Current Issue

2012, Volume 26 Issue 02 Publication date: 26 February 2012 Previous Issue Next Issue

Research Progress in Preparation of Biodegradable Polymer Porous Scaffolds

2012, 26 (02): 1-6 ; DOI: 10.19491/j.issn.1001-9278.2012.02.001

Abstract ( 1549 )

The key issue in the tissue engineering is to apply biodegradable polymers to produce three dimensional scaffolds with certain shapes，highly interconnected structure, and excellent mechanical properties. The fabrication methods and hotspots of scaffolds in recent years were reviewed in this paper. The future prospect of the porous scaffolds based on biodegradable polymer was also discussed.

Research Process in Recycled PET Used for Food Packaging Materials

ZHOU Lili CHEN Huiming YU Wenlian SONG Naining ZHANG Jing

2012, 26 (02): 7-12 ; DOI: 10.19491/j.issn.1001-9278.2012.02.002

Abstract ( 1453 )

The recycling method, determination methods, and development trend of poly(ethylene terephthalate) (PET) in both domestic and international were introduced. The recycling methods could be categorized as physical and chemical ones. The determination methods included gas chromatography, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. It was urgent to establish the determination standards for recycled plastic food packaging materials and its relevant regulations.

Flame Retardancy Methods for Polymer Materials

LIU Ji-Chun

2012, 26 (02): 13-19 ; DOI: 10.19491/j.issn.1001-9278.2012.02.003

Abstract ( 1769 )

The research progress in flame retardant polymer materials at home and abroad in recent years was reviewed. The flame retardant methods, such as adding flame retardants, chemical reaction, surface modification, alloying, nano-compounding, and synergizing, were introduced. The characteristics of the various methods were analyzed. The developing trend of flame retardant methods for polymer materials was envisioned.

Morphology and Thermal Property of SAtype Transparent Polyamide

陈金周 CHEN Jin-Zhou

2012, 26 (02): 20-22 ; DOI: 10.19491/j.issn.1001-9278.2012.02.004

Abstract ( 1448 )

A serial of SAtype transparent polyamide(SATPA) with different melt flow rate were developed by postsolidstatepolycondensation (PSSP). The morphology and thermal property of sythesized SATPA were studied. The SATPA by PSSP was amorphous. The glass transition temperature(Tg) increased from 102 ℃ to 120 ℃, indicating its better resistance to heat. Further more, the higher the glass transition temperature, the lower the melt flow. The starting decomposition temperature of all SATPA by PSSP was above 440 ℃.It had good thermal stability.

Effect of Amino Ester Elastomer on Crystallization Behavior of PLA

HUANG Jin JIA Qingqing WU Wenqian XIANG Aimin

2012, 26 (02): 23-27 ; DOI: 10.19491/j.issn.1001-9278.2012.02.005

Abstract ( 1463 )

The cold crystallization properties of the blends of poly(lactic acid) (PLA) and amino-ester elastomer were studied. It was found that the amino-ester elastomer promoted the crystallization of PLA. The crystallization rate and crytallinity of the blends decreased with increasing content of amino-ester elastomer and also with increasing heating rate.

Study on Crystallization Kinetics of Poly(butylene succinate)

XIA Xinshu CHEN Qinghua XU Jing XIAO Liren LIU Xinping HUANG Baoquan QIAN Qingrong

2012, 26 (02): 28-32 ; DOI: 10.19491/j.issn.1001-9278.2012.02.006

Abstract ( 1449 )

Fractions of poly(butylene succinate) (PBS) were obtained via precipitation from a solution in chloroform. Isothermal and non-isothermal crystallization kinetics, crystal structure, and morphology of the PBS fractions were investigated using wide angle X-ray diffraction, differential scanning caborimetry, and polarized optical microscopy. It was found that with increasing molecular weight of the fractions and molecular weight distribution, the half crystallization time, and half width of crystallization peak decreased, whereas the degree of crystallinity increased. However, the crystal structure and morphology of various PBS fractions had no evident change.

Study on Mechanical Properties of Injection Molded Short Carbon Fiber Reinforced Polyethylene Composites

XU Xianfeng HU Yanyan AO Xuedong

2012, 26 (02): 33-36 ; DOI: 10.19491/j.issn.1001-9278.2012.02.007

Abstract ( 1548 )

Adding carbon fiber in PE by injection molding,the samples were prepared in this paper. The tensile strength,hardness,elastic modulus have been studied. The results show that with the incresement of carbon fiber content,the tensile strength,hardness,elastic modulus of composites is improved. When the carbon content is lower than 3.3% ,the hardness, elastic modulus and strength increases linearly; when carbon fiber content is higher than 3.3% ,they increase significantly.

Prepolymers of Amino-terminal Non-isocyanate Block Copolymerized with Polyether-based Polyurethane

2012, 26 (02): 37-40 ; DOI: 10.19491/j.issn.1001-9278.2012.02.008

Abstract ( 1346 )

Modified polyether polyurethane and its film was prepared by prepolymer of amino-terminal non-isocyanate polyurethane and prepolymer of polyether-based polyurethane with method of block copolymer. Synthesis condition of non-isocyanate prepolymer was analyzed; The impact of film-forming temperature and value of NCO and NH2 ratio on mechanical properties of membrane were investigated; Mechanical properties of different polyurethane materials were compared; Degree of phase separation was studied using differential scanning calorimetry(DSC). Results showed that carbamate group was successfully synthesized in the amino-terminal non-isocyanate prepolymer; the best film-forming temperature was 140 ℃; When NCO/NH2 of prepolymer was 1/0.9, it obtained the best performance, tensile strength was 25.1 MPa, elongation 100% modulus was 5MPa; Compared with ordinary polyurethane, polyurethane block with amino-terminal non-isocyanate polyurethane prepolymer had higher mechanical properties; DSC curve showed two different glass transition temperatures, phase separation was significant.

Preparation and Thermal Characterization of Modified Poly(vinyl formal)/Sillica Composite Foamed Plastics

JIANG Yu

2012, 26 (02): 41-45 ; DOI: 10.19491/j.issn.1001-9278.2012.02.009

Abstract ( 1354 )

Poly(vinyl formal) (PVF) was modified with hydrolyzed tetraethoxysilane (TEOS) via a solgel process. The effects of TEOS content on the physical and mechanical properties of PVF foam were studied using fourier transform infrared spectrometer(FTIR) and thermogravimetric analysis(TG). When TEOS content was 15 % based on PVA, the foam showed an initial decomposition temperature of 322.5 ℃, which was 94 ℃ higher than that of virgin PVF.

Study on Morphology and Properties of PP/CaCO₃/PP -g- AA Composites

2012, 26 (02): 46-49 ; DOI: 10.19491/j.issn.1001-9278.2012.02.010

Abstract ( 1404 )

PP-g-AA was prepared via melt grafting using a two screw extruder equipped with a liquid feeding, which was used as compstibilizer in PP/CaCO3 system. The resulted system was studied using FTIR, DSC, and SEM. When content of CaCO3 was 10 % and content of PP -g- AA(grafting ratio 2.204 %) was 10 %, a set of optimal mechanical properties was obtained.

Study on Intumescent Flame Retarded Polyethylene

2012, 26 (02): 50-54; DOI: 10.19491/j.issn.1001-9278.2012.02.011

Abstract ( 714 )

Expandable graphite (EG) and traditional intumescent flame retardant (IFR) were introduced into polyethylene (PE). The flame retardant properties of the system was studied using differential scanning calorimetery (DSC), Fourier transform infrared spectroscopy (FTIR) and testing of limited oxygen index. A strong synergistic effect between EG and IFR was observed. As a result, a limited oxygen index value of 31.5 % was achieved by adding 30 phr EG/IFR in PE, which was much higher than that of PE/EG or PE/IFR. The physical interaction between EG and IFR during thermal degradation was proved by their individual degradation behavior and char structure of the composite. The char formed by thermal degradation of EG and IFR was integrated to form an efficient barrier to oxygen and heat, which were in favor of the flame retardant properties.

Controlling Porosity of PES Porous Microspheres Prepared via Electrospraying

Lihua WANG Quanchao ZHANG Xiaojun WANG Shengru LONG Jie YANG

2012, 26 (02): 55-58 ; DOI: 10.19491/j.issn.1001-9278.2012.02.012

Abstract ( 1423 )

The focus of this work is to effectively control the porosity of microspheres prepared via electrospraying, which would establish the foundation for the following application. Scanning electron microscopy (SEM) and thermogravimetry (TG) were employed to evaluate the morphology and the porosity of microspheres, respectively. According to the investigation result, adding hydrophilic polymer polyethylene glycol (PEG) and polyving akohol (PVA) to electrosprayed solution could effectively control the porosity of microspheres. Specifically: adding hydrophilic polymer could improve porosity; and that, with increasing hydrophilic polymer, the porosity of porous microspheres first increased and then decreased; the control effect of PVA for the porosity of microspheres was better than that of PEG, when the addition of PVA was 3 %, the porosity of microspheres was the highest value of 91.35 %.

Study on Formula and Technology of High Transparent and Low Temperature Resistant CPP Packaging Films

SHI Fengyan

2012, 26 (02): 59-62 ; DOI: 10.19491/j.issn.1001-9278.2012.02.013

Abstract ( 1366 )

Cast polypropylene (CPP) film was prepared via three laminar casting, the influences of toughener and nucleating agent on transparency, haze, and low temperature falling dart impact quality of CPP film were studied. When adding to 10 phr POE and 1.5 phr nucleating agent in core layer，keeping the melt temperature at 255~265 ℃, chilled roll temperature at 24 ℃, the CPP film acquired a good low temperature resistant，a high transparency, and a low haze.

Design of Injection Mould for Telephone Based on CAD/CAE/CAM

ZHOU Huilan KUANG Tangqing TANG Xuehui

2012, 26 (02): 63-67; DOI: 10.19491/j.issn.1001-9278.2012.02.014

Abstract ( 1610 )

Applications of Pro/E in the injection mould design, Moldflow in the injection molding analysis, and UG in mould forming parts were introduced. Using the design of telephone as a model, the technology of injection mould design and analysis with CAD/CAE/CAM was elaborated in details, and then tool path simulation of telephone cavity could be gained in UG. By means of CAD/CAE/CAM tool, injection mould design cycle could be induced and quality could be increased greatly.

Investigation on Fluid-solid Coupling Deformation in In-Mold Assembly Molded Micro Polymeric Parts

Guofa ZHOU Zhixun XU Cen LIU

2012, 26 (02): 68-73 ; DOI: 10.19491/j.issn.1001-9278.2012.02.015

Abstract ( 1235 )

The influence of the second stage polymer melt rheological parameters on the fluid-solid coupling interaction and fluid-solid coupling deformation of the first stage polymer micro-component were systemically studied using finite element numerical simulation, and the mechanisms were finally revealed by theoretical analysis. Research results showed that the fluid-solid coupling interaction between second stage melt filling flow and first stage polymer solid micro-component became enhanced with increasing melt zero-shear viscosity of second stage，which in turn increased the micro-shaft of fluid-solid coupling pressure and uniformed the temperature field. Therefore, the bending stress and deformation of first stage micro-shaft depended on fluid-solid coupling pressure increases, but the thermal stress and deformation depended on temperature field uniformity reduces.

Effect of Blending Processes and Mica Content on Properties of PP/Mica Composites

DONG Jinhu

2012, 26 (02): 74-77 ; DOI: 10.19491/j.issn.1001-9278.2012.02.016

Abstract ( 1495 )

Polypropylene (PP)/mica composites were prepared using melt blending and double-phase blending, separately. Effects of content of mica and blending method on mechanical properties and thermal properties of the composites were studied. The microstructure of the composites was analyzed by SEM. It showed that the interface adhesion of mica and PP matrix and the properties of the composites prepared by double-phase blending were better than those by melt blending. When the content of mica was 15 %, the composites prepared by double-phase blending displayed optimal comprehensive properties.

Effect of Antioxidant on Thermal Oxidative Stability of PMMA and Its Kinetic Analysis

2012, 26 (02): 78-72; DOI: 10.19491/j.issn.1001-9278.2012.02.017

Abstract ( 1340 )

The behavior of several antioxidant in poly(methyl methacrylate)(PMMA) was studied using thermo gravimetric analyzer（TG）and the kinetics of thermal degradation was analyzed with Kissinger, Flynn-Wall-Ozawa, and Flynn methods. It showed that four kinds of antioxidant, 1010, 1076, 702, and BHT increased the initial thermal degradation temperature by 70 °C at a content of 0.5 wt ‰. Further increasing the loading the change was moderate. The kinetics analysis showed that the antioxidant could only improve the thermal oxidative stability at the initial period of degradation（the weight loss less than 30 %）, after which the stabilizing effect of antioxidant on PMMA were reduced due to the antioxidant escaped from the system at a higher temperature than the melting point of antioxidant.

Research Progress in Structure Design and Synthesis of Dialkylphosphinic Salts Flame Retardants

Jia CHEN

2012, 26 (02): 83-87 ; DOI: 10.19491/j.issn.1001-9278.2012.02.018

Abstract ( 1407 )

This review summarized various dialkylphosphinic salts with different structure and discussed the latest advancement in preparing dialkylphosphinic salts. According to the alkyl structure in molecule, dialkylphosphinic salts could be classified into unbranched-, branched-, aryl-, cycloalkyl-, heterocyclic- phosphinic salts, and dimmer of dialkylphosphinic salts. The preparation of the salts could be carried out with AlCl3 catalytic method, Grignard reagent, or free radical addition. The AlCl3 catalytic method had disadvantages of low yield and environmental pollution. The reaction using Grignard reagent was complex, which was impractical for large-scale manufacturing. Free radical addition method was relatively simple and suitable for industrial production.

Study on PE-HD/Waste Rubber Powder Blends

ZHANG Ning

2012, 26 (02): 88-92 ; DOI: 10.19491/j.issn.1001-9278.2012.02.019

Abstract ( 1464 )

Molecular structure of waste rubber powder was modified via desulfurization, free radical polymerization, curing cross-linking, and grafting reaction in order to improve the compatibility with high density polyethylene (PE-HD). The effect of the modification of waste rubber powder on the blends was investigated. When untreated waste rubber powder was used, the tensile strength and elongation at break of the blends decreased with increasing rubber loading. However, with adding 60 % of treated waste rubber powder, 2 % of PTC-R, 1.2 % of DCP, 1 % of sulfur, and 1 % of promoting agent, the tensile strength and elongation at break of the blends reached 25 MPa and 250 %, increased by 350 % and 201 %, respectively, compared with those based on untreated waste rubber powder. Sulfur was effectively stripped down by catalytic regeneration of rubber reducer PTC-R. The tensile strength and elongation at break were developed significantly because of synergistic effect between DCP and sulfur.

Optimal Research on Force Increasing Mechanism of Injection Machine Based on Genetic Simulated Annealing Algorithms

2012, 26 (02): 93-98 ; DOI: 10.19491/j.issn.1001-9278.2012.02.020

Abstract ( 1229 )

The analysis of motion and mechanical property was carried out on a force increasing mechanism of injection machine which was five hinged incline arranged and double elbowed. A complete optimization design procedure was carried out using genetic simulated annealing algorithms, so as to increase the stroke ratio and the amplification of the force, and to decrease the total length of mechanism. Its optional mathematics model was established. The procedure of optimal design belongs to multiobject optimization problem. The optimal solution of the force increasing mechanism was found with genetic simulated annealing algorithms. Compared with the traditional methods, the stroke ratio was increased by 5.97 %, the amplification of the force increased by 14.10 %, and the total length of mechanism decreased by 5.25 %.

Effect of Screw Assembly on Glass Fiber Length and Mechanical Property of Glass Fiber-Reinforced Nylon-66 Composite

Jiang Zhao-Yin

2012, 26 (02): 98-103 ; DOI: 10.19491/j.issn.1001-9278.2012.02.021

Abstract ( 1926 )

The fiber brakeage in compounding glass fiber-reinforced nylon-66 with different screw assemblies of the co-rotating twin screw extruder was studied, and the change rule of the fiber length in the extruding direction was analyzed by sampling along the screw axis. The effect of different screw assemblies on mechanical properties of the composite was also studied, and the optimal screw assembly was designed. The result shows that the proper screw assembly could improve the residual fiber length and the mechanical property of the composite effectively.