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2009, Volume 23 Issue 08 Publication date: 26 August 2009 Previous Issue Next Issue

Technological Progress in High Speed Extrusion of Single-screw Extruders

PAN Long, ZHANG Yu-xia, JIN Ming, XUE Ping

2009, 23 (08): 1-6 ; DOI: 10.19491/j.issn.1001-9278.2009.08.001

Abstract ( 2023 )

The technology of high speed single-screw extrusion was briefly reviewed. The extrusion, heating and cooling, and drive systems on regular and high speed extruders were compared, the innovation in screw parameter and placement, barrel cooling, flow layout, and drive mode of the high speed extruders were summarized. The shortcomings in current high speed extruders were pointed out, the developing trends in materials adaptability and analog control were discussed. The latest extruders supplied by the top manufacturers were listed.

Preliminary Research on Needleless electrospinning for fabricating polymer nanofibres

XU Zhi-Juan, LIN Xue-chun, ZHOU Jian-guo

2009, 23 (08): 7-12 ; DOI: 10.19491/j.issn.1001-9278.2009.08.002

Abstract ( 1620 )

The fundamental mechanisms on the needleless electrospinning were described. The three typical approaches to induce perturbed surface waves during needleless electrospinning, namely magnetic field, aerated solution bubbling, and rotating disc electrodes, were introduced, with their principles, features and applications analyzed. The advantages of needleless electrospinning in feasibility and efficiency over needle electrospinning were confirmed in the experiments using rotating disc electrode method.

Preparation and Characterization of PC/PA1010 Alloy with Solvent Resistance

2009, 23 (08): 13-17 ; DOI: 10.19491/j.issn.1001-9278.2009.08.003

Abstract ( 2199 )

The mechanical property, heat resistance, solvent resistance, and dynamic rheological property of the PC/PA1010 and PC/PA1010/PE-g-GMA blends were investigated, in which PE-g-GMA was as a reactive compatibilizer. It showed that PA1010 improved the solvent-resistance of polycarbonate without reducing its impact strength. PE-g-GMA improved the interaction between PC and PA1010 resulting in the enhancement of interfacial adhesion and mechanical properties. The optimum properties were obtained when the weight ratios of PC/PA1010/PE-g-GMA were 80/15/5.

Structure and Property of Fully Biodegradable Poly(butylene succinate)/Poly(butylene adipate/Terephthalate)(PBS/PBAT) Blends

XU Guo-zhi

2009, 23 (08): 18-21 ; DOI: 10.19491/j.issn.1001-9278.2009.08.004

Abstract ( 1904 )

Fully biodegradable poly(butylenes succinate)/poly(butylenes adipate/terephthalate) (PBS/PBAT) blends were prepared via melt mixing. The melt flowability, crystallization behavior, mechanical properties, and compatibility of the blends were studied with MFR, DSC, XRD, SEM, and mechanical test. With increasing PBAT content, the tensile strength increased first and then decreased slightly, the impact strength decrease first and then increased, the elongation at break kept increased. When the loading of PBAT was 20wt%, impact strength increased by 82%, elongation at break increased by 1000%, tensile strength decreased only by 6%, compared with neat PBS.

Preparation of Glass Fiber Reinforced Flame Retardant PBT Composite With High CTI 2

ZHANG Chao, XIE Hong-de, HE Shun-lun

2009, 23 (08): 22-26 ; DOI: 10.19491/j.issn.1001-9278.2009.08.005

Abstract ( 2447 )

The influence of an organic phosphorus flame retardant (CJ1002) on the mechanical properties and the flame-retardancy of Glass fiber (20wt%) reinforced polybutylece terephthalate (PBT) was investigated. When the content of the CJ1002 was 18wt%，the tensile strength and flexural strength of the composite changed a little，impact strengh decreased by 33%，the oxygen index reached to 30.1%，and the flame retandant grade was V0. When 2 wt% of CTI synergists was introduced in PBT/GF composition，the comparative tracking index(CTI) reached the maximum of 600V, however, the mechanical properties and flame-retardancy decreased. When the CTI synergists content was 1 wt%，the optimal comprehensive properties were observed.

Mechanical Properties of Octavinyl-polyhedral oligomeric silsesquioxane/ABS Composites

LIU Jun-hui, LV Ke, YANG Rong-jie

2009, 23 (08): 27-30 ; DOI: 10.19491/j.issn.1001-9278.2009.08.006

Abstract ( 2156 )

In this paper the tensile fracture-surface of octavinyl-polyhedral oligomeric silsesquioxane(OVP)/ABS composites was observed using a field emission scanning electron microscopy (SEM). The dispersion of OVP in ABS were analyzed，the influence of OVP content on the micro-morphology of fracture-surfaces of composites were investigated as well. When an initiator was introduced, OVP was grafted onto ABS, resulting in better dispersion and improved mechanical properties.

Rheology and Thermal Properties of Long Chain Branching Polypropylene by Reactive Extrusion

2009, 23 (08): 31-34 ; DOI: 10.19491/j.issn.1001-9278.2009.08.007

Abstract ( 1515 )

Long chain branched polypropylene (LBPP) were prepared via reactive extrusion in the presence of pentaerythritol triacrylate (PETA) and a peroxide. The rheology and thermal properties of linear PP and modified LBPP were evaluated using rotational rheometer and differential scanning calorimetric (DSC). Moreover, the influence of the type of peroxide on the properties and branching degree of LBPP were also evaluated. LBPP exhibited a higher G’ at low frequency, lower Tan δ at low frequency, higher zero shear viscosity, and stronger shear shinning, which constituted the features of long branching. DSC determination showed that the crystallization temperature of LBPP was higher than that of linear PP. In addition, it was found that the type of peroxide did not significantly affect the thermal and rheological properties and branching degree of modified LBPP.

Synthesis of hexaphenoxyl cyclotriphosphazene and its flame retardance on epoxy molding compound for large-scale integrated circuit packaging

YANG Ming-Shan Yang LIU Li-Kai LI Jie DING

2009, 23 (08): 35-38 ; DOI: 10.19491/j.issn.1001-9278.2009.08.008

Abstract ( 2169 )

Hexaphenoxyl cyclotriphosphazene (HPCTPZ) was synthesized using titrating technology from a hexachlorocyclotriphosphazene solution, the structure of HPCTPZ was confirmed using FTIR. The obtained HPCTPZ was introduced as a flame retardant into epoxy molding compound(EMC) for packaging of large-scale integrated circuits. The resulted EMC exhibited a flame-retardance rating of UL 94 V0 and an oxygen index of 33.1.

Effects of Metal Oxides on the Release Characteristic of HCl from the Combustion of Poly (vinyl chloride)

2009, 23 (08): 39-42 ; DOI: 10.19491/j.issn.1001-9278.2009.08.009

Abstract ( 2096 )

Thermogravimetry and electric conductivity determinations were carried out to study the effects of metal oxides on the release characteristic of HCl from the combustion of PVC. It was found that the electric conductivity was linearly related to the concentration of HCl solution in the range of 0 ~ 5.5×10^-4 moL/L. Zinc oxide (ZnO), ferric oxide (Fe₂O₃), copper oxide (CuO), and manganese dioxide (MnO₂) decreased the initiative temperature of PVC during thermal degradation, and shortened the initiative time of HCl releasing, and thus accelerated the HCl emission. In the other hand, titanium dioxide (TiO₂), molybdenum dioxide (MoO₂), and vanadium oxide (V₂O₅) increased the initiative temperature of PVC during thermal degradation, extended the initiative time of HCl releasing, and thus inhibited the HCl emission. The total volume of HCl released from PVC/metal oxides didnot exceed that of neat PVC.

Morphology Construction and Properties of the Conductive PP/EPDM/CB Composite with Sandbag Structure

Xu Xiang-Bin

2009, 23 (08): 43-47 ; DOI: 10.19491/j.issn.1001-9278.2009.08.010

Abstract ( 2048 )

In this paper, a boxing sandbag liked hard core-soft skin structure was proposed for a filled conductive polymer composite with both high conductivity and toughness. Via a two-step method, a polypropylene/ethylene propylene diene monomer/carbon black (PP/EPDM/CB) ternary composite with a sandbag structure was prepared, in which PP constituted the continuous phase and EPDM the dispersed phase with CB particles selectively distributed in EPDM. Quantitative calculation confirmed that CB preferably distributed in EPDM for both dynamical and thermodynamical reasons, which provided the mechanism of the formation of “sandbag” microstructure. It was found that the volume conductivity and notched impact strength increased simultaneously with increasing CB loading.

Crystalline Morphology of PLLA-PDLA Copolymers Films

LI Hai-dong, LIN Yu-han, NIE Wei, JI Xiang-ling

2009, 23 (08): 48-52 ; DOI: 10.19491/j.issn.1001-9278.2009.08.011

Abstract ( 1822 )

PLLA-PDLA copolymer film was obtained through spin-coating and crystallized at constant temperature. Thermal property, crystalline morphology, and crystalline structure of the film were studied uisng DSC、AFM, and XRD. At 128-153℃, an obvious crystallization peak was observed. AFM was applied to characterize the crystalline morphology of the film from different crystallization temperature, solution concentration, time, solvent, and substrate. Several rod-shaped and branching crystals with different size were observed. Especially, branching and entangled structures were observed on glass substrate, with a higher coverage density than on the silicon substrate. The XRD gave diffraction peaks at 2q values of 12.01°, 20.88°, and 24.18°.

Study on crystallization behaviors of polyethylene/clay nanocomposites

WANG Xiang-dong Yuxia Zhang

2009, 23 (08): 53-60 ; DOI: 10.19491/j.issn.1001-9278.2009.08.012

Abstract ( 1565 )

In this article, high density polyethylene/clay nanocomposites were prepared via melt intercalation. The crystallization behavior was investigated uisng differential scanning calorimetry (DSC) at various cooling rates. Avrami, Ozawa, and Mo methods were applied to describe the crystallization process under nonisothermal conditions. The crystallization temperature, melting temperature, and crystallinity of nano-composites were found higher than those of neat PE-HD. The values of t_1/2, , and showed that clay played a role of heterogeneous nucleating agent and accelerated the crystallization process of PE-HD, which could be attributed to the "intercalation" structure formed between PE-HD and clay.

Study of Biaxially Self-reinforced Polypropene Pipes under Complex Stress Field

PAN Yi-liang, ZHAO Guo-dong, ZHENG Wei, CAI Xu-fu, SHEN Kai-zhi

2009, 23 (08): 61-65 ; DOI: 10.19491/j.issn.1001-9278.2009.08.013

Abstract ( 2078 )

Polypropene pipe (F401) was extruded using a home-made shearing/draw biaxial complex stress field die. Compared to regularly extruded pipes, the circumferential and axial tensile strengths of F401 were 21.4 % and 21.1 % higher, respectively, when the shear casing rotational speed was 10 r/min and the shear casing temperature was 190 ℃. F401 samples were characterized by SEM, WAXD, and DSC. It was found that the spherulites of F401 pipe was not obvious and arranged more regularly. The melting points drift to higher temperature and the degree of crystallinity increased. XRD showed the orientation in both directions of F401 was higher than regular ones.

Study on the Preparation of the Environmental Protective Flame Retardant Wet-process PU leather

LI Dao-peng, HUANG Wan-lin, YAO He-ping, WANG Yi-feng, WANG Yan-wu

2009, 23 (08): 66-68 ; DOI: 10.19491/j.issn.1001-9278.2009.08.014

Abstract ( 2115 )

Liquid phosphate ester flame retardants were applied onto polyester / cotton fabric at a loading of 5wt% based on dry fabric via impregnation, resulting a fabric with B level of United States FMVSS-302 standard. Six flame retardants were introduced into polyurethane to study the fire retardant effect. It was found that aluminum hydroxide/resorcinol dual/phosphate (12/2/2 by weight) composite fire retardant system may result in a combustion rate of 0 mm / min, achieving A level, from which environment-friendly, fire-retardant synthetic leather could be produced.

Studies on Water Absorption of Wood Flour-Filled Polyethylene composites

LI Shan-shan, LV Qun, LI Wei, LAI Guo-qiao, YANG Hai-tang

2009, 23 (08): 69-74 ; DOI: 10.19491/j.issn.1001-9278.2009.08.015

Abstract ( 2087 )

MAH-g-polyethylene (PE)/neat PE/ wood-flour composites were prepared by extrusion. The influence of the content of MAH-g-PE and wood-flour on the water absorption of the composite was studied. Kept the weight ratio of MAH-g- PE/neat PE constant, the water absorption decreased with decreasing wood-flour content. At high wood-flour loading, the higher the content of MAH-g-PE, the lower the water absorption. The lower the water absorption, the higher the wet mechanical properties.

Effect of γ-irradiation on HDPE and Properties of wood Fiber/γ- HDPE Composites

Zhang Feng Bin Li Li-hua Guo

2009, 23 (08): 75-78 ; DOI: 10.19491/j.issn.1001-9278.2009.08.016

Abstract ( 2122 )

The effect of γ-irradiation on the molecular structure, melt flow rate, melting point, and crystallization structure of PE-HD and on the mechanical properties of PE-HD/wood-flour composites were studied through FT-IR , DSC, TEM, and mechanical properties testing. Because polar groups were generated on the PE-HD chain by γ-irradiation, the interfacial adhesion with wood-flour was enhanced, and the mechanical properties of the composite were improved. Both tensile and flexural strengths were increased by 80%, impact strength increased by 36%. SEM micrographs revealed that wood-flour was finely dispersed in polymer matrix.

The studied on application of Microbicidal SiOx Nanoparticle to Preparation of PVC/ (Quaternary Ammonium Salt)- SiO_x Composites

WANG Guang-li, TANG Yu

2009, 23 (08): 79-82 ; DOI: 10.19491/j.issn.1001-9278.2009.08.017

Abstract ( 1526 )

PVC/microbicidal nanometer-SiOx powder composite materials were prepared by direct melt blending. When the loading of microbicidal nanometer-SiOx powder was 1wt%, the bactericidal rates for E.coli and S.aureus were 92% and 89%, respectively. The microbicidal composites possessed a long-term antibacterial and a toughening effect. The tensile and impact strengths of the composite increased 66.3% and 124.1%, respectively. Electric probe with plane element-scanning showed that microbicidal SiOx nanoparticles were finely dispersed in PVC matrix.

Antioxidation of Rosemary antioxidant in Polypropylene

2009, 23 (08): 83-86 ; DOI: 10.19491/j.issn.1001-9278.2009.08.018

Abstract ( 1552 )

Effects of rosemary antioxidant (RAO) on the antioxidantive properties of PP were evaluated by comparing the rheological and mechanical properties before and after natural weathering. For neat PP, after 150d’s aging, the tensile strength decreased from 32 to 24Mpa, the melt flow rate increased from 2.7 to 18.8 g/min; after 30d’s aging, the impact strength decreased from 3 to 1 kJ/m². For RAO containing PP at the same conditions, the tensile strength from 34MPa to 29Mpa, the melt flow rate increased from 2.5g/min to 5.3g/min, the impact strength decreased from 4 to 3.2 kJ/m². In the melt torque determination, the torque of RAO containing system was obviously higher.

Preparation and Application of polysiloxane flame retardant

2009, 23 (08): 87-90 ; DOI: 10.19491/j.issn.1001-9278.2009.08.019

Abstract ( 2069 )

Polysiloxane flame retardants were synthesized through co-hydrolysis condensation reaction using tetraethoxysilane, phenyltrimethoxysilicone, diphenyldimethoxysilane, and methyltrimethoxysilane as the starting materials. Taking the weight ratios of TEOS/Si, R-Si, and Ph-R as 0.17, 0.9, and 0.75, respectively, the product was used in polycarbonate at 5 wt%, the LOI was increased from 26 to 35.5.

The Synergy of Boron –Aluminium in the Intumescent Flame Retardant PP

2009, 23 (08): 91-94 ; DOI: 10.19491/j.issn.1001-9278.2009.08.020

Abstract ( 2057 )

The synergy of boron - aluminum in the intumescent flame retardant PP was studied using thermal analysis and cone calorimeter. The thermal analysis showed that when introducing aluminum into KDIFR, the charred residue was reduced to 14.6% owing to catalytic dehydration; when adding boron in KDIFR, the charred residue was reduced to 5.9% owing to boron can promote the generation of small combustible molecule and catalytic degradation. When B-Al co-existing, the decomposition rate in the high temperature zone reduce, and the charred residue increased to 19.7%. The cone calorimeter showed that the addition of either aluminum or boron increased the heat release rate, total heat release, CO, CO₂, and smoke emissions, with boron being more effective in pre-combustion and smoke inhibition. The co-existing of B-Al in the KDIFR can reduce heat release rate, total heat release, CO, CO₂ and smoke emissions significantly and enhance the flame retardant effect greatly.

Effect of Screw Configuration on Mechanical Property of PP/PA6 Blend System

Wei-Wei Xu Xiao-Wu Wang

2009, 23 (08): 95-100 ; DOI: 10.19491/j.issn.1001-9278.2009.08.021

Abstract ( 2048 )

The influence of six different screw configurations on the phase morphology and performance of PP/PA6 blends in a co-rotating twin screw extruder was studied. Setting tension-type elements in the melting section, the blends exhibited good tensile and impact strengths, but fair flexural strength and melt flowability. Setting shear-type elements in the melting section and FTX elements in the melt conveying section, the blends gave rise to the best processing properties.

Injection Mould Design for the Multi-color Meter Lid Based on the Principle of Co-injection Molding Process

Qiang FU

2009, 23 (08): 101-104 ; DOI: 10.19491/j.issn.1001-9278.2009.08.022

Abstract ( 1701 )

The principle of co-injection molding was illustrated and was applied to the injection procedure for the multi-color meter lid. Based on the material characters and the structure analysis of the part, a set of multi-color and multi-component injection mold with two different gating systems composed of six different dimensioned cavities was developed, which could fill three lids in the different cavities with different kind or different color plastics simultaneously. This set of mold could exchange the position of two cavities and strip the lids successively by a rotary mechanism and a eccentric mechanism.