Current Issue

2015, Volume 29 Issue 02 Publication date: 26 February 2015 Previous Issue Next Issue

Progress on Modification of Polyimide By Nanoscale Materials

2015, 29 (02): 1-7 ; DOI: 10.19491/j.issn.1001-9278.2015.02.001

Abstract ( 994 )

The lastest progress on the modification of PI by nanoscale materials including nano-Al2O3, nano-SiO2, nano-TiO2, nano-MgO , nano-ZnO, nano-BaTiO3, POSS, graphene and carbon nanotube was reviewed. The influence of coupling agents on properties of hybrid films was analyzed. Finally the future development trend was prospected.

Advances in Study on Dicarboxylate β-Nucleating Agents of Polypropylene

2015, 29 (02): 8-14 ; DOI: 10.19491/j.issn.1001-9278.2015.02.002

Abstract ( 1061 )

The advances in β-nucleating agents of polypropylene including four kinds of important polypropylene β-nucleating agents were reviewed, especially the dicarboxylate β-nucleating agents of polypropylene.This review aimed to summarize the current research of the β-nucleating agents and the influence of the β-nucleating agents on the properties of polypropylene. Finally, the development trends of β-nucleating agents were discussed.

Research Progress in Fully Biodegradable PLA/PPC Blends

2015, 29 (02): 15-21; DOI: 10.19491/j.issn.1001-9278.2015.02.003

Abstract ( 1044 )

Research progress in fully biodegradable PLA/PPC blends was reviewed. Their compatibility，melting and crystallization behavior，mechanical properties，rheological behavior and processing ability, etc. were introduced.

Preparation and Property of Expanded Polytetrafluoroethylence Material

2015, 29 (02): 22-26; DOI: 10.19491/j.issn.1001-9278.2015.02.004

Abstract ( 1140 )

Prepare the microporous structure of expanded polytetrafluoroethylence material, using the pore-forming agent method. Study the effect of pore-forming agent treatment on the compressibility and recovery of polytetrafluoroethylence. It showed that the density and hardness of polytetrafluoroethylence decreased, while the porosity increased with the increase of processing content pore-forming agent. Compressibility and recovery of polytetrafluoroethylence vary with different kind of pore-forming agent.

Study On The Conductivity of Nickel-Coated Carbon Fiber/ Nickel-Graphite Powder Filled PC/ABS

2015, 29 (02): 27-31; DOI: 10.19491/j.issn.1001-9278.2015.02.005

Abstract ( 1022 )

A novel filled conductive plastics was prepared by adding nickel-coated carbon fiber/ nickel-graphite powder into PC/ABS. The effects of the conductive filler content and the L/D radio of NiCF on the conductivity of the composites were studied. The results showed when the conductive filler content was increased, the volume resistivity of the composites would decrease, which means the conductivity was improved. Compared with nickel-graphite powder, the effect of NiCF on the conductivity of composites was more significant. The composites have percolation effect, when the NiCF content was between the range of 10% to 15%, the volume resistivity of the composites declined, and the conductivity improved sharply. When the length of the composite particles was about 10mm, the conductivity of the injection molded composites was the best.

Study on Crystallization and Rheological Behaviors of PBT/PP/POE-g-GMA Blends

2015, 29 (02): 32-38; DOI: 10.19491/j.issn.1001-9278.2015.02.006

Abstract ( 701 )

Abstract: The poly(butylenes terephthalate)/(propylene)(PBT/PP) blends compatibilized by poly(ethylene-octene) (POE-g-GMA) grafted glycidyl methacrylate were prepared by melting using torque rheometer and were characterized by scanning electron microscope(SEM), dynamic rheological testing, differential scanning calorimeter(DSC) and polarizing microscope(POM), respectively. It was clear that the introduction of POE-g-GMA into PBT/PP blends results in, (1) the size of particles in the PBT/PP system decreased and the interface between phases became obscured, (2) new macromolecular chains with a prolonged the relaxation time formed, which increased the system viscosity and finally created a kind of gel network structure, (3) the crystalline property of the PBT/PP blends showed component-dependence.

Study on toughening and keeping strength properties of domestic polyoxymethylene copolymer

2015, 29 (02): 39-43; DOI: 10.19491/j.issn.1001-9278.2015.02.007

Abstract ( 1014 )

In this research, silicone rubber powder and nano-vulcanized styrene butadiene rubber (SBR) were selected to toughen the domestic polyoxymethylene copolymer (POM). By the universal tensile tester, thermogravimetric analysis, differential scanning calorimetry, polarizing microscope, X-ray diffraction and scanning electron microscopy, the crystallization behavior and mechanical properties of the modified polyoxymethylene were analyzed and researched. It was shown that the optimum amount of silicone rubber was 3% of the total mass and the optimum amount of nano-vulcanized SBR is 1% of the total mass; the toughening agent can be refined crystal of POM; the impact resistance of the modified POM was improved more than 30% while the tensile strength of it was almost no decline.

Study on the performance of carbon fiber composite materials based on TDE-85/PES resin matrix

2015, 29 (02): 44-48 ; DOI: 10.19491/j.issn.1001-9278.2015.02.008

Abstract ( 752 )

Short carbon fiber reinforced TDE-85 epoxy resin composite material was prepared, the effects of carbon fiber content on the mechanic properties and heat resistance of composite material were studied. The results show that the mechanical properties and thermal stability of composites could be improved obviously by adding carbon fiber, as the content of carbon fiber was 0.25%, the tensile strength, impact toughness, flexural strength and flexural modulus were maximum, increased by 29.33%, 25.31%, 30.28% and 68.93%. In addition, the morphology of the bending fracture surface of the composites were analyzed, the results show that a certain amount of carbon fiber can be well dispersed in the resin matrix, besides, the precursor of carbon fiber and resin matrix interfacial bonding was relatively weak, as mainly depends on the physical fitted between the carbon fiber and resin matrix.

Preparation and Performance Research of the PBC-PLA Biodegradable Film

2015, 29 (02): 49-52; DOI: 10.19491/j.issn.1001-9278.2015.02.009

Abstract ( 813 )

PLA ( Polylactic acid ) as the main raw material were blown special resin mixture obtained by twin-screw extruder, and then we blew out of the PBC / PLA multi-component film on film blowing machine. To study the tensile testing and the processing performance we could conclude that when the mass ratio of PLA: PBC: citrate : erucic acid amide: antioxidant (1010) : chain extender agent was equal to 100:20:10:2:0.2:0.5, the processing performance and the mechanical properties are good, and the tensile strength reached to 58.50 MPa, elongation at break reached up to 192.50% , it greatly enhanced the toughness of the PLA; It was found by enzymatic degradation experiment, the degradation of the multicomponent biodegradable films of PBC/PLA gradually increased with the increase of the content of PBC but it didn’t increase too much comparing with the pure PLA.

Kinetics of Thermal Degradation of Nano-diamond/Polypropylene Composite Material

2015, 29 (02): 53-58 ; DOI: 10.19491/j.issn.1001-9278.2015.02.010

Abstract ( 859 )

The different proportions of Nano-diamond/ polypropylene(PP) composites were prepared by melt blending, and thermal degradation kinetics of the composite material was investigated by means of thermogravimetry analysis(TGA). The thermal degradation activation energy(Ea) of the blends was calculated by Flynn-Wall-Ozawa, Friedman and Kissinger methods. The results show that the non-isothermal degradation of Nano-diamond/PP composites is a one-stage degradation process and Nano-diamond could visibly enhance thermal stability of the composite material. However, the enhancement of thermal stability becomes obvious with the increasing of Nano-diamond concentration, and then slight. When the content of Nano-diamond is 3%, the enhancement stands at maximum. And the increase of thermal degradation Ea varies from 5 kJ/mol to 30 kJ/mol.

Preparation and properties of intumescent APP/MA/PEPB flame retardant ABS

2015, 29 (02): 59-62; DOI: 10.19491/j.issn.1001-9278.2015.02.011

Abstract ( 859 )

Acid (1 - oxo-2 ,6,7 - three oxa-1 - P-bicyclo [2.2.2] octan-4 - yl) methyl ester (PEPB) as carbon agent was Synthesized by Oxygen-4 - (hydroxymethyl) -2, 6, 7 -trioxa - phosphabicyclo [2, 2, 2] octane (PEPA) and benzoyl chloride.The accuracy of structure was proved by FT-IR and 1H-NMR. PEPB and melamine（MA）with ammonium polyphosphate (APP) were mixed as intumescent flame retardants. when the mass ratio of APP,MA and PEPB were 2:1:2 ,the mass fraction was 30%, vertical buming test of the flame-retarded ABS composites reached V-0. The tensile strength and absorbency of composites were 40.15MPa and 1.77%.Compared to the intumescent flame retardants made of APP,MA and PER, the tensile strength increased by 33.4% and absorbency decreased by 84.2%. The char layer microstructure was compact.

Star Poly(ε-caprolactone) as a Nonmigrating flame retardant Plasticizer for Polylactide

2015, 29 (02): 63-67; DOI: 10.19491/j.issn.1001-9278.2015.02.012

Abstract ( 657 )

Star-shaped poly(ε-caprolactone)(SPCL) was synthesized by ring-opening polymerization of ε-CL from hydroxyl end-capped cyclophosphazene initiators. The SPCL was used as flame-retardant plasticizers for polylactide(PLA) and compared with liner poly(ε-caprolactone)(LPCL) and acetyltributyl citrate(ATBC). The experiment data the plasticization efficiency of SPCL was higher than that of LPCL, but lower than that of ATBC. When 20 phr SPCL was added, the ultimate elongation of the PLA/SPCL composites increased from 7.40% to 18.86%. Meanwhile the tensile strength of the PLA/SPCL composites was obviously superior to the other composites. Thermo-gravimetric analysis (TGA) and limited oxygen index (LOI) results indicated that the addition of SPCL can promote the flame retardancy of the composites and had tiny effect on crystallinity and thermal stability of PLA. Migration tests showed that there no migration was determined for PLA/SPCL composites. Compared with ATBC SPCL, SPCL was an excellent nonmigrating plasticizer.

The Study of Heat Transfer Coefficient in Film Blowing of PLA

2015, 29 (02): 68-72; DOI: 10.19491/j.issn.1001-9278.2015.02.013

Abstract ( 636 )

In this paper, the cooling process of film blowing of Polylactic Acid (PLA) was studied. The temperature at the outside surface of the bubble was measured as a function of vertical distance from the die by an infrared pyrometer. The heat transfer coefficient (h) was studied at different airflow rates (Qv=0,0.66,1.33,2L/s) and different BUR (BUR=1.7,2.3). The correlation between heat transfer coefficient and axial distance is also reported. The results show that: the temperature decreases faster as the airflow rate increases; the heat transfer coefficient changes so small at lower airflow rates; the heat transfer coefficient inside the air ring are higher for higher airflow rates at higher airflow rates; the temperature decreases faster as the BUR increases and the heat transfer coefficient inside the air ring are higher for higher BUR; the heat transfer coefficient (h) is a function of the axial distance (Z) at different airflow rates.

Preparation and Properties of Waterborne Polyacrylate /Modified Chlorinated Polypropylene Composite Primer

2015, 29 (02): 73-78; DOI: 10.19491/j.issn.1001-9278.2015.02.014

Abstract ( 686 )

Waterborne polyacrylate (WPA) was obtained by copolymerization of acrylic acid(AA), butyl acrylate (BA), methyl methacrylate (MMA) in solution. Grafted modified chlorinated polypropylene (MCPP) was obtained through modification of chlorinated polypropylene used acrylic acid(AA) and butyl acrylate (BA). Composite primer was obtained by the combination of WPA and MCPP. The effects of the content of AA (compared to the mass of WPA) and the molecular weight of WPA on the emulsion properties were investigated. The optimum content of AA was 12% and the optimum molecular weight of WPA was 20277. The effects of different ratio between WPA and MCPP on the emulsion properties, surface tension and adhesion were also investigated. The results showed that the particle size of the emulsion decreased, the surface tension of the primer increased, the adhesion decreased slightly with the increasing of the content of WPA. When m(WPA):m(MCPP)=3:7, the particle size was 98nm, surface tension was 47mN/m, adhesion was grade 0. The emulsion of the composite primer was stable and the surface properties and adhesion were good. The composite primer has broad application prospects.

Study on fatigue fracture properties of aeronautical laminated directional PMMA by stroboscopic method

2015, 29 (02): 79-83; DOI: 10.19491/j.issn.1001-9278.2015.02.015

Abstract ( 697 )

The fatigue fracture properties of the aircraft canopy are important for the safety of the aircraft. The stroboscopic method combined with the digital image correlation method is used for the fatigue testing. This method can transform the dynamic process into the static process. This method is used to study the fatigue fracture properties of the laminated directional PMMA. Through analyzing the experimental results the fatigue crack extends along the declining direction in the stress concentration area. The conclusion is uniform with the actual extending direction which can express the experimental results are accurate.

Effects of annealing conditions on oriented lamellar structures of PP cast precursor and microporous membrane formation by uniaxially stretching

2015, 29 (02): 84-89 ; DOI: 10.19491/j.issn.1001-9278.2015.02.016

Abstract ( 625 )

Abstract: The effects of annealing temperature, annealing time and tensile stress applying to precursors during the annealing process on the oriented lamellar structures of PP cast precursors and micropore-forming performance by uniaxially stretching were investigated. Crystallinity, lamellar thickness, lamellar crystalline orientation and elastic recovery of PP casting precursors were characterized by DSC, FT-IR, SEM and electronic mechanical tester. Microporous structure was evaluated with porosity and Gurley value. It was found that the oriented lamellar structure of PP casting precursor was gradually improved as the annealing temperature increased from 120℃ to 145℃, leading to an higher elastic recovery value of PP casting precursor and better micropore-forming performance by uniaxially stretching. Further raising annealing temperature, however, would damage the oriented lamellar structure of PP casting precursor, giving rise to lower levels of porosity and permeability after uniaxially stretching. By prolonging annealing time at 145℃, crystallinity, lamellar thickness, lamellar crystalline orientation and elastic recovery of PP casting precursors kept increase at first, and leveled off after 30 min. Applying moderate tensile stress to precursor film during annealing process could increase lamellar crystalline orientation and elastic recovery value of the film, resulting in better micropore-forming performance.

Analysis of Process Parameters’ Influence on the Infusion Bottle Embryo Injection’s Molding Properties

2015, 29 (02): 90-97; DOI: 10.19491/j.issn.1001-9278.2015.02.017

Abstract ( 999 )

In order to study the effect of processing parameters on the 250ml infusion bottle embryo’s injection molding properties, the mathematical model of which melt flowing in the mold cavity was set up on the basis of the heat transfer and plastics processing rheology theory. According to the principles of orthogonal experiment, the L16 (44) orthogonal test table of four factors and four levels by .the combined effect of. melt temperature, packing pressure, mold temperature, holding time and other parameters was established,. the infusion bottle embryo flowing molding process was simulated by using the Moldflow software, and the optimum process parameters were obtained using range and variance analysis method. By tryout test under the above conditions, the quality of the bottles embryo was qualified, size tolerance requirement was satisfied.

The effect of Non-toxic and environmentally friendly plasticizers on the properties of Poly(vinyl chloride)

2015, 29 (02): 98-102; DOI: 10.19491/j.issn.1001-9278.2015.02.018

Abstract ( 784 )

Effects of six different plasticizers on the mechanical property,thermal stability of poly(vinyl chloride) (PVC) compound were studied.The changes of Tg were studied by DSC,also shows the effectiveness of different plasticizers.The results showed that PVC plasticized by DOTP and TOTM have better static thermal stability at 180℃.The effect of plasticizers on the mechanical properties of PVC have no evident difference,while DOTP and TOTM plasticized PVC has higher hardness than others.The Tg of TOTM and ATBC plasticized PVC were about -22℃,other four plasticizer plasticized PVC has almost the same Tg of about -25℃.

Synthesis of Hexaphenoxycyclotriphosphazene and Its Flame Retardant Application in Acrylic Resin

2015, 29 (02): 103-108; DOI: 10.19491/j.issn.1001-9278.2015.02.019

Abstract ( 877 )

Hexaphenoxycyclotriphosphazene (HPCP) was synthesized by using Hexachlorocyclotriphosphazene (HCCP), phenol and sodium hydride as raw materials, with K2CO3 as catalyst and acetone as solvent. The product was characterized by FTIR, 1H NMR, 13C NMR, 31P NMR, DSC, TGA. HPCP was applied in acrylic resin as flame retardant and the effect of HPCP’s content on the thermal and flame-retardant properties was investigaged. The results showed that when the addition of 20 wt % HPCP, the acrylic resin could pass UL-94 V-0 classification and its limiting oxygen index (LOI) value was increased from 17.5 % to 32.2 %, and the residual mass up to 18.95 % in air at 700 ℃, mean heat release rate (Mean HRR) and total heat release (THR) were reduced to 43 kW/m2 and 42 MJ/m2, respectively.

Evaluation on Melt Conveying Capacity of Three-screw Extruder

2015, 29 (02): 109-114 ; DOI: 10.19491/j.issn.1001-9278.2015.02.020

Abstract ( 953 )

A comprehensive evaluation on melt conveying capacity of triangle arrayed triple-screw extruder, line arrayed triple-screw extruder and twin-screw extruder was carried out through the experiment of silicone oil extrusion. Dimensionless groups and traditional parameters were both used to evaluate the pressure generation capacity and energy consumption of the three extruders. And the experiments also reflected the influence of screw speed and throughput on the conveying capacity of the extruders. The research showed the triangle arrayed triple-screw extruder has better melt conveying performance than the others. And the reliability of the dimensionless evaluation was also proved, it can be applied to more evaluation between varies kinds or sizes of extruders.