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2014, Volume 28 Issue 06 Publication date: 26 June 2014 Previous Issue Next Issue

Research Progress of Novel Flame Retardant System for Polylactide

2014, 28 (06): 1-7 ; DOI: 10.19491/j.issn.1001-9278.2014.06.001

Abstract ( 552 )

This paper reviewed the research progress of novel flame retardant system used in polylactide（PLA）,which were sorted according to the flame retardancy mechanism. For the condensed phase mechanism, intumescent,charring, catalytic charring, salt hypophosphite, and inorganic nano-filler flame retardant systems were presented. For gas phase mechanism, delayed release and gas catalysis were introduced. Finally, a prediction was made for highly effective and environmentally friendly flame retardants.

Research Progress and Applications of Graphene Supercapacitors

2014, 28 (06): 8-18 ; DOI: 10.19491/j.issn.1001-9278.2014.06.002

Abstract ( 698 )

This article summarized the research process of graphene supercapacitors, including graphene electrode materials, modification of graphene, compounding with pseudo-capacitance electrode, structure design, choosing of electrolytes, and flexible supercapacitors. In practial manufacturers and tis application were introduced. Future applications of supercapacitors will not be limited to consumer electronics, but extend to the field of hybrid electric vehicles.

Research Progress of Heat Transfer Models of Rotational Molding Process

2014, 28 (06): 19-28 ; DOI: 10.19491/j.issn.1001-9278.2014.06.003

Abstract ( 667 )

In this paper, the importance of heat transfer mechanism in the rotational molding process was first introduced, and then heat transfer at every phase of rotational molding process was described. Both domestic and international research work on heat transfer model of rotational molding process were summarized. These models were categorized and compared, and their limitations were analyzed. Moreover, the future trend of research work was also prospected.

Preparation of Ablative Silicone-Epoxy Resins and Their Synergistic Effect for Char Formation

2014, 28 (06): 29-32; DOI: 10.19491/j.issn.1001-9278.2014.06.004

Abstract ( 448 )

Methyl silicone resin（R610）was blended with epoxy resin（E44）,an ablative silicone-epoxy resin was prepared using phthalic anhydride curing systim. The char formation and flame retardant property of the resin were investigated. When mass ratio of R610 and E44 was7:3, the resin had a high char yield and a synergistic effect was observed. Introducing 10 % of the APP flame retardant, the oxygen index of the resin reached 38 %, and the residual carbon content reached 68 %.

Morphologies and Properties of SEBS/PPO Blends

2014, 28 (06): 33-40 ; DOI: 10.19491/j.issn.1001-9278.2014.06.005

Abstract ( 611 )

SEBS/PPO blends were prepared with a twin-screw extruder, and the morphology was studied by atomic force microscope（AFM）and its mechanical properties were compared. With increasing PPO content light spot increased and the PPO and PS phase were completely miscible. When the ratio of SEBS and PPO was 80/20, EB segment was continuous phase and PS segments and PPO were dispersed phase. The hard segment structure was from dispersed phase to two continuous phase and then to continuous phase（SEBS/EB=20/80）.The tensile strength of the SEBS/PPO blends increased sharply and the elongation at break decreased with increasing PPO. Both tensile strength and elongation at break declined with increasing oil amount.

Effects of Phosphor-nitrogen Intumescent Flame Retardant on the Flame Retardancy Performance of Polypropylene

2014, 28 (06): 41-45 ; DOI: 10.19491/j.issn.1001-9278.2014.06.006

Abstract ( 400 )

In this paper, the flame retardancy and mechanical properties of polypropylene（PP）were tested by differential scanning calorimetry（DSC）,thermogracimetic analysis（TG）,cone calorimetry, and stereo microscope. It was found that as the content of IFR-3 increased, the tensile strength and charpy notch impact strength increased first, and then decreased; flame retardant IFR-3 increased the crystallization temperature and melt temperature, and decreased the decomposition temperature, increased the residual mass. The limiting oxygen index of PP increased with increasing content of flame retardant IFR-3. When IFR-3 was 30 and 35 phr, PP/IFR-3 specimen gave rise to a UL 94 V-0 rating at 3.2 and 1.6 mm, respectively. IFR-3 could also decreased the heat release rate（HRR）and smoke produce rate（SPR）of PP.

Modification of the Radiation Cross-linking of Cable Materials

2014, 28 (06): 46-51 ; DOI: 10.19491/j.issn.1001-9278.2014.06.007

Abstract ( 484 )

A cable jacket resin using PE-LD/EVA as a matrix, Mg(OH)2 as a flame retardant, OMMT as a filler, and POE as a toughener was prepared. The material mechanical and flame retardant properties of the resin and the effect of γ-ray radiation on these properties were investigated. It was found that, with increasing POE content, the tensile strength and elongation at break increased, and its hardness decreased. During burning process, there was a good synergistic effect between Mg(OH)2 and OMMT. When the radiation dose was 90～100 kGy, the optimal recipe was PE-LD/EVA/Mg(OH)2/OMMT＝50/50/60/4, whose limited oxygen index reached over 32 %, tensile strength was 11 MPa and the elongation at break was above 900 %.

Surface Immobilization of Poly(ether ether ketone) with Chitosan

2014, 28 (06): 52-56 ; DOI: 10.19491/j.issn.1001-9278.2014.06.008

Abstract ( 527 )

Chitosan was grafted on the surface of poly(ether ether ketone) (PEEK) by UV radiation and wet chemical method for bacteriostasis and disinfection. Compared with the unmodified PEEK, the hydrophilicity of grafted PEEK film was increased. It showed that chitosan was successfully grafted on the surface of PEEK by SEM and XPS. In addition, the degree of grafting of chitosan on the surface of the material increased with increasing chitosan concentration.

Preparation and Properties of Waterborne Hybrid UV-curable MAP-POSS modified PU-acrylate/O-cresol Formaldehyde Epoxy Resin

2014, 28 (06): 57-62 ; DOI: 10.19491/j.issn.1001-9278.2014.06.009

Abstract ( 526 )

Waterborne polyurethane acrylate（PUA）and o-cresol formaldehyde epoxy resin（o-CFER）were synthesized, and the blend of PUA and o-CFER was modified using methylacyloxylpropyl-POSS（MAP-POSS）.The obtained material was cured with UV and characterized by FTIR, DMA and TGA. DMA analysis indicated that the three components in the system were well compatible and MAP-POSS improved the thermal properties of the material. The glass transition temperature Tg reached 122.3 ℃ when the amount of MAP-POSS. TGA analysis showed that the thermal decomposing activation energy Ea and reaction order n were 41.44 kJ/mol and 1.38 when the content of MAP-POSS was 12 wt %, respectively. The tensile and modulus of the product were 201.15 MPa and 8.17 MPa, respectively. The pencil hardness of the film was 3 H, the impact strength reached 50 kg·cm.

Transfer of Plasticizers in PVC products in Liquor of Different Degrees

2014, 28 (06): 63-68 ; DOI: 10.19491/j.issn.1001-9278.2014.06.010

Abstract ( 591 )

The migration of plasticizers DOP, DOTP, ATBC, and TBC from PVC container in 42 °,46 °,and 55 °liquor was studied using a high performance liquid chromatography（HPLC）.It was found that the plasticizer migration rate was related to the time and liquor degree. With increasing time and liquor degree, the migration rate increased. The migration mechanism was simulated using Gaussian 03 program. It showed that the greater the molecular polarity, the better the compatibility for plasticizer with PVC, and the smaller the mobility. The order for the migration rate of plasticizers, from large to small, was citrate, acetyl citrate, phthalate, and terephthalate.

Synthesis and Properties of Recast Perfluorosulfonic Acid-PTFE Copolymer/Sulfated Zirconia Composite Membrane

2014, 28 (06): 69-72 ; DOI: 10.19491/j.issn.1001-9278.2014.06.011

Abstract ( 805 )

Composite membranes consisting of sulfated zirconia（SZ）and perfluorosulfonic acid-PTFE copolymer（Nafion?）were prepared by solution recasting. The microstructure, morphology, and properties of as-synthesized composite membrane were studiedd by XRD, SEM, and TGA. It showed that rod-like SZ particles were evenly distributed in Nafion? membrane matrix, and slightly modified the thermal stability at medium temperature range. Under the conditions of 45 ℃ and 5 mol/L methanol, the peak power densities of direct methanol fuel cell（DMFC）with 3 % and 6 % Nafion?/SZ composite membranes were 46.27 mW/cm2 and 59.47 mW/cm2, respectively, higher than that of DMFC with pristine Nafion? menbrane.

New Approach to Cooperative Control of Product Precision with Cavity Deformation

2014, 28 (06): 73-76 ; DOI: 10.19491/j.issn.1001-9278.2014.06.012

Abstract ( 416 )

The influence of elastic micro-deformation of cavity on the precision of product was analyzed. A new approach to cavity design was proposed for the controlling of product precision. In order to realize precision molding, it was necessary to strictly control the value and fluctuation of the hold pressure.

The experimental research for the process of UV curing injection molding

2014, 28 (06): 77-81 ; DOI: 10.19491/j.issn.1001-9278.2014.06.014

Abstract ( 593 )

Based on traditional injection molding process, parameters for UV curing injection molding were studied and the effect of temperature and pressure on the precision of products was analyzed. Overall precision of UV curing products was measured by the average weigh of the molded products. In addition, the microstructure was evaluated through comparing the cross section of the products. The experimental indicated that UV curing injection molding was well feasible.

Shrinkage Prediction of Cylindrical Thin-walled Parts in Plastic Injection Molding Base on Design of Experiments

2014, 28 (06): 82-87 ; DOI: 10.19491/j.issn.1001-9278.2014.06.015

Abstract ( 415 )

This paper provide a nonlinear mathematical model for the prediction of shrinkage of thin-well plastic cylindrical parts based on design of experiments（DOE）.Four most influential parameters were screened by using fractional factorial design（FFD）：mold temperature, pack time, pack press, and melt temperature. For the four principal processing parameters, a mathematical model was formulated by using central composite design（CCD）of experiments and FE simulation. Finally, the results of statistical analysis were collected from software Moldflow, and engineering tests ware also used. The results suggested that the mathematical model could be used to predict shrinkage with reasonable accuracy.

Study on Dynamics Simulation of Vane Plasticizing Transportation Unit During Polymer Processing

2014, 28 (06): 88-92 ; DOI: 10.19491/j.issn.1001-9278.2014.06.016

Abstract ( 484 )

The kinetic and dynamic characteristics of vane plasticizing transportation unit were simulated using multi-body system dynamic software ADAMS. It showed that kinetic nature of the unit is a simple harmonic vibration. With increasing rotor speed, the vibration frequency of the vane increases, the vibration strength of displacement keeps the same, that of the velocity increases. Interactive force between vane and fixed barrel increases, and amplitude of interactive force enhances, which improve the impact of vanes in stretching motion with fixed barrels. The influence of eleventh mode on the unit system vibration is the biggest. The unit system would take place resonance at the induced vibration frequency of 5.7544, 24.36, 153.7 Hz. However, eccentric induced vibration does not bring about the vane resonance fracture.

A Highly Active β-nucleating Agent for Isotactic Polypropylene

2014, 28 (06): 93-97 ; DOI: 10.19491/j.issn.1001-9278.2014.06.017

Abstract ( 616 )

Crystal form of iPP nucleated with salts of bicycle [2.2.1] hept-5-ene-2-dodecanamide -3-carboxylate（NBDA30）was investigated with differential scanning calorimeter（DSC）and wide angle X-ray diffraction（WAXD）. The results revealed that 0.2 wt % of NBDA30 on the mechanical properties and crystallization behavior were investigated. When the content of NBDA30 increased from zero to 0.8 wt %, the impact strength of iPP increased from 31.8 to 91.0 J/m. Meanwhile, the tensile strength and flexural modulus of iPP were not decreased. The crystallization peak temperature of iPP nucleated with NBDA30 first decreased and then increased with increasing concentration of nucleating agent.

Study of Ultraviolet Photocatalytic Degradation of Poly（vinyl chloride ）Film by Niobium Acid Silver Photocatalyst

2014, 28 (06): 98-103 ; DOI: 10.19491/j.issn.1001-9278.2014.06.018

Abstract ( 542 )

PVC/AgNbO3 composite film was prepared by glass coating method. The photo-catalytic degradation experiments were carried out under UV light irradiation and compared with neat PVC film. The sample were characterized by scanning electron microscope（SEM）,X-ray diffraction（XRD）, and Fourier transform infrared spectroscopy（FTIR）.The PVC/AgNbO3 composite film extent of the film was evaluated directly by the weight loss. The weight loss rate of the PVC/0 % AgNbO3,PVC/3 % AgNbO3,PVC/6 % AgNbO3,PVC/9 % AgNbO3,PVC/15 % AgNbO3 films after 480 h irradiation, were 3.92, 19.16, 22.94, 26.59 and 31.75, respectively. This proved that the AgNbO3 remarkably promoted the photo-catalytic degradation of PVC film.

3D Simulation of Screw Axial Motion Influencing on Plasticization Homogeneity

2014, 28 (06): 104-107 ; DOI: 10.19491/j.issn.1001-9278.2014.06.019

Abstract ( 394 )

The three-dimensional nonisothermal melt flow fields in metering section of injection and extrusion during plasticizing process were simulated by Polyflow. Comparisons of their temperature, viscosity, velocity and pressure fields showed that distributions of temperature and viscosity in extrusion were more homogeneous and more stable than injection. The back motion of screw is favorable for increasing melt transportation.

Study on the Wear of Toggle Mechanism in Clamping Units of Precision Injection Molding Machines

2014, 28 (06): 108-111 ; DOI: 10.19491/j.issn.1001-9278.2014.06.020

Abstract ( 501 )

A model was established to describe the wear characteristics of toggle mechanism in clamping units of precise injection molding machines. The corresponding calculation formula was derived, and the influence of various parameters on wear life of toggle mechanism was analyzed. The research showed that the wear of toggle mechanism mainly occurs on the frictional interface of interfacial material, equivalent elastic modulus, wear constant, load, structure parameters of pin and sleeve. It also showed that the wear rule of pin and sleeve were different from conventional friction pairs: the clearance between pin and sleeve had great influence on the wear life of toggle mechanism, however, the radius of pin had little influence on it, and it was a power function between the wear life and the clamp force.

Design of Large and Double Layer Injection Molds for Refrigerator Spacers

张维合 allenzhang

2014, 28 (06): 112-116 ; DOI: 10.19491/j.issn.1001-9278.2014.06.021

Abstract ( 426 )

A large volume double-layer injection mold was designed for refrigerator spacers. The various parts, gating system, side core-pulling mechanism, cooling system, guide positioning system, opening mechanism, and ejection system of the mold was studied. By employing a hot runner gating system and a mold opening mechanism of gear and rack, the designed mold was well met the requirements for the quality and molding cycle of the refrigerator spacers.