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2014, Volume 28 Issue 12 Publication date: 26 December 2014 Previous Issue Next Issue

Research Progress in Toughening Modification of Polyoxymethylene

2014, 28 (12): 1-5; DOI: 10.19491/j.issn.1001-9278.2014.12.001

Abstract ( 354 ) PDF (0 KB)( 65 )

Due to the high crystallinity and the lower notched impact property, the application fields of polyoxymethylene（POM）were limited. In this paper, the main toughening modification methods and research progress were reviewed. The toughening mechanism of POM with elastomer, rigid inorganic particles, and other plastics were discussed. At last, a prospect of POM toughening modification was made.

Situation and Developing Trend of Flame Retardancy of XPS Foam

2014, 28 (12): 6-11; DOI: 10.19491/j.issn.1001-9278.2014.12.002

Abstract ( 313 ) PDF (0 KB)( 61 )

The developing situation of flame retardancy of extruded polystyrene foam (XPS) was reviewed. Mechanism of flame retarded XPS foam was discussed, especially using hexabromocyclododecane (HBCD) as flame retardant. Influencing factors on flame retardancy of HBCD were also analyzed. Finally, the developing trend of flame retardancy of XPS foam was pointed out.

Research Progress in Physical Toughening Modification of Poly(vinyl chloride)

LIU Yunpeng

2014, 28 (12): 12-16; DOI: 10.19491/j.issn.1001-9278.2014.12.003

Abstract ( 383 ) PDF (0 KB)( 52 )

Research progress in physical toughening modification of poly(vinyl chloride) was summarized at home and abroad. The present situation of modification by elastomer, rigid organic particle, rigid inorganic particle and fibrous filler was introduced especially. The present main problems of physical toughening modification of poly(vinyl chloride) were analyzed, and the future development trend was pointed out.

Surface organic modification of aluminum powder and its influence on dielectric properties of epoxy matrix composites

2014, 28 (12): 17-20; DOI: 10.19491/j.issn.1001-9278.2014.12.004

Abstract ( 520 ) PDF (0 KB)( 45 )

The aluminium powder(Al) is coated with silicon dioxide (SiO2) to prepare SiO2 @ Al by sol-gel method, and the SiO2@Al-KH550 is getted by organic modification using silane coupling agent KH550. The coating and the treatment effect are characterized by FT-IT, the corrosion resistance and hydrophobicity are verified by the corrosion efficiency experiment and static water contact angle experiments, and the microstructure is tested by SEM analysis. SiO2@Al-KH550/EP composite materials are prepared by casting method. Dielectric performance tests show that when the content of SiO2@Al-KH550 reaching 35%wt, the dielectric constant reaches 30, 6 times of pure epoxy resin, and the dielectric loss reaches 0.065, a new idea of the preparation of metal particles/epoxy resin dielectric composite materials is provided.

Preparation of Silicon Rubber Composites Filled with Ionic Liquid Modified Expanded Graphite

2014, 28 (12): 21-24; DOI: 10.19491/j.issn.1001-9278.2014.12.005

Abstract ( 479 ) PDF (0 KB)( 63 )

Milled ionic liquid-expanded graphite (IL-EG)/room temperature vulcanized silicone rubber (RTVSR) composite was successfully prepared. In order to investigate the role of IL, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6), modified fillers on the electrical properties and thermal character of SR composite, XRD, SEM, TEM and some other test methods were used. The results demonstrate that EG is successfully exfoliated into single layer graphene with the aid of IL.It confirms the presence of ionic liquid on the surface of graphene. Graphene is uniformly dispersed in the SR composite with the modification of IL, which facilitates the formation of conductive net work and decreases the volume resistivity of composite.

Synthesis of MMA-b-BA-b-MMA Triblock Copolymer via RAFT Emulsion Polymerization and Application to PVC

2014, 28 (12): 25-29; DOI: 10.19491/j.issn.1001-9278.2014.12.006

Abstract ( 466 ) PDF (0 KB)( 61 )

Abstract: The MMA-g-BA-g-MMA (MBM) triblock copolymer was synthesized via RAFT emulsion polymerization and was blended with PVC. The plasticizing behavior and Dynamic mechanical properties were studied using torque rheometer and dynamic mechanical analyzer, and the mechanical properties were tested. The results indicate that MBM can efficiently reduce the plasticizing time and the balance torque; The blends show the best impact strength when the MBM content is 25 wt%, which is 3.0 times higher than neat PVC. As the MBM content increases, the storage modulus decreases to some extent, the tanδ peak value falls down and then rises and the Tg increases by about 5 oC to pure PVC. MBM can be used as processing and toughing aid for PVC.

Study on Silicone Rubber Surface Grafted Polyacrylamide by Ultraviolet

2014, 28 (12): 30-34; DOI: 10.19491/j.issn.1001-9278.2014.12.007

Abstract ( 373 ) PDF (0 KB)( 60 )

The surface of silicone rubber was modified via the grafting of polyacrylamide ( PAAM) by Ultraviolet, The surface composition and morphology of the modified silicone rubber were characterized by Fourier transform infrared spectroscopy (FT-IR) , contact angle measurement and scanning electron microscopy (SEM). The results showed that under 1kw Ultraviolet, the optimum distance between the silicone rubber and UV was 15cm, the optimum volume ratio of C3H3O/H2O was 6:4 and the optimum photoinitiator content was 0.3%.

Preparation of Extruded Polystyrene Foam hing Plate with Carbon Dioxide and Ethanol Blends as Blowing Agent

2014, 28 (12): 35-40; DOI: 10.19491/j.issn.1001-9278.2014.12.008

Abstract ( 530 ) PDF (0 KB)( 62 )

Extruded polystyrene foaming plate was prepared using carbon dioxide (CO2)and ethanol (EtOH) as physical blowing agents. The effect of CO2/EtOH ratio on expansions and cellular morphology of the foam plate were discussed. The foam density and foam morphology of extruded polystyrene foaming plate were tested by densitometer and scanning electron microscopy. The density of extruded polystyrene foaming plate decreased with increasing content of blowing agents. Specially, the cell density increased and cell size decreased with increasing CO2 content and the cell size increased with increasing EtOH content.

Preparation and Properties of Polytetrafluoroethylene Functionalized Carbon Nanotubes/Epoxy Composites

WANG Dengwu, WANG Fang

2014, 28 (12): 41-44; DOI: 10.19491/j.issn.1001-9278.2014.12.009

Abstract ( 386 ) PDF (0 KB)( 76 )

Carbon nanotubes (CNTs) were functionalized by polytetrafluoroethylene and fluorinating CNTs (F-CNTs)/epoxy composites were prepared by ultrasonication and mold casting method. As a comparison, raw CNTs and F-CNTs have been characterized by using FTIR, XRD, TEM. The results showed that C–F bonds were created on the side wall of CNTs, successfully synthesized F-CNTs. The F-CNTs could form stable suspension solutions in organic solvents, which disperse easily in polymers. Their impact strength and flexural strength of F-CNTs/epoxy composites were investigated with different content of F-CNTs. The results show that when the content of F-CNTs is 1.5wt%, the impact strength and flexural strength are 25.85kJ/m2、128.1MPa, respectively.

The Preparation and Characterization of Polyimide/Hydrotalcite Composite

2014, 28 (12): 45-49; DOI: 10.19491/j.issn.1001-9278.2014.12.010

Abstract ( 261 ) PDF (0 KB)( 55 )

The mixture of 4,4’-diaminodiphenyl ether (ODA), 3,3’,4,4’-biphenyltetracarboxylic dianhydride (BPDA) and hydrotalcite were thoroughly ground to get oligomer by solid phase prepolymerized. After polymerized in solvent, the composite of polyimide/hydrotalcite was obtained through thermal imidiation process. The structures and components of composite materials had been characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The thermal property, mechanical property and surface character of the composites had been studied also. The results show that the polyimide/hydrotalcite composites with better dispersed hydrotalcite were gained by this method. And the heat resistance and mechanical performance of the composites were improved when the contents of hydrotalcite in a certain range.

Morphology and Properties of PP/POE Blends Prepared by Supercritical C0₂一aided Extrusion

2014, 28 (12): 50-59; DOI: 10.19491/j.issn.1001-9278.2014.12.012

Abstract ( 424 ) PDF (0 KB)( 54 )

Polypropylene/Ethylene-octene copolymer blends(PP/POE = 100/10)were prepared using a two-stage extruder with the aid of supercritical carbon dioxide(sc-CO2).The morphology of PP/POE blends was characterized by scanning electron microscope, and the size distribution of POE in PP based on SEM images was carried out quantitatively using a computerized image analyzer with Image-Pro Plus software. n differential scanning calorimeter was used to study the crystallization and melting behaviors of the samples，and the crystal morphology of PP/POE blends was observed by polarized optical microscopy equipped with a hot stage. The results showed that PP2. 5 sample, in which POE elastomer droplets were uniformly dispersed，had minimum average diameter(0. 34 μm) and size distribution(1. 44)of POE elastomer domains. PP2. 5 sample also had the highest degree of crystallinity (53. 57%)，and the smallest size of crystallites in all of the samples.

Curing properties of hydrogenated bisphenolA tape epoxy resin

2014, 28 (12): 60-66; DOI: 10.19491/j.issn.1001-9278.2014.12.013

Abstract ( 590 ) PDF (0 KB)( 60 )

The curing reactions of hydrogenated bisphenol A type epoxy resin with three different kinds of curing agents, such as polyether amine (D-230, T-403) and methyl tetrahydrophthalic anhydride (MeTHPA) were researched in this paper. The curing reaction kinetics, the apparent activation energy, the gel time, the shear strength and the surface morphology of the impact toughness of composites had been extensively characterized by various analytical techniques. As a result, with the temperature increasing, the gel time of the three adhesive systems has a noticeable decrease and the gel time of MeTHPA epoxy adhesive system was the shortest. The shear strength of T-403 epoxy adhesive system reached up to 30.059MPa. However, the impact toughness of D-230 epoxy composite was the best. The apparent activation energy of those three system were 56.55kJ/mol, 63.99kJ/mol and 67.60kJ/mol, respectively. The reaction order were 0.865, 0.902 and 0.998, respectively.

Effect of Thermal Aging on internal Structure of RVV Cable Insulation

2014, 28 (12): 67-72; DOI: 10.19491/j.issn.1001-9278.2014.12.014

Abstract ( 386 ) PDF (0 KB)( 65 )

Abstract: The mechanism of the internal structure and the insulation failure of RVV cable insulation are studied by the FFT infrared spectrometer. The test data shows that there are not alcohols, phenols, organic acids, alkyne and olefinic compounds and its characteristic peak is associated with functional groups or compounds. Due to the extension of standard thermal aging time, the components of cable insulation changes and the characteristic peak decreases gradually. The formation of the C=C conjugate structure and the O－H strong polar enhance the conductivity of the insulating layer during the process of thermal aging of RVV cable insulation. The deeper the thermal aging degree is, the easier the insulation failure of RVV cable insulation layer is.

Application to UPVC processing of Hapro torque Rheometer

2014, 28 (12): 73-78; DOI: 10.19491/j.issn.1001-9278.2014.12.015

Abstract ( 412 ) PDF (0 KB)( 60 )

UPVC formula design and it’s application in moulding were introduced.Including the choice of stabilizer ,Lubrication balance adjustment , additives performance test ,production process optimization and quality control.

Research on Preparation and Use of Polyurethane/SiO2 Ultrafiltration Membrane

2014, 28 (12): 79-83; DOI: 10.19491/j.issn.1001-9278.2014.12.016

Abstract ( 341 ) PDF (0 KB)( 49 )

The PU/SiO2 composite ultrafiltration membranes with different content and diameter of SiO2 were prepared based on wet phase transition method. The properties and structures of the membrane were investigated via membrane instrument and SEM. The results showed that with the adding of SiO2 the pure water flux of the composite membrane can be improved acutely. The effect of SiO2 with different diameter is not the same. The retention and porosity of the micrometer SiO2 composite membrane increased firstly then decreased when the percent of SiO2 is too high, but the effect and the dosage were different because of the diameter of SiO2. The ultrafiltration membrane was used to treat the black paper-making liquor and gained good results.

Poly(vinyl chloride) plasticized with polyester based Glycery Monolaurate—synthesis and characterization

2014, 28 (12): 84-87; DOI: 10.19491/j.issn.1001-9278.2014.12.017

Abstract ( 348 ) PDF (0 KB)( 76 )

poly(sebacic acid -glycery monolaurate) was synthesized with sebacic acid and glycery monolaurate using tetrabutyl titanate as catalyst. The polyester was characterized by gel permeation chromatography (GPC), nuclear magnetic response spectroscopy (1HNMR) and fourier transform infrared spectroscopy(FT IR). The blend of the polyester and poly(vinyl chloride)(PVC) was Thermoplastic molding. The mechanical properties and the thermodynamic properties of the blends were characterized using thermogravimetric analysis(TG), differential scanning calorimetry(DSC) and universal tensile testing machine. The results showed that the polyester could improve the thermal stability and reduce the glass transition temperature of PVC, the excellent mechanical and thermal PVC products will be prepared by using polyester and phthalate as mixed plasticizer.

Synthesis of Composite carboxylic lanthanum for PVC and Study on Its Thermal Stability Mechanism

2014, 28 (12): 88-92; DOI: 10.19491/j.issn.1001-9278.2014.12.018

Abstract ( 263 ) PDF (0 KB)( 85 )

Using lauric acid, tetradecane diacid, citric acid and lanthanum nitrate as precursors, a composite carboxylic lanthanum was synthesized, which was used in PVC as thermal stabilizer. By Congo red and torque rheometer, the static and dynamic thermal stability of PVC was tested. The results showed that the products behaved good thermal stability for PVC and good synergistic effect with additives. FT-IR showed that, when heated, coordination of lanthanum ion was the major factor for reducing degradation of PVC. Meanwhile, the carboxylate also could absorbed HCl. UV showed that lauric acid lanthanum was a early stage thermal stabilizer, but tetradecane diacid lanthanum and citric acid lanthanum behaved a long-term thermal stability.

Structure and Property of Polypropylene /Waste Printed Circuit Boards Nonmetallic Powder Composites

2014, 28 (12): 93-98; DOI: 10.19491/j.issn.1001-9278.2014.12.019

Abstract ( 249 ) PDF (0 KB)( 50 )

Polypropylene matrix composites was prepared by melt blending which filled with nonmetallic powder from waste printed circuit boards. Changes of crystallization and melting behavior, thermal stability, dynamic mechanical properties and impact fracture surface morphology of composites were analyzed with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and scanning electron microscope analysis（SEM）, respectively. The results demonstrate that crystallization rate, crystallinity, thermal stability and storage modulus of composites enhance obviously, while melting point, mechanical loss factor and glass transition temperature decrease slightly. The waste PCB powder are evenly distributed on PP, the interfacial adhesion is better.

Advanced Manufacturing Technology for All-plastic Body of New Energy Vehicles

2014, 28 (12): 99-103; DOI: 10.19491/j.issn.1001-9278.2014.12.020

Abstract ( 380 ) PDF (0 KB)( 63 )

Lightweight technology is the current car one of the most effective way of energy saving and emission reduction. All-plastic body molding method is the key technology to the breakthrough lightweight of automobile. Rotational molding process can be applied to achieve the overall automobile plasticizing manufacturing. This paper mainly describes the overall lightweight design, molding equipment, body mold, processing technology and other advanced manufacturing technology of all-plastic body, and carries on the research contrast test. The results show that the application of computer-aided design, mechatronics and polymer materials in advanced technology, through the rotational molding equipment by heat analysis and optimization of energy efficiency, the use of wireless temperature measurement technology in the mold, the blocking unit quick clamping technology and micro-foam technology can meet the all-plastic body forming a whole.

Application of genetic algorithm in optimization of injection molding for complex and thick-wall parts

2014, 28 (12): 104-108; DOI: 10.19491/j.issn.1001-9278.2014.12.021

Abstract ( 256 ) PDF (0 KB)( 48 )

Took a complex thick-wall part as the research subject, established the finite model. Analyzed it’s maximum warping deformation under the initial process by CAE. Build the plastic part warpage quantity optimization model, based on the BP neural network combined with genetic algorithm to optimize the processing parameter of the model, optimal process parameters were showed the maximum warping deformation was 0.2313mm, compared to the initial maximum warping deformation which obtained in the initial process by CAE was reduced by 21.53%, improved the quality of the plastic parts and satisfied the requirements of the assembly parts. Research results further confirmed the validity and reliability of the proposed BP-GA based optimization method for plastic injection forming.