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2014, Volume 28 Issue 02 Publication date: 26 February 2014 Previous Issue Next Issue

Research progress for High Densitye Polyethylene Pipe Resin

2014, 28 (02): 1-5; DOI: 10.19491/j.issn.1001-9278.2014.02.001

Abstract ( 1471 )

Research Progress in Flame Retardation and Smoke Suppression of Poly(vinyl chloride) Modified by Aluminium Hydroxide

2014, 28 (02): 6-11; DOI: 10.19491/j.issn.1001-9278.2014.02.002

Abstract ( 1422 )

The research progress in flame retardancy and smoke suppression of poly(vinyl chloride) (PVC)using aluminum hydroxide and its complex system in recent years was reviewed in this paper. Several types of cooperative flame retardant agents and smoke suppression agents were discussed. In addition, some inorganic radiationresistant and antibacterial modifiers were introduced.

Research Progress in Polystyrene Interpenetrating Polymer Networks

Bengang Liu Yan Liu

2014, 28 (02): 12-14; DOI: 10.19491/j.issn.1001-9278.2014.02.003

Abstract ( 1456 )

Research progress in the preparation and properties of polystyrene interpenetrating polymer network was introduced. Details on preparation technologies of polystyrene interpenetrating polymer networks such as sequential interpenetrating polymernet works,simultaneous interpenetrating polymer networks,semiinterpenetrating polymer networks,and latex interpenetrating polymer networks were introduced.Effect of component and preparation method of interpenetrating polymer networks on morphology and compatibility of interpenetrating polymer networks was introduced.Effect of component and structure on the mechanical properties, thermodynamic property，rheological properties，gas permeation rate，and adsorption properties was summarized.In the last,problems and trends of polystyrene interpenetrating polymer network were sketched out.

Morphology and properties of biodegradable thermoplastic starch/poly(butylene adipate-co-terephthalate) composites

2014, 28 (02): 25-30; DOI: 10.19491/j.issn.1001-9278.2014.02.004

Abstract ( 1163 )

A series of fully biodegradable composites were prepared by melt blending thermoplastic starch(TPS) and poly(butylene adipate-co-terephthalate) (PBAT) using a twin screw extruder．The microstructure and fracture behavior of the composites were studied with scanning electron microscopy(SEM) before and after drawing, the properties of the composites with different compositions were tested．The results indicated that the skin-core structure formed after injection, TPS was inclined to disperse in the core and then distributed from core to skin with increasing content of TPS. It was obviously that the continuous fiber morphology from core to skin can improve the mechanical properties of composites, the addition of TPS also can change the stress-strain behavior of composites, of which took a transition from semicrystalline polymer stress-strain behavior to typical yield cold-drawing behavior.

reparation and Properties of Epoxy/Silver Plating Graphite Nanosheet Thermally Conductive Composites

2014, 28 (02): 31-34; DOI: 10.19491/j.issn.1001-9278.2014.02.005

Abstract ( 1410 )

Silver coated graphite nanosheet (AgNanoG) was prepared by treating expanded graphite with the method of ultrasonic dispersion and chemical plating, and then it was filled into epoxy(EP) matrix to obtain EP/AgNanoG composites. It showed that the nanosheet was plated with a uniform and compact layer of silver particles, about 100 nm in thickness. The mechanical and thermal conductivity properties of EP/AgNanoG composites were improved. When the mass fraction of AgNanoG was 3%, the thermal conductivity of EP/AgNanoG composites was 1.827 W·(m·K)-1, which increased almost 5 times based on neat epoxy.

Preparation of High Melt Strength Polypropylene by Reactive Extrusion

2014, 28 (02): 35-40 ; DOI: 10.19491/j.issn.1001-9278.2014.02.006

Abstract ( 1263 )

Polypropylene(PP) was melt grafted with 1,6hexanediol diacrylate (HDDA) and styrene in order to increase the melt strength. β nucleating agent was added to the reaction system to change the crystalline of PP. The influences of screw speed, dosage of initiator, molar ratio of monomers, and material mass on melt flow rate and melt strength were studied. The structure and properties of modified PP were analyzed using infrared spectroscopy, thermalgravimetric analysis, and Xray diffraction. The melt flow rate and melt strength of grafted PP were 0.70 g/10 min and 10.00 kPa·s, respectively. The heat stability was also improved through the grafting.

Properties of Rigid Polyurethane Foam with Environmentally Friendly Blowing Agent

2014, 28 (02): 45-49; DOI: 10.19491/j.issn.1001-9278.2014.02.008

Abstract ( 1000 )

Rigid polyurethane foam was prepared using a third generation blowing agent HFC365mfc. The factors influencing the properties of the foam including isocyanate index, dosage, and foaming dynamics were studied. When the isocyanate index was about 1.2, blowing agent dosage was 25 phr, the foam provided the optimal comprehensive properties, which were better than those with HCFC141b and water. The foaming technology using HFC365mfc and HCFC141b was similar, and the blowing agent HFC365mfc could be easily applied.

Study on Red Phosphorus Intumescent Flameretarded Polyoxymethylene

2014, 28 (02): 50-54; DOI: 10.19491/j.issn.1001-9278.2014.02.009

Abstract ( 1025 )

The effects of an intumescent flame retardant (IFR) on flame retardant, melt flow rate, and mechanical propeties of POM were studied. When the weight ratios of POM/red phosphorus/PURT/MCA were 65/20/10/5, the material was selfextinguished, leaving a compact layer of carbon layer, with least reduction of mechanical properties and processability. When a compatibilizer KT3 was introduced, the mechanical properties were further improved.

Study on Properties of Nanometer Polyimide/Carbon Black Composites

2014, 28 (02): 55-58; DOI: 10.19491/j.issn.1001-9278.2014.02.007

Abstract ( 1005 )

The polyimide/nanometer carbon black composites were prepared by in situ polymerization. The influence of the volume fraction of nanometer carbon black on the degree of imidization and mechanical and tribological properties of the composites were studied using fourier transform infrared spectrometer, universal testing machine, and friction and wear tester. It was found that a moderate amount of the addition of nanometer carbon black could improve the tribological properties and mechanical properties. When the content of nanometer carbon black was 28%, the material gave excellent tribological properties, the surface of the composite was very smooth.

Preparation and Properties of Polyurethane Gas Sealing Material

2014, 28 (02): 57-61 ; DOI: 10.19491/j.issn.1001-9278.2014.02.010

Abstract ( 1219 )

Effect of trichloroethyl phosphate (TCEP) on the microstructure, flame retardancy, expansion ratio, and compression strength of polyurethane sealing materials was studied. Maximum limited oxygen index of polyurethane sealing materials increased from 20.0 % to 23.4 % when the TCEP content increased from 0 to 20 %, The expansion ratio of polyurethane sealing materials decreased at first and then increased with the content of TCEP increasing. Main structure of polyurethane sealing materials with flame retardant is not changed，but flame retardant has effect on the properties and morphology of the foam.

Nonisothermal Crystallization Kinetics of PPR with Amide βnucleating Agents

2014, 28 (02): 59-63 ; DOI: 10.19491/j.issn.1001-9278.2014.02.011

Abstract ( 1292 )

The nonisothermal crystallization behavior of ethylenepropylene random copolymer(PPR) with and without β nucleating agents was studied. The addition of β nucleating agents increased the peak crystallization temperature of PPR. At the same cooling rate，the t1/2 and Zc of β nucleating agent modified PPR was more and less than of those of weat PPR. Meanwhile the required cooling rate of pristine PPR was smaller than that of PPR containing β nucleating agents to get the same crystallinity，which shows that the addition of β nucleating agents can decrease the crystallization rate of PPR. Mo method can describe nonisothermal crystallization behavior of PPR and β nucleating agent modified PPR very well.

Effect of Different Electrodes on Electric Field and Fibers in Melt Electrospinning

Haoyi LI Yumei DING

2014, 28 (02): 64-68 ; DOI: 10.19491/j.issn.1001-9278.2014.02.012

Abstract ( 1283 )

For melt electrospinning, the effect of electric field distribution, voltage, and electrodes on the fibers was studied by finite element simulation and experiment. The shape of the electrodes and plate hollow, determined the distribution of electric field in the spinning chamber.Both electric fields were concentrated to the spinning region to stretch melt jet and the maximum field strength occurred at the edge of nozzle. The hollow electrode may provide more stable and persistent electric field than the plate electrode with gasassisted. The voltage was also a major factor impacting electric field and fiber diameter.

Internal Mixing Behavior of Polymer/SnZn Alloy Composites

张国艳 ZHANG Guo-Yan LIU Tao LIU YI Yong YI TAN Xiu-Lan TAN LUO Jiang-Shan LUO HE Jiang-Ping HE

2014, 28 (02): 69-75; DOI: 10.19491/j.issn.1001-9278.2014.02.013

Abstract ( 1442 )

The alloy separation during the preparation of polymer/SnZn alloy was studied. The effects of composition and content of SnZn alloy, the internal mixing process parameters, as well as polymer matrix on the amount of alloy separation were investigated. When the alloy loading was low, no alloy separation occurred. When the content of SnZn alloy was high, the separation increased with increasing SnZn alloy. The separation could be inhibited by a higher proportion of Zn in the alloy. Elevating mixing temperature may also suppress the alloy separation. With increasing mixing speed, the alloy separation increased, however, the size of alloy particles was reduced. The optimal mixing time of the alloy (Zn 30 wt%) and PEHD was 35 min. Higher polarity of the polymer could restrain the alloy separation.

Effects of Posttreatment on Mechanical Properties of Transparent Semiaromatic Polyamide

2014, 28 (02): 76-78; DOI: 10.19491/j.issn.1001-9278.2014.02.014

Abstract ( 1132 )

Semiaromatic transparent polyamides with different melt flow rate were synthesized by solid state polycondensation. The effect of water absorption and post treatment on the mechanical properties was studied. It showed that SATPAs water absorption was low, and independent on the molecular weight. The temperature of water and humidity of environment had effects on the water absorption. The higher the temperature of water and the higher air humidity, the faster the SATPA absorbed water. After dipping in the water for 24h, the dimension of the sample didnt change basically. After being treated in water at room and high temperatures, the mechanical properties increase dlittle, on the contrary, elongation at break reduced obviously; after annealing treatment, tensile strength，elongation at break，and notched impact strength all increased.

Preparation and Characterization of Ploy(lactic acid)/Cinnamic Aldehyde Composite Nanofiber Membrane

Li Lin-Jian Jun-Bo Liu Shan-Shan Tang Hai-Bo Chang Da-Dong Liang

2014, 28 (02): 79-85; DOI: 10.19491/j.issn.1001-9278.2014.02.016

Abstract ( 1008 )

A cinnamic aldehyde/βcyclodextrin complex was prepared by saturated aqueous solution method, then the complex was added to a PLA aqueous solution. The obtained solution was electrospun to a PLA/cinnamic aldehyde composite membrane. The effects of weight ratio of acetone to N,NDimethyl formamide (DMF)，PLA concentration, applied voltage, distance of needle to collector on the diameter of the nanofiber and morphology of membrane were investigated by scanning electron microscope (SEM). The functional groups of the composite membrane were analyzed via fourier transform infrared spectrum (FTIR). The thermodynamic, mechanical, and antibacterial properties of the composite membrane were studied. The result showed that the average diameter of nanofiber in the composite membrane was 175 nm, thermal decomposition temperature was 265.52 ℃, the tensile strength was 245 MPa. FTIR showed that the interaction between cinnamic aldehyde and PLA was physical in nature. The composite membrane possessed an antibacterial ability to Escherichia coli, Staphylococcus aureus and Bacillus subtilis.

Application of Oil Based Multifunctional CaZn Composites Thermal Stabilizer for Poly (vinyl chloride)

Jianchun Jiang

2014, 28 (02): 86-90 ; DOI: 10.19491/j.issn.1001-9278.2014.02.017

Abstract ( 1294 )

Calcium and zinc salts of polymerized fatty acid were prepared from natural unsaturated oil, leading to a multifunctional CaZn composite thermal stabilizer (OMFCTS). Its structure was examined by inductively coupled plasmaatomic emission spectrometry and FTIR. OMFCTS was introduced into PVC together with an antioxidants and βdiketone. The thermal stability and mechanical properties of the PVC compound were determined. The mechanical property and thermal stability of the system PVC/DOP/OMFCTS=100/30/3 were comparable to the system PVC/DOP/commercial CaZn stabilizer=100/40/3. OMFCTS rendered PVC products better thermal stability as it simultaneously provided an extra plasticizing effect.

Study on preparation of blending of PHBH/PBAT and its performance

Yunxuan Weng

2014, 28 (02): 91-95 ; DOI: 10.19491/j.issn.1001-9278.2014.02.018

Abstract ( 1320 )

An epoxy resin was introduced into PLA/PBAT blends as a compatibilizer by melt blending using a twin screw extruder. The effect of the compatihilizer on thermal performance, mechanical properties, and microstructure of PLA/PBAT blends were investigated. It showed that the interface bonding force in the blends was enhanced by the compatibilizer, and the comprehensive mechanical properties of the blend were increased greatly. An inclusion of 14 phr compatibilizer increased the impact strength and elongation at break from 268 kJ/m2 to 621 kJ/m2 and 222 % to 357 %, respectively.

Numerical Simulation of Effect of Water Injection Parameters on Waterassisted Injection Molding Filling Process

2014, 28 (02): 96-100 ; DOI: 10.19491/j.issn.1001-9278.2014.02.019

Abstract ( 930 )

In order to investigate waterassisted injection molding process numerically, a twodimension, transient, kω turbulence flow model was formulated. Volume of Fluid (VOF) method was used to trace the moving interfaces. The influence of water injection speed, water temperature, and water injection delay time on water penetration was studied by numerical simulation using powerlaw viscosity for the melt. The simulation showed that increasing water injection speed increased the water penetration length and reduced the residual wall thickness. Water temperature had little influence on the water penetration length and residual wall thickness. Increasing waterinjection delay time increased both water penetration length and residual wall thickness.

Elimination of Radial Force in Gear Pump for High Viscosities

2014, 28 (02): 101-105 ; DOI: 10.19491/j.issn.1001-9278.2014.02.020

Abstract ( 927 )

A new type of gear pump for high viscous liquids was designed by introducing the principle of harmonic gear drive into gear pump. The structure and mechanism of radial force balance in the new gear pump were analyzed. It showed that the radial force for the new pump was balanced because the force would not increase with increasing pump pressure. Two higher pressure chambers could discharge flow two times in a period of one revolution, which increased the pumping efficiency and stability in pressure.

Injection Mould Design for Highgloss and Nonweld Line Front Cabinet of TV Based on Moldflow

Hong Jian-Ming

2014, 28 (02): 106-110; DOI: 10.19491/j.issn.1001-9278.2014.02.021

Abstract ( 1179 )

With the front cabinet of LCD TV as an example, the design of runner system, temperature control system, and complex corepulling mechanism were discussed, to complete the overall design of a highgloss and nonweld line injection mold. The mold design was also simulated using Moldflow software, the working situation of complex runner and temperature control systems was verified in variation of moldtemperature.