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2014, Volume 28 Issue 07 Publication date: 26 July 2014 Previous Issue Next Issue

Germany’s New Industrial Revolution and Its Influence and Enlightenment to China

2014, 28 (07): 1-5 ; DOI: 10.19491/j.issn.1001-9278.2014.07.001

Abstract ( 523 )

This paper introduced the basic concept of Germany industrie 4.0 launched at the end of 2013. What impacts the industrie 4.0 would impart on the global and domestic economy and what enlightenments our plastics industry may draw from it were discussed.

Application and Progress of Green Plasticizers

2014, 28 (07): 6-10 ; DOI: 10.19491/j.issn.1001-9278.2014.07.002

Abstract ( 709 )

This paper summarizes the progress and the latest application of green plasticizers. Preparation methods, physical and chemical properties, thermodynamic and mechanical properties of the green plasticizers were introduced. The application of the citric acid ester, vegetable oil based and epoxy ester, polyester, and novel non phthalate plasticizers were reviewed. Their future application was also forecast.

Study Progress in Failure Analysis and Lifetime Prediction of Plastic Pipes

2014, 28 (07): 11-16 ; DOI: 10.19491/j.issn.1001-9278.2014.07.003

Abstract ( 541 )

Two kinds of common failure modes of plastic pipes, slow crack growth (SCG) and rapid crack propagation (RCP), were reviewed. The failure mechanisms and lifetime prediction methods of plastic pipes, such as the linear elastic fracture mechanics, the standard extrapolation method, the elastic plastic fracture mechanics and the craze mechanics theory, were elaborated. The limitations of those methods were analyzed. At present, the theory of lifetime prediction of plastic pipes is not mature and the methods are not perfect. Further study is needed in this field.

Preparation of Poly(butyl acrylategraftedmethyl methacrylate)/Montmorillonite Composite and Its Toughening on PVC

2014, 28 (07): 17-21 ; DOI: 10.19491/j.issn.1001-9278.2014.07.004

Abstract ( 413 )

MMT modified poly(butyl acrylate) grafted poly(methyl methacrylate) coreshell structured copolymer modifier (P(BA-g-MMA)) was prepared by seeded emulsion polymerization as a reinforcer for PVC resin. The effect of MMT on mechanical properties of the system was investigated. The intercalation and dispersion effect of montmorillonite were observed by X-ray diffraction and scanning electron microscopy. Xray diffraction analysis indicated that polymerization of monomers occurred between the interlayer of MMT, which resulted in the increasing of interlayer space from 1.25 to 1.5 nm. When the ratio of coreshell in P(BA-g-MMA) was 85∶15 and the loading of P(BA-g-MMA) in PVC was 9 phr, the impact strength of PVC/P(BA-g-MMA) blend reached 1106 J/m, providing a typical ductile fracture.

Effect of Curing Accelerator Type on Curing Behavior of IC Packaging Materials

2014, 28 (07): 22-26 ; DOI: 10.19491/j.issn.1001-9278.2014.07.005

Abstract ( 382 )

Epoxy molding compounds for integrated circuits (IC) packaging were prepared by using phenolic resin as a curing agent, either 2-methyl imidazole or triphenyl phosphine as a curing accelerator. The curing behavior of the compounds was investigated by non-isothermal DSC method. Based on Kissinger, Crane, and Ozawa methods, the kinetic parameters such as activation energy and reaction order of the curing reaction were obtained. The characteristic temperatures of the curing process such as gel temperature, curing temperature, and postcuring temperature were calculated by extrapolation. It was found that the compound using 2-methyl imidazole had a lower activation energy compared with that using triphenyl phosphine.

Preparation and Flame Retardancy of Polyurethane Thermoplastic Elastomers with Mica and Aluminum Trihydrate (ATH)

2014, 28 (07): 27-30 ; DOI: 10.19491/j.issn.1001-9278.2014.07.006

Abstract ( 585 )

Two types of aluminum trihydrate (ATH), with or without surface treatment, and mica were incorporated into TPU composites. The flame retardancy of these composites was subjected to vertical burning (UL 94) and oxygen index test. When the loading of ATH was between 70 and 80 phr, the composites showed a good flame retardacy with those containing surface treated ATH being better. The inclusion of mica did not affect the flame retardancy of the composites. However, it may improve the processability of the composites.

Properties of Ramie Fiber-reinforced PE-HD Composites

2014, 28 (07): 31-37 ; DOI: 10.19491/j.issn.1001-9278.2014.07.007

Abstract ( 439 )

The high density polyethylene（HDPE）/ramie fiber composites were prepared by twin-screw extruder and injection molding, and the ramie fiber content to the effect of composite material performance was researched. The interfacial bonding between the ramie fiber and HDPE was enhanced by introducing compatilizer and increasing the ramie fiber. On the TGA showed that the composites can be applied to the environment with temperature between 0-100℃，while the DSC showed that introducing ramie fiber decreased the crystallinity of HDPE. The thermostability of the composites was improved by increasing the ramie fiber.

Non-isothermal Decomposition Behavior of PE-LD and PE-LD-g-HEA in Air

2014, 28 (07): 38-43 ; DOI: 10.19491/j.issn.1001-9278.2014.07.008

Abstract ( 374 )

Low density polyethylene (PE-LD) was grafted with 2-hydroxyethyl acrylate (HEA) forming a copolymer (PE-LD-g-HEA) by solidphase method. The structure of the PE-LD and PE-LD-g-HEA during aging treatment at different temperatures in air was studied using Xray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR), and the thermal decomposition kinetics was studied by thermogravimetry. Because PE-LD-g-HEA had more long chain branches than PE-LD, its crystallinity was less influenced by aging treatment, the main chain was less scissored, and the thermal stability was better than PELD. The apparent activation energy, preexponential factor, and reaction order were determined by Kissinger and Crane methods were 8863 kJ/mol, 1.17×106 s-1 and 0.88 for PE-LD, and 217.35 kJ/mol, 5.92×1015 s-1 and 0.95 for PE-LD-g-HEA, respectively. The value of the apparent activation energy determined by Ozawa method was close to that by Kissinger method.

Properties of Flame Retardant and Smoke Suppression Polylactic Acid/Bamboo Flour Composites

2014, 28 (07): 44-48 ; DOI: 10.19491/j.issn.1001-9278.2014.07.009

Abstract ( 465 )

Aluminum hydroxide (ATH) and/or ammonium polyphosphate (APP) was introduced into polylactic acid/bamboo flour (PLA/BF) composites to render it flame retarding and smoke inhibiting properties. Microscopic structure of the composites, tensile fracture surface, and combustion char layer the were observed by SEM. Mechanical properties, thermal stability, and combustion the performance were tested. ATH and/or APP decreased the mechanical properties of the composites but increased thermal properties. For systems containing ATH, APP, and ATH+APP, the char percentage on 600 ℃ achieved 20.3 %, 27.9 %, and 26.3 %, respectively. ATH provided a significant smoke inhibiting effect on the composite, but exhibited a larger heat release than APP. When both APP and ATH were introduced, the composites gave rise to both good heat inhibitory and smoke suppression.

Preparation and Properties of PPMF/TiO2 Nano-composites

2014, 28 (07): 49-54 ; DOI: 10.19491/j.issn.1001-9278.2014.07.010

Abstract ( 430 )

N-phenyl maleimide modified phenolic resin/nano-TiO2(PPMF/TiO2) composites were prepared，and the effects of nanoTiO2 on curing reaction and properties of PPMF/TiO2 were studied. Structure，micro-morphology, and properties of PPMF/TiO2 nanocomposites were characterized by FTIR，TG，and SEM,respectively. It was found that the nanoTiO2 can be attached to surface of phenolic via condensation of surface hydroxyl groups, on the condensates to resin by chemical bond，the nano-TiO2 may also play a catalytic role in the curing process. When the content of nano-TiO2 was 5 %，it could be uniformly dispersed in the resin matrix, and the mechanical properties were optimal. Adding dicumyl peroxide (DCP) in the curing system could effectively increase the degree of crosslinking of PPMF. Thermal resistance PPMF/TiO2 composites was better than that of conventional phenolic and neat PPMF resins.

Process and Properties of Reinforced Composites by Basalt Fiber Unidirectional Fabric

2014, 28 (07): 55-59 ; DOI: 10.19491/j.issn.1001-9278.2014.07.011

Abstract ( 386 )

Mechanical properties of unidirectional basalt fabric reinforced boronphenolic resin composites were studied using an orthogonal experiment, with the cooling way, molding pressure, content of fiber, and molding temperature as the influencing factors. It was found that the influence of molding temperature on the composites was the greatest, that of the content of reinforcing fibers the second. Increasing the molding pressure was helpful for the improvement of the bending performance of the composites, and had little effect on the tensile properties. Extending cooling time had a positive effect on the mechanical properties.

Modification of Unplasticized PVC with Three Kinds of Modifiers

2014, 28 (07): 60-64 ; DOI: 10.19491/j.issn.1001-9278.2014.07.012

Abstract ( 434 )

In this paper, PNBR, Elvaloy741, and MBS were introduced into unplasticized PVC. The effect of contents of the modifiers on transmittance, haze, mechanical property, lowtemperature performance, hardness, and micromorphology were studied. It showed that the transparency of PVC/MBS and PVC/Elvaloy741 were fine. With the addition of the modifiers, the tensile strength of the blends decreased, the elongation at break increased, the lowtemperature performance improved, and the hardness were changed a little. The fracture of the sample showed a clear ductile behavior.

Numerical Simulation of the Influence of Melt Extrusion Velocity on the Parison Die Swell of Coextrusion-blow-molded Parisons

2014, 28 (07): 65-71 ; DOI: 10.19491/j.issn.1001-9278.2014.07.013

Abstract ( 420 )

Based on the finite element numerical simulation technology of threedimensional nonisothermal viscoelastic melt multiphase stratified flow, the influence of melt extrusion velocity on the die swell of multilayer coextrusionblowmolded parisons and initial temperature distribution were studied. The mechanism of the parison die swell was revealed by theoretical analysis. It showed that the die swell during the multilayer coextrusion blow molding was induced by the secondary flow of the melt, which was proportional to the secondary flow strength in which polymer melt flowed from head into free swell segment. The secondary flow strength increased with increasing melt extrusion velocity, therefore the parison die swell increased with increasing melt extrusion velocity. It was also found that secondary flow strength was proportional to the second normal stress difference. The result of numerical simulation was fully consistent with B. Debbaut’s experimental conclusion which showed that the secondary flow was driven by second normal stress difference.

Controlling of Compressive Strength of XPS

2014, 28 (07): 72-76 ; DOI: 10.19491/j.issn.1001-9278.2014.07.014

Abstract ( 416 )

This article carried out a research for production control of compressive strength of XPS foam board. A multiregression equation was built for the analysis. Through test and verification, it was confirmed that the multiregression equation had a good prediction of compressive strength. With this multiregression equation as a predictive model, and with help of functions of Excel VBA programming software, a compression strength prediction system was established, which could provide process parameters for the practical production.

Optimization of Warping Uniformity in Airconditioner Blades Through a Hybrid of Back Propagation Neural Network and Genetic Algorithm

2014, 28 (07): 77-81 ; DOI: 10.19491/j.issn.1001-9278.2014.07.015

Abstract ( 332 )

A method combining back propagation neural network (BP neural network) and genetic algorithm was proposed in this paper in order to improve the warping uniformity of air-conditioner blades. Mold temperature, melt temperature, injection time, packing time, and packing pressure were taken as design variables and Z axis maximum difference in the blade tip was as optimization goal. After that, CAE simulation was conducted based on Taguchi method. A BP neural network model was developed to obtain the mathematical relationship between the optimization goal and design variables, and genetic algorithm was applied to optimize the process parameters. Consequently, the optimal process parameters were obtained as: mold temperature 45 ℃，melt temperature 205 ℃，injection time 1.8 s，packing time 6 s，packing pressure 50 MPa. Finally，the CAE simulation was simulated under the optimized parameters. As a result, the target variable was 0.08 mm, lower than the experimental scheme, and the blade warping uniformity was improved.

Development of Slowlyburning Masterbatch for ABS Resin

2014, 28 (07): 82-85 ; DOI: 10.19491/j.issn.1001-9278.2014.07.016

Abstract ( 351 )

The influence of dispersants, flame retardants，and carriers on the burning rate of ABS masterbatch was studied. It was found that the dispersant accelerated the combustion, the burning rate of ABS could be decreased by flame retardant and CPE carrier. A slowly-burning grade of ABS masterbatch was developed by optimizing the formulation design. When being applied to ABS products, UL 94 HB standards and a uniform surface color were achieved. The retention rate of impact strength and tensile strength were above 90 %.

Application of LDHs Compound Thermal Stabilizers in Rigid PVC

2014, 28 (07): 86-90 ; DOI: 10.19491/j.issn.1001-9278.2014.07.017

Abstract ( 345 )

In this paper, an LDHs-Ca/Zn-organic tin compound thermal stabilizer was used to modify rigid PVC plastics. Rheological behavior and thermal stability of the modified PVC were studied by dynamic rolling aging, static hot oven aging, Congo red test, chromatic aberration test, thermogravimetric analysis(TG), and torque rheometer. It suggested that LDHs could act as an auxiliary thermal stabilizer in PVC, and had synergistic effect with Ca/Zn-organic tin compound system. SEM and aging experiments showed that 05 wt% LDHs may render dispersive ability and thermal stability.

Research on Mechanical Properties of Airless Plastic Tires with Wheel Spokes Under Static Load

2014, 28 (07): 91-95 ; DOI: 10.19491/j.issn.1001-9278.2014.07.018

Abstract ( 337 )

This paper proposed a new kind of airless plastic tires in which a polyurethane spoke was combined with a rubber tread. By using finite element software ABAQUS under static load conditions the grounding performance and mechanical performance of such airless plastic tires were analyzed and compared. Compared with radial rubber tires, the airless plastic tire was more reasonable, grounding pressure distribution along the lateral tread was more uniform, which reduced the wear at the tire shoulder. Radial stiffness of airless plastic tires was significantly higher, and the deformation of support plates in the grounding area played an important role in buffering and bearing, which made the drive more comfortable.

Experimental Investigation of the Effects of Water Parameters on Water Penetration During Overflow Waterassisted Injection Molding Process

2014, 28 (07): 96-99 ; DOI: 10.19491/j.issn.1001-9278.2014.07.019

Abstract ( 407 )

Experiments of water assisted injection molding (WAIM) were carried out on a labdeveloped system to investigate the influences of parameters such as water pressure, water temperature, and water injection delay time on overflow WAIM process. It showed that the higher the water-injection pressure, the thinner the residual wall thickness and the more smooth and bright the inner surface. Water eccentric penetration occurs under low waterinjection pressure. Increasing water-injection pressure led to a less eccentric water penetration. Water temperature had less influence on the residual wall thickness. Increasing waterinjection delay time increased the residual wall thickness and reduces the water eccentric penetration under low water-injection pressure effectively.

Design of mold and flow balance of mouse multi-cavity of different workpiece on CAE

2014, 28 (07): 100-104 ; DOI: 10.19491/j.issn.1001-9278.2014.07.020

Abstract ( 268 )

A multicavity gating system of mouse covers with three lids and two lateral lids was designed. Filling analysis was carried out with the help of CAE Moldflow software. In order to obtain flow balance, the flow channel cross-sectional dimension was optimized. The location of gate was adjusted according to the channel cross-sectional dimension, and the flow balance was basically realized.