delay time and higher melt temperature, the smaller the residual wall thickness. In addition, shorter delay time, lower melt temperature, and larger short-shot size may result in larger penetration length. By comparison, the residual wall thickness ratio obtained from this experiment was consistent with that from a previous simulation.
JU An-qi, GAO Yu-ling, GE Yan-xia, WANG Na, ZHANG Hui-xuan
Abstract (
3225 )
the effects of stabilizer and plasticizer on the thermal stability of blend of polyvinyl chloride) (PVC) and acrylonitrile-butadiene-styrene(ABS) were studied via thermogravimetric analysis and Congored method. Both stabilizer and plasticizer DAP improved thermal stability of PVC/ABS with a cost of mechanical properties. The dosage of the stabilizer and DAP should be limited below 5 and 15 phr, respectively. DC}P improved not only the processability, but also the dispersion of stabilizer in the blends.
QIAN Yun-hua, CHEN Jing, JIN Ye-ling, HU Tao, TAN Li-qiang
Abstract (
2896 )
Stearic acid was found effective as a milling aid in the ball milling of attapulgite. Stearic acid milled attapulgite could be finely dispersed in polyurethane leather without re-agglomeration, which was confirmed by SEM observation. the polyurethane leather containing 10 wt % such treated attapulgite satisfied the requirement of }B 1646-92. When the content of stearic acid milled attapulgite was 1 wt % , the radial and latitudinal tensile strengths of polyurethane leather were 149.8 N and 151.4N，tearing strength 35. 7 N and 53.3 N, elongation at break 331.9%and 118.3%，respectively. the improvement of mechanical performance of the polyurethane leather could be attributed to the interaction between stearic acid milled attapulgite and polyurethane.
MENG Ping-rui, KANG Zhi-hui, LI Liang-bo, DONG Chen-guang, SONG Qing-qun
Abstract (
1939 )
Water pipes of high-density polyethylene (PE-HD)，crosslinked polyethylene pipes (PE-X)，and rigid polyvinyl chloride) (PVC-U) were tested with respect to migration of volatile organic components ( VOC) into water. the odour of water in contact with plastic pipes was assessed according to the quantitative threshold odour number (SON).the major migrating component from PE-HD pipe was 2，4-di-tert-butyl-phenol (2，4-DTBP) which is a degradation product from phenol antioxidants. In addition, esters, aldehydes, ketones, aromatic hydrocarbons, and terpenoids were identified as migrationproducts from PE-HI)pipe. Water in contact with 5/7 PE-HDpipe was assessed as TON≥4.A significant amount of VAC migrated from PE-X pipe into water with TON≥5，some of the migrated VOC were not identified. In contrast, PVC-U pipes released few volatile migrants into water, from which no obvious odour detected.
LUO Bing, LONG Zhi-bin, HE Min
Abstract (
2462 )
the flow field of VCR and the triple screw elements in intermeshing counterrotating twin screw extruder was simulated using POLYFLOW software. }Che shear rate field, pressure field, average shear rate distribution, average pressure distribution, residence time distribution, and density distribution of max shear rate distribution were compared and studied. It was concluded that both elements possessed good mixing ability. Flame-retarded PP samples were extruded using extruders of two screw configurations with the two elements. The samples exhibited good mechanical properties with the determined values being agreement with simulation results.
