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2014, Volume 28 Issue 10 Publication date: 26 October 2014 Previous Issue Next Issue

Research Progress in Coating Absorbing Matrix Materials

2014, 28 (10): 1-7 ; DOI: 10.19491/j.issn.1001-9278.2014.10.001

Abstract ( 479 )

The applications of absorbing coating in daily life and national defense was introduced in this paper. The materials used in recent years were reviewed. The properties and research work of the coating materials were discussed in detail, where in the rubbers were mainly silicon rubber and EPDM, plastics were mainly polyurethane foam, polymethcrylimide foam and polystyrene foam. The future developing direction of the absorbing coating was proposed.

Epitaxial Crystallization of Polymers on Highly Oriented Thin Polymeric Films

2014, 28 (10): 8-13 ; DOI: 10.19491/j.issn.1001-9278.2014.10.002

Abstract ( 587 )

A great deal of work has been done on epitaxial crystallization of polymers on highly oriented thin polymeric films in recent years. This paper summarized research works on oriented thin film epitaxial crystallization. The crystallization mechanism and influence factors on epitaxial crystallization, such as lattice matching, crystallization kinetics, and secondary nucleation, were discussed.

Effect of MoO3 on Smoke Suppression of Flame Retardant Rigid Polyurethane Foam

2014, 28 (10): 14-18 ; DOI: 10.19491/j.issn.1001-9278.2014.10.003

Abstract ( 297 )

The effect of molybdenum trioxide (MoO3) on smoke suppression of rigid polyurethane foam (RPUF) filled with expandable graphite and ammonium polyphosphate was studied by smoke density test, limiting oxygen index, and horizontal-vertical burning test. Meanwhile, the role of MoO3 in condensation phase was analyzed by thermal gravimetric analysis and X ray photoelectron spectroscopy. It was found that with a MoO3 loading of 4 parts per hundred polyol, the maximum smoke density of the RPUF was reduced by 22 %, the amount of residual char was increased from 8.0 % to 16.2 % at 835 ℃. The reason was that MoO3 can promote the cross linking of RPUF to form char and retain more phosphorus containing compounds in condensation phase.

Porous β-Cyclodextrin Copolymer for Separating Phenol from Wastewater via Concentrated Emulsion Copolymerization

2014, 28 (10): 19-23 ; DOI: 10.19491/j.issn.1001-9278.2014.10.005

Abstract ( 560 )

Per(2,6-di-O-allyl)-β-cyclodextrin was prepared by the modification of β-cyclodextrin with allyl bromide using sodium hydroxide as a catalyst. The effect of catalyst, modifying agent, time, and temperature on the yield of the product was discussed. The best reaction condition was obtained as follows: n(β-CD)∶n(C3H5Br)=1∶76.0, n(NaOH)∶n(C3H5Br)=1.34∶1, temperature was 5 ℃ and time was 48 h. The porous β-cyclodextrin copolymer were synthesized by concentrated emulsion polymerization with the mixture of allyl-β-CD, styrene, DVB as the continuous phase and an aqueous solution of K2S2O8 and K2SO4 as the dispersed phase. The effect of β-cyclodextrin on the hydrophilic property and phenol adsorption capability of the porous materials was studied. It was found that the porous materials presented obvious improvement in both hydrophilicity and phenol adsorption capability when β-cyclodextrin was introduced.

Research of Liquid Crystal Compounds Thoughening Heat Resistance Epoxy Resin

2014, 28 (10): 24-28 ; DOI: 10.19491/j.issn.1001-9278.2014.10.006

Abstract ( 328 )

A novel schiffbase monomer DP-1 was prepared via addition condensation with p-aminophenol and 1,4-phthaldiadehyde, based on which an liquid crystalline epoxy resin EP-1 was prepared. The structure of EP-1 was investigated by the Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy (1H-NMR), and differential scanning calorimetry. Using EP-1 as a toughener, 4,4’-diamino diphenyl sulfone (DDS) as a curing agent, cured epoxy system AG-80/EP-1/DDS was prepared. Testing of mechanical properties of the epoxy system showed that impact strength, bending strength, flexural modulus, and heat distortion temperature were 23.27 kJ/m2, 126.39 MPa, 414 GPa, and 232.5 ℃, respectively.

Preparation and Dyeing of Benzylated Polystyrene/Fir Powder Composites

2014, 28 (10): 29-35 ; DOI: 10.19491/j.issn.1001-9278.2014.10.007

Abstract ( 343 )

Benzylated fir powder was solution compounded with polystyrene in CHCl3 forming plastic composites (WPC), the latter was dyed with dispersing dyes and characterized with infrared spectroscopy (IR) and scanning electronic microscopy (SEM). It was found that the dyeing rate of WPC was influenced by the molecular structure and molecular weight of the dispersing dyes. The color shade of dyed WPC was similar to that of dyed polyester fabric, and was becoming deeper with increasing dyeing temperature and increasing dye concentration. The dyeing rate and washing fastness of dyed samples decreased with increasing dye concentration, and increased with increasing temperature.

Preparation and Properties of Biodegradable Composite Films

2014, 28 (10): 36-39 ; DOI: 10.19491/j.issn.1001-9278.2014.10.008

Abstract ( 348 )

Into a blend of oxidation acetate starch (PMS) and poly(vinyl alcohol) (PVA) carboxyl methyl cellulose (CMC), sodium alginate (SA), and agar (AG) were introduced, based on which a biodegradable composite film was prepared by casting method. The morphology of the composite membrane were characterized using infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). CMC and SA could effectively improve the mechanical properties and water resistance of the composite film. When the mass ratio of CMC and SA was 1∶1, the tensile strength reached 20.84 MPa and water absorption was 124.00 %. The water resistance of the film could be further improved by adding AG and the water absorption decreased to 83.35 %.

Study on Performance of Polymer Latex Particles by Cyclodextrin

2014, 28 (10): 40-44 ; DOI: 10.19491/j.issn.1001-9278.2014.10.009

Abstract ( 399 )

Using styrene and butyl methacrylate (BMA), coreshell latex particles was prepared by emulsion polymerization. The effect of β-cyclodextrin (β-CD) on the polymerization and the latex particle was studied. DLS determination showed that the size distribution of the latex particles was narrow. The contact angle test indicated that the hydrophilicity and surface energy of particles are improved. AFM and TEM showed that when β-cyclodextrin content was 5 %, the size of coreshell latex particles became more uniform.

Synthesis and Properties of the Composite Superabsorbent Polymer from Waste Material Cultured Pleurotus Nebrodensis and Potassium Polyacrylate

2014, 28 (10): 45-51 ; DOI: 10.19491/j.issn.1001-9278.2014.10.010

Abstract ( 357 )

A composite superabsorbent resin was synthesized through microwave irradiation copolymerization of potassium polyacrylate with waste material cultured pleurotus nebrodensis (WMCPN). The influence of the synthesizing formulation, microwave power, and the neutralization degree of polyacrylic acid (AA) on the properties of superabsorbent resin was investigated. Optimal synthesis condition was found as: the loading of WMCPN, initiator, crosslinker were 50 %, 1.33 % and 1.0 %，based on the weight of AA, respectively; microwave power 450W, neutralization degree of AA 80 %. The maximum water absorbencies were found to be 974 g/g for distilled water and 59 g/g for 0.9 % NaCl solution. In addition, the water loss rate was 6.2 % after centrifuging at 6000 r/min for 60 minutes.

Research and Application of High Glow Wire Flame Retardant Enhance PET/PA6 Alloy Material

2014, 28 (10): 52-55 ; DOI: 10.19491/j.issn.1001-9278.2014.10.011

Abstract ( 345 )

Three flame retardants, organophosphate, decabromdiphenylethane, and inorganic hydroxide were introduced separately into PET/PA blends and their glow wire property, flame retardancy, and the mechanical property were compared. The glow wire property, scanning electronic microscope and the mechanical test showed that the glow wire property was the best and the glow wire property was less than 2 second when a mixture of decabromdiphenylethane and phosphoric acid esters were used. PA6 played a positive role for the glow wire property. When the content of glycidyl methacrylate was 7 %, the blend exhbited optimal comprehensive mechanical properties.

Wear Behavior of PA6 Affected by Nano-Al₂O₃ Under Elevator Operating Condition

2014, 28 (10): 56-60 ; DOI: 10.19491/j.issn.1001-9278.2014.10.012

Abstract ( 338 )

The wear behavior of polyamide 6 (PA6)/nanoAl2O3 composites in the elevator operating condition was investigated using MMW1A friction testing. The interactive mechanism between PA6 and nanoAl2O3 was discussed. It was found that with increasing wearing time, friction coefficient of PA6/nanoAl2O3 composites experienced a rapidly increasing, subsequent decreasing and then level off. With increasing content of nanoAl2O3, friction coefficient and wear volume of PA6/nano-Al2O3 composites firstly decreased then increased. When the loading of nanometer Al2O3 was 4 %, the improvement of antiwear behavior was the most significant, with friction coefficient and wear volume 23.5 % and 84.3 % lower than neat PA6, respectively. Wear behavior of PA6/nano-Al2O3 composites was associated with nanoAl2O3 content. The main wear mechanism of neat PA6 was abrasive wear and adhesive wear. With increasing nanoAl2O3 content, the abrasive wear part first increased, then decreased; while adhesion wear first decreased and then increased.

Research on the Monomer for Replication Fidelity of Micro Parts in UV-Curing Injection Molding

2014, 28 (10): 61-64 ; DOI: 10.19491/j.issn.1001-9278.2014.10.013

Abstract ( 422 )

The UV material was molded by injection molding in this paper, and the effect of the kinds and content of monomer for the replication fidelity of micro parts was discussed. Meanwhile, the height of the micro parts and the cross section shape of the micro parts were served as two criterions to evaluate the effect degree. Experimental result showed that with the active groups increaseing in every kind of the monomer, the replication fidelity presents the downtrend, and with the UV monomer content increaseing in the UV material, the replication fidelity exhitited the downtrend also, but the trend was not obvious as the first experiment.

Study of Mechanical Properties of Films for Outside Mold Decoration

2014, 28 (10): 65-69 ; DOI: 10.19491/j.issn.1001-9278.2014.10.014

Abstract ( 337 )

To study the mechanical properties of outside mold decoration films, the true stressstrain curves under the corresponding conditions were obtained by uniaxial tensile tests of PMMA plastic sheets at high temperature with different temperature and strian rates, the coefficients of the viscoelastic constitutive model of DSGZ of different temperature and strian rate were calculated, and the predicted curve of DSGZ model and experimental data were compared and analysed. The analysis results show that at the same temperature the true stress, tensile ratio and yield strength would increase when the strain rate rose; at the same strain rate, the strain softening and yield phenomenon would decrease and then disappear, the true stress would also decrease when the temperature rose. The predicted curve of DSGZ model and experimental data were basically anastomotic, the mechanical properties of PMMA could be better reflected by the DSGZ model.

Numerical Simulation of Effects of Melt Layer Thickness on L-shaped Coextruded Coated Plastic Profiles

2014, 28 (10): 70-75 ; DOI: 10.19491/j.issn.1001-9278.2014.10.015

Abstract ( 301 )

Extrusion swell of L-shaped profiles during coating co-extrusion was analyzed by the Phan-Thien-Tanner (PTT) constitutive equations and finite element. It was found that the overall extrusion swell ratio kept constant when the thickness of core layer changed, but the swell rate in shell, core layer and along the X, Y direction of the concave right angle in L-shaped die were all changed dramatically. When the overall size of the die kept constant, the maximum shear rate at the die exit kept constant.

Elastic Characteristics of Polymer Melts Through Microchannels

2014, 28 (10): 76-82 ; DOI: 10.19491/j.issn.1001-9278.2014.10.016

Abstract ( 408 )

The melt elastic character of four kinds of polymers (PMMA, PS, PP, and PE-HD) was investigated using a double capillary rheometer. The effects of temperature on entrance pressure drop and stress relaxation time of melt were discussed. The entrance pressure drop and stress relaxation time of all polymer melts increased with decreasing channel size, and the smaller the channel size, the more obvious the effect. The entrance pressure drop increased with increasing shear rate, however, the effect became less obvious under high shear rates. The entrance pressure drop and stress relaxation time decreased with increasing temperature.

Study on Preparation and Application of Maleopimaric Acid Cerium

2014, 28 (10): 83-88 ; DOI: 10.19491/j.issn.1001-9278.2014.10.017

Abstract ( 258 )

Cerium maleopimarate was synthesized from maleopimaric acid and cerium acetate under nitrogen atmosphere, the influence of the technologic parameters on the preparation was investigated. When the mole ratio of maleopimaric acid and cerium acetate was 1∶1.8, reaction temperature was 60 ℃, reaction time was 6 hours, and the product yield reached 95 %. The product was characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDAX), and Xray diffraction (XRD). Congo red and thermal testing were used to study the thermal stability of PVC stabilized by cerium maleopimarate and cerium acetate. It was showed that cerium maleopimarate was a kind of environment friendly heat stabilizer for PVC.

Synthesis and Application of the Efficient Silicon, Chlorine and Bromine Elements Coordination Flame Retardant

2014, 28 (10): 89-93 ; DOI: 10.19491/j.issn.1001-9278.2014.10.018

Abstract ( 308 )

A novel flame retardant was prepared from tetrabromo bisphenolA diepoxypropyl ether, tetrachlorinated silicon, and epoxy chloropropane, in which three elements, silicon, chlorine, and bromine were expected to provide a synergetic effect. The effect of temperature, time, solvent, and mole ration of raw materials was investigated. The optimum condition was as follows: acetonitrile was used as a solvent, molar ratios of (tetrabromo bisphenolA diepoxypropyl ether)/ (tetrachlorinated silicon)/(epoxy chloropropane) was 1∶2∶7; first reaction, 70 ℃ for 4 h, second reaction, 80 ℃ for 7 h; the yield was 99 %. It may render PVC a good flame retardacy.

Dimensional Accuracy Control of the Precise Injection Molded Plastic Parts Based on Iteration Reverse Deformation Method

2014, 28 (10): 94-99 ; DOI: 10.19491/j.issn.1001-9278.2014.10.019

Abstract ( 308 )

An automotive rear lamp housing was selected as the research model in this study. First, the warpage of lamp housing based on the optimum injection parameters was obtained using finite element (FE) software Moldflow. After that, CAE numerical simulation was conducted for the plastic part with reverse deformation design, and the results were compared with that based on original design. After three iterations, the dimension deviation of the simulated warpage from the original model decreased from previous 0.8595 to 0.10875 mm. In the engineering test the feasibility of this approach was confirmed.

CAE Analysis and Design of Cooling System of Household Juicer Body Injection Mold

2014, 28 (10): 100-105 ; DOI: 10.19491/j.issn.1001-9278.2014.10.020

Abstract ( 385 )

Two design schemes of injection mold cooling system for household juicer body, the cooling time, cooling medium temperature, and warpage of inhomogeneous cooling were compared and analyzed by using Moldflow 2012 software. It showed that the multilayer straightthrough cooling system was more efficient than multilayer returncircuit cooling system. The design of multilayer straightthrough cooling system was further optimized.

Research on Simulation Technology of Sequence Valve Control Injection Molding Process for Bumpers

2014, 28 (10): 106-111 ; DOI: 10.19491/j.issn.1001-9278.2014.10.021

Abstract ( 399 )

The injection process for car bumpers was numerically simulated using software Moldflow in this paper. A set of injection parameters were determined, which was subjected to further adjustments based on molding window analysis. It showed that the injection molding simulation technology could reduce mold modification and the cost of the products, and thus is of great practical significance to bumper manufacturing.