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2009, Volume 23 Issue 04 Publication date: 26 April 2009 Previous Issue Next Issue

Development of Extensional Viscosity of Polymer Melts or Solutions

peter.lim

2009, 23 (04): 1-7 ; DOI: 10.19491/j.issn.1001-9278.2009.04.001

Abstract ( 1776 )

Extensional viscosity is also known as Trouton viscosity. This paper briefly describes the extensional viscosity of hundred year’s history study, cites several measurement methods and principles and analyzes the changes of the Trouton viscosity measured in different ways.

Advance in Research of Polydicyclopentadiene Materials

2009, 23 (04): 8-14 ; DOI: 10.19491/j.issn.1001-9278.2009.04.003

Abstract ( 2406 )

Advances in polydicyclopentadiene (PDCPD) materials were reviewed. Chemical structure of dicyclopentadiene and PDCPD was introduced. The research on PDCPD materials formed by reaction injection molding and copolymerization of dicyclopentadiene were emphatically discussed. A briefly introduction to PDCPD nanocomposites, linear PDCPD and PDCPD self-healing materials was given. Finally，future trends in PDCPD materials were viewed.

The Quantitative Description of the Microstructure of Inorganic Nanoparticles Filled Polymer Composite Materials

XIAO Sheng-Ming HE Chun-xia

2009, 23 (04): 15-19 ; DOI: 10.19491/j.issn.1001-9278.2009.04.004

Abstract ( 2017 )

This article elaborated the importance of quantitative description of the microstructure of nanoparticles filled polymer composite. Summarized the domestic and foreign quantitative description method of the nanoparticles dispersed level in polymer composites, mainly includes the statistical method, the fractal theory, the group subTheory and other quantitative description method. Demonstrated with the computer graph technologys development, the microstructure of inorganic nanoparticles filled polymer composite could be quantitative described by the combination of digital image processing and the mathematical method.——’

The effect of composition of matrix on transparent ABS resin properties

2009, 23 (04): 20-23 ; DOI: 10.19491/j.issn.1001-9278.2009.04.005

Abstract ( 2077 )

Abstract: a series of poly Methylmethacrylate-Butadiene-Styrene (MBS) resin were synthesized by seeded emulsion polymerization techniques, methylmethacrylate-styrene -acrylonitrile (MSAN) resin was synthesized by suspension polymerization. Matrix polymer of transparent Acrylonitrile-Butadiene-Styrene (ABS) resin were blend of polymethylmethacrylate (PMMA) resin and poly Acrylonitrile-styrene(SAN) resin or methylmethacrylate-styrene-acry- lonitrile(MSAN) resin.TransparentAcrylonitrile-Butadiene-Styrene (ABS) resin was prepared by blending these MBS resins with matrix polymer. Influence of different composions of PMMA/SAN-T on properties of transparent ABS resin were research and the effect of MSAN matrix on property of transparent ABS resin was also studied. It is found that when matrix polymer was PMMA/SAN resin, impact strength and transmittance of transparent Acrylonitrile-Butadiene- Styrene (ABS) resin increase first, and then decrease；Haze of ABS decrease first, and then increase with the increase of content of PMMA in matrix polymer.Transparent ABS resin,with MSAN as matrix, has better mechanical properties but worse optical properties.

Study on structure and properties of different molecular weight PVC/ABS alloy

2009, 23 (04): 24-28 ; DOI: 10.19491/j.issn.1001-9278.2009.04.006

Abstract ( 2063 )

Use of conical twin-screw extruder mechanism for the preparation of different molecular weight PVC plastic injection-class PVC/ABS alloy，which have high-performance integrated mechanical. Using torque rheometer，scanning electron microscopy (SEM) study on the molecular weight PVC for PVC/ABS alloy rheological behavior, structure and mechanical properties. The results showed that: ABS "particles" in the PVC scattered, dispersed phase size smaller, PVC/ABS alloy showed a typical "sea - island" structure, which has good compatibility, with the increase in molecular weight PVC , ABS with a slight increase in the size of the average district size and wider distribution; PVC molecular weight increases so that the PVC/ABS blends balance significantly increased torque, increased apparent viscosity; with the content of ABS, PVC of different molecular weight PVC/ABS alloy toughness have been a substantial increase, when the ABS content increased to more than 10phr, PVC of different molecular weight PVC/ABS alloy are up to super-tough, PVC increased weight makes PVC/ABS Toughening of the alloy more significant effect.

Property characteristics of HDPE-g-MAH/PA6 alloy of much component HDPE

CHUAI Cheng-Zhi

2009, 23 (04): 29-31 ; DOI: 10.19491/j.issn.1001-9278.2009.04.007

Abstract ( 2111 )

ABSTRACT:Maleic anhydride grafted HDPE (HDPE-g-MAH) and HDPE-g-MAH/PA6 blend alloy were prepared by melt grafting. The grafting degree was controlled by alternating the ratio of maleic anhydride and dicumyl peroxide. The relationship between the properties of HDPE-g-MAH/PA6 blend alloy and the graft ratio of HDPE-g-MAH was studied. The results indicated that the mechanical properties and heat resistance of HDPE-g-MAH/PA6 blend alloy increased compared pure HDPE. The better properties of the blend alloy were observed when the ratio of HDPE:PA6:MAH:DCP was 60:40:1:0.3.

Morphologies and dynamic rheological behavbior of Polystyrene/Polyamide 6 blend and their blends compatibilized with styrene-ethylene/butylene-styrene elastomer grafted with maleic anhydride

DING xuejia deqiang zhang bin tang hongbo li haijiao xue

2009, 23 (04): 32-35 ; DOI: 10.19491/j.issn.1001-9278.2009.04.008

Abstract ( 1398 )

The blends of Polystyrene/Polyamide6 compatibilized by styrene-ethylene/butylene-styrene elastomer grafted with maleic anhydride were prepared by melt blending. The phase morphologies were investigated using scanning electron microscope (SEM). As the content of SEBS-g-MA increased, although the phase morphology of co-continuous PS/PA6 didn’t change, the phase size became smaller. However, when the content of SEBS-g-MA exceeded 10%, the phase size tended to larger. The reasearch on dynamic rheology found that the complex viscosity (η*), storage modulus and loss modulus became higher because of the addtion of SEBS-g-MA. That is, incorporation of SEBS-g-MA improved the viscosity and elasticity. It also indicated that the more the addtion amount of SEBS-g-MA, the smaller viscosity-elasticity rate. Keywords: Polystyrene;Polyamide6;styrene-ethylene/butylene-styrene elastomer grafted with maleic anhydride; co-continuous; dynamic rheology

Research on diallyl phthalate resin toughened by vinyl ester oligomers

KONG Zhen-Xing

2009, 23 (04): 36-40 ; DOI: 10.19491/j.issn.1001-9278.2009.04.009

Abstract ( 2420 )

The diallyl phthalate (DAP) resin was toughened by two kinds of vinyl ester oligomers (VEO1 and VEO2) with different molecular weight. The gel time of the mixed resins and the insoluble fraction of the cured samples were measured. The cured samples were characterized by static mechanical testing, Dynamic Mechanic Analysis (DMA), Thermogravimetric Analysis (TGA), and Scanning Electron Microscope (SEM). The results show that the impact strength increases by 73% with 5% VEO1 and by 120% with 20% VEO1, as well as the increment of flexural strength and the enhancement of thermal property. As a toughener for DAP resin, the VEO2 with higher molecular weight, is more advantageous.

Curing Reaction of UP in Supercritical Carbon Dioxide

2009, 23 (04): 41-43 ; DOI: 10.19491/j.issn.1001-9278.2009.04.010

Abstract ( 2048 )

In this paper, author study the curing reaction of UP in Supercritical Carbon Dioxide. The results show that supercritical carbon dioxide to make the time of exothermic peak of unsaturated polyester resin system has Significant shortening, to achieve the original solid 53.8 percent of the time. With the addition of supercritical carbon dioxide, double bond reactions rate become significantly lower, however, double bond reactions rate did not as high pressure continues to decrease.

Study on the Suspension Graft Polymerization of MMA onto nano-Basic Magnesium Chloride Whisker Surface in the Methanol/Water Disperse Medium

2009, 23 (04): 44-48 ; DOI: 10.19491/j.issn.1001-9278.2009.04.011

Abstract ( 1770 )

The nano-sized basic magnesium chloride whisker, which was prepared via liquid reaction at the atmospheric pressure with brine and ammonia, were modified with 3-(trimethoxysilyl) propyl methacrylate (γ-MPS). And then the nanocomposite particles were synthesized via free radical polymerization, which was initiated by K2S2O8 (KPS), a water-soluble initiator, in ethanol / water mixture. The nanocomposite particles were characterized by Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The influences, such as disperse medium and reaction time, on the morphology of the whisker were studied. And then, the effect factors, such as reaction temperature and time, concentration of initiator and monomer, on the graft ratio and graft efficiency were discussed. The optimum conditions, as it is, of the graft polymerization of MMA onto nano-BMC were determined by orthogonal experiments.

The Effects Of Alumina On The Crystallization And Thermal Conductivity Properties of Polyethylene

2009, 23 (04): 49-52 ; DOI: 10.19491/j.issn.1001-9278.2009.04.012

Abstract ( 1945 )

Abstract The effects of alumina(Al2O3) on the crystallization and thermal conductivity properties of Polyethylene (PE) were studied in this paper. The experimental results show that the addition of Al2O3 has no effect on the crystallization behavior of PE. With the increase of Al2O3 content, the thermal conductivity and diffusivity of PE/Al2O3 blend increase. Due to the high crystallinity of HDPE and the easiness of forming the thermal conductive channels, the thermal conductivity and diffusivity of HDPE/Al2O3 blend are higher that those of LDPE/Al2O3 blend at the same Al2O3 content. In addition, the thermal conductivity measured through experiments corresponds with the data calculated with Agari model.

Temperature field of Kevlar Fiber/MC nylon 6 composites during preparation process

2009, 23 (04): 53-57 ; DOI: 10.19491/j.issn.1001-9278.2009.04.013

Abstract ( 1282 )

Numerical Simulation of cast-forming process and crystallization of Kevlar fiber reinforced MC nylon6 was performed with polymerization and latent heat as internal heat sources by finite difference method. Crystallization had great effect on the temperature of reaction system when the mould temperature ranged from 145 to 160℃. However, the effect weakened with the drop of mould temperature and disappeared as the mould temperature reached 175℃. The highest temperature of reaction system reduced with increase of the fiber mass. Compared with the simulated results, experimental results falled far behind at the reaction beginning, and they agreed well with each other later. What the reasons for the deviation between simulated results and experimental results are slow endothermic velocity, crystallinity tested by density method and fibers distributed non–uniformly.

Preparation and Solid-Phase Photocatalytic Degradation of LDPE Nanocomposite Film Filled with Grafted Nano-TiO₂

LUO-Ying LIU Ying-ju YOU Jing-wu

2009, 23 (04): 58-60 ; DOI: 10.19491/j.issn.1001-9278.2009.04.014

Abstract ( 1568 )

A novel photodegradable low-density-polyethylene nanocomposite film filled with grafted nano-TiO2 (TiO2-g-PS/LDPE) was prepared by embedding polystyrene (PS) grafted TiO2 into the commercial LDPE. Solid-phase photocatalytic degradation of TiO2-g-PS/LDPE nanocomposite film was carried out in ambient air at room temperature under ultraviolet irradiation. The properties of the nanocomposite film were compared with that of pure LDPE film and TiO2/LDPE film by TG, FTIR and scanning electron microscope (SEM). The results showed that the photo-induced degradation of TiO2-g-PS/LDPE nanocomposite film was significantly faster than that of pure LDPE film and TiO2/LDPE film. The weight loss of TiO2-g-PS/LDPE nanocomposite film reached 36.2 % under ultraviolet irradiation for 336 h.

Anti-warpage Gate Design Analysis for Plastic Injection-molding of a Long-armed PBT lamp Holder

XIANG Hui-Yu

2009, 23 (04): 61-63 ; DOI: 10.19491/j.issn.1001-9278.2009.04.015

Abstract ( 2025 )

The principal factors affecting the warpage of long-armed product during plastic injection process were discussed. With a practical case ,an approach to decrease the warapge degree of the product by means of using multi-gates is introduced. Taken one vehicle used long armed PBT lamp holder as an sample, the rule of warpage caused by uneven cooling and shrinkage with two or three gates injection was studied respectively with numerical simulation method. The result shows that three gates injection molding is more reasonable to decrease warpage for this type of product. It is an significant way to use simulation method during design stage to improve mold design quality and optimize injection process.

Study on preparation of Nylon-6 / glass fiber reinforced composites by reactive extrusion on a pilot scale

杨小燕 Yang Xiao-Yan

2009, 23 (04): 64-67 ; DOI: 10.19491/j.issn.1001-9278.2009.04.016

Abstract ( 1963 )

On the basic of reactive extrusion Nylon-6 / glass fiber reinforced composites by laboratory research method, the composites prepared by pilot test was studied in this paper , the results indicate that the comprehensive mechanical properties of reactive extrusion Nylon-6 / glass fiber reinforced composites is better when the temperature of each section of twin screw reactive extruder were 240℃, the screw revolution speed was 100rpm and the glass fiber content was 0.5%.For operation process, the degree of operation difficulty using in pilot test is lower on the whole level.

The effect of vibration on the crystal structrue of isotactic polypropylene

2009, 23 (04): 68-70 ; DOI: 10.19491/j.issn.1001-9278.2009.04.017

Abstract ( 1796 )

Lately, vibration technology of polymer melt has been widely studied as an effective way to morphology controlling. In the injection molding samples of IPP prepared with vibration field, WAXD shows that shear force can induce the formation of βcrystal but there exists a optimal shear value, shear force will destroy the unstable βform crystal when it exceeds this value. It also shows high pressure vibration injection is propitious to the formation of γcrystal. SEM and PLM test show that vibration field brings about orientation of sphere crystal in the melt flow direction and reduction of the sphere size.

Synthesis of Halogen-free Phosphorus-nitrogen Containing Flame Retardant and Its Flame Retardancy in PC

TANG Jun-Jie

2009, 23 (04): 71-75 ; DOI: 10.19491/j.issn.1001-9278.2009.04.018

Abstract ( 2020 )

A novel halogen-free nitrogen-contained phosphaphenanthrene flame retardant DOPMI was synthesized from 9,10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide (DOPO) and N-phenyl maleimide (N-PMI). DOPMI was characterized by FT-IR, LC/MS, TG and DSC. The effect of DOPMI and other flame retardants on the flame-retardancy, mechanical properties, thermal degradation behavior, and charmorphology of PC was investigated after blending these retardants with PC. Results showed that LOI was raised to 30.4% and V-0 rating was observed from UL 94 when 3% DOPMI, 2% methyl phenyl silicone (MPS) and 24% phosphorus-containing flame-retardant PET were blended with PC. Notched impact strength and tensile strength decreased after the flame retardants were added. DOPMI couldn’t improve the char yield of PC, but it could accelerate crosslinking and char forming of PC. Additionally, SEM photos indicated that DOPMI could promote PC foaming, and MPS had the synergistic effect on PC.

Study on Removal of Polymaleic Anhydride from the Graft byproduct of Maleic Anhydride with Water-Washing Method

2009, 23 (04): 76-79 ; DOI: 10.19491/j.issn.1001-9278.2009.04.019

Abstract ( 1945 )

In the paper the chlorinated polypropylene was grafted with maleic anhydrid. The polymaleic anhydride from the byproduct of CPP-g-MAH was removed by water-washing method instead of acetone extraction method. Washing graft product was characterized by infrared spectrum and the parameters of adhesion and solubility was also determined. The effect of temperature, time and water addition on the removal rate of water washing were investigated. Results showed that when the temperature was 90℃, time was 2h, water addtion was 325ml the removal rate of water washing was the highest. Using water washing method could not affect the adhesion of graft on polypropylene board.

The Study on Cracking of Wasted Expanded Polystyrene Catalyzed by Cinder

宋学君 SONG Xue-jun

2009, 23 (04): 80-82 ; DOI: 10.19491/j.issn.1001-9278.2009.04.020

Abstract ( 1954 )

Causing environmental pollution easily, wasted expanded polystyrene (EPS) should be fully used. Using cracking-method to recycle EPS usually has two problems. One is how to avoid catalyst-poisoning, the other is how to deal with remnants. So cinder was used as catalyst for recycling EPS in this paper. The cracking products of EPS were analyzed by Gas Chromatography. The results showed that: The speed of elevating temperature and the cracking temperature had certain influence on the yield of styrene. Elevating of temperature slowly at 380℃, the content of styrene in liquid products was the highest ( 63%). Compared with other catalysts, the cinder-catalyzed yield of cracking products was higher. Under atmospheric pressure, when the amount of catalyst was over 8%, the yield (89%) of liquid products no longer increased. As waste from coal-fired equipment, cinder has the characteristics of light quality and large ratio surface area. The main chemical components of cinder were SiO2, Al2O3, Fe2O3 and CaO. Using wasted cinder as catalyst had no waste of resources due to catalyst-poisoning. After simple processing, the cracking residues can be reused as roadbed through-hole materials.

Separation of Waste Plastics ABS and PS by Dissolved-air Flotation

BAI Yang Hui WANG

2009, 23 (04): 83-87 ; DOI: 10.19491/j.issn.1001-9278.2009.04.021

Abstract ( 1998 )

The aim of this study was to separate waste plastics ABS and PS. The effects of parameters such as wetting agent, froth agent, conditioning time, flotation time etc. on flotation behaviors of ABS and PS were investigated in an especially designed dissolved-air flotation column and the optimized separation conditions were gained. The results showed when using 25mg/L wetting agent tannic acid, 5mg/L froth agent terpineol and conditioning time 15min, flotation time 15min, mixtures of waste plastics ABS and PS were separated successfully by dissolved-air flotation technique and the results revealed that the purity and recovery of PS in the floated was 90.12% and 97.45% respectively, the purity and recovery of ABS in the sank was 97.24% and 89.38% respectively. The study also showed that to overcome the adverse effects of mixed plastics in flotation process, further systematic research on interaction between plastic particles was important in this field.

Investigations of Structure and Property of Biaxial Oriented Polypropylene (BOPP) Resins and Films by Comparison Method

KE Yang-Chuan Yan-Xiao FAN Ying-Nian WANG

2009, 23 (04): 88-93 ; DOI: 10.19491/j.issn.1001-9278.2009.04.022

Abstract ( 1392 )

BOPP resin and film samples of both native and abroad are investigated and compared on their molecular and condensed structure. The solvent soluble and insoluble fractionations, their molecular weight by GPC and molecular sequence identifications by 13C-NMR were characterized to clearly distinguish the resin structure. The high molecular end (HME) and low molecular end (LME) in GPC curves were defined. Results showed that the random sequence of 4wt.%6wt.% and over 10wt.% HME were required for BOPP. The foreign resins have higher flow index, lower melt shear deformation index of * 1 and lower thermo degradation temperature than these of the native ones (*1). There appeared gas bulbs in native samples but not in abroad ones. X-ray revealed the higher  form, smaller crystallites and lower crystallization degree in SEB1 and SEB2 than these in the native ones. In PP copolymer with PE of 0.20.5 wt.%, the high performance SEB1 and SEB2 BOPP resins were obtained. SEM surface morphology showed the gel on thick SDB1 films with particle-like while silk-like orientation in SEB3.

Long-Term Thermal Conductivity Prediction on Rigid Polyurethane Foam Blown with Cyclopentane

2009, 23 (04): 94-98 ; DOI: 10.19491/j.issn.1001-9278.2009.04.024

Abstract ( 1848 )

Thermal conductivities are tested periodically on two different density rigid polyurethane foams blown with cyclopentane. By cutting products into thin slices and after aging 165 days in room temperature, the rising curves display two different ascending steps during test period and they are proved to be true of logarithmic relationship by function fitting. Finally the values obtained from logarithmic function need to be corrected by subtracting surface cell size destroyed in cutting. The results indicate that thermal conductivity of 50mm thick product will not exceed 0.029 W(m•K)-1 after using 25 years in practice.

Design of the plastic-injection mould for the steering protection board of the automobile interiors

ZHAO Long-Zhi Ming-Juan ZHAO

2009, 23 (04): 99-103 ; DOI: 10.19491/j.issn.1001-9278.2009.04.025

Abstract ( 1405 )

Based on CAD/CAE technology, the injection mould for the steering protection board of the automobile inner decoration was designed rationally in this paper. By the use of Pro/E soft, the three dimensional injection mould was achieved. And the optimum gating location was attained, the exhaust system was rationally designed on Moldflow soft, which innovated the way of the fabrication of the injection mould. According to the structure of the product, the layout of the central convex surface in the moving mould was achieved. The special tilt mandril of the core side-pulling mechanism were designed, which simplized the injection mould structure and economizes the cost.

A Study on Chaotic Mixing Process of Two Rotor Continuous Mixer

2009, 23 (04): 104-108 ; DOI: 10.19491/j.issn.1001-9278.2009.04.026

Abstract ( 1603 )

Two rotor continuous mixer is a kind of continuous mixing device with excellent dissipation and distribution properties. In this paper, the chaotic mixing characteristic of twin-rotor continuous mixer has been analyzed, and a modified Lyapunov index based on the residence time of material, which can be used to describe the tensile strain in the process of mixing, has been put forward. In addition, by finite element analysis, the modified Lyapunov indexes of most flow field region, computed by Polyflow software, are all more than zero. Vortical flow of stretch and fold can be found in the mixing flow field, which is very favorable for mixing and endows the two rotor continuous mixer with excellent dissipation and distribution mixing abilities.