Current Issue

2010, Volume 24 Issue 01 Publication date: 26 January 2010 Previous Issue Next Issue

Situation and Development Trend of Plastics Pipe Industry in China

WANG Zhanjie

2010, 24 (01): 1-5 ; DOI: 10.19491/j.issn.1001-9278.2010.01.001

Abstract ( 2486 )

The basic fact about the output and export of Chinese plastics pipe industry was introduced. It was pointed out that the PVC-U and PE pipes will remain the major of pipe industry, their modification and composite will be developed. Finally, the development goals and some suggestion of the plastics pipe industry were given.

Surface Modification of Poly (aryl ether ketone)s and Their Biomedical Applications

SUN Hui SUN Jie XU Yingkai XU Guozhi

2010, 24 (01): 6-10 ; DOI: 10.19491/j.issn.1001-9278.2010.01.002

Abstract ( 2324 )

In this paper, various methods for surface modification of poly(aryl ether ketone)s and their biomedical applications were described. The selective wet chemistry, plasma treatment, and the surface biofucntionalization via immobilization of extracellular matrix, e.g. fibronectin, were introduced. The application of such polymer as cell-culture substrates, trauma implants, load-bearing joint surface, and spine cages was also discussed. The future development in this area was forecast.

Organic Modification of Mesoporous Silica and Its Effects on Tensile Properties of Epoxy Resins

JIAO Jian LIU Panbo ZOU Liang

2010, 24 (01): 11-16 ; DOI: 10.19491/j.issn.1001-9278.2010.01.003

Abstract ( 2031 )

A series of mesoporous silica was prepared from tetraethylorthosilicate (TEOS) and γ-aminoproplytrimethoxysiliane (APTMS) by polycondensation. The introduction of APTMS decreased the pore size, pore volume, and specific surface area of the mesoporous silica. When the loading of APTMS was 20 %, the meso-pore-structure in silica was no longer observed. The mesoporous silica was introduced into epoxy resin via melting blending forming a composite. With increasing amount of mesoporous silica from 2 % to 10 %, the tensile properties and toughness of the composites increased observably, and the elongation at break was little changed.

Synthesis of Star-shape SAN Resin and Its Effect on Properties of ABS Resin

CAO Chunlei XIAO Linghan

2010, 24 (01): 17-22 ; DOI: 10.19491/j.issn.1001-9278.2010.01.004

Abstract ( 2049 )

T-SAN and M-SAN resins were synthesized with tetra- and mono-functional initiators via high temperature continuous solution polymerization in toluene, respectively. With nearly the same molecular weight and molecular weight distribution, T-SAN possessed better thermal resistance and melt flow behavior. The two SANs were blended with a same ABS resin forming T-ABS and M-ABS resins. The T-ABS possessed the same tensile strength as M-ABS, but 17 % higher impact strength than M-ABS. The rubber particles in T-SAN were finer and more uniformly dispersed than in M-SAN. At whiten zone, more distinct deformation of the rubber particles in T-ABS was observed.

Study on Compatibility of PC/PET Alloys

XUE Jirong NING Ping

2010, 24 (01): 23-27 ; DOI: 10.19491/j.issn.1001-9278.2010.01.006

Abstract ( 2606 )

The compatibility of polycarbonate/poly(ethylene terephthalate)（PC/PET） blends was studied using DSC, SEM, and other testers. Without compatibilizers, the two glass transition temperatures of PC and PET shifted closer to each other with increasing content of PET, which meant that this blend was partially miscible. The melt flowability was improved by the addition of PET and achieved the optimum effect when PET content was about 65 %. The addition of different compatibilizers reduced the tensile and flexural properties in some extent, however, the impact strength was increased greatly. By adding only 3 phr of ethylene-butyl acrylate-glycidyl methacrylate copolymer (PTW) or 7 phr of ethylene-ethyl acrylate copolymer (EEA) into PC/PET(30/70), the impact strength increased from 5.5 to 10 kJ/m2. Compatibilizer PTW with glycidyl methacrylate (GMA) groups resulted in the best improvement of the two-phase interface.

Study on Preparation and Properties of Silicone Rubber and Chlorinated Polyethylene Blends

CHENG Qingmin LUO Shikai DING Guofang

2010, 24 (01): 28-32 ; DOI: 10.19491/j.issn.1001-9278.2010.01.007

Abstract ( 2127 )

Blends of silicone rubber and chlorinated polyethylene were prepared via mechanical blending. The influence of chlorinated polyethylene content on mechanical property, thermal stability, damping property, and morphology of the blends was investigated. It was found that, with increasing content of chlorinated polyethylene, the mechanical property and thermal stability decreased, but the damping property and compatibility increased obviously. When the dosage of chlorinated polyethylene were 100 phr, compared with neat silicone rubber, the effective damping temperature range of the blends was broadened from 15℃ to 50℃, the maximum loss factor was increased from 0.11 to 0.43, the glass transition temperature increased by 30℃. The compatibility of silicone rubber and chlorinated polyethylene was good.

Effect of OMMT on Crystallization and Compatibility of PE-HD/PA6 Alloys

SUN Li XIANG Saifei

2010, 24 (01): 33-37 ; DOI: 10.19491/j.issn.1001-9278.2010.01.008

Abstract ( 2216 )

The microstructure and crystallization behavior of high density polyethylene/polyamide 6/organic montmorillonite (PE-HD/PA6/OMMT) nanocomposites were characterized using XRD, TEM, SEM, and DSC. Without OMMT, PA6 dispersed in PE-HD as spherical particles with diameters between 30 and 40 μm. When OMMT of 3 phr was introduced, the interfacial tension between PE-HD and PA6 phases was reduced and the size of PA6 domains was decreased to about 10 μm. OMMT also improved the barrier properties of PE-HD/PA6 alloys to organic solvents. With increasing OMMT content, more γ crystals were formed in PA6.

Thermal Behavior and Tensile Property of Epoxy Resin/ Rice Husk Silica Nanocomposites

LIU Jiyan LIU Xueqing ZHANG Yuanfang GAN Yanmei

2010, 24 (01): 38-42 ; DOI: 10.19491/j.issn.1001-9278.2010.01.009

Abstract ( 2114 )

Rice husk silica with a purity of 99.3% and a specific surface area of 212 m2/g was obtained by burning the HCl treated rice husk at 600℃. After being modified with γ-glycidyloxipropyltrimethoxysilane (KH-550), amorphous silica particles with size ranging from 30~50 nm were used as a filler in epoxy-based nanocomposites. The thermal degradation behavior and thermal stability of the epoxy resin/SiO2 nanocomposites were studied with thermo gravimetric analysis determining the initial decomposition temperature (Ti), temperature of maximum rate of weight loss (Tmax), and 50 % weight loss temperature (T50%). With increasing SiO2 content the thermal stability of epoxy resin was improved, which was further enhanced by the modification of SiO2. In addition，with the addition of silica, the tensile strength，elongation at breaking, and modulus were also increased.

Study on Hydrophilicity of Hydroxymethyl Acrylamide Grafted Polypropylene

FENG Jie FENG Shaohua XIANG Yixin FENG Chang

2010, 24 (01): 43-46 ; DOI: 10.19491/j.issn.1001-9278.2010.01.010

Abstract ( 2011 )

PP-g-NHA and PP-g-NHA/St have been prepared via melt grafting by using a twin-screw extruder using dicumyl peroxide (DCP) as an initiator. FTIR confirmed the grafting of NHA and St onto polypropylene (PP) chains. The effect of the content of monomer, initiator, extrusion temperature, and screw speed on the grafting degree and the resulted contact angle of grafted PP were investigated. When the content of NHA was 3%, the obtained grafting degree and contact angle were 1.6 % and 83°, respectively. With increasing loading of DCP, the grafting degree increased and then decreased. The screw speed should be higher than 40 r/min.

Study on Compatibilizers for PBT/ABS Alloys

TIAN Ye DUAN Chunlai ZHOU Ting LI Rongqun XIN Minqi

2010, 24 (01): 47-51 ; DOI: 10.19491/j.issn.1001-9278.2010.01.011

Abstract ( 2294 )

The effect of three kinds of compatibilizers on the mechanical property and melt flow rate of poly(butylenes terephthalate)/acrylonitrile-butadiene-styrene copolymer (PBT/ABS) alloys was studied. The interface property, compatibility, and crystallinity of PBT/ABS alloy were characterized using scanning electron microscope (SEM) and differential scanning calorimeter (DSC). It was found that the compatibility of PBT/ABS alloys could be effectively improved by adding a compatibilizer containing epoxy functional groups, KS-TD-00202, as a result, the notched impact strength was obviously enhanced without reducing the tensile strength, flexural strength, and processing properties. In addition, the crystallinity of PBT in the alloy was also increased.

Numerical Simulation for Filling Stage of Injection Molded Parts with Ribs

LIU Yongzhi ZHAO Zhenfeng MA Lan SHEN Changyu

2010, 24 (01): 52-55 ; DOI: 10.19491/j.issn.1001-9278.2010.01.012

Abstract ( 2332 )

The filling stage of injection-molded ribbed parts was simulated with finite element method. In two examples, the distribution of velocity, pressure, and melt front in thickness direction was computed. The fiber orientation distribution induced by flow could be obtained from changes of velocity and shearing fields.

ANSYS Software Simulation of Mechanical Properties of Steel Skeleton Reinforced PE-HD and Its Experimental Verification

SUN Jianan CHEN Bingbing JIN Yangfu GAO Zengliang QIAN Xin

2010, 24 (01): 56-58 ; DOI: 10.19491/j.issn.1001-9278.2010.01.013

Abstract ( 2191 )

Based on ANSYS finite element analysis software, steel mesh discrete models were formulated for simulating the mechanical properties of steel skeleton reinforced PE-HD composites. Both Young's and bending moduli of the composites increased with increasing diameter of the steel skeleton and mesh density. The calculated moduli agreed well with the experimental data.

Numerical Simulation of Residence Time of Flow in Coat-hanger Dies Inserted with Different Cores

ZHOU Wenyuan XIONG Chuansheng MENG Yaxin YANG Baohong WANG Jinglu

2010, 24 (01): 59-63 ; DOI: 10.19491/j.issn.1001-9278.2010.01.014

Abstract ( 1865 )

The die channel was simulated using Polyflow software in order to find a way to produce films with different breadth using a same die through inner-die insertion. The effect of core angle on the residence time was investigated. It showed that the flow was most resided at the end of the channel; the longest residence time was mostly affected by the smallest angle of the channel. When the angle of the core angle was 40°, the least residence time of the flow was observed

Effect of Processing Technology on Dispersion of Carbon Black in Polyethylene / Acetylene Black Composites

ZHANG Wenlong LANG Dandan LING Jun

2010, 24 (01): 64-68 ; DOI: 10.19491/j.issn.1001-9278.2010.01.015

Abstract ( 1495 )

Based on statistical analysis of surface resistance, mechanical properties testing, and observation of scanning electron microscopy (SEM), the effect of processing parameters on the dispersion of carbon black in low-density polyethylene was studied. It showed that the surface resistance of the samples made by internal mixing was lower than that of by open mill mixing. In the internal mixing technology, the materials were first mixed for 5 mins at 30 r/min, cutting the materials into small pieces, which were further mixed for another 5 mins. Thus the carbon black could be finely dispersed in the matrix. Severe and long time mixing would break the aggregation of carbon black.

Study on Extrusion Foaming of Polypropylene with Supercritical C0₂ as Foaming Agent

ZHANG Yuxia LIU Bengang WANG Xiangdong LI Ying XU Guozhi

2010, 24 (01): 69-73 ; DOI: 10.19491/j.issn.1001-9278.2010.01.016

Abstract ( 2082 )

Foamed sheet with width of 300 mm of polypropylene(PP) modified by nano-clay and high-melt-strength propylene was extrusion foamed with supercritical CO2 as foaming agent. Effect of CO2 content, die temperature, and nano-clay on the sheet density and cell density was researched. Results showed that nano-clay can improve the quality of the PP foam sheet. The sheet density and cell density were 0.454g/cm3 and 3.37×107 cells/cm3 respectively when the gas injection shift was 0.5 and mold mold temperature was 157 ℃.

Properties of Intumescent-flame-retardant Retarded PP/SBS/POE Blends

WANG Yanxiang ZHANG Liqun LI Hongxia LIANG Wenli TIAN Ming

2010, 24 (01): 74-80 ; DOI: 10.19491/j.issn.1001-9278.2010.01.017

Abstract ( 2191 )

The effect of two intumescent flame retardants, ammonium polyphosphate (AP) and phosphate ester (NP), on the mechanical properties, flammability, and anti-water-blooming properties of PP/SBS/POE blends was studied. The kinetics of the retardants blooming was also analyzed. It showed that NP exhibited a higher thermal decomposition temperature and more char residue than AP. As the retardants increased, mechanical properties of the blends decreased but their flame retardancy were improved. At the same loading amount, the blends with NP showed the higher tensile strength and limited oxygen index. AP inversely promoted the charring of polymer matrix. Part of AP and NP moved outside from inside after the blends were soaked in heated water. The blooming is a processing that extends from the surface to inside of the samples. The amount of blooming increased with the soaking time. NP showed the lower amount of blooming at the same soaking time. As to the soaked blends, tensile strength and flame resistance were deteriorated.

Properties of Spirophosphate Cyanuric Acid Flame Retarded Polypropylene

JIANG Dawei SUN Caiying XIANG Haiwang DONG Chunmei HU Shulin

2010, 24 (01): 81-84 ; DOI: 10.19491/j.issn.1001-9278.2010.01.018

Abstract ( 1549 )

The influence of spirophosphate cyanuric acid (SPCA) on the flame retardancy and mechanical properties of polypropylene (PP) was studied. When the content of SPCA was 25 %, the flame retardant efficiency was the highest and the limited oxygen index of PP was 25.6 %. The content of SPCA had no significant influence on the mechanical properties. With 25 % SPCA, the tensile, flexural, and impact strengths were 27.62 MPa, 38.03MPa, and 3.68kJ/m2, respectively. The thermal analysis showed that SPCA improved the high temperature stability of PP.

Study on Relationship between Mechanical Properties and Molecular Structure of Repetitous Injection Molded HIPS

ZHANG Yubing GAO Zhaoming XU Qingqiang XU Bing

2010, 24 (01): 85-93 ; DOI: 10.19491/j.issn.1001-9278.2010.01.019

Abstract ( 2182 )

Two types of high impact polystyrene(HIPS) resins were injection molded several times to determine the changes in mechanical properties and chemical structure. After multiple injections, all the bending strength, elongation at break, fracture strength, and impact strength of the material decreased. The molecular structure of HIPS was detected with 13C-NMR. The relationship between mechanical properties and molecular structure was discussed. A new conception of multiple-mold-factor was proposed to evaluate the plastic process stability.

Study on Molecular Weight and Molecular Weight Distribution of PE-UHMW

WANG Xinwei SHEN Xianting GUO Ning ZHANG Wei ZHANG Yumei WU Xiangyang XU Jingan

2010, 24 (01): 94-98 ; DOI: 10.19491/j.issn.1001-9278.2010.01.020

Abstract ( 2236 )

Methods for determining the molecular weight and distribution of ultra-high molecular weight polyethylene (PE-UHMW) were introduced in this paper, including intrinsic viscosity, rheology, and gel permeation chromatography (GPC). Viscosity method was the most widely used one, in which Ubbelohde viscometer was used. Since PE-UHMW possessed a very long relaxation time, rheological method was tedious. The GPC method had to be carried out at high temperatures and thus was subjected to some limitations.

Research and Development of Rapid Design System for Injection Moulds Based on Standard Moldbases and Modular

WAN Jiangtao SHEN Mingqian SHEN Jie

2010, 24 (01): 99-102 ; DOI: 10.19491/j.issn.1001-9278.2010.01.021

Abstract ( 1448 )

A plastic injection mold in the standard moldbase was chosen as the base, a framework for rapid design systems was formulated. The significance, object of the modular, and establishing methodologies of modules library were analyzed. Finally, rapid design system for injection mold based on standard moldbase and modular was established. The system can improve the utilization of three-dimensional software, the rate of design, and production efficiency, and shorten the product development cycle. Modern design concept, including the people-oriented, green design was reflected in this system, so it was of certain theoretical and practical application value.

Inverse Numerical Simulation of T-shape Dies for the Extrusion of Plastics Profiles

XU Lei LIU Hesheng HUANG Xingyuan HUANG Yibin

2010, 24 (01): 103-106 ; DOI: 10.19491/j.issn.1001-9278.2010.01.022

Abstract ( 2341 )

Using Polyflow software，numerical simulation was implemented for inverse design with three kinds of extrusion die. The die lip shape of T-shape，velocity field，pressure field was obtained. The simulation displayed that the die lip shape of T-shape was unrelated to shape of transition section. The widened transition section was beneficial to balance the outlet velocity and extrusion pressure.