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2014, Volume 28 Issue 04 Publication date: 15 April 2014 Previous Issue Next Issue

China Plastics Industry(2013)

2014, 28 (04): 1-6 ; DOI: 10.19491/j.issn.1001-9278.2014.04.001

Abstract ( 619 )

General situation of China plastics industry in 2013 was reviewed, including the output and export/import of plastics products, synthetic resins, and plastics processing machinery, as well as major economic data, such as the total industrial values, sales and profits of plastics products, etc. Analysis of the market of plastics products in 2013 was made, and the developing trend of China plastics industry in 2014 was proposed.

Progress in Modification of Nanoparticles by Atom Transfer Radical Polymerization

2014, 28 (04): 7-13 ; DOI: 10.19491/j.issn.1001-9278.2014.04.002

Abstract ( 617 )

The application of atom transfer radical polymerization(ATRP) on the modification of nanoparticles was reviewed. Several catalysis systems were used in different ATRP techniques including reverse atom transfer radical polymerization(RATRP) and activators generated by electron transfer for ATRP(AGETATRP). An outlook of initiating ATRP on surface of nanoparticles was also presented.

An Overview of Evaluation Testing Methods on Degradation of Polyolefins

2014, 28 (04): 14-22 ; DOI: 10.19491/j.issn.1001-9278.2014.04.003

Abstract ( 548 )

Based on the aging behavior and characterization methods, various evaluation methods for degradation of polyolefins were summarized. Standards related to testing methods on degradation of polyolefin were introduced and compared. A methodology system of aging evaluation was proposed, and the future trend of degradation evaluation of polyolefins was forecasted.

Conductivity and Mechanism of pToluene Sulfonic Acid Doped Polyaniline

2014, 28 (04): 23-27 ; DOI: 10.19491/j.issn.1001-9278.2014.04.004

Abstract ( 856 )

Polyaniline was doped with ptoluene sulfonic acid(TSA) using a method of redoping.The effect of doping time and concentration of ptoluene sulfonic acid aqueous solution on the conductivity and structure of polyaniline was studied.A fourprobe technique and FTIR were employed to explore the doping mechanism.The thermal stability of doped polyaniline was studied by TG.When the doping time was 12 h and the TSA concentration was 0.5 mol/L,the best conductivity was observed.

Preparation and Performance of Weatherresistant Polyoxymethylene Compounds

2014, 28 (04): 28-33 ; DOI: 10.19491/j.issn.1001-9278.2014.04.005

Abstract ( 529 )

The weatherresistant polyoxymethylene(POM)compounds were prepared through meltcompounding of dimethylsiloxane,UV absorbers,UV stabilizers,UV shielding agents,antioxidants,and formaldehyde absorber.The retention of mechanical properties of the POM compounds was investigated the light ageing,thermooxidative aging,and hydrothermal aging.The thermal stability of the weatherresistant POM compounds was evaluated by thermogravimetric analysis before and after aging experiments,and the crystalline structures of POM and the additive distribution in matrix were also investigated by polar optical microscopy.The addition of weatherresistant additives significantly increased the retention of mechanical properties of POM.The aging of POM mainly occurred in the amorphous region,and POM was particularly sensitive to light,heat,and oxygen,but less effect to the hot water.Weatherresistant additives were mainly distributed in the amorphous region,and meanwhile,they performed the weatherresistant effect on POM.These weatherresistant additives were also gradually expended during the aging process with the exposure of UV irradiation.

Study of Dynamic Rheological Behavior of ABS/Lignin Composites

2014, 28 (04): 34-38 ; DOI: 10.19491/j.issn.1001-9278.2014.04.006

Abstract ( 534 )

Lignin was purified from calcium lignosulfonate by using recovery treatment.FTIR showed that the peak at 622 cm-1 owing to SO disappeared after being purified.Composites of ABS/lignin were prepared via meltblending method.The dynamic rheological behavior of composites was investigated by rotational rheometer.It showed that the storage modulus G′ of the composites kept invariant in linear viscoelastic region.When strain was over critical value γc, “Payne effect” occurred and G′ decreased rapidly with increasing strain.The critical value γc decreased with increasing content of lignin.The composites presented a shear thinning behavior and the complex viscosity decreased with increasing shear rate.With increasing content of lignin,the complex viscosity increased and the intersection of G′ and G″ increased firstly and then dropped.

Preparation and Properties of PAAK/Waste Material Cultured Pleurotus Ostreatus Superabsorbent Resin

2014, 28 (04): 39-45 ; DOI: 10.19491/j.issn.1001-9278.2014.04.007

Abstract ( 560 )

A superabsorbent copolymer of potassium polyacrylate/cultured pleurotus ostreatus was synthesized with microwave radiation heating. The influence of initiator, crosslinker,neutralization degree of AA, and the microwave power on the performance of superabsorbent resin was investigated. The maximum water absorbency of the superabsorbent resin reached 827 g/g in distilled water and 87 g/g in 0.9 % NaCl solutionThe structure, thermal stability, morphology, and element distribution of the superabsorbent composites were analyzed by Fourier transform infrared spectroscopy, elemental analysis,thermogravimetric analysis, scanning electron microscopy,and energy spectrum analysis. In addition,the water-loss rate was only 5.2 % by centrifugation at a rotatation speed of 6000 r/min in 50 min.

Effect of PEUHMW on Mechanical Properties and Nonisothermal Crystallization of Polyoxymethylene

2014, 28 (04): 46-51 ; DOI: 10.19491/j.issn.1001-9278.2014.04.008

Abstract ( 586 )

Blends of polyoxymethylene(POM)/ultrahigh molecular weight polyethylene(PE-UHMW) were prepared. The structure and performance of the blends were analyzed by mechanical property testing, DSC and SEM. When the content of PEUHMW was 1 wt %, the notched impact strength of the blends was 1.24 folds that of neat POM. Two methods, namely, Avrami and Mo, were used to analyze the nonisothermal crystallization kinetics of POM and POM/PE-UHMW(100/1)blends. The activation energy was evaluated by the Kissinger method. The crystallization rate and crystallization activation energy of POM decreased with adding 1 wt % PEUHMW, while the crystallinity increased.

Influence of Citric Acid on Properties of Color Changing Cast PVA Films

2014, 28 (04): 52-55 ; DOI: 10.19491/j.issn.1001-9278.2014.04.009

Abstract ( 971 )

Colorchanging film was prepared using PVA as a master liquor,and citric acid as a crosslinking agent,the mechanical and optical properties and thermal stability were studied.With increasing citric acid,the tensile strength of the film increased but elongation at break decreased,the mist degree increased.Citric acid content also had a greater impact on the color of film and color change.The addition of citric acid increased the thermal decomposition temperature of the film.

Heat Stabilization of N-(Substituted Phenyl)-N′-Cyanoacetylureas on PVC—Progressive Change Law of Performance and Mechanism

2014, 28 (04): 56-61 ; DOI: 10.19491/j.issn.1001-9278.2014.04.010

Abstract ( 494 )

The heat stabilization of several N-(substituted phenyl)-N′-cyanoacetylureas on PVC was studied by oven discoloration method.It was found that the N-(substituted phenyl)-N′-cyanoacetylureas gave rise to an initialstage heat stabilization and a remarkable synergitic effect with calcium stearate and epoxidized soybean oil.The heat stabilizing performance of N-(substituted phenyl) -N′-cyanoacetylureas improved with increasing electrondrawing ability of the group linked to the urea’s imino group,based on which a progressive change law of heat stabilizing was deduced that the N-(substituted phenyl)-N′-cyanoacetylureas stabilized PVC by electrophilic reaction with PVC using their carbonyl carbon atoms as an electrophilic atom.This meant that the traditional Frye and Horst’s theory on mechanism of heat stabilization of heat stabilizers did not apply to N-(substituted phenyl)-N′-cyanoacetylureas,and therefore,the exact mechanism of heat stabilization needs to be clarified by further research.

Preparation and Properties of PVA/Starch/MMT Nanocomposites

2014, 28 (04): 62-67 ; DOI: 10.19491/j.issn.1001-9278.2014.04.011

Abstract ( 538 )

PVA/starch/montmorillonite (MMT) nanocomposites were prepared through melt processing. The effect of MMT on the structure and properties of PVA/starch composites was investigated by X-ray diffraction (SAXD), differential scanning calorimeter (DSC), scanning electron microscope (SEM), thermogravimetric analysis (TG), mechanical testing, etc. Starch and PVA molecules destroyed layered structures of MMT during thermal processing. MMT could increase the crystallization temperature, and decrease the crystallinity and melting enthalpy of composites. Significant improvement of tensile strength and Young’s modules were observed due to the fine dispersion of the MMT layers and the strong interaction between MMT and the matrix. The water sorption decreased and water resistant property was improved with the incorporation of MMT, resulting by the restricted swelling of the matrix by MMT nanolayers.

Numerical Simulation of Dispersive Mixing of Carbon Black/HDPE in Kneading Blocks

2014, 28 (04): 68-72 ; DOI: 10.19491/j.issn.1001-9278.2014.04.012

Abstract ( 589 )

The threedimensional quasisteady flow fields of PE-HD in three kinds of kneading blocks were calculated by using Polyflow software. The model for dispersive mixing of carbon black in polymer melts was introduced. The size distribution of carbon black agglomerated in different kneading blocks was calculated. The dispersive mixing effect of carbon black in PE-HD in the three kinds of kneading blocks was compared. The numerical results showed that the shearing and stretching was stronger and dispersive mixing effect was better for the kneading block with wider kneading discs.

Numerical Reconstruction of Thermal Ablation Trace of PVC Plastic Plates

2014, 28 (04): 73-77 ; DOI: 10.19491/j.issn.1001-9278.2014.04.013

Abstract ( 494 )

A semiphysical model to predict the thermal ablation traces of PVC plastic plate was established according to the factors which influence the thermal ablation trace formation,and the model was embedded in FDS source code,a program was compiled to reconstruct the wall thermal ablation traces.At the same time,the experiment of PVC plastic plate thermal ablation trace was set up,and using the compiled FDS program to reconstruct the experiment.It showed that the thermal ablation trace of the reconstruction was slightly smaller than the entity experiment in width,and slightly larger in height,but the variation tendency was the same.There was a growth retardation relationship between the width and height of thermal ablation traces and the heat release rate of the fire; there was a linear growth relationship between the width and height of the thermal ablation traces and the burning time; the width and height of the thermal ablation traces decreased with increasing distance between the fire and the wall or the corner.The thermal ablation traces generated by the fire in the corner of the wall was higher and darker than those generated by the fire at the middle of the wall.The results of the reconstruction and the entity experiment were consistent.Combined with other proofs in fire investigation,a chain of mutually supporting evidence could be formed.

Numerical Simulation of Effects of Structure Size on Molding Accuracy of Precision Injection Molded Plastics Parts

2014, 28 (04): 78-86 ; DOI: 10.19491/j.issn.1001-9278.2014.04.015

Abstract ( 507 )

Based on the numerical simulation analysis,the influence of structure size on the dimensional accuracy of the precise injection molded plastics parts was studied in the same processing conditions.The study found that for plastics parts of inhomogeneous thickness,the aspect ratio of the cross section to the thickness played an important role,but the length played a moderate one.Through orthogonal experiments and optimization analysis,structure size injection molded met the design requirements of precise injection molded plastics parts.

Study on Preparation and Antiaging Performance of Inlaid Type Drip Irrigation Tapes

2014, 28 (04): 78-82 ; DOI: 10.19491/j.issn.1001-9278.2014.04.014

Abstract ( 399 )

Through artificial accelerated aging and natural climate exposure aging test, the mechanical functions of Drip irrigation tape before and after aging were characterized by using tensile test method. In addition, their structural changes were analyzed by the infrared absorption, and the effects of aging-resistant additives to the mechanical performance of the irrigation tape were studied. Natural aging of 120 days and 0 days compared with the artificial aging of 12 days, the elongation retention of formula C were 84.7% and 83.2%; the elongation retention of formula C-0 were 59.8%, 58.2%; the main changes of molecular structure in the infrared spectrum curve are generated carbonyl peak with 1723cm-1. The results showed that adding self-made anti-aging master batch played anti-ultraviolet roles.

Synthesis and Flame Retardancy of DAM-DOPO

2014, 28 (04): 87-91 ; DOI: 10.19491/j.issn.1001-9278.2014.04.016

Abstract ( 669 )

A novel reactive flame retardant was synthesized by a twostep procedure from 9,10-dihydro-9-oxa-10-[N, N-bis-(2-hydroxyethylaminomethyl)]-10-phosphaphenanthrene-10-oxide(DAM-DOPO), formaldehyde and diethanolamine, with a strong acid ion exchange resin as a catalyst. The structure of DAM-DOPO was identified by FTIR, 1H-NMR and 31P-NMR. The flame retardant was employed in polyurethane(PUF) and was evaluated using limiting oxygen index, horizontal burning test and CAL 117D. It was found that the melting point of DAM-DOPO was 165~167 ℃. Limited oxygen index of polyurethanes foam(PUF) containing 12 phr DAM-DOPO was 26.5 %. The flame retardancy of PUF passed the CAL TB 117D test and GB 8410—2006.

Application of Several Non-ionic Antistatic Agents in Polypropylene Film

2014, 28 (04): 92-96 ; DOI: 10.19491/j.issn.1001-9278.2014.04.017

Abstract ( 603 )

Antistatic film was prepared from PP, with monoglyceride, borate, liquid ethoxyamine, and solid ethoxyamine as additives. Propertis of antistatic PP film were characterized using Fourier transform infrared spectrometer, electric performance testing instrument, contact angle tester, and the friction coefficient testing instrument. It was found that monoglycerides made the surface resistance of the film dropped from 1016 Ω to 1011 Ω, and liquid ethoxyamine made it reduced to 108 Ω under conditions of humidity of 70 %. Nonionic antistatic agent in low humidity didn't have antistatic effectIts surface resistance was reduced to 1013 Ω in low humidity by using borate. The migration rate, the contact angle, and coefficient of friction were not affected by humidity.

Microstructure and Rheological Behavior of Recycled Multilayer Co-extrusion Film Scraps Modified Asphalt

2014, 28 (04): 97-102 ; DOI: 10.19491/j.issn.1001-9278.2014.04.018

Abstract ( 537 )

The recycled coextrusion multilayer film scraps(r-MCEFS) were employed to modify asphalt(heavy traffic 70#). The effect of r-MCEFS dosage on the general performances, microstructure, and rheological property of the modified asphalt were investigated. It showed that the softening point of the modified asphalt increased with increasing r-MCEFS content. The microstructure of the modified asphalt converted from the “sea-island” into the “web-like” structure at 4 phr r-MCEFS content. The elastic recovery and high temperature stability were improved by the introduction of r-MCEFS. Interfacial interaction between asphalt and r-MCEFS was increased.

Influence of Wedge Angle on the Mixing Performance of New-type Rotors in a Continuous Mixer

2014, 28 (04): 103-107 ; DOI: 10.19491/j.issn.1001-9278.2014.04.019

Abstract ( 531 )

The model of new-type rotors with three edges in a double-rotor continuous mixer was built and a three-dimensional non-Newtonian isothermal simulation of the dynamic flow field of rotors with different wedge angles was conducted using the polymer processing analysis software POLYFLOW, the residence time distribution of the flow field in the rotor, cumulative max shear stress distribution, weighted average shear stress and segregation scale were obtained by statistical method. The results showed that rotors with smaller wedge angle had a better dispersing mixing performance and its distribution mixing performance was not that good, while rotors with bigger wedge angle had a better distribution mixing performance, but its dispersing mixing performance was poor. The new-type rotors possessed the best dispersing and distribution performance when the wedge angle was around 15°.

Numerical Simulation of Effect of Intermittent Baffle Geometry on Chaotic Mixing in Singlescrew Extruders

2014, 28 (04): 108-113 ; DOI: 10.19491/j.issn.1001-9278.2014.04.020

Abstract ( 608 )

The physical and mathematical models of the unwound screw channel of metering zone in chaos singlescrew extruder were proposed. The corresponding incompressible fluid obeyed the Carreau flow model. With the help of the mesh superposition technique provided by a polymer analysis package Polyflow, the flow and mixing of polymer melt in such an extruder, which inserted a intermittent baffle into the screw channel of metering zone, were numerically simulated. Applying the particle tracking technique and statistical methods, the mixing performance was investigated and characterized in terms of different parameters such as residence time distribution, segregation scale, mixing efficiency,and mixing index. When the baffle intermitted frequently and height slightly lower than screw channel, the chaos single-screw was better for mixing.

Design of Injection Molds for Cars′ Airtank-lefts

2014, 28 (04): 114-118 ; DOI: 10.19491/j.issn.1001-9278.2014.04.021

Abstract ( 607 )

According to the structure characteristics of cars′ left lids of air tanks, an injection mold with hot runners and 13 side core-pulling mechanism was designed. The gating system, the side core-pulling mechanism, given-distance parting mechanism, cooling system, and release system were analyzed and studied. The mold structure was advanced and reasonable, safe and reliable, the quality of plastic parts fully met the requirements of test.

Design of Injection Molds for the Bottom Cover Based on UG

2014, 28 (04): 119-122 ; DOI: 10.19491/j.issn.1001-9278.2014.04.022

Abstract ( 633 )

The design of injection molds based on UG software was exemplified by a bottom cover.It emphasized the parting design method for the mold structure using Mold Wizard of UG software.Through the use of patch repaired of the plastic parts,the work piece was divided into two parts,the cavity and the core,quickly and accurately.It significantly reduced the time of design,saved production costs,and increased economic efficiency.