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2011, Volume 25 Issue 12 Publication date: 26 December 2011 Previous Issue Next Issue

Technical Development Trends of Lead-free Thermal Stabilizer for Plastics

Jie LI Fang LIU Fei XIA

2011, 25 (12): 1-6 ; DOI: 10.19491/j.issn.1001-9278.2011.12.001

Abstract ( 1678 )

The domestic and foreign thermal stabilizer industry and market were introduced. The problems in the production and application of lead-free thermal stabilizer for polyvinyl chloride (PVC) were analyzed and discussed. The calcium, zinc, and organic tin based thermal stabilizers were considered as non- or low toxic ones, which would lead the development trend of future plastic thermal stabilizer industry.

Research Progress in Novel Polyolefin Foaming Materials

Jiahui WU Liting YANG Keming SONG Shaoquan LIN

2011, 25 (12): 7-11 ; DOI: 10.19491/j.issn.1001-9278.2011.12.002

Abstract ( 1821 )

The current research works in five types of polyolefin foams was reviewed, including cross-linked, copolymerization-modified, wood-polyolefin composites, flame retardant, and additive enhanced foam materials. It was suggested that the future formulations and processing research works should be carried out in the crossover region of above five types.

Research and Preparation of Nonel Tubes

Linmei WU Qiang HUANG Yanfang WANG

2011, 25 (12): 12-16 ; DOI: 10.19491/j.issn.1001-9278.2011.12.004

Abstract ( 1495 )

The classification, ignition principles, of nonel tube as well as its foreign and domestic production and application were introduced. Two domestic PE-LD-based nonel tubes, trademark 1I2A and 18D0, were compared. Although the general properties (MFR and Density) of the two nonel tubes were similar, the gunpowder adhesion of 1I2A was better. This was attributed to the difference in the thermal stability and crystallization behavior of the materials.

Properties of Epoxy Resin/Aluminum Methylcyclohexyl Phosphinate Flame Retardant Composites

Xueqing LIU Jiyan LIU Shan SUN Jia CHEN Shaojun CAI

2011, 25 (12): 17-20 ; DOI: 10.19491/j.issn.1001-9278.2011.12.005

Abstract ( 1531 )

In this study, a novel aluminum salt of methylcyclohexylphosphinate (AMHP) was used as a flame retardant filler in EP. The flame retardant, thermal, mechanical properties, and morphology of EP/AMHP composites were investigated. It was found that the EP/AMHP composite with only 15 % AMHP achieved the optimal flame retardancy (LOI value of 28.8 and UL-94 V-0 rating). In addition, a char yield of 16.34% at 700℃ of EP/AMHP was observed. However, the addition of AMHP slightly decreased the impact and flexible properties.

Structure and Properties of MMA-BA Free Radical Copolymer

Tong LUO Zhidong WANG Ruoyu XU Fanghong GONG

2011, 25 (12): 26-30 ; DOI: 10.19491/j.issn.1001-9278.2011.12.007

Abstract ( 1780 )

In this paper, random copolymer of methyl methacrylate and butyl acrylate was prepared via bulk polymerization. The influences of concentration of initiator, monomer ratio on the mechanical, optical, and other properties were investigated. The structure and properties of copolymers were characterized using 1H-NMR, DMA, and SEM. With the increasing content of butyl acrylate, the loss modulus decreased. When the content of butyl acrylate was 25 %, the impact strength increased by 43 %, while light transmission remained at 92 %.

Toughening of PA 6 with MAH Functionalized Acrylate-styrene-acrylonitrile Copolymer

DENG Yun-Jiao LIU Zhen-Guo LIU SUN Shu-Lin SUN YANG Hai-Dong YANG Huixuan ZHANG

2011, 25 (12): 31-34 ; DOI: 10.19491/j.issn.1001-9278.2011.12.008

Abstract ( 1665 )

Maleic anhydride (MAH) functionalized acrylate-styrene-acrylonitrile (ASA) copolymers （ASA-g-MAH）was prepared via an emulsion polymerization process, and was used to toughen nylon-6. Molau tests showed that some reactions between PA6 and ASA-g-MAH had taken place. The effect of MAH content on mechanical properties of PA6/ASA-g-MAH blends was studied. The mechanical properties of PA6/ASA-g-MAH blends increased with increasing MAH content. When MAH content was 4%, notched impact strength of the blend reached 1008 J/m. Compared with the PA6/ASA blend, the PA6/ASA-g-MAH blends had higher tensile strength and elongation at break. Scanning electron microscopy (SEM) showed ASA particles dispersed in the PA6 matrix uniformly when MAH content was 4%. The cavitation of rubber particles and shear yielding of the PA6 matrix were the major toughening mechanisms.

Study on Cross-linking Behavior and Crystallization Behavior of Dicumyl Peroxide Crosslinked High-density Polyethylene

2011, 25 (12): 35-38 ; DOI: 10.19491/j.issn.1001-9278.2011.12.009

Abstract ( 1437 )

In this paper, the effect of dicumyl peroxide (DCP) content on crosslinking behavior of high density polyethylene (PE-HD) was investigated. The gel fraction of PE-HD increased with increasing DCP content and reached 73.9% with a DCP content of 3.0 %, a temperature of 170 ℃, and a reaction time of 30min. The effect of DCP content on crystallization behavior of PE-HD was studied using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). It showed that with increasing DCP content, the melting point and crystallization temperature decreased, the crystallinity degree and grain size decreased, however, the crystal structure was not affected.

Influence of Talc on Morphology and Properties of PP

Tiantian GUO Xuejia DING Yu ZHAGN Kebin ZHOU

2011, 25 (12): 39-42; DOI: 10.19491/j.issn.1001-9278.2011.12.010

Abstract ( 1702 )

Polypropylene (PP) /talc composites were prepared via melt extrusion. The effects of surface modification with silane and the addition of ethylene-octene copolymer (POE) on the mechanical, rheological properties, and microstructure morphology of composites were investigated. It showed that the talc surface modification significantly improved the impact strength of PP. while PP/talc mass ratio was 100/10 and 100/30, the notched impact strength of PP/talc composites increased by 37.8% and 36.4%, respectively, by the silane modification. However, the surface modification of talc decreased the storage modulus. POE promoted the dispersion of talc in PP matrix. The impact strength of the composites increased with increasing POE content.

Rheological Behavior of PET/Nano-attapulgite Composites

Yonghong DING Xiaofeng XU Jingru LIU Qiang YU Chao YAO

2011, 25 (12): 43-46 ; DOI: 10.19491/j.issn.1001-9278.2011.12.011

Abstract ( 1415 )

Silane modified nano-attapulgite was melt blended with poly(ethylene terphtalate) (PET) forming composites, whose rheological, dynamic mechanical properties, and microstructure were investigated. It showed that the nano-attapulgite was finely dispersed in the PET matrix and reduced the viscosity and glass transition temperature of PET.

Curing Kinetics of Studying on Modified Bismaleimide and Cyanate Ester System with Different Epoxy Resins by Non-isothermal Method

Guanglei WU Kaichang KOU Min CHAO Longhai ZHUO Yang JIANG

2011, 25 (12): 47-50 ; DOI: 10.19491/j.issn.1001-9278.2011.12.012

Abstract ( 1545 )

The cure kinetics of epoxy resin (AG-80 and TDE-85) modified bismaleimide/cyanate (BMI/CE) system was investigated at different heating rate, using non-isothermal differential scanning calorimetry (DSC). The curing kinetics parameters of the system were obtained by Kissinger, Ozawa equation, and Crane's theory. For epoxy resin (AG-80) modified system, the average activation energy was 81.55kJ/mol, and the reaction order was 0.93. For epoxy resin (TDE-85) modified system, the average activation energy was 69.25kJ/mol, the reaction order was 0.92.Compared to epoxy resin (AG-80) modified system, the results indicated that the addition of epoxy resin (TDE-85) could lower the activation energy of the modified system and the curing reaction could occur at a relative low temperature.

Preparation of Vinyl Nano-silica and Its Effect on Melt Strength of Polypropylene

2011, 25 (12): 51-54 ; DOI: 10.19491/j.issn.1001-9278.2011.12.013

Abstract ( 1377 )

Vinyl groups were introduced on the surface of nano-silica through surface modification by the vinyl coupling agent. Then the vinyl modified nano-silica was mixed with polypropylene (PP) by the melt mixing method. The effect of different nano-silica on the melt strength of PP was studied. The reactions in the experiment were characterized by FT-IR, TG, Haake mixer, ARES, and melt strength tester. The research result demonstrated that the melt strength of PP was enhanced by addition of vinyl modified nano-silica in PP using the melt mixing method, compared with pure PP or the PPfilled with nano-sillica,the melt strength of PP increased gradually with the increaseing of vinyl nano-silica content.

Application of BP Neural Network on PP/POE-g-MAH/PP Toughening PA6

Kun CHEN Tihe ZHENG Kedong SONG Xiangru TIAN Yu ZHANG

2011, 25 (12): 55-58 ; DOI: 10.19491/j.issn.1001-9278.2011.12.015

Abstract ( 1463 )

The research of POE-g-MAH/PP toughening PA6 was conducted by BP neural network and homogeneous design in this paper. On this basis，a 3-layer BP neural network prediction model for composite between impact strength and the composition was established. The prediction by the model agreed well with the experiments. The impact strength of the toughening nylon6 reached 92.12kJ/m2 when the content of POE-g-MAH was 14.00% and PP content was 9.00%.

Research on Shrinkage of Modification Ploypropylene

Xiaoan LOU Jiying SU Chengming MENG Hao DUAN

2011, 25 (12): 59-62 ; DOI: 10.19491/j.issn.1001-9278.2011.12.017

Abstract ( 1527 )

The influence of inorganic fillers, POE, PE-LLD, and nucleating agent on the shrinkage of polypropylene was studied. When glass fiber, POE, PE-LLD of 30wt% was incorporated separately, the shrinkage of polypropylene reduce from its devoid value of 1.6 7% to 0.34 %, 1.16 %, and 1.39 %, respectively. Other thermoplastic plastics and nucleating agent may also cause the decrease of the shrinkage.

Effect of PEG on Properties of Poly( lactic acid)/Glutinous Rice Flour Blends

Jianmei LIU Rongrong QI Yu LUO Jiaqi LU Xinli HU

2011, 25 (12): 63-66 ; DOI: 10.19491/j.issn.1001-9278.2011.12.018

Abstract ( 1456 )

Blends of poly(L-lactide)(PLA), glutinous rice flour, and polyethylene glycol (PEG) were prepared and studied. Glutinous rice powder increased the water absorption of PLA, but reducing its mechanical properties. The impact strength of the composite first increased then decreased as the amount of PEG increased, and showed a maximum of 22.8 kJ/m2 when PEG amount was 12 %, which was 4 times that of neat PLA. With increasing PEG content, the compatibility between glutinous rice flour and PLA increased.

Preparation and Properties of LSR Heat-insulation Composites Filled with Hollow Glass Beads

2011, 25 (12): 67-70 ; DOI: 10.19491/j.issn.1001-9278.2011.12.019

Abstract ( 1377 )

Liquid silicon rubber acetate (LSR) filled with hollow glass beads was studied as a heat-insulation composite. The effect of hollow glass beads on the thermal conductivity and tensile strength was investigated. It indicated that as the content of hollow glass beads increased, the thermal conductivity of the composites first increased then declined. At the same loading of hollow glass beads, the thermal conductivity decreased with decreasing particle size. The composite filled with 15 phr of hollow glass beads (diameter of 40μm) gave rise to the minimum thermal conductivity of 0.0135 W/m·K. The tensile strength and elongation at break decreased with increasing loading of hollow glass beads and decreasing particle size of the hollow glass beads.

New Alternative Technologies for HCFCs of XPS Foam

Yong WANG Ying LI

2011, 25 (12): 71-75 ; DOI: 10.19491/j.issn.1001-9278.2011.12.020

Abstract ( 1651 )

New alternative technologies for HCFCs of extruded polystyrene foam (XPS) sector in China were reviewed, including with CO2, hydrocarbon and hydrofluorocarbon as blowing agents. The characteristics and difficulties of alternative technologies were discussed from properties of blowing agents, metering system for blowing agents, and extrusion foaming equipments. Finally, the CO2 technologies would be the developing trend of XPS foam sector in China.

Research on Synthesis of Charring Agent Containing Silicon and Its Application in Flame Retarded PP

Guojing LUO Yongbing YANG Wei ZHANG Jinchun LI Qiang CHEN

2011, 25 (12): 76-80 ; DOI: 10.19491/j.issn.1001-9278.2011.12.021

Abstract ( 1485 )

An organic silicon-containing charring agents (CA) was synthesized from cyanuryl chloride，3-Triethoxysilylpropylamine, and p-phenylenediamine, which was introduced into polypropylene (PP) together with ammonium polyphosphate (APP) as an intumescent flame retardant (IFR). The effect of APP/CA on flame retardancy, mechanical properties, and thermal stability of PP was investigated. It showed that APP/CA had excellent flame retardancy in PP. CA had a good function in char formation. The organic silicon group could accelerate charring performance of PP, made the structure of char layer continuous and compact. The addition of APP/CA improved the thermal stability of PP, effectively restrained the further burning of PP. When the weight ratio of APP/CA was 3/1, and the loading was 28% in PP, the LOI value of APP/CA /PP reached 32.5 and passed UL94V-0 grade.

Preparation and Application of Novel Maleic Anhydride Grafted Propylene-based Elastomer

Junjie TANG Hao DUAN Tao YANG Jianpeng GUO Chengming MENG

2011, 25 (12): 81-85 ; DOI: 10.19491/j.issn.1001-9278.2011.12.022

Abstract ( 1465 )

Maleic anhydride was grafted onto propylene-based elastomer via melt reaction in a twin-screw extruder. The influences of initiator, MAH concentration, crosslinking inhibitor, and processing condition on the structure and properties of product were analyzed using FTIR, neutralization titration. It indicated that with increasing initiator concentration the grafting degree increased first and then dropped. With increasing MAH concentration, the grafting degree increased first and then leveled off. The crosslinking during grafting was best inhibited by hexanolactam. The toughening effect of the product and traditional POE-g-MAH were compared in nylon, and it was found that the grafted product achieved both better tougheness and flowability of polyamide.

Research on Al₂O₃ Component Extracted from Fly Ash and Modify PP

DONG Jinhu

2011, 25 (12): 86-89 ; DOI: 10.19491/j.issn.1001-9278.2011.12.023

Abstract ( 1302 )

Al2O3 was extracted from fly ash via high-temperature alkali calcinations. The properties of PP containing such extracted Al2O3 were compared with commercial PP/Al2O3 resins. It showed that, the tensile and impact properties of PP/extracted Al2O3 were similar to commercial resins. When the content of the extracted Al2O3 increased to 2 %, the microstructure of PP matrix change from smooth structure to slight lamellar structure, and the tensile strength, elongation at break, and impact strength increased by 6 %, 23 %, and 14 %, respectively, based on neat PP. However, when the content of extracted Al2O3 increased to 5%, the impact strength of PP decreased dramatically.

Investigation of Extensional Flow Mixer for Single-screw Extruder Based on Extensional Disagglomeration

Xiang LIN Dongyun REN Kuisheng WANG

2011, 25 (12): 90-94 ; DOI: 10.19491/j.issn.1001-9278.2011.12.024

Abstract ( 1330 )

The deformation of polymers in processing contains shear and extensional components. It is identified that the dispersive mixing is strongly depended on shear stress or extensional stress and distributive mixing is mainly depended on the number of interfaces. Multiple-phase polymers can achieve a better mixing through extensional stress based on extensional disagglomeration. In this paper, a new mixing element prototype for single-screw extruder was developed and its dispersive and distributive mixing capacities and probability functions for stress and deformation rate in single screw processing was analyzed by Polyflow. The flowing trajectories obtained suggested that more and more particles were subjected to greater shear and extensional rates with increasing of time. Meanwhile, a long resistance time, no vortex flow and no stagnation of material in the processing showed a good shear and extensional mixing capacities of the new mixing element. Moreover, it was clear that the extensional mixing property was superior to that of shear mixing at low deformation rates from probability functions.

Design and Numerical Simulation of Series Disc Extruder Based on Elongational Flow

Tianlei LIU Yaoxue DU Shaoqing CHEN

2011, 25 (12): 95-100 ; DOI: 10.19491/j.issn.1001-9278.2011.12.025

Abstract ( 1455 )

Based on elongation flow mechanism, structure improvement was carried out on the disc face of traditional series disc extruder. Numerical simulation was carried out on the disc mixing section using CFD software POLYFLOW, and comparative study was performed between taper-face disc and flat-face disc on the shearing rate, stretching rate, instantaneous stretching efficiency and time-averaged instantaneous stretching efficiency, and the effect that disc clearance and disc ledge have on the elongational flow of the taper-face disc. The simulations showed that melt particles in taper-face disc runner took an irrotational flow, experience larger actions governed by elongational flows and shear flows, and get better instantaneous and time-averaged efficiency of stretching compared with traditional disc. Moreover, there existed a proper distance between discs and disc ledge for getting stronger elongational flow.