LIAO Zheng-pin
Abstract (
2312 )
General situation of China plastics industry in 2007 was reviewed, including the economic technical indicator of the plastics processing industry, output/sales and export/import of plastics products, s5mthetic resins and plastics processing machinery. A few suggestions for its future were listed.
LIU Lin, DAI Guang-Yu, LI Wen-feng
Abstract (
2812 )
the properties, applications, and research trends of epoxy resin, cyanate ester resin, bismaleimide resin, and polyimide which are widely used in aviation and aerospace fields were discussed in this article. The recent developments of these high performance thermosetting resins were also reviewed. the expected research emphasis in future was proposed, such as increasing the interfacial strength between resins and reinforced fiber, improving stability of composites and toughness of resins,and reducing cost and processing temperature of composites.
CHEN Shu-guo, YU Hai-yang, WANG Ru-yin, ZHANG Yong
Abstract (
2399 )
the recent development in the halogen-free flame-retardants for ethylene-vinyl acetate copolymer ( EVA) was reviewed. }Che effect of different halogen-free flame retardants(like aluminium hydroxide, magnesium hydroxide, natural hydroxide and intumescent flame-retardants) and flame-retar-dant synergists (like red phosphorus and zinc borate) in the EVA composite were observed via limited oxygen index, UL-94，cone calorimeter and other performance indexes. the main EVA based fireproof materials were categorized according to their feature and flame-retardant mechanism. The future development of EVA flame-retardant composite was forecasted.
LU Qin, ZHANG Jing, HfE Chun-xia
Abstract (
2747 )
the friction and wear properties of polytetrafluorethylene(PTFE) composites filled with nano-titanium nitride (TiN) were evaluated with an MM-200 friction and wear tester. the worn surfaces of the composites were examined by means of scanning electron microscopy (SEM).It has been found that the incorporation of nano-TiN into PUFF increased the hardness and wear resistance of PTFE. the best wear-resistance of the composite was reached at a mass fraction of nano-TiN about 7%，and the wear amount of composites increased with increasing load. the addition of the nano-TiN also decreased the friction coefficient of PTFE.
WANG Lan, LI Xin, ZHAO Zi, YE Zhi-yin
Abstract (
2013 )
Phase change energy storage composites were prepared using paraffin as the phase change material, High-density polyethylene ( PE-LD，high-density polyethylene (PE-HD)，polypropylene ( PP，and polystyrene(PS) as the supporting materials. }Che phase transition enthalpy of 68.44，45.52,40 .06，and 1 .19J/g were observed for PE-LD，PE-HD，PP, and PS matrixes, respectively. PE-LD was considered the best phase change matrix because of the highest phase transition enthalpy, which increased with increasing paraffin content. Diatomite and activated carbon could also improve the phase transition enthalpy and stability of phase change materials.
WU Xiang-feng, HUGuo-sheng, WANG Biao-bing JIN Xu-dong, LI Zhan-xiong
Abstract (
139 )
The effects of nanometerCaCOand hexaphenoxycyclotriphosphazene(POP) as a halogen- free fire-retardant on the mechanical and combustion properties of polypropylene/magnesium hydroxide(PP/Mg(OH)2)blends were studied in this paper.It showed that, when the total amount of inorganic powder kept at 90 phr, the mechanical properties of the blends increased firstly and decreased with in- creasing content ofCaCO3,with the optimum content being 40 phr.The addition of POP could reduce the loading level of Mg(OH)2 and may improve the mechanical properties and fire-retardant performance of the blends. When POP content was 8 phrelongation at breaktensile strength,impact strength and oxygen index reached 264.76%，2234MPa4865kj/m，and28.2%，respectively.
YANG ding-kun, HU Fu-xin, YANG din
Abstract (
2817 )
The thermal degradation of chloroprene rubber/butyl methacrylate grafting copolymer ( CR-g-BMA) in air atmosphere was studied using thermo gravimetric analysis. It was found that the degradation of CR-g-BMA occurred in two steps. The characteristic initial and termination degradation tempera-tures were 571 .66 K and 754. 35 K, respectively. thirty common mechanism functions were compared with Achar' s and Coats-Redfern’s methods, the differential and integral mechanism functions for the two steps were formulated. the average activation energies of the first and second steps were 176.06 and 171 .09kJ/mol, respectively. The model of thermal degradation kinetics was proposed and the parameters of CR-g-BMA were determined.
TANG Zhong-feng
Abstract (
2961 )
Epoxy resin was modified with star siloxane-terminated oligomers and cured via sol-gel technology. The thermal and mechanical properties of the modified resin were studied.The morphology on the fractured surface was viewed using SEM. It showed that the tensile strength and elongation at break were improved by the introduction of star siloxane-terminated oligomers and coupling agent(KBE-9103).Because of the presence of Si-O-Si in the network, the heat stability was also improved.
JIANG Yang, HU Yue-xin, LI Hai一dong
Abstract (
2186 )
Hollow glass beads (HGB) were used to improve the mechanical properties of high-density polyethylene (PE-HD).the effect of HGB content，mean diameter，coupling agent treatment, and the toughness of the PE-HD matrix on the structure and mechanical properties of PE-HD/HGB blends were studied using Izod impact, differential scanning calorimetry (DSC)，and scanning electron microscopy (SEM) tests. The notched impact strength of the blends increased gradually at first and then decreased with increasing HGB content. the smaller the mean diameter of HGB, the higher the notched impact strength. Surface treatment of the coupling agent improved the dispersion of HGB in PE-HD matrix and thus improved the toughness. the notched impact strength of the PE-HD matrix should be higher than
5 .0 kJ/m2 in order to obtain tough PE-HD/HGB blends.
Abstract (
111 )
The non-isothermal crystallization of polypropylene(PP)with or without a rosin type nucle ating agent was studied using differential scanningcalorimetry(DSC).The result shows that the crystal lization temperature of PP filled rosin type nucleating agent can be improved.The analysis using Jeziorny methods showed that Zand todecreased with the introduction of nucleating agent and dispersant. The Avrami index n was also changed indicating a somewhat different nucleation mechanism.
XIA Ming, LU Cui一xia
Abstract (
3040 )
The effect of sensibilizers and antioxidants on the cross-linking degree in radiation crosslinked polyethylene pipes was investigated. The optimal recipe was obtained as: weight ratio of high density polyethylene/linear low density polyethylene 80/20，sensibilizer M-1 2. 5%，and antioxidant agent 2. 5%。，based on total amount of polyethylene. Since the crosslinking and degradation occurred simultaneously, the tensile strength and elongation at break decreased with increasing radiation dose. However,at 10一15 Mrad these properties were satisfied. The degree of crystallinity showed no change with increasing radiation dose, which indicated that the crosslinking occurred only in amorphous region or interface.
ZHENG Jin-yang, GAO Yong jian, LI Xiang, LI Ya-xian, ZHfU Yan-cong
Abstract (
3009 )
Because of the presence of initial geometric defects, the analysis of plastic-matrix steel composite pipe (PSP) buckling is complicated for nonlinear and large deformation was involved. In this paper, numerical simulations were carried out using FEA code ANSYS 10. 0 to study the mechanical response of PSP under external pressure, based on the eigenvalue and nonlinear method. the critical buckling pressures and buckling mode shapes of PSP were obtained. the critical buckling pressures analyzed by eigenvalue and nonlinear method are 0 .97 MPa and 0. 83 MPa, respectively. By analyzing the influences of boundary conditions and initial imperfection on the stability of external pressure, the reladons of the critical buckling pressure and ripple number versus the length-diameter ratio were obtained.
YANG Jun-hong, LIU Yue-jun, LI Xiang-gang, TAN Hui
Abstract (
2830 )
The rheological property for blends of high density polyethylene (PE-HD) and ethylene/vinyl acetate copolymer (EVA) were studied using a double capillary rheometer of constant speed type. the major attention was paid to the effects of EVA contents on the viscosity and the extrusion pressure oscillation. At low shear rate, the viscosity of the blend was sensitive to EVA contents, and exhibited almost a linearly decrease with increasing content of EVA. By blending PE-HD with EVA, the extrusion pressure oscillation can be suppressed; the critical shear rate was increased and the amplitude of pressure oscillation was reduced.
ZHAO Peng, ZHOU Hua-min, CUI Shu-biao, LI Ji-quan, LI De-qun
Abstract (
3555 )
注射成型;简化模型;注射时间;注射压力;熔体温度;优化
TU Zhi一gang
Abstract (
2997 )
The change in shrinkage of bi-axially oriented polypropylene (BOPP) cigarette pack film with temperature and time was studied. }Che thermo-shrinkage of the film decreased continuously after it was prepared, the decreasing rate in winter was lower than summer because of low temperature. A novel time-stability masterbatch was developed and introduced into the cigarette pack film. The masterbatch lowered the sensitivity of thermo-shrinkage to both temperature and time, thus retarded its decrease with time and eliminated the effect of high temperature in summer. In addition, the masterbatch did not result in negative effect on mechanical properties, gloss, haze, heat seal property, slip behavior, and processing of the film.
DENG Hao, XIANG Ai一min
Abstract (
2004 )
Films of polyvinyl alcohol) (PVA) /iodine/nano-silica were prepared by solution casting. UV spectrophotometer showed that the transmittance of PVA film increased first and then decreased with increasing nano-silica loading. F7L}-IR confirmed the formation of hydrogen bonds between silica and PVA.XRD indicated that the crystallinity in PVA was decreased with the introduction of nano-silica.TG determination demonstrated that nano-silica enhanced the thermo-stability of PVA polarizing film.
WANG Na, SUO Yan-hui, SUN Zhi-jian, GAO Chun-Jing, CAO Zhi-chen, ZHANG Hui-xuan
Abstract (
519 )
Hindered phenohc antioxidants triethylene glycol bis-3(3-tert-butyl-4一hydroxy-5methyl phenyl) propionate(Irganox245)and n-octadecyl-(3-(4-hydroxy-3，5一di-tert-butyl-phenyl ) propionate(Irganox1076 ) were separately compounded with sulfur-containing antioxidant dilauryl thiodipropionate (DLTP).the compounded antioxidants were introduced as emulsions into acrylonitrile-butadiene-styrene (ABS) emulsion. The stabilization effect of the antioxidants was studied by determining the aging time of yellow, thermal weight loss rate，and yellowness index. It showed that a strong synergistic effect was exhibited by the compounded antioxidant of Irganox245 and DL}CP, however, no synergistic effect was observed for Irganox1076 and DLTP. through the investigation, it was confirmed that the
degradation of ABS began with the destruction of double bonds followed by the formation of hydroperoxides, carbonyl，and alkyloxy compounds.
ZHOU Qi, WANG Yong, QIU Gui-xue
Abstract (
2770 )
Effect of dicumyl peroxide (DCP) on the properties of ethylene-octene copolymer/polypropy-lene (POE/PP) blends was studied. It showed that crosslinking degree of POE increased, but elongation at break, tensile strength, and permanent deformation decreased with increasing content of DCP.Over loading of DCP may result in degradation of PP, and the melt flow rate increased. DSC showed that the degree of crystallinity of POE/PP decreased with increasing DCP loading. the influence of content of DCP on the phase structure was obvious. When the content of DCP was 1 phr, a fine dispersion of crosslinked POE in PP matrix was observed.
ZHANG Fei, KOU Kai-chang, YAN Lu-ke, DI Xi-yan, WU Hai-wei
Abstract (
2679 )
the high-temperature compression creep behavior of polytetrafluoroethylene(PTFE)was characterized using a home-made tester . the PTFE samples 6 mm x 6 mm x 50 .8 mm in size were tested at 250 C with a load of 5. 226 kg. the results showed that the stress of pure PTFE sample was 1.452 MPa, the creep quantity was 0. 56 mm, and the strain was 0. 011.the creep curve of the sample agreed with standard one.
CAI Jin-ping, HUANG Xing-yuan, LIU He-sheng
Abstract (
1947 )
the distribution of pressure and velocity in the pressure drop die for microcellular polymer extrusion was simulated using FLUENT software with the structures and boundary conditions simplified.It was found that the pressure drop decreased with increasing melt temperature and CO2 concentration and increased with increasing melt flux. the velocity distribution in the vessel was uniform, but increased suddenly at the entrance of capillary. Pressure drop and velocity was influenced greatly by melt flow and CO2 concentration and only moderately by temperature.
SUN Xin-mei, XIE Lin-sheng, TANG Xian-wen, LI Shuai-Liang, MA Yu-Lu
Abstract (
1819 )
Polye.thylene/organic-montmorillonite nano-composites were prepared using two-rotor continuous mixer via directly melting intercalation. the interlayer spacing was investigated by X-ray diffracLion (XRD).the effects of rotor speeds and feed rates on the interlayer spacing and the properties of nano-composites were investigated. It showed a proper shearing strength was important for preparing intercalated nano-composites. the maximum interlayer spacing could be achieved when the rotor speed was 400 r/min and the feed rate was 1 .35 kg/h，and the best tensile and impact strength of composites were obtained.
