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2009, Volume 23 Issue 05 Publication date: 26 May 2009 Previous Issue Next Issue

Research Progress in Extrusion Theory of the Single-Screw Extruder

Zhang Yuxia XUE Ping

2009, 23 (05): 12-19 ; DOI: 10.19491/j.issn.1001-9278.2009.05.003

Abstract ( 2341 )

The development history of extrusion theory for the single-screw extruder has been retrospected in this paper. The latest theories progress of solid conveying、melting、melt conveying and mixing have been reviewed in detail. With the existing deficiencies being designated，the prospective research directions for the single-screw extruder have been put forward.

Progress on Functionalized PTFE Porous Membrane

LUO Yan-Hui

2009, 23 (05): 20-25 ; DOI: 10.19491/j.issn.1001-9278.2009.05.004

Abstract ( 2219 )

Functionalized polytetrafluoroethylene (PTFE) porous membranes possess the excellent performance of PTFE porous membranes and functional polymer, and have a great application potential in many fields such as catalysis, drug delivery, antibiotic, proton exchange and so on. This paper puts forward a summarization of the properties of PTFE porous membranes, as well as the latest research progress of functionalized PTFE porous membranes using different methods in application. Finally, the problems and challenges that still should be resolved and the research prospects are pointed out.

Study on the crystalline morphology of PET/PTT alloys

2009, 23 (05): 26-31 ; DOI: 10.19491/j.issn.1001-9278.2009.05.005

Abstract ( 1657 )

The crystalline morphology and the affecting factors of poly(ethylene terephthalate)(PET)/poly(trimethylene terephthalate)(PTT) were studied by thermal plataform polarized light microscope.The results showed that the induction period of PET/PTT alloy became longer with the ascent of the isothermal crystallization temperature, and the dimensions of each specimen spherulite growed larger with the extension of the time within the range of the time observed , and the line growth rate and the dimensions of the specimen spherulites increased with the increment of PTT content. When the morphology of isothermal crystallization spherulites at different temperatures was compared, it can be concluded that the dimensions of the PET/PTT(100/0) specimen spherulites were largest at 190℃, the dimensions of the PET/PTT(40/60) and PET/PTT(0/100)specimen spherulites were largest at 180℃.And the complicated ribbon sphrulites appeared when PET/PTT(0/100)specimen crystallized isothermally.

Study of Dynamic Rheological Properties of Bitumen Modified with EVA and EPDM

DING xuejia haijiao xue hongbo li bin tang

2009, 23 (05): 32-36 ; DOI: 10.19491/j.issn.1001-9278.2009.05.006

Abstract ( 1854 )

Modified bitumen were prepared using matrix method. The dynamic mechanical properties of Ah-70# asphalts modified with Ethylene-vinyl Acetate Copolymer (EVA) and Ethylene-propylene-diene Terpolymer (EPDM) was discussed. Dynamic mechanical shear test was implemented on several content of EVA and EPDM composite modified asphalt, and compared the dynamic rheological properties with the base bitumen. Results indicate that, EVA and EPDM improves the high temperature anti-rutting and low temperature anti-cracking performance. Additionally, through compared with the viscidity temperature curves of between the base bitumen and modified asphalt analyzed the flow activation energy. The results show that the bitumen modified with EVA and EPDM has little sensitivity to temperature, which was beneficial to the construction technology.

Study on the Relationship between Flame-retardant and the Overall Stabilization Effect of High Density Polyethylene Filled with Ammonium Polyphosphate

Jie YU

2009, 23 (05): 37-41 ; DOI: 10.19491/j.issn.1001-9278.2009.05.007

Abstract ( 1992 )

The flame retardant modification of High Density Polyethylene（HDPE）was made by filling with ammonium polyphosphate（APP）,prepared in different APP content of composite materials. The flame retardant effects of APP on the prepared composite were studied by means of limiting oxygen index (LOI) and horizontal-vertical burning .The test methods of thermogravimetric analysis (TGA) and the overall stabilization effect (OSE) were applied to measure the thermal stability, analysed the relation between thermal stability and flame retardant . The results indicated that the measure of OSE can commendably measure the overall thermal stability of composite. And the addition of suitable content of APP not only improved the flame retardant of the composite, but also advanced the thermal stability. Enhancing the overall thermal stability of HDPE fire-retardant composite can improve its flame retardant.

Effect of Grafting Agent: ALMA on Preparation of PBA/P(MMA-ITA) Core-Shell Particles and its Application to Toughness of Nylon 6

2009, 23 (05): 42-47; DOI: 10.19491/j.issn.1001-9278.2009.05.008

Abstract ( 1716 )

Abstract: Study the effect of grafting agent: allylmethacrylate(ALMA) on preparation of poly(butyl acrylate )/poly(methyl methacrylate - itaconicacid )(PBA/P(MMA-ITA)) core-shell particles and its application to toughness of nylon 6. The paper discusses effect of the amount of ALMA on average diameter of core-shell particle、gel content、mechanical properties and processing properties of toughened nylon 6. Experimental data indicated : grafting agent increase gel content, but no effect on average diameter. Introduce of suitable amount of ALMA enable impact strength and tensile strength of toughened nylon 6 reaching 20kJ/m2 and 35MPa respectively; melt viscosity、crystallinity degree and melting point all is decreased. Observe the section morphology of toughened nylon 6 by scanning electron microscope(SEM), showed that the toughening mechanism conformed to cavitation theory.

Toughing Effect of EPDM-g-MAN on Polyvinylchloride Resin

ZHU Yong-ping

2009, 23 (05): 48-52 ; DOI: 10.19491/j.issn.1001-9278.2009.05.009

Abstract ( 1937 )

EPDM-g-MAN, synthesized by suspension grafting copolymerization of methyl methacrylate and acrylonitrile onto EPDM, was blended with polyvinylchloride(PVC) resin. The mechanical properties、thermal stability、phase structure and toughening mechanism of the PVC/EPDM-g-MAN blends were studied by TG、SEM and TEM. The results show that: comparing with chlorinated polyethylene(CPE), EPDM-g-MAN had a better toughening effect on PVC resin. TEM and SEM analysis of the blends shows that PVC/EPDM-g-MAN were were partially compatible .When the EPDM content was low, the toughening mechanism of the blends was branch and termination of crack, and then changed into shear yielding and cavition as EPDM-g-MAN increasing.TG and DTG analysis shows that the thermal stability of PVC was improved after being blended with EPDM-g-MAN.

The Kinetic Study on Thermal Degradation of Novel Intumescent Flame Retardant Polypropylene

2009, 23 (05): 53-60; DOI: 10.19491/j.issn.1001-9278.2009.05.010

Abstract ( 1904 )

Thermal stability and thermal degradation kinetics of polypropylene(PP) and flame retardant polypropylene (IFR/PP) were investigated by a conventional dynamic thermogravimetric analysis(TG) under highly purity N2 atmosphere at different heating rates between 15 and 35 ℃/min-1and the flame retardant of PPand IFR/PP were studied by limiting oxygen index (LOI) and Cone method. The thermal degradation activation energyof PP and IFR/PP were determined by using Kissinger and Flynn-Wall-Ozawa method. The thermal degradation kinetic mechanism and the isothermal kinetic equations of PP and IFR/PP were determined by Coast-Redfern method. The flame retardant of PP by the addition of IFR was improved, and thermal stability of IFR/PP was lower than that of PP because the IFR degradated in advance, The thermal decomposition mechanism of PP and IFR/PP was random nucleation reaction and the kinetic equation can be expressed as g(α)=-ln(1-α), and the reaction order was n=1.

Study on the curing kinetics of unsaturated polyester resin and complex initiation system by DSC

LIU Chun-lin ZHANG Lan-fen Guo-liang TAO GONG fang-hong

2009, 23 (05): 61-65 ; DOI: 10.19491/j.issn.1001-9278.2009.05.011

Abstract ( 2044 )

Several curing kinetic models for unsaturated polyester resin were introduced in this paper. The isothermal curing kinetics of unsaturated polyester resin with complex initiation system was studied by Differential Scanning Calorimetry(DSC). The modified autocatalytic kinetic model was chosen to deal with the isothermal cure DSC data under isothermal condition, then the reaction rate constant k0 and reaction order m, n were required by nonlinear regression with least-squares method, and the curing kinetic equation of this system was obtained. The results showed that the dependent coefficients under different temperatures were above 98%, and matched experiment data reasonably. It suggested that the chosen model be right for the system, and provided the theoretical and practical reference for studies of compounds based on unsaturated polyesters.

Influence of atmospheric pressure plasma jet on properties of poly(vinyl alcohol) film

2009, 23 (05): 66-69; DOI: 10.19491/j.issn.1001-9278.2009.05.012

Abstract ( 1890 )

Poly(vinyl alcohol) (PVA) films with moisture content（1.85%MC and 41.33%MC） were exposed to atmospheric pressure plasma jet（APPJ）. The surface morphology changes of the films were observed with SEM. Chemical changes and crystalline structures were analyzed with FTIR, XPS and XRD. The results showed that the existence of water significantly increased the etching and oxidation effect during He/O2 plasma treatment. The etching rate could reach 0.68μm/min and oxygen content increased from 30.8% to 34.8%. Meanwhile, the degree of crystallinity was enhanced by 48%.

The research on robust design of injection moulding based on relation degree and Kriging model

HUANG Feng-Li

2009, 23 (05): 70-75 ; DOI: 10.19491/j.issn.1001-9278.2009.05.013

Abstract ( 1385 )

As the parameters of injection moulding is an optimum problem of multi influencing factors and strong nonlinear, the study on optimum design of injection moulding is developed early. It wasn’t considered that random factors influence the molding quality in existing study. Aiming at this problem, the maximum warpage quantity is selected as a measurement of molding quality, and the method of robust design is provided based on relation degree and Kriging model. Under the quality limit of injection moulding, it can adjust the sigma level in the process of robust optimum automatically. The result of optimum design shows the improved sigma level in maximum warpage. And the dimension tolerance of plastic product is improved by this method, according to CAE and actual injection moulding.

The Effect of Injection Molding Process Parameters of Warpage about PP Produce and Causation

2009, 23 (05): 76-79; DOI: 10.19491/j.issn.1001-9278.2009.05.014

Abstract ( 2299 )

The process parameters such as melt temperature, mould temperature, inject and holding pressure and rate of injection, etc.on the warpage of the PP produce was analysed by orthogonal experiment. The process parameters can influence the crystallinity and explain the causation of warpage.

Study on Sliding Friction and Wear of Ulter-high Molecular Weight Polyethylene

Wang Xin-Wei

2009, 23 (05): 80-85; DOI: 10.19491/j.issn.1001-9278.2009.05.015

Abstract ( 2030 )

Based on the test of plastic sliding friction and wear，the sliding friction and wear process was researched between Ulter-high molecular weight polyethylene and sand paper. The aim was to provide the method to evaluate the anti-wear properties of UHMWPE flat and pipe materials. In this paper, along with various friction distances, the wear value and wear width of UHMWPE changed in evidence, and the worn surfaces of UHMWPE took distinct tribological characters. The strong heat was produced in the friction process, and oxidation happened. The friction and wear process were analyzed via the various mechanisms involving abrasive wear, adhesive wear and fatigue wear.

The Study of Synergism Between Metallic Compounds and IFR System

2009, 23 (05): 86-90 ; DOI: 10.19491/j.issn.1001-9278.2009.05.016

Abstract ( 1848 )

This paper studied the synergism effect between IFR and metallic compounds.The flame retardancy, thermal stability and the char layer were analyzed by LOI, DSC-TG and SEM.The synergism effect mechanism of metallic compounds was discussed.The LOI results show that, when the composition contained 3%ZEO, 1% ZnO and 3% Al2O3, LOI of 29.6, 29.0 and 29.4 were achieved. It was higher 4.6, 4.0 and 4.4 than IFR separately.The DSC-TG and SEM results indicate that ZEO, ZnO and Al2O3 can help the PE-HD/IFR to accelerate the formation of charring layer and strengthen it.But there is little contribution to the quality of the charring layer.

The Synergy of Boron Element in the Intumescent Flame Retardant PP

2009, 23 (05): 91-94 ; DOI: 10.19491/j.issn.1001-9278.2009.05.017

Abstract ( 1914 )

Abstract:The effect of boron in the intumescent flame retardant PP was studied by horizontal combustion test, thermal analysis and cone calorimeter. The thermal analysis showed that KDIFR made the PP’s char residual increase and heat release reduce, but the introduction of boron made the char residual decrease and heat release increase slightly. Cone calorimeter graphs indicated the KDIFR significantly reduced the heat release rate, total heat release, and CO2, CO emissions in the combustion process of PP, which was promoted by boron, but was weakened as the combustion process continued. In a word, experiments results showed that KDIFR changed the PP’s typical polyolefin type combustion to fiber type combustion, which was promoted by boron, and slowed down the flame propagation, and had more prominent flame retardance.

Research on Making Use of Polymer Particles and Phosphogypsum to Manufacture Architectural Formwork

2009, 23 (05): 95-98; DOI: 10.19491/j.issn.1001-9278.2009.05.018

Abstract ( 1961 )

Abstract:Made use of polymer particles (PE,PS,PP) and phosphogypsum to blend,adopted the technology of hotpressing molding to manfacture architectural formwork.The density and water absorption,the heat expansion ration and cold shrink ration,the impact strength and the mumber of times of heating molding about the formwork were researched on the different formulation conditions.Result showed the density and solution rate of the formwork with the increase of fla ash dose enlarged.The heat expansion ration and cold shrink ration of the formwork with the increase of phosphogypsum dose minished. The impact strength of the formwork with the increase of phosphogypsum dose minished. When heating molding times less than five times,the impact strength of the formwork with the increase number of heating molding times enlarged. Then,the impact strength diminish when heating molding times were greater than five times. The diminish tendency of impact strength became mild.

Determination of overall migration from plastic microwave articles by use of olive oil as fatty food stimulant

2009, 23 (05): 99-103 ; DOI: 10.19491/j.issn.1001-9278.2009.05.019

Abstract ( 1698 )

In this paper, olive oil was used as fatty food stimulant to determine overall migration from plastic articles under condition of microwave heating or high temperature. In the study, the overall migration from plastic microwave articles was also determined using n-hexane as fatty food stimulant, which was the standard method of China currently in effect. The experiment results indicated that there were only 20% of the plastic articles up to grate by use of olive oil as fatty food stimulant, and there were 100% of plastic articles up to grate when use of n-hexane as fatty food stimulant. Survey says in this study, using standard method of china to evaluate the safety of plastic microwave containers have definite defect.

Test Bias and Reason Analysis of Plastic Tensile-elasticity Modulus Test of Different Laboratories in China#br#

Liu Shansheng

2009, 23 (05): 104-109; DOI: 10.19491/j.issn.1001-9278.2009.05.020

Abstract ( 1878 )

Energy-saving and no-welding-line plastic injection mould and its process

Wu Xiao-yu

2009, 23 (05): 110-112 ; DOI: 10.19491/j.issn.1001-9278.2009.05.022

Abstract ( 2657 )

The paper presented a energy-saving mould structure for no-welding-line injection moulding which not only has a conformal medium trough in the near location from the cavity surface of the fixed mold but also heat isolation layers in the near location from the trough. It can heat and cool the cavity surface uniformly, lower the heat exchange volume, and only need heating the fixed mold and cooling the moving mold to avoid switch of heat and cold media and reduce a lot of energy waste.