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2012, Volume 26 Issue 08 Publication date: 26 August 2012 Previous Issue Next Issue

Research Progress in Intumescent Flame Retardant

TANG Shuo Yujuan JIN

2012, 26 (08): 1-8 ; DOI: 10.19491/j.issn.1001-9278.2012.08.001

Abstract ( 1672 )

Intumescent flame retardants (IFR) had been taken more and more attention for its environmentfriendly, high efficiency, and antidripping behaviors. This paper summarized the composition, flame retardant mechanism, and applications of PNbased and the expansible graphitebased IFR. The approaches to enhance the flame retardant efficiency of IFR were also discussed, including synergistic technology, surface modification, and microencapsulation. In the end, the future development of IFR was forecast.

Rheological Characterization of Phase Separation in Partial Miscible Polymer Blends

Lijuan LOU Yanfang WANG Linmei WU Qiang HUANG Zhuoni WANG

2012, 26 (08): 9-15 ; DOI: 10.19491/j.issn.1001-9278.2012.08.002

Abstract ( 1404 )

Recent development of studies on rheological characterization of phase separation in partial miscible polymer blends with different dynamic asymmetry was reviewed in this paper, including timetemperature superposition principle and temperature ramp under oscillatory shear, as well as temperature ramp under steady shear; reasons for different dependences on temperatures for complex structures in blends were well analyzed, and advantages and applicability of the methods were summarized and compared according to blending systems with weak or strong dynamic asymmetry.

Applications of NanoSiO2 in Polymers

Xi Chen LIU Yong-mei

2012, 26 (08): 16-25 ; DOI: 10.19491/j.issn.1001-9278.2012.08.003

Abstract ( 1620 )

Applications of nanosilica in polymers were introduced. Properties of polymer/nanosilica composites such as microstructrue, crystallization behavior, mechanical properties, thermal properties and flame retardancy were reviewed.

Study on Toughening Modification of POM with Elastomers and Rigid Particles

Jingjing CAI Mingfei ZHANG Xufu CAI

2012, 26 (08): 26-30 ; DOI: 10.19491/j.issn.1001-9278.2012.08.004

Abstract ( 1440 )

The synergetic toughening effect of TPU and nanoSiO2 on POM was investigated in this paper. The structure of the toughened system was characterized using DSC and SEM. When 20 % TPU was incorporated into POM alone, the notched impact strength was 89 % higher than that of neat POM, but the tensile strength and flexural modulus were lowered by 18 % and 40 %, respectively; When 2 % SiO2 was added to POM, the increase in notched impact strength was only 22 %. When 20 % TPU and 2 % SiO2 were incorporated into POM, the notched impact strength was 230 % higher than that of POM, and the tensile strength and flexural modulus were 8 % and 13 % lower, respectively.

Study on Nonisothermal Crystallization Kinetics of Glass Fiber Reinforced PA66 Composites

Kun CHEN Tihe ZHENG Zhicheng ZHOU Kedong SONG Zhe CAO

2012, 26 (08): 31-34 ; DOI: 10.19491/j.issn.1001-9278.2012.08.005

Abstract ( 1406 )

The crystallization behavior of glass fiber reinforced PA66 composites was characterized using DSC. Parameters of isothermal and nonisothermal crystallization kinetics were calculated using of Mo and Kissinger methods. It showed that glass fiber played as a heterogeneous nucleating agent, which increased the crystallization rate of PA66. When the glass fiber content was 30 %, the crystallization rate reached the maximum. The greater the cooling rate, the greater the degree of crystallinity. The crystallization activation energy of the composites were -297.22, -356.32, -481.00, and -365.59 kJ/mol, respectively, when the glass fiber contents were 0, 15 %, 30 %, and 45 %.

Effect of Scratchresistant Agent on Scratch Resistant Property of PC/Silicon Whisker System

Xiaowen SUN Bin LIU Die QIU

2012, 26 (08): 35-39 ; DOI: 10.19491/j.issn.1001-9278.2012.08.006

Abstract ( 1652 )

Scratchresistant agent was introduced into PC system containing five percent of silicon whisker. Scratch resistant properties, thermodynamic properties, mechanical properties, and rheological behavior of the modified PC system were studied using pencil tester, vicat apparatus, electronic universal testing machine, and highpressure rheometer. It was found that the PC system with the best scratch resistance properties was PC/5 % silicon whisker/1.2 % scratchresistant agent, which reached a pencil hardness of 2H.

Study on Macroproperties of Polyurethane Elastomer Based on NDI

Chengke YU Huijuan FU Jianxun LUO Lixin MAO Liqun ZHANG

2012, 26 (08): 40-44 ; DOI: 10.19491/j.issn.1001-9278.2012.08.007

Abstract ( 1614 )

Casting twocomponent polyurethane elastomers were synthesized with polytetramethylene ether glycols (PTMG), 1,5naphthalene diisocyanate (NDI), 1,4butanediol (BDO), and trimethylolpropane (TMP) as the main precusors. The obtained polyurethane elastomers had superior mechanical properties, good flexibility at low temperature, low dynamic heat, and high storage modulus. With increasing NCO content, the platform modulus and hardness increased, the glass transition temperature of soft segments and the loss factor reduced, while tensile strength first increased and then decreased.

Friction and Wear Properties of NanoSiC Modified PTFE Composites

Qin LU Shaohui LV Chunxia HE

2012, 26 (08): 45-49 ; DOI: 10.19491/j.issn.1001-9278.2012.08.008

Abstract ( 1426 )

NanoSiC was treated with different coupling agents, the effect of coupling agent content on tribology properties of PTFE composites was investigated. The worn surface of PTFE composites was examined with a scanning electron microscope (SEM). It showed that hardness and tribology properties of PTFE composites filled with treated nanoSiC were higher than those with untreated nanoSiC, and the titanate (NDZ101）was the most effective among various coupling agents. The wear mass loss and friction coefficient of PTFE composites decreased with increasing coupling agent, however, the effect was inversed when the loading of coupling agent was larger than 1 %. SEM micrograph of fracture surface revealed that there was favorable interface bonding between NDZ101 treated nanoSiC and PTFE matrix. The wear mechanism of PTFE composites was also discussed.

Characterization of Branched Chain of PE-LD Cable Material and Its Effects on Processing Property

Shan XUE Kefeng XIE Zhenqin XU Pengpeng LI Fuqing WEI

2012, 26 (08): 50-54 ; DOI: 10.19491/j.issn.1001-9278.2012.08.009

Abstract ( 1299 )

The physical and mechanical properties of PELD cable materials, and their branched structure were studied. The dynamic rheological analysis was used to characterize the long chain branching index (LCBI) of the materials was used to characterize. The long and total chain branching contents were studied through extensional flow and infrared spectrometry, respectively. The study of rheological properties and crosslinking performance showed that: under the premise of similar molecular weight and the total branching content, the more the content of the short branched chain, the lower the activation energy. The short branched chain improved the processing performance and crosslinking performance. Long chain branching could result in the increase of entanglement point and activation energy. It was not conducive to crosslinking.

Study on Phase Morphology and Rheological Behavior of PBT/ASA Blends

Ting CHEN QINGRONG QIAN XINSHU XIA JING XU XINPING LIU LIREN XIAO Baoquan HUANG Qinghua CHEN

2012, 26 (08): 55-59 ; DOI: 10.19491/j.issn.1001-9278.2012.08.010

Abstract ( 1509 )

Acrylonitrilestyreneacrylates terpolymer(ASA) was employed to toughen polybutylene terephthalate (PBT). Scanning electron microscope (SEM) and dynamic rheometer were used to investigate the phase morphology and rheological property of PBT/ASA blends. It was clear that ASA could effectively improve the melt strength of PBT, and the PBT/ASA blend was a partly compatible system with compositon dependence. The microphase of the blends showed a typical “seaisland” structure at low ASA content, and a phase inversion occurred in an ASA content range of 40 wt %～60 wt%.

Effect of Organmontmorillonite on Flame Retardancy of EVA/IFR Composites

Xiaoguang XU

2012, 26 (08): 60-63 ; DOI: 10.19491/j.issn.1001-9278.2012.08.011

Abstract ( 1322 )

A flame retarded EVA was prepared by using ammonium polyphosphate (APP) and pentaerythritol (PER) as the main flame retardants. Organmontmorillonite was used to further improve the flame retardancy of EVA. Limiting oxygen index, thermal gravimetric analysis and cone calorimetry were used to characterize the flammability and thermal behavior of the EVA composites. The morphology of the composite was observed and analyzed using SEM. Montmorillonite could enhance the char formation and improve the char layer quality, and hence reduced the HRR and smoke release amount. The limited oxygen index reached 29.4 % and UL 94 reached V0 level when 3 phr montmorillonite was added.

Study on Crystallization Behavior of PTFE/ZrO₂ Composite Microporous Membrane

Yuyang HAN Xinhua DENG Weining YANG Yanhui LUO Rui MAN

2012, 26 (08): 64-68 ; DOI: 10.19491/j.issn.1001-9278.2012.08.012

Abstract ( 1263 )

In this paper, PTFE/ZrO2 composite microporous membrane was prepared via mechanical tensile method, using PTFE resin emulsion as a matrix phase and micronanozirconium dioxide (ZrO2) powder as a reinforcer. The crystallinity of the microporous membrane was determined using XRD. The effects of the ZrO2 content, draw ratio, heattreatment temperature and time on the crystallinity of the microporous membrane were studied through a singlefactor method. It showed that the crystallinity was positively proportional to the draw ratio, calcination time, and temperature, but inverse proportional to the ZrO2 content. The optimal comprehensive performance was obtained with following parameters: ZrO2 content 7 %, draw ratio 1~2.5 times, heat treatment temperature 310 ℃, and heat treatment time 10 min.

Numerical Simulation for Fluid Flow in Ultra High Molecular Weight Polyethylene Sintered Pipe

Xiaofeng FANG Jimin HE Qiang ZHANG

2012, 26 (08): 69-72 ; DOI: 10.19491/j.issn.1001-9278.2012.08.013

Abstract ( 1280 )

The classical particle packed bed model equation of Ergun in dynamics of fluids in porous media was introduced. Under the same pressure drop and same aperture condition, using finite element analysis software ANSYS, the simulated permeation rate through particles in cubic and hexagonal packing were compared. Based on simulation and experiments, the powder packing model in powdersintered PEUHMW microporous tube was analyzed for various permeation rates and apertures. It showed that the formation of microporous in powdersintered PEUHMW pipe was mostly through hexagonal closepacked structure of powder particles.

Effect of PTFE on Pervaporation of PDMS Composite Membrane in Dilute Organic Solution

De SUN Rongmin kang Wanli Yu Yanan Sun Bingbing LI Dong WANG

2012, 26 (08): 73-76 ; DOI: 10.19491/j.issn.1001-9278.2012.08.014

Abstract ( 1366 )

A novel composite membrane of micron PTFE powder filled PDMS was prepared for the pervaporation of organic components (ethanol, 1propanol and acetone) from water. The physical structure of this kind of composite membrane was investigated by SEM, FTIR and TG. The solubility for organic components (ethanol, 1propanol and acetone) in the composite membrane was achieved. The results showed that the addition of PTFE from 0 to 10 % in PDMS membrane increased the surface area and thermal stability of PDMS membrane as well as the solubility of above organic components from 0.0923 to 0.0991 g/g, from 0.1589 to 0.1678 g/g and from 0.2691 to 0.2773 g/g respectively, and also the pervaporation of this PDMS membrane.

Birefringence Experiment of Molecular Orientation Distribution of PC in Injection Molding

yuan YUAN Peng YUE Gang LI

2012, 26 (08): 77-80 ; DOI: 10.19491/j.issn.1001-9278.2012.08.015

Abstract ( 1515 )

The birefringence along the thickness direction of PC plate was studied using Wedgemethod. From the distribution of birefringence and molecular orientation with different processing parameters and different positions in the molded plate, an asymmetrical distribution of birefringence on the sideway of the plate was found. On the subsurface near the cold model, there occurred a birefringence peak or a noncontinuous distribution in the thickness direction. The influence of melt temperature and holding pressure on the birefringence was serious, but the annealing had no effect on the birefringence and molecular orientation.

Influence of Different Foaming Agents on Foaming Behavior of PVA

Weining YANG Qingqing JIA Qin WANG Qiang ZHANG Bagen GAOLUN Aimin XIANG

2012, 26 (08): 81-84 ; DOI: 10.19491/j.issn.1001-9278.2012.08.016

Abstract ( 1447 )

The foaming behavior of PVA influenced by different foaming agents (including the thermal release, thermal absorption, thermal equilibrium and reaction type) was studied, and the foaming samples were processed through the extruding method. The results of differential scanning calorimetry and thermogravimetric analyzer showed that all types of the foaming agents improved the degrees of crystallization and the crystallization temperature of PVA, while the thermal stability of PVA matrix reduced in different degrees. The results of electron microscopy scanner, density spectrometer and mechanical test showed that foamed PVA with the reaction typefoaming agent had more uniform cells and the lowest density, while its mechanical propertits was poor.

Injection Molding Simulation of Lower Plaques for Apillars of Vehicles

Feng WANG Bin ZHOU Jiling BU Guanghua LIU

2012, 26 (08): 85-89 ; DOI: 10.19491/j.issn.1001-9278.2012.08.017

Abstract ( 1386 )

Using orthogonal experiments and Moldflow simulation, the process in the injection molding of lower plaques for Apillars of vehicles was simulated. The influences of different molding process parameters such as mold temperature, melt temperature, injection time, and packing pressure on the warp deformation and residual stress were studied. It was found that the melt temperature constituted the most influential factor to warp deformation, packing pressure was the most influential factor to the residual stress. A set of optimal process parameters was found to be mold temperature 40 ℃，melt temperature 205 ℃, injection time 5 s, the packing pressure 45 MPa. Compared with regular processing parameters, warp deformation decreased from 3.847 mm to 3.121 mm, residual stress decreased from 66.95 MPa to 65.21 MPa.

Preparation and Properties of Poly(vinyl chloride)/Nano Aluminium Oxide Composites

Dong HE Dong Shuhua QI Bo CHENG Lina MA

2012, 26 (08): 90-93 ; DOI: 10.19491/j.issn.1001-9278.2012.08.018

Abstract ( 1330 )

Nano aluminium oxide (nanoAl2O3) was modified with silane coupling agent (KH550), which was introduced into a PVC matrix. The structure of nanoAl2O3 was characterized using FTIR, the dispersion of nanoAl2O3 in PVC resin was observed using SEM, the heatresistant properties and the mechanical properties of the composites was also studied. It showed that the modified nanoAl2O3 dispersed uniformly in PVC resin matrix. By adding nanoAl2O3, the heatresistant properties and the mechanical properties of the composites were improved. When the mass fraction of nanoAl2O3 was 3.0 %, the tensile strength and notched impact strength achieved the maximal values, which was 16.25 % and 20.27 %, respectively, higher than those of neat PVC.

Study on Slipping Masterbatch Used in BOPP Films for Cigarette Packaging

Sufen ZHAO Zhigang TU Liqiong ZHANG Xiaoyan LIU

2012, 26 (08): 94-96 ; DOI: 10.19491/j.issn.1001-9278.2012.08.019

Abstract ( 1312 )

In this article, effects of ratio of dimethyl silicone oil to wax and kinematic viscosity of dimethyl silicone oil on optical properties and coefficient of friction were studied. It indicated that with the increase of dimethyl silicone oil, the static and dynamic friction coefficient of the films decreased from 0.31 and 0.19 to 0.22 and 0.18, and a small amount of wax could maintain a relatively stable optical properties, the synergistic effect between dimethyl silicone oil and wax ensured the comprehensive use of the master batch. With the same ratio of dimethyl silicone oil to wax and increase of the kinematic viscosity of dimethyl silicone oil, the static and dynamic friction coefficient of the films decreased by 7.4 % and 10.5 %, respectively, while little effect on the optical properties.

Uncertainty Assessment Based on Measurement Result of Tensile Strength of High Resilience Polyurethane Foams

Liu Shansheng wei Yuan

2012, 26 (08): 97-100 ; DOI: 10.19491/j.issn.1001-9278.2012.08.020

Abstract ( 1732 )

The uncertainty in the measurement of tensile strength of polyurethane foam for individual and a group was compared. Seven personals participated the assessment. It was found that the uncertainty of the group was higher than any individual. It was proposed that the uncertainty of a group could reflect the measurement capability of a laboratory.

Application of Flow Analysis Technology in Design of Injection Molds for an Oil Cup of Steering Booster Pump

Tangqing KUANG Huilan ZHOU PuLiang Deng

2012, 26 (08): 101-106 ; DOI: 10.19491/j.issn.1001-9278.2012.08.021

Abstract ( 1253 )

During the design of the injection mold for an oil cup of steering booster pump, flow analysis technology was adopted to optimize its runner system, processing parameters, and cooling system. The optimized gate location was determined based on the process window analysis and the characterization of the cup structure. The optimized process parameters were obtained: the mold temperature was 85 ℃，the material temperature was 278 ℃, and the injection time was 1 s. Side gate and twocavity mold were used to mold the oil cup. The injection molding pressure and clamping force were 113 MPa and 111 t. Runner system was built to predict the injection pressure and clamp force, which provided the reference data to select molding machine. The optimized cooling system ensured the uniform cooling effect. Finally, the structure of the oil cup injection mold was introduced in detail.

Application of Corotating Twin Screw Extruders in Polymer Devolatilization

Zhaoyang JIA Xiaoying ZHAGN Xiaogang LIANG

2012, 26 (08): 107-110 ; DOI: 10.19491/j.issn.1001-9278.2012.08.022

Abstract ( 1805 )

This paper introduced the sort and basic information of polymer devolatilizition equipment, especially the twin screw extruder, its advantages, development, and application in polymer devolatilizition. Based on the industrial practice, the devolatilization technology, the design requirements of corotating twin screw extruders and the assessory were introduced. Key words:corotating twin screw extruder; polymer; devolatilizition