YANG Tao
Abstract (
2775 )
this paper introduces the production capacity, market demand, import and export tonnages of PVC resin in China. the market price of PVC resin varies in different seasons: it increases with increasing sales in the spring and maintains a high level in the summer, sometimes goes higher. In the autumn, it decreases gradually with fluctuations, and levels off a position during the winter. Comprehensive meta-analysis was made for the factors affecting the prices of PVC, such as the cost of raw materials, electricity prices, production increasing, import and export volume, and administrative policies,
transportation, weather, etc..
CHEN Jun, ZHENG De, JIA De-min, HUANG Rui
Abstract (
2464 )
Several flame retardants, including hydroxide, phosphors-based, intumescent, silicon-based,and nanoclay types, applied in polypropylene have been introduced. Also reviewed was the progress of synergistic agent applied in the magnesium hydroxid and intumescent flame retardant. the drawback of above halogen-free flame retardants was pointed out. Further strengthening the synergistic effect and improving the compound flame retardant constituted hot topics in the future.
SHEN Bo, TANG Hui, WANG Su-jing, HUANG Xi-jian
Abstract (
2040 )
Preparation methods and applications of functionalized polymer microspheres were reviewed.Functionalized polymer microspheres were prepared via either direct polymerization or by modification.the former included emulsion, suspension, and dispersion polymerization. the latter could be categorued seeded polymerization and surface reactions. All the methodology was compared and commented.the applications of functionalized polymer microspheres in chemical engineering and biomedicine were discussed.
GAO Yu-ling, JU An-qi, CAO Chun-lei, GE Yan-xia, ZHANG Fang-fang, ZHANG Ming-yao
Abstract (
4167 )
A series of α-methylstyrene-styrene-acrylonitrile copolymers(α-MSAN)was synthesized via emulsion polymerization, which was employed to modify heat resistance and mechanical properties of ABS resin. DSC showed that at constant content of AN，the Tg of the α-MSAN copolymers increased linearly with increasing proportion of α-MSt. DMA indicated that the Tg of ABS resin containing α-MSAN shifted to higher temperature, while mechanical properties decreased slightly. When the ratio of α-MSt/St was 50/50 and the content of AN was 25%，the optimal comprehensive mechanical property of ABS resin was observed.
QI Zong, XUE Ping, DING Jun, JIA Ming-yin, LI Jian-li
Abstract (
2243 )
EVA was employed to modify the surface of wood-flour in order to improve its compatibility with polyolefin. the diffuse reflectance spectroscopy, thermo-gravimetric analysis, and SEM were used to examine the changes of surface groups, thermal stability, and surface morphology of wood-flour, respectively. EVA prevented the adsorption of water from air, reduced the polarity of wood-flour. Termal stability of treated wood-flour was enhanced by the modification of EVA.SEM showed that when the EVA mass content was 15 wt，the wood-flour was completely encapsulated.
CHEN Yi-lan, LIN Lang, XIAO Li-ren, LIU Xin-ping, XIAO Liang-jian, CHEN Qing-hua
Abstract (
3007 )
the flame retardant properties of PE based composite with Ca(OH)2 and Mg(OH)2 were characterized with oxygen index analyzer, vertical horizontal analyzer, SEM, and TG. When the totalcontent of Ca(OH)2 and Mg(OH)2 was 35 wt%，the LOI of the composite reached 24.5%，and the Tmax lagged neat PE by 9.2℃ .The formation of dense char layer was promoted.Ca(OH)2 and Mg(OH)2 had some synergistic effects to the flame retardant properties of PE. It could be expected to replace some of Mg(OH)2 with low cost Ca(OH)2.
HU Qiao-qing, FAN Xiao-dong, ZHU Guang-ming, YAN Hong-xia
Abstract (
3178 )
Composites of perfluorinated ethylene-propylene copolymer (FEP) with Ti02 and Al2O3 were prepared via thermoforming. the effects of oxide content on dielectric constant, dielectric loss, and high-frequency breakdown performance of the composites were studied. the dielectric constant and loss of FEP composites increased with increasing oxide content, with the influence of Ti02 being more obvious. Ti02 possessed a negative effect on the high-frequency breakdown performance. At 4. 0 wt，the damage threshold of FEP/Ti02 composite was only 48. 9%that of neat FEP. In contrast, the high-frequency breakdown performance increased with increasing Al2O3 content. When the content of Al2O3 was 1 .2 wt，the damage threshold of FEP/Al2O3 composite reached 313 J/m2，that was twice that of neat FEP.
DAI Jing-qi, XIONG Kai, WANG Lian-shi, CAI Tong-min, ZHANG An-qiang
Abstract (
2091 )
Styrene-EPDM一acrylonitrile tripolymer(EPDM-g-SAN)was prepared by grafting styrene
(St) and acrylonitrile(AN)onto ethylene-propylene-dime mischpolymer ( EPDM) via phase inversion emulsion copolymerization using benzoyl peroxide as an initiator and n-heptane as a solvent. AES was obtained via melt blending the prepared EPDM-g-SAN with SAN resin. the effects of weight ratios of AN/St and EPDM/co-monomers on the monomer conversion and degree of grafting were investigated DSC and DMA showed that EPDM-g-SAN and SAN resin were partially compatible. TEM and SEM indicated that when AN weight percentage was 35 wt，the interface between two phases became smeared, EPDM-g-SAN dispersed finely in the SAN matrix. When AN weight percentage in the comonomers was between 35 wt % and 40 wt，the degree of grafting was about 35%，the notched Izod impact strength of AES reached 50 .7 kJ/m2.the main toughening mechanism was cavitation accompanied with shear yielding.
WANG Li-ming, LI Xiao-yan, WU Zhi-ming
Abstract (
1859 )
Molecularly imprinting polymer microspheres for 4-aminopyridine were prepared by means of an emulsifier-free seed emulsion polymerization from ethyl acrylate and styrene using octanol and a very small amount of OS as the dispersive reagent. When the octanol and OS were employed at certain ratios,a small size and uniform distribution of the microspheres were observed. The optimal condition was found, i. e.，the dosage of octanol was 3 . 0 wt，weight ratio of ethyl acrylate/styrene was 1:0 .229，PH was 8 .0，and the polymerization temperature was 85 ℃
ZHOU Wei-ping, ZHU Qing-Ying, LIN Wen-biao, ZHANG Ji-lan
Abstract (
690 )
Aluminum hydroxide was modified with rare earth complex coupling agent and the performance of the product was compared with those modified with other coupling agents including silane and titanate. Modified with rare earth complex, the activation index increased from zero to 99%，while the oil absorption value falls from 0.4214g to 0.2747g，which indicated that the surface of aluminuet hydroxide was transformed to hydrophobic. Measured by differential thermal analysis, the initial thermal decomposition temperature of aluminum hydroxide was increased to 249 C .the elongation at break of polypropylene (PP) containing rare earth complex modified Al (OH):was 5 .24 times higher than that containing unmodified Al(OH)3，and was 59 .5%higher than that of neat PP. the impact toughness of polypropylene (PP) containing rare earth complex modified Al (OH):was 17. 7% times higher than that containing unmodified Al(OH):，and was 14 .8%higher than that of neat PP. the rare earth complex modification also improved the fire retardant properties of PP.
ZHOU Guo-fa, ZHANG Sheng-jun
Abstract (
2222 )
the warpage, residual stress, molding pressure, and temperature field in microcellular injection molding were compared with those in conventional process. Based on rheology theory, the microcellular injection molding mechanism was disclosed. It showed all the warpage, residual stress, molding pressure, and molding time of the microcellular injection molding were obviously smaller than those of conventional molding. The warpage and residual stress decreased with decreasing initial filling volume fraction of the foaming melt. For microcellular injection molding, a lower melt temperature near the gate and a higher melt temperature were needed than those for conventional injection molding.
ZHENG Jing-xin, PANG Hao, CHEN Yong, LIAO Bing
Abstract (
2150 )
Malefic anhydride(MAH)was introduced into the reactive extrusion system of PE-HD/bagasse, and properties of resulted product were compared with those resulted by two other coupling agents, amino-silane and isopropyl triisostearoyl titanate. It was found that the grafting of MAH occurred during the extrusion, and consequently the compatibility between PE-HD and bagasse was improved. With addition of 6% MAH，the tensile strength of the composites increased by 120%，impact strength by 24%，and water uptake reduced to 0. 5%.
ZHENG Jin-yang, LI Xiang, ZHU Yan-cong, GAO Yong-jian, LI Ya-xian, SHAO Tai-qing, SHAO Han-zeng
Abstract (
1989 )
the stability of steel wire cross-wound high density polythene ( PE-HD)pipes ( PSP ) was investigated. Instantaneous and long-term critical buckling pressures-time, deformation-time curves were obtained. For PE-HD pipes with a nominal diameter of 250 mm and a wall thickness of 16.5 mm wound with steel wire of diameter 1 .0 mm and volume fraction of 2. 9 wt，the instantaneous critical buckling pressure increased by 33.3%compared with neat PE-HD pipe with the same wall thickness. the instantaneous critical buckling pressures of the PSP decreased with increasing pipe diameters. Because of the time dependence behavior of the matrix, the critical buckling pressure of the PSP also showed the time dependent behavior.
XIA Ying, DUAN Xiao-wei, ZHAO Jian, YIN Yue, JIAN Xi-Gao
Abstract (
3054 )
Citric acid modified βzeohte(N-β)was prepared via impregnation method. IR showed that citric acid had a function to increase the content of aluminum in β zeolite. the influences of N-β on the thermal stability, flame retardant performance, microstructure, mechanical properties, and processability of ABS/intumescent flame retardant(IFR) system were investigated using the tests of thermogravimetric analysis (TGA)，limiting oxygen index (LOI)，scanning electron microscopy (SEM)，etc.It showed that a lower content N-β had a synergistic effect with intumescent on the flame retardancy,which promoted the formation of stable, continuous and compact char structure at high temperature.When the content of N-βwas 2 wt，the LGI and the mass of residual char of ABS/IFR composites were 31.3%and 24. 86%，respectively. As the content of N-β increased, the impact and tensile strength of the composites increased at first and then decreased.
YU Bao-gang, LU Liu-gang, HE Yi, TANG Kai
Abstract (
2697 )
Phloroglucin tri(diphenyl phosphate) was synthesized based on phloroglucin, phosphorus oxychloride, and phenol. the optimal reaction conditions were as following:using aluminum chloride as a catalyst, molar ratio of phloroglucin to phosphorus oxychloride was 1:5，reacted for 7 h at 70℃，followed by 8 h at 130℃.A gross yield of 87.2%was obtained. A mixture of the product andmelamine ( mass ratio 3:1)was introduced into epoxy resin (mass ratio of epoxy/mixture=85/15)，the limiting oxygen index and UL94 of the latter became 32. 2%and V-0，respectively.
LAI Ming, TAO Guo-liang, YU Wei-zhong, LIU bin, TAO Yu
Abstract (
3829 )
Mechanical properties of polyethylene(PE)/waste tire rubber powder (WARP) blends werestudied. When raw WARP was introduced, the tensile strength and notched impact strength of PE were obviously decreased. the surface of WARP was treated with an activator and mixed with 0.1 phr of dicumyl peroxide(DCP)，5 phr of a compatibihzer (A171 grafted high density polyethylene)，the tensile strength increased from 14.4 MPa to 20.7 MPa, and the notched impact strength increased from 14.8 kJ/m2 to 39.6 kJ/m2.the degree of surface activation of WARP was characterized by gel content.
YANG Wei-min, WANG Jian, XIE Peng-cheng, DING Yu-mei
Abstract (
3623 )
the importance and eight application areas of pressure-volume-temperature(PVT) testing were expatiated. And most of PVC testing techniques, including conventional techniques, improved experimental techniques are explicated in detail .Conventional technique is attributed to direct method and indirect method, improved experimental techniques include the techniques considered the effect of cooling rate and deformation, techniques based on injection molding machine and extruder and ultrasonic technology. And several PVC testing products were introduced, including PVC-100 from Germany,PVT testing system from Japan, dilatometer from USA and domestic PVC on-line testing apparatus.
LIU Xu-hong, DU Di-sheng
Abstract (
2013 )
the optimization of fixed platen structure of injection molding machine was carried out using criteria method, and the SIMP model was solved based on variable density method. the ribs were distributed properly according to the optimal design of structure to obtain better material configuration.With satisfaction of the technical indexes, the deformation of the fixed platen decreased by 3. 5%，the weight decreased by 9. 5%，and stiffness was improved. It was concluded that the optimization model of fixed platen was suitable for engineering application
ZHAO Ming-juan, ZHAO Long-zhi, ZHANG Shang-bing, SONG Jin-liang, LIN Qiu
Abstract (
2532 )
Based on Pro/E software, an injection mould for the automobile rearview mirror crust of the automobile inner decoration was designed properly. According to symmetry and boundary mix approaches,the parting surface was assembled by a primary and a secondary parting surfaces using a slide block. A unique asymmetric core side-pulling mechanism was designed, which ensured the product being taken off from the injection mould. A cooling system of nearly circle shape with bi-directional water tubes in the same plane was also designed, which not only increased the cooling effect and the quality of the product,but also reduced the machining cost and the molding period.
