WU Qiye
Abstract (
1066 )
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The scaling concepts and the scaling laws were introduced from the self similarity and the fractal of macromolecular chains in this work. With several examples the basic concepts, thinking and methods of scaling theory were presented for description of the intrinsic quality and complex behaviors of polymer materials. And it is indicated, that with scaling theory the research fields of polymer science were widened and deepened；the more important is the scaling theory is also a new expanding in methodology for polymer science to substitute the mean field approximation. The universal statistic laws and behaviors of polymers and of other soft matters were clear described with more compendious concepts and expressions in new theory. This was a very important contribution for the development of modern sciences.
YANG Junlong, HUANG Yajiang, LI Guangxian
Abstract (
503 )
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93
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The advantages and disadvantages of several strategies in preparing exfoliated graphite, including physical methods (micromechanical cleavage, direct exfoliation) and chemical methods (chemical vapor deposition, epitaxial growth, unzipping carbon nanotubes, reduced of graphite oxide), are reviewed. Various methods for dispersing graphene into polypropylene (PP) are also summarized. Special emphasis is putted on the effect of graphene on the electrical, mechanical, thermal, crystallization and rheological properties of PP nanocomposites prepared by different methods. Existing problems and challenges for PP/graphene nanocomposites are also concerned.
LEI Xiaohui, DING Xuejia, WANG Linsheng, SU Leijing, WU Yongzhen, WANG Guosheng
Abstract (
531 )
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106
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The effects of the composition of the polymer, additives，the solvent evaporation time,and the gelation media on the membrane structures/morphology which are prepared by phaseinversion process will he represented in the paper. The structure of membranes become thick shinlayer from thin skin layer with increase in the composition of the polymer. The appropriate structure and permeability of membranes can he prepared by using additives in the casting solution.The macropore structure will he suppressed by adding solvent in the gelation media. The structure of top surface become the loose structure with increase in the solvent evaporation time, and it will he a certain degree after a specific value of the solvent evaporation time.The effects of the composition of the polymer，additives，the solvent evaporation time，and the gelation media on the membrane structures/morphology which are prepared by phase inversion process.
MEI Wenjie, XIONG Yuzhu, LIU Zhenyu,
Abstract (
369 )
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94
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The aging of PP can he identified as physical and chemical aging. TiO2 possesses theability of absorbing ultraviolet light to slow down PP aging. This article reviewed the recentprogress of improving the aging resistance PP using TiO2.In order to avoid the aggregation, thesurface of TiO2 should he modified. The better the dispersion of TiO2，the higher the agingresistance. The anti-aging mechanism of TiO2 in PP was also summarized.
CHEN Xingyou, CAI Xufu, SUN Tong
Abstract (
503 )
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120
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In order to improve the flame retardant effect of acrylonitrile-butadiene-styrene copolymer(ABS)/ammonium polyphosphate(APP)/poly(p-ethylene terephthalamide）(PETA)System,some commonly used synergists，such as zinc borate(ZB)，red phosphorus(RP ) and ZB, wereseparately introduced into the ABS/APP/PETA system. The improvement in the flame retardancycaused by the synergists was investigated using the limiting oxygen index(LOI）test，UL-94（vertical flame)test，thermogravimetric analysis(TGA)，and scanning electron microscopy（SEM）.Without adding the synergists, the ABS/APP/PETA(70/22. 5/7. 5)system gave LOI=30 and V-0 in the UI, 94 test.After adding 2. 5 phr ZB and 4 phr RP, the LOI value increased to 41%and the UI, 94 grade remained V-0. Meanwhile, ZB was effective in enhancing the thermal
stability and the char residue ratio of the ABS/APP/PETA system and RP was effective in improving the char residue ratio markedly. In addition, the ABS/APP/PETA/ZB/RP(70/22.7. 5/2. 5/4) system formed more uniform and compact intumescent charred layers.
ZHANU Shan, JIA Die, DINU Changkun, WU Qiong, CHENU Bowen
Abstract (
423 )
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97
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Biodegradable PLLA/PHBHHx composites were prepared by means of solution blending. The effect of PHBHHx on the thermal and crystalline properties of PLLA were investigated by different scanning calorimetry (DSC) and polarized optical microscopy (POM). The results showed that there existed certain misbility and interactions between PLLA and PHBHHx. The glass transtion and cold crystallization behavior of PLLA changed with the blend compositions. The larger the molecular weight of PLLA was, the worse the regularity of spherulitic morphology was. When the content of PHBHHx reached 30%, the movement of molecular segments of PLLA can be promoted. The nucleation density of PLLA crystallization can be increased and the crystallization rate can be accelerated.
YANG Yin, WAND Rumin, YANG Guowu, WANG Dejun
Abstract (
488 )
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93
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A-stage phenolic resin was synthesized with excessive formaldehyde and alkali catalyst in this paper. According to orthogonal test method, different experimental design was getted.The content of methylol group and free formaldehyde was investigated by hydroxylamine hydrochloride and iodometric methods,aiming at optimum technology,which is reaction temperature 80℃,reactant molar ratio 1.2,the molar ratio of catalyst and phenol 0.025,reaction time 90 min. The FTTR analysis further show that a large number of methylol group was existed in resol.
WENG Yunxuan, WU Lizhen, ZHOU Yingxin, DIAO Xiaoqian, WANG Lei, ZHANG Min
Abstract (
656 )
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103
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Blends of poly(hydroxhutyrate-co-hydroxyvalerate) /poly(hutylene succinate)(PHBV/PBS)were prepared by means of melting mixing added with triethyl citrate(TEL) and polyethylene glycol(PEG)as plasticizers respectively. The melting rate, thermal, crystalline, mechanical properties and phase morphology structure of the blends were characterized by means of MFI, DSC, XR1)，SEM and tensile tester. The results showed that the performance of the blends changed significantly with the increase of the content of plasticizers. When the content of plasticizers (PEG and TEL) was 10 phr, the melt flow rate of blends was 3 times and 1. 8 times more than pure PHBV/PBS blend respectively. The elongation at break was the maximum wherein the contents of PEG and TEL were 2. 5 phr and 10 phr.The crystalline temperature(Tc)and melting temperature(Tm) were slightly decreased when the amount of two plasticizers increased. SEM micrographs indicated that the joining of both plasticizers promoted interface combination between two phases.
WU Changcheng, LIU Xijun,
Abstract (
450 )
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104
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In this paper, a series of reactive compatibilizer—ethylene propylene terpolymer (EPT) graft copolymer (EPT-g-ITA and EPT-g-MAH) were prepared successfully via solution grafting. By means of FT-IR analysis, it was proved that the grafted monomer ITA and MAH have been grafted onto EPT backbone, respectively. The effects of the dosage of grafted monomer and initiator on the graft ratio and gel content of graft copolymer were investigated. The graft ratio of EPT-g-ITA reached to 3.16 % and gel content was 8.8% when EPT︰ITA︰BPO = 100︰20︰4; The graft ratio of EPT-g-MAH reached to 3.58 % and gel content was 6% when EPT︰MAH︰BPO = 100︰8︰0.64. EPT graft copolymer was introduced into PA6/EPT blend system through twin screw extruder, the impact strength of PA6/EPT/EPT-g-MAH blends containing 15% of EPT-g-MAH was 20 times higher than neat PA6. By analyzing the graft ratio, gel content and notched impact strength of PA6 alloy, it was defined that MAH branched chain grafted onto EPT backbone is shorter and the grafting point is more, but ITA branched chain grafted onto EPT backbone is longer and the grafting point was less.
HONU Xiaodong, DENG Enyan, YANG Dongxu
Abstract (
592 )
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108
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The surface modification on the nano-ZnO particles was made by using coupling agent of KH550, and the thin film of PMMA/nano-ZnO was prepared by spin-coating method, and the ultraviolet shielding properties of thin films was studied in this article, the results show that the modified nano-ZnO have no sediment in water and toluene, and the solubility of particles improve obviously; a new absorption peak is found at 877 cm -1 in the FTIR spectrum of modified nano-ZnO, which confirm that the particle surfaces have been modified by the coupling agent; optical microscope and AFM show that the agglomeration of modified nano-ZnO decrease remarkably in the PMMA film, and dispersity of the particles improve; when the concentration of PMMA in toluene was 0.04 g/mL, and the weight content of nano-ZnO in PMMA was 10%, the film has a best ultraviolet shielding properties, and the transmission rate of ultraviolet is 0.66, compared with the film above, the ultraviolet shielding properties of the film with the same content of modified nano-ZnO improve distinctly, and the transmission rate of ultraviolet is 0.53.
NI Maojun, WANG Chunlei, WANG Jingxia, CHEN Yuheng, CHEN Zhuping
Abstract (
509 )
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89
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NVP was grafted onto surface of polyurethane to prepare TPU-g-PVP copolymer by 60Co-γ irradiation. Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscope(SEM)were used to characterize the copolymer structure, and the absorbed dose，solvent composition，NVP content，and the solution pH value were studied. It showed that the grafting ratio of the copolymer increased with increasing radiation dose and NVP content，it had a higher grafting ratio with ethanol content of 60%in neutral and alkaline conditions. Hydrophilic and lubrication performance test showed that the hydrophilicity and luhricity of the copolymer increased significantly with increasing grafting ratio. The optimum process conditions for this system were: ethanol 60%，pH 7，NVP 20%，and irradiation dosel0 kGy, the grafting ratio may reached 20%.
SHI Liping, DING Lanying, ZHANG Jin, LU Qin
Abstract (
326 )
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89
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UPR composites filled with nano- SiO2 and glass fibers(GF) cloth were prepared by using hand lap-up room temperature curing method and also the tribological behaviors and mechanical properties of the composites were studied. The results showed that the addition of nano-SiO2 and GF cloth could considerably improve the tribological and Mechanical properties of UPR composites. When the UPR has 0.5% or 1% content of nano-SiO2, its wear properties were 5.3 times or 3.1 times, while its tensile strength were 5.8 times or 5.1 times and bending strength were 3.9 times or 3.2 times compared with the pure UPR specimen. Under the experiment conditions, the optimal filler contents for the composites were 0.5 % nano-SiO2. Photos taken by SEM illustrated that worn surfaces of UPR were adhesive wear, while the main wear mechanism of the composites were adhesive wear and abrasive wear.
YANG Fanwen, CHEN Xiaoming
Abstract (
594 )
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97
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Abstract, The effect of phenol resin on the properties of dynamic vulcanized PP/EPDM/SEBS elastomer was studied. With increasing phenol resin content，the hardness and tensile strength first increased and then remained constant; elongation at break, tear strength, and melt flow index decreased，compression set first decreased and then increased. The PP/EPDM/SEBS vulcanized with 10phr phenol resin was characterized with excellent compression set，which were respectively 23. 9%and 28. 3%at 70℃and 125℃，about 9. 8%and 20. 7%lower than those without SEBS. The viscosity of vulcanizing system decreased with increasing shear rate. With increasing phenol resin content，the viscosity first increased then decreased，and the maximum value was observed at 10phr phenol resin.
LI Yuling, GU Xiaoyu, LIU Xishan, DUNG Mingzhe, ZHANG Sheng
Abstract (
588 )
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90
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The technological process and parameters of preparing expandable polystyrene(EPS) in laboratory scale were investigated. The foaming performances of EPS foam coated with prepolymer of melamine-formaldehyde(MF) together with ammonium polyphosphate and zinc borate(ZB)were characterized. The flammability and the thermal properties were evaluated using limiting oxygen index(LOI) test and thermogravimetric analysis (TGA)，respectively. It indicated that coating was an effective method to improve the flame retardancy of EPS foams:the LOI value was increased from 18.0% to 22.6%;the char residue increased 85%;shrinkage was significantly reduced during burning process;combustion rate was also reduced to 51.7%.The presence of ZB which acted as a dehydration catalyzer，could increase both the amount and strength of char residue and hence further improved the flame retardancy.
SUN De, YU Wanli, WANG Dong, KANG Rongmin, LI Bingbing
Abstract (
627 )
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102
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Hydrophobic nano-silica filled PDMS composite pervaporation membranes were prepared and their sorption and diffusion properties were investigated. The solubility parameter(δM)and permeability coefficient (PE) for ethanol in the composite membrane were calculated. The addition of SiO2 increased the solubility of ethanol in the membranes(SE).When the content of SiO2 in PDMS increased from zero to 10%，PE at 60℃ of the membrane increased from 1. 42 X 10-13 m2，the SE at 30℃ increased from 0. 0026 to 0. 0064. Further increasing SiO2，PE increased first and then decreased. High temperatures would he beneficial to the permeation of ethanol. The pervaporation properties of PDMS composite membranes were studied with ethanol/water system and the results showed that it was very similar to its permeability coefficient.
WANG Xu, BI Songmei
Abstract (
436 )
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101
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In order to reveal frequency characteristics of acoustic emission (AE) signal from different damage modes of self-reinforced polyethylene(PEA composites (PE-UHMW/PE-LDP，damage (matrix damage, fiber breakage，interface damage，and delaminating)and non-damage (environment noise and pencil lead break test) signals were extracted from PE-LD resin，filament composite, 90° laminate, and +45°/-45°laminates.The difference between damage and non-damage AE signals in was identified. These results could he used to investigate damage mechanisms of self-reinforced PE composites.
FU Zhihong, XIAO Xionghui, CHEN Yuhui
Abstract (
492 )
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89
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The influence of drawing on the morphological and rheological property of polymer fluid system near the die exit during extrusion was studied. Numerical simulation of micro-tube extrusion was carried out using software POLYFLOW for analyzing the pressure field, velocity field，the extrusion swelling，and the change of boundary position. The study also showed that as the drawing velocity increased, the inlet pressure extrudate was affected significantly, however，the little affected. reduced，the shape of cross-section of the
XU Jianzhong, HE Zhanmeng, QU Hongqiang
Abstract (
459 )
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94
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Abstract: Hexphenoxycyclotriphosphazene(HPCP)was introduced into polycarhonate(PC ) as a flame retardant. When the loading of HPCP was 15 and 20 phr, the LOI of the material was 23.%and 30.%，respectively, and a UI, 94 rating V-0 was obtained. The generation of carboxyl groups during the rearrangement of PC chain was inhibited by the addition of HPCP. The tensile strength of PC was little affected with addition of HPCP，whereas，impact strength decreased to 53. 84%of pure PC when 20 phr was added.
WANG Pingjiang, LI Fangpu, TANG Xiaoqi
Abstract (
401 )
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91
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Abstract: According to requirements of temperature control in the all-electric precision injection molding and，the geometry and thermodynamics of barrel，combining fuzzy-PID and prediction, an innovative temperature-controlling algorithm was proposed. The system-controlling hardware and software were designed based on STM32 insert chip. The comparative experiments showed that the new algorithm worked better. With the new control method, the accuracy of the temperature could he improved to 1. 5 0C.
KUANG Tangqing, DENG Yang
Abstract (
264 )
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96
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Based on the power law model，a transient，pure viscous，non-isothermal theoretical model of water-assisted co-injection molding was developed, and finite volume method was adopted to simulate the filling stage of water-assisted co-injection molding process. The influence of these factors, such as inner-outer injection volume, inner-outer rheological index ratio, water injection temperature, water injection velocity, water injection delay time, inner melt temperature and mold temperature on the fluids filling patterns of water-assisted co-injection molding process were investigated. And the simulation results were explained theoretically based on rheological theory.
