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2012, Volume 26 Issue 04 Publication date: 26 April 2012 Previous Issue Next Issue

China Plastics Industry(2011)

2012, 26 (04): 1-3 ; DOI: 10.19491/j.issn.1001-9278.2012.04.001

Abstract ( 1252 )

General situation of China plastics industry in 2011 was reviewed, including the output and export/import of plastics products,synthetic resins, and plastics processing machinery, as well as major economic data, such as the total industrial values,sales and profits of plastics products,etc. Analysis of the market of plastics products in 2011 was made, and the developing trend of China plastics industry in 2012 was proposed.

Research Progress in Foaming Technologies for Biodegradable Polymers

2012, 26 (04): 4-15 ; DOI: 10.19491/j.issn.1001-9278.2012.04.002

Abstract ( 1949 )

Advances in foaming technologies for some biodegradable polymers were introduced,including poly(lactic acid),polycaprolactone,poly(butylene succinate),poly(vinyl alcohol), and starch, as well as their blends and nanocomposites with montmorillonite, which deals with super critical carbon dioxide foaming process and chemical-foaming agent foaming process etc.

Study on Polyphosphazene Materials and Its Applications in Aviation and Military Field

2012, 26 (04): 16-21 ; DOI: 10.19491/j.issn.1001-9278.2012.04.003

Abstract ( 1331 )

In this paper, structure and characteristics of polyphosphazene were briefly introduced. The synthetic methods of hexachlorocyclotriphosphazene, poly (dichloro)phosphazene, and poly phosphazene were summarized. The progress on applications of polyphosphazene in aviation and military field was reviewed，including high-temperature flame retardancy coating, fire-resistant flame retardancy coating, flame retardancy foaming rubber, insulation of rocket motor, sealing materials. The existing problems of polyphosphazene material were pointed out. At last, the development of polyphosphazene material in the future was prospected.

Research Progress in Polyethylene-based Electrical Conductive Composites

DU Yan JI Tiezheng TANG Ting

2012, 26 (04): 22-26 ; DOI: 10.19491/j.issn.1001-9278.2012.04.004

Abstract ( 1250 )

Research progress in polyethylene-based electrical conductive composites was reviewed, including polyethylene/carbon black, polyethylene/graphite, and polyethylene/carbon nanotube composites. The electrical conductive mechanism of the composites was analyzed. It was pointed out that the kinds and properties of conductive filler, matrix, and processing technology would affect the properties of the composites. Thermo-resistive effect of the composites was summarized. Finally, the application prospect was discussed.

Study on Properties of Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/ Maletic Anhydride Blends

GE Huanhuan HAO Yanping YANG Fa ZHANG Huilian DONG Lisong

2012, 26 (04): 27-30 ; DOI: 10.19491/j.issn.1001-9278.2012.04.005

Abstract ( 1412 )

A series of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/ maletic anhydride (MA) blends was prepared via melt blending. The effect of MA content on the mechanical/thermal properties of the blends was studied. It indicated that with MA added, the mechanical properties of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) were enhanced, thermal stability and processability were improved. The heat decompose temperatures increased by 19.31 ℃. Meanwhile, MA could improve the compatibility between 3-hydroxybutyrate and 4-hydroxybutyrate.

Study on Non-halogen Intumescent Complex Flame Retardant for PE-LD

2012, 26 (04): 31-34 ; DOI: 10.19491/j.issn.1001-9278.2012.04.006

Abstract ( 1366 )

Melamine cyanurate(MCA), microcapsule red phosphorus(MCP), and magnesium hydroxide[Mg(OH)2] were compounded with an intumescent flame retardant PNP to prepare a multi-components flame retardant. The performance of the flame retardants in low-density polyethylene/ethylene-vinyl acetate (PE-LD/EVA) blends was studied. When the matrix resins of PE-LD/EVA was 70/30, the content of complex flame retardants was 35 %, the weight ratio of PNP/MCA was 3/2, limited oxygen index reached 30.8 %. When weight ratios of PNP/MCA/P =24/16/4 were used, the limited oxygen index was 32.3 %. A limited oxygen index of 30.9 % was observed at weight ratios of PNP/MCA/P/MH=24/16/4/22，the vertical combustion level reached UL 94 V-0, and the tensile strength was 11.1 MPa, the elongation at break was 80.6 %.

Research on Compatibility and Crystallization of PET/PLA Blends

2012, 26 (04): 35-39 ; DOI: 10.19491/j.issn.1001-9278.2012.04.007

Abstract ( 1490 )

The effects of tetrabutyl titanate[Ti(OBu)4] and poly(lactic acid)(PLA) on the compatibility of poly(ethylene terephthalate)(PET)/ PLA blends were investigated. The melting/crystallization behavior and morphology of the blends were studied. It showed that the blends was compatible when the Ti(OBu)4 content was 4 % of PLA contents; When PLA content was above 30 %, the blends appeared phase separation. The addition of PLA to PET increased the crystallization rate and the crystallization temperature. Besides, the crystal size decreased.

Study on Curing Kinetics of Cyanate Ester/Polyphenylene Oxide/Nano-SiO2 Electronic Encapsulating Material

Mengmeng ZHANG Hongxia YAN Xinghua GUAN Qianqian WANG

2012, 26 (04): 40-44 ; DOI: 10.19491/j.issn.1001-9278.2012.04.008

Abstract ( 1460 )

Silane treated nano-silica was introduced into cyanate ester resin/polyphenylene oxide curing system as inorganic filler. Kinetic analysis of cyanate ester/polyphenylene oxide/nano-SiO2 was carried out using differential scanning calorimetry. It showed that the process parameters and curing kinetics parameters of cyanate ester/polyphenylene oxide/3 % nano-SiO2 curing system were obtained as follows：gel temperature 150 ℃, cuing temperature 181 ℃, post-treating temperature 239 ℃; The curing kinetic parameters were: apparent activation energy 15.46 kJ/mo1, reaction order 0.82, frequency factor 38174.38 s-1, respectively. The addition of nano-SiO2 could lower the activation energy of cyanate ester resin / polyphenylene oxide curing system and the curing reaction could occur at a relative lower temperature.

Effects of Different Compatibilizers on PTC Behaviors of PE-HD/PC/CB Conductive Composites

Tang Jun-Hui Xin Wang

2012, 26 (04): 45-49 ; DOI: 10.19491/j.issn.1001-9278.2012.04.009

Abstract ( 1341 )

Effects of three kinds of compatibilizers, maleic anhydride grafted high-density polyethylene (PE-g-MAH), ethylene vinyl acetate (EVA) and styrene-butadiene-styrene block copolymer (SBS), on electrical properties of high-density polyethylene (PE-HD) / polycarbonate (PC) /carbon black (CB) composites were studied. It showed that the addition of compatibilizers to PE-HD/PC/CB composites promoted the positive temperature coefficient （PTC）, and the modification effect of SBS was the best among the three compatibilizers. When the content of SBS was 4 wt %, the PTC intensity of the composite increased by 14.3 % based on neat PE-HD/PC/CB composite. The promotion of PTC intensity by PE-g-MAH was less than that of SBS. EVA had the advantage to inhibit the negative temperature coefficient （NTC） phenomenon, the NTC intensity of the composites decreased from 0.3 to 0.08.

Synergistic Toughening Effect of ABS Resin Blends with Different Rubber Particle Sizes

ZHANG Meng LIU Zhengu YANG Haidong

2012, 26 (04): 50-53 ; DOI: 10.19491/j.issn.1001-9278.2012.04.010

Abstract ( 1534 )

In this work, acrylonitrile-butadiene-styrene copolymers (ABSs) were prepared based on different rubber particle sizes (L-PB and S-PB). Effect of weight ratio of L-PB to S-PB on the mechanical properties of ABS resins was investigated when the rubber content was fixed at 15 %. It indicated that the impact and yield strengths increased with decreasing bigger rubber particles L-PB. When the ratio of L-PB to S-PB was 1/9, the impact and yield strengths were the highest. Synergistic effect of rubber particles with different particle sizes was found. Moreover, deformation mechanisms of ABS resins were also investigated.

Preparation of Polypropylene/Inorganic/Profiled Fibers Composites

SUN Qiang

2012, 26 (04): 54-60 ; DOI: 10.19491/j.issn.1001-9278.2012.04.011

Abstract ( 1526 )

Polypropylene (PP)/nano-CaCO3/profiled fibers composites were prepared via melt blending. The profiled fibers had cylindrical, flat, or triangular cross-sections. The structure of untreated and treated CaCO3 was investigated and the dispersion condition was observed by means of SEM. It showed that silane coupling agent was better than stearic acid. Fibers with different cross-sections have different influence on the mechanical properties. The composite containing triangular fiber with the largest surface area was much better than others. When the mass fraction of nano-CaCO3 was 3 % (silane coupling agent was 2 %) and the volume fraction of triangular fibers was 2 % (coupling agent was 4 %)，length/diameter(L/D) was 80, the yield strength and elastic modulus of the composites were increased by 21 % and 82 %, respectively.

Effect of Relative Molecular Weight on Properties of β-Form Isotactic Polypropylene

Mu DONG Liying ZHANG Kai XU Yun LV Shijun ZHANG

2012, 26 (04): 61-65 ; DOI: 10.19491/j.issn.1001-9278.2012.04.012

Abstract ( 1704 )

Melt flow rate was taken as a rough measure of molecular weight of isotactic polypropylene (IPP). Influence of molecular weight on the crystallization behavior, thermal property, and mechanical property of β-form IPP(β-PP) were studied using differential scanning calorimeter, X-ray diffraction, and mechanical property test. It was observed that after adding β-nucleating agent, both the crystallization temperature and heat distortion temperature of IPP increased about 10 ℃, relative content of β-form crystallization increased to 60 %~70 %. The impact strength of β-PP of high molecular weight increased at least 100 % while that of low molecular weight had little improvement. The flexural modulus and flexural strength of β-PP decreased compared with neat IPP, the lower the molecular weight, the more the decrease.

Research Progress on Warpage of Injection Molding Parts

2012, 26 (04): 66-71 ; DOI: 10.19491/j.issn.1001-9278.2012.04.013

Abstract ( 1681 )

The classification of warpage, causes of forming warpage, and the characterizations of warpage deformation were summarized. The factors that effected warpage, including materials, parts structure, mould structure, and processing parameter, were analyzed. The application of computer aided engineering technique in analysis of warpage deformation of injection molding plastic parts was introduced. Besides, the methods for solving warpage were presented.

Effects of SEBS-g-MAH on TPEE Foaming Performance

李明昆 LI Ming-Kun

2012, 26 (04): 72-76 ; DOI: 10.19491/j.issn.1001-9278.2012.04.014

Abstract ( 2126 )

Using dicumyl peroxide (DCP) as an initiator agent, maleic anhydride grafted SEBS(SEBSgMAH) was prepared via melting reaction in a twinscrew extruder. FTIR indicated that MAH was grafted onto the molecular chain of SEBS. MAH grafting rate was determined by acidbase titration. TPEE foamed sheet was prepared by melting reaction in a singlescrew extruder. The effects of SEBSgMAH on mechanical properties and apparent density of TPEE foamed sheet were studied. It showed that SEBSgMAH decreased the melt flow rate of TPEE obviously. SEBSgMAH had a significant impact on the mechanical properties and apparent density of TPEE foamed sheet. With increasing SEBSgMAH contents, the compression deformation and elongation at break of foamed sheet decreased. The compression deformation and elongation at break tended to be stable when the SEBSgMAH content was 4 phr, and the cells had well distributed in the foamed TPEE, and the cell size was uniform.

Study on Preparation and Properties of Modified Polycarbonate

ZHOU Ke-Bin Yuhong Chen

2012, 26 (04): 77-80 ; DOI: 10.19491/j.issn.1001-9278.2012.04.015

Abstract ( 1378 )

Polycarbonate（PC） plate with UVprotection coating, which was made with acrylic resin, organic solvents and ultraviolet absorber（UVA）, was prepared. Effect of coating on the optical and mechanical properties of PC plate was studied using light transmittance/haze locator, the tester of accelerated ageing and spectrophotometer. It showed that there was an excellent adhesion between UVprotection coating and the surface of PC plate. The coating had a good UVprotection property, the yellowness index of uncoated PC was about 11 after 120 hours UV ageing, but about unity for coated PC. The UVprotection coating could permit above 85 % visible light to go through and the coating also could keep optical properties and mechanical properties after 120 hours UV ageing experiment.

Preparation of Rigid Bromine Carbon Polyurethane Foam

CUI Jinfeng LIU Yongliang REN Chunfeng GUO Junhon YANG Baoping ZHOU Yingpin CUI Zhuo

2012, 26 (04): 81-85 ; DOI: 10.19491/j.issn.1001-9278.2012.04.016

Abstract ( 1439 )

A flame-retarded polyehter polyols was synthesized from diethanolamine and homemade tetrabromo-bisphenol-A epoxy resin E-21. An isocyanate was polymerized from these materials step by step which were TDI, PEG-400, and TMP under the effect of dibutyltion dilaurate. Flame retarded rigid polyurethane foams were prepared from these two components, and were characterized by means of TG and horizontal burning tester. The properties of flame retarded rigid polyurethane foams were affected by isocyanate index, blowing agents, and flame retardants. It showed that decalescence temperature was increased from 294.8 ℃ to 303.8 ℃.

Effect of Nano-ZnO on Properties of Poly(butylene succinate)

Wenguang LIU Xiucheng ZHANG Hongyuan LI Bin LIU Chunfan LI

2012, 26 (04): 86-91 ; DOI: 10.19491/j.issn.1001-9278.2012.04.017

Abstract ( 1448 )

Nano-ZnO was surface modified with KH-550, with which poly(butylene succinate)(PBS)/nano-ZnO composites were prepared via melt blending. The mechanical, thermal, and non-isothermal crystallization behavior of the composites were studied using SEM, TG, and DSC, respectively. The thermal degradation behavior was analyzed using Ozawa-Flynn-Wall method. It showed that the tensile and flexural strengths of PBS/ nano-ZnO composites increased with adding nano-ZnO, but impact strength decreased. Surface modification could improve the interfacial compatibility between nano-ZnO and PBS matrix and the dispersion of nano-ZnO in PBS matrix. Thus the mechanic properties of composites were enhanced. The crystallization rate of PBS was increased when nano-ZnO was added, and the thermal degradation activation energy was decreased.

Study on the Application of Novel P-N Intumescent Flame Retardant in Polypropylene

Xiang ZHANG Fan Zhang

2012, 26 (04): 92-96 ; DOI: 10.19491/j.issn.1001-9278.2012.04.018

Abstract ( 1319 )

In this work, a flame retardant system containing P-N intumescent flame retardant (melamine phosphate, IFR), ammonium polyphosphate (APP), and polytetrafluoroethylene (PTFE) was applied in polypropylene (PP). The burning property of the IFR/APP/PTFE system flame retarded PP was tested by limited oxygen index and UL 94 measurement. Using thermogravimetric, Fourier transform infrared spectroscopy, scanning elecreon microscope, and X-ray photoelectron spectroscopy, the burning property, thermal degradation process, and the components of residual carbon of flame retarded PP were analyzed, and the flame retardancy mechanism of PP/IFR/APP/PTFE system was studied. It showed that the IFR/APP/PTFE flame retardant system showed significant synergistic effect, and the PP/IFR/APP/PTFE could reach a limited oxygen index value of 30.1 % and UL 94 V-0 with only 24 % IFR/APP/PTFE flame retardant (APP 6 %, IFR17.5 %, PTFE 0.5 %). In addition, the thermal stability of PP was improved by the introduction of the flame retardant.

Synthesis of Pentaerythritol Abietate Stearic-acid Composite Ester and Its Application in PVC

QIU Liling XU Jun CHEN Zhaohan WANG Tujing LIN Ronglin

2012, 26 (04): 97-101 ; DOI: 10.19491/j.issn.1001-9278.2012.04.019

Abstract ( 1517 )

Levopimaric acid transannular peroxide was prepared from levopimaric acid, which was purificationed from abietic resin, through direct photo-oxidation and peroxidation reaction. Then the composite ester was prepared from a mixture of stearic acid, levopimaric acid transannular peroxide, and pentaerythritol, using heteropolyacid quaternary ammonium as a catalyst with microwave heating. It showed that the composite ester constituted an excellent stabilizer for PVC. The effects included improving static heat stability, damanic heat stability, Congo-red time, water absorption, electric property, and so on.

Study on Structure and Mechanical Properties of Recycled Polypropylene/Old Paper Fiber Composites

ZHANG Xiaolin WANG Rumin

2012, 26 (04): 102-105 ; DOI: 10.19491/j.issn.1001-9278.2012.04.020

Abstract ( 1334 )

Recycled polypropylene/old paper fiber（PP/OMGF）composites were prepared by means of compression molding. The effects of OMGF content on the tensile and flexural properties of the composites were investigated. The structure of OMGF was analyzed using FTIR. The tensile fracture surface of the composites was characterized by means of SEM. It showed that, when OMGF loading was 30 %, the tensile strength reached 29.53 MPa and flexural strength reached 33.67 MPa, increased by 51.6 % and 31.7 %, respectively, compared to recycled PP. With increasing OMGF contents, elongation at break decreased and flexural modulus of the composites exhibited a gradual increasing trend. SEM images indicated that, when OMGF content was low, good interfacial properties existed between OMGF and PP. When the fiber loading increased to 50 %, interface compatibility decreased obviously.

Simulation of Injection Molding and Analysis of Molding Defect for Automotive Exterior Parts Based on Moldflow

ZHOU Zhangtian LI Xiaoxing

2012, 26 (04): 106-109 ; DOI: 10.19491/j.issn.1001-9278.2012.04.021

Abstract ( 1441 )

Automotive exterior trim panel under the front windscreen was studied, and Moldflow software was used to simulate the injection molding process for it. Optimization measures were proposed for the possible formation of defects. Finally, the results were applied to the mold cavity design. It was verified that Moldflow could find future potential defects of the products in the designing stage. It could reduce the number of trial and the production cycle, thus reduce production costs and increase productivity.

Study on the capacity expansion of twin screw extruder based on the equivalent mixing performance

2012, 26 (04): 110-114 ; DOI: 10.19491/j.issn.1001-9278.2012.04.022

Abstract ( 1280 )

The capacity expansion method of twinscrew extruder was studied which based on energy equivalence principle. The finite element method was employed for the analysis, and the mixing characteristics was evaluated by parameters of average deagglomerating energy, the logarithm of area stretch ratio, and the modified Lyapunov index. It showed that the satisfy mixing performance could be obtained by adding two discs at the mixing section and the production output increased 15 %.