QU Yan-song, GAO Chun-yu
Abstract (
3584 )
The impact of recent financial crisis on global synthetic resin industry
introduced in detail. Domestic and international supply and demand of synthetic resins
analyzed and predicted. It is pointed out that market demands for synthetic resins in
remain depressed and its price would fluctuate at a low level.
WANG Zhao, ZHANG Teng, SUO Hong-li
Abstract (
3326 )
Recent progress in composites of liquid crystal polymers and polyamide was reviewed，including lyotropic liquid crystal polyamide/polyamide, thermotropic liquid crystal polyester/polyamide, and thermotropic liquid crystal polyamide/polyamide systems. The compatibility in these systems and its influence factors were discussed. The hydrogen-bond interaction between thermotropic liquid crystal polyamide and polyamide was considered a promising approach to the compatibilization.
WANG Yu, SUN Yuan, DENG Xin-hua
Abstract (
2740 )
The recent research progress in nonisocyanate polyurethane (NIPU) prepared by cyclocarbonate- and amino-oligomer and synthetic mechanism wherein were reviewed in this paper. The synthetic methods of cyclocarbonate oligomer and amino-oligomer were studied. The application area and prospect of NIPU were introduced, including research and industry development abroad. Combined with work practice, easily prepared, non-toxic, and cheap precursors were considered the important research field in the future.
MA Chuan-guo, YU Ying-jun, ZHANG Peng
Abstract (
3757 )
Carbon nanotubes (CNTs) were surface modified first with Fenton reagent and then with a glycidyl oxygen propyl silane coupling agent. Thus modified CNTs were introduced into epoxy resins (EP), and the properties of the composites were investigated. It showed that hydroxyl and epoxy groups were introduced onto the surface of CNTs by Fenton reagent treatment and KH560 modification, respectively. Moreover, the component of Fenton reagent could effectively control the quantities of hydroxyl groups, and further decide the number of epoxy functional groups. The Fenton reagent treatment improved the dispersion of CNTs in EP, the glass transition temperature (Tg) and thermal stability of EP were increased. Such improvement was further enhanced by subsequent modification with coupling agent.
LEI Cai-hong, GOU Yu-hui, CHEN Da-hua
Abstract (
2401 )
The effect of silicone phosphate on the transesterification reaction in the PBT/PET blend was studied using differential scanning calorimetry by observing the crystallization and melting behavior during two cycles of heating and cooling scannings. Upon addition of silicone phosphate, the crystallization temperature of PBT/PET blend increased by 4.5℃, the relative viscosity increased by 0.1 dL/g, and the heat deflection temperature increased by 7.0℃, based on the neat system. In contrast, the counterpart containing TPPi showed a decrease of 1.5C in crystallization temperature. Silicone phosphate was more effective than TPPi in decreasing the content of end hydroxyl groups and thus more effective in depressing the transesterification between PBT and PET. The introduction of inhibitors did not influence much the mechanical properties of the blends.
LIU Sheng-peng, CHENG Jun, LI Jiao, XU Li-li
Abstract (
2501 )
Micron-magnesium hydroxide (MH), which was modified by titanate, silane and in-situ emulsion polymerization, respectively, was filled into polypropylene（PP）with the mass ratio of MH particle and PP was 20:80. The effects of surface treatment on the morphology, mechanical properties and rheology property of PP/MH composites were studied by DSC, morphology observations and rheological behaviors testing. It was shown that the modification of polymer encapsulated MH via in-situ polymerization improved the interfacial adhesion between MH and PP matrix, and increased the impact strength of PP/MH composites by 26.4%. In addition, the melt index (MI) of PP/MH composite filled with encapsulated MH particles was increased 64% compared to pure PP. The melt viscosity of PP/MH composites filled with encapsulated MH particles was decreased than that of PP/MH composites filled with unmodified MH particles at same shear rate. It was indicated that the polymer encapsulated on the surface of MH reduced the particles’ block effect and improved processing behavior of the composites.
WU Ai-min, SUN Zai-jian, JI Fa-xiang
Abstract (
3039 )
：The surface tensions of polymers with different molecular structure and molecular weight have been measured using a polymer melt suspending drop instrument. The dependence of surface tension on the molecular structure and molecular weight has been summarized. Besides other variables, the influence of chemical constitution was considered, the derived relationship was more appropriate polymer systems than traditional ones.
GAO Li-min, ZHANG Jin-xia, LI Ning-ning, LU Wei, ZHANG Li-qun, QU Xiong-wei
Abstract (
2149 )
Polyaniline (PANI) is one of the most promising conducting polymers for its high environment stability, tunable electrical properties and relatively low cost. Chemical oxidative polymerization of aniline was performed in micellar solution of dodecylbenzene sulfonic acid (DBSA), using ammonium persulfate (APS) as an oxidant to obtain conductive nanorods. DBSA was used to play double roles of a surfactant and a dopant. The products of PANI doped with DBSA were characterized with FTIR, UV-vis, XRD and SEM. The crystalline morphology was determined by TEM. It was first found that the distance between the crystalline layers was 5.99 Å. The effects of reaction conditions on the conductivity were discussed such as the molar ratio of DBSA to aniline, oxidant to aniline, reaction time, and reaction time. The highest conductivity of PANI doped with DBSA was 0.72 S/cm.
ZHANG Xue-ying, ZHANG Wen-gen, HU Bao-lin, WANG Jun-long, LIANG Guo-zheng
Abstract (
2791 )
The cyanate ester resin (CE)/nano-SiC composites were prepared by moulding method. Influences of nano-SiC and its surface treatment on the static mechanical properties of CE were characterized through impact and flexural strengths. The reinforcement mechanism was discussed. It indicated that nano-SiC efficiently improved the static mechanical properties of CE, and the surface treatment with KH-560 of nano-SiC further improved the impact and flexural strengths. When the content of nano-SiC was 1 %, the impact and flexural strengths of the composites containing untreated nano-SiC increased 73.66% and 20.85%, those containing KH-560 modified nano-SiC increased 86.26% and 29.56%, respectively, based on neat CE resin.
WANG Zhen-hua, WANG Pei-zhang
Abstract (
2688 )
Rare earth luminescent material was modified with silane coupling agent, which was further encapsulated with a layer of polystyrene (PS) through in-situ emulsion polymerization. FTIR, TG and microscopy showed that PS uniformly grafts on the surface of rare earth luminescence materials in the form of lamella. Analysis of contact angle showed that PS/rare-earth composite luminescence materials required an excellent resistance to water. Such PS coated rare earth composite luminescence materials maintained good fluorescence performance and their original luminescence centers.
WANG Dan-ling, QIAN Xin
Abstract (
2869 )
The effects of UV irradiation on the morphology and surface structure of α-nucleated PP(α-PP), β-nucleated PP(β-PP), and neat PP were studied. Lower degradability was found in β-PP as compared with α-PP and neat PP. The gross degree of crystallinity of all samples showed an initial increase in on short-time exposure followed by decrease with prolonged exposure. The maximum degree of crystallinity for β-PP was 65.5% at 312h and for α-PP was 74.6% at 456h. The β-phase in β-PP reached a maximum of 30.9% at 144h exposure, followed by a decrease with prolonged exposure. The α-phase in β-PP increased after short-time and then decreased, leveling off to 48% after 312h exposure.
CHEN Bin-yi, LIU Ben-gang, CHEN Shi一hong, WANG Xiang-dong, ZHANG Yu-xia
Abstract (
2707 )
PP-g-MAH modified PP/nano-clay composite was prepared on a twin-screw extruder.Effect of the compatibilizcr, PP-g-MnH，on the sag resistance of the composite was studied by XRD analysis and sag resistance testing. Experimental results show that the compatilizcr properties and dosages have certain influences on the intercalation structure and the sag resistance of the
composite. When the compatilizcr with lower melt flow rate and lower grafting rate was used，the composite exhibited excellent sag resistance. The layer spacing of the different intercalated structure of the composite was related to the sag resistance，there was optimal layer spacing. While
the layer space of the clay is 2. 90一3. 00 nm, the sag resistance of the PP/nano-clay composite
reached its highest value.
XIN Yong, ZHAO Guo
Abstract (
2289 )
Defects emerge more easily in thin wall injection molding because of the higher injection pressure, higher injection speed, and higher melt temperature. In this case, it is necessary to study process condition by simulation and control the defects. Injection molding defects are mainly researched by applying the theory of artificial intelligent and vague theory. The diagram of vague expert system in product quality control and the inference flow diagram of the system were given in the paper. The membership function of process parameters and defects and the fuzzy rules were constructed. The membership function reflected the fault vague and vague connection. Vague reasoning based on the rules was realized. A case study was carried out to test the defects optimization module.
LU Xi-lin, YU Cheng-bing, ZHAO Xiu-lan, ZHANG Yun
Abstract (
2691 )
Maleic anhydride and styrene were grafted from polypropylene via melt reaction, which was confirmed using the IR spectrum. The grafted PP was introduced into PP/wood flour composites in order to improve the mechanical properties. Morphology of impact fractured surface was studied using SEM. It was proved that the interfacial compatibility between PP and wood flour was improved more efficiently by MA/St grafted PP than MA alone grafted PP, thus the resulted mechanical properties of the composites were superior. The grafting degree of PP significantly affected mechanical properties of the composites, with the optimal grafting degree being 2.8%.
XIAO Fang-cheng, BU Hai-tao, DING Zhi-tian, HONG Jian-cheng, WU Shi-jian
Abstract (
2433 )
Numerous weld lines were formed in the course of dashboard manufacturing by traditional injection molding, which seriously influenced the appearance and mechanical properties of dashboard. In order to solve the problem, sequence control injection molding technology of hot runner was proposed, and its processing principle was introduced, optimized runner system of mould was designed on the basis of its processing principle. Through MOLDFLOW simulating analysis, formative causes of each weld line and air trap were studied, and each gate-opening time was optimized. The study found that by optimizing gate—opening time, filling sequence and flow route of melt could be effectively controlled, and thus reduced or even eliminated weld lines and air traps. Sequence control technology was of great practice significance in dashboard manufacturing.
JI Zheng-wei, ZHANG Yi-hua
Abstract (
1975 )
Current CAD software provides only a unified shrinkage and does not meet the design requirements of complex parts which have different shrinkage in same direction. Aiming at this problem, Moldflow was used as a data measurement platform to simulate the deformation of product. A method for modification of injection mold cavity size based on reconstruction of product model was proposed. Reconstruction of this model provided a way to improve the relationship between cavity and product, could control the non-uniform contraction of parts, thus to enhance the size precision and reduce the repair of model.
YANG Zhi-tao, GAO Jun, QU Jin-ping
Abstract (
2595 )
The influencing factors of orientation structure in conventional processing are studied in this paper, the effect of vibration field on the orientation structure is analyzed from microstructure configuration. It is found that dynamic molding processing can improve the orientation structure efficiently compared with the conventional molding processing method. The tensile strength of the products by vibration injection is superior to that by conventional processing. The orientation index of dynamic molding product is determined by infrared spectrometer (FT-IR). It is found that the orientation of core layer of the product was enhanced more evidently than the skin layer, thus the difference in orientation between the core layer and skin layer is decreased. It is showed that the mechanical property can be improved by enhance the orientation structure.
LI Guang-ming, YIN Guo-fu, YU Ling
Abstract (
2239 )
In view of the complexity present in the process of the design and control of the gas-assisted injection, a response surface model was formulated based on orthogonal experimental design and response surface design combined with correlative significance test. The melt temperature, delay time, air pressure, and time were determined as the highly significant factors. The mesh adaptive search algorithm was applied to optimize the model and a satisfactory solution was found rapidly and exactly. At last, a case study was carried out which demonstrated the method was effective in numerical simulation and the simulation result was in accord with the optimal ones.
LUO Zhen-yang, SHI Yi-jun, HE Ming, GU Xiao-li
Abstract (
2946 )
The flame retardancy of phosphorus- and halogen-containing flame retardants for rigid polyurethane foam was investigated by means of oxygen index tester and cone calorimeter. It showed that the flame retardancy of rigid polyurethane foam based on phosphorus-containing flame retardants was better than that on halogen-containing ones. Moreover, combinations the two kinds flame retardants provided even better results. For individual flame retardant, AK8803 was the most effective in extending the ignite time and reducing the heat damage, L580 was best one for inhibiting smoke and poison gas.
HAN Wei-heng, WU Hai-ping, YIN De-shu, YU Qiang
Abstract (
2393 )
Thermal decomposition of PP-g-MAH was studied using a thermogravimetric analyzer and the effects of grafting ratio, βchain scission and maleic anhydride residue on the thermal stability of PP-g-MAH were investigated. The results indicated that the grafting of MAH improved the thermal stability of PP. Compared with the virgin PP, thermal decomposition temperature of PP-g-MAH with an MAH grafting ratio of 0.72 % increased by 28℃and its thermal decomposition rate constant at 420℃ decreased by 57.6%. Theβchain scission and degradation that occurred during the melt grafting process injured thermal stability of the resulting PP-g-MAH. By contrast with minimum degradation of the graft, thermal decomposition temperature of maximum one decreased by 20℃and its thermal decomposition rate constant at 420℃ increased by 115 %. Maleic anhydride remaining in the grafted PP make the initial decomposition temperature 4.3℃ lower.
LI Wan-qing, LU Can-hui
Abstract (
2420 )
In this paper, the recover of cross-linked polyethylene (XLPE) from waste insulation cable was conducted through mechanochemical technology. It showed that the mechanochemical treatment was an efficient way to realize thermoplastic processing of waste XLPE. The tensile strength and elongation at break of mechanochemically treated XLPE reached 13.7 MPa and 383%, respectively. The apparent viscosity of waste XLPE was gradually decreased with milling processing and the processability was remarkably improved after mechanochemical treatment. The tensile strength and elongation at break of XPLE/PE-HD blend achieved 18.5MPa and 500%, respectively. The incorporation of PE could further improve the processing property of XLPE. The SEM observation of fractured surface of XLPE/PE-HD blend illustrated that mechanochemical treatment was beneficial to the improvement of the compatibility XLPE and PE-HD.
HE Yue-long, YANG Wei-min, DING Yu-mei
Abstract (
1966 )
：The history and latest developments of multi-component injection molding and its technologies and equipment are summarized. The advantages and limitations of multi-shot molding are described elaborately. The developing trend of multi-shot molding is forecasted.
ZHAO Long-zhi, ZHAO Ming-juan, YANG Zi-cheng, ZHANG Shang-bing
Abstract (
2529 )
Application of Pro/E and Moldflow software in the design of injection mould for the button lid of the automobile inner decoration was introduced in this paper. Using Pro/E software, a product model was formulated, the block configuration and parting surface were determined, which ensured the mould working reliably. By aid of EMX module, the mould frame was designed transferable and adjustable. Based on CAE/CAD technology, the design of product and mould could carried out directly, which decreased the production cycle, improved the quality of the injection mould.
