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2014, Volume 28 Issue 05 Publication date: 26 May 2014 Previous Issue Next Issue

Research Progresses in Poly(ether ether ketone) Blends

2014, 28 (05): 1-10 ; DOI: 10.19491/j.issn.1001-9278.2014.05.001

Abstract ( 531 )

Research progress in blends of PEEK with other high performance engineering plastics such as poly(ether imide) (PEI), polytetrafluoroethylene (PTFE), thermotropic liquid crystalline polymer(TLCP) and poly(ether sulfone)(PES)was reviewed, and the miscibility,crystallization behavior,morphology,thermal behavior,and mechanical properties of PEEK blends were discussed.In melt and amorphous states,PEEK is completely miscible with PEI,and their blend is generally used in the fundamental studies on the crystallization behaviors and microstructures. Blending PEEK with PTFE,TLCP and PES is an effective way to improve the friction and wear performance, processability and thermal stability.Based on these research results,further research directions and contents in PEEK blends are also anticipated.

Recent Advances in Flame Retardant of Polycarbonate/Acrylonitrile-butadiene-styrene(PC/ABS)

2014, 28 (05): 11-15 ; DOI: 10.19491/j.issn.1001-9278.2014.05.002

Abstract ( 379 )

This paper presented an overview of recent literature on flame retardant polycarbonate/acrylonitrile-butadiene-styrene alloys, the mechanism of thermal decomposition of polycarbonate was also presented. Halogen-free flame retardants including phosphorus, silicone-based compounds and the related flame retarding mechanism were discussed. It was pointed that halogen-free, high efficiency, low toxicity, and environmental friendliness constituted the developing trends for the flame retardants.

Advance on Preparation of Polymer Shish-kebab Structure

2014, 28 (05): 16-20 ; DOI: 10.19491/j.issn.1001-9278.2014.05.003

Abstract ( 563 )

Preparation methods of polymer shish-kebab structure have been reviewed. Melt extruding casting, melt spinning, and solution crystallization method have been introduced. Research progress in formation mechanism and crystallization model for shish-kebab has been discussed. It was observed that spherulites and shish-kebabs will be formed from the isotropic and oriented melt via fold and bundle nucleus, respectively. In the process of shish-kebab formation, shish crystals and kebab crystals will form simultaneously. Shish crystals consists of extended chain, and kebab crystals consist of folded chain. Finally, prospect for application of shish-kebab structure has been indicated.

An Investigation Into Mechanism of Smoke Generation In Burning Rigid Polyurethane Foams

2014, 28 (05): 21-26 ; DOI: 10.19491/j.issn.1001-9278.2014.05.004

Abstract ( 327 )

This paper focused on the smoke generation mechanism of burning rigid polyurethane foams(RPUF). A smoke generation model was verified using thermogravimetric-differential scanning calorimeter(TG-DSC), Fourier transform infrared spectroscopy (FTIR),X-ray photoelectron spectroscopy(XPS), pyrolysis gaseous chromatography mass spectrometry(Py/GC-MS), transmission electron microscope(TEM). It was found that smoke generation started from the thermal decomposition in the condensed phase, which was subsequently broken forming a carbon layer, and then grew into aromatic smoke particles in the gas phase.

Study on the Compatibilizing of Long Chain Branched Polypropylene to the Polypropylene Blends

2014, 28 (05): 27-31 ; DOI: 10.19491/j.issn.1001-9278.2014.05.005

Abstract ( 390 )

A long chain branched polypropylene（LCBPP）was prepared with polypropylene（PP） as a raw material in the melting process. The LCBPP was added to following blends: PP/polystyrene（PS）, PP/styrene-acrylonitrile block copolymer（SAN）, and PP/polyethylene terephthalate（PET）.Fourier transform infrared（FTIR） and extensional rheology were adopted to characterize the LCBPP. According to the SEM,LCBPP exhibited a good compatibilizing effect on the blends system in which the dispersed phase was a polar component. After adding 5 %LCBPP into the PP/SAN（70/30）and PP/PET（70/30）systems separately, the size of the dispersed phase significantly refined and dispersed evenly. However, the compatibilizing effect of LCBPP was not better than that of polypropylene grafted with maleic anhydride（PP-g-MAH）.The compatibility of PP/PS system was improved only slightly by using LCBPP.

Preparation of Unsaturated Poly（ester-amide）Resin/ Nano-hydroxyapatite Composites and Their Properties

2014, 28 (05): 32-36 ; DOI: 10.19491/j.issn.1001-9278.2014.05.006

Abstract ( 407 )

A new unsaturated poly（ester-amide）resin was synthesized and characterized, and nano-hydroxyapatite（n-HA）was used to strengthen unsaturated poly（ester-amide）.UPEA possessed an excellent thermal stability. Upon being loaded with n-HA, the flexural property of UPEA increased. When the n-HA content exceeded 10 %, flexural properties decreased. However, a high content of n-HA may reduce the decay rate and mass loss rate during the first 3 months of the degradation. After a hydrolysis in a 1.0 mol/L NaOH standard solution for 10 days, the more the n-HA content, the higher the rate of hydrolysis.

Effect of Fe2O3-coated Mica on Non-isothermal Crystallization Kinetics of PET

2014, 28 (05): 37-41 ; DOI: 10.19491/j.issn.1001-9278.2014.05.007

Abstract ( 498 )

The non-isothermal crystallization behavior of poly（ethylene terephthalate）was investigated by differential scanning calorimetry （DSC）, using Fe2O3-coated mica was used as a nucleating agent. Jeziorny and Mo methods were used to analyze the non-isothermal crystallization process of neat PET and composite of PET/Fe2O3-coated mica, and the activation energies of the systems were calculated by Flynn-Wall-Ozawa method. The results showed that the Fe2O3-coated mica acted as an efficient nucleating agent, and the crystallization rate of PET was obviously increased. Mo method appropriately described the non-isothermal crystallization of PET and the PET/ Fe2O3-coated mica composite. The incorporation of Fe2O3-coated mica particle did not obviously change the nucleation and crystal growth mechanism of PET，and simply decreased the crystallization activation energy of PET.

Preparation and Properties of Blends of Poly(trimethylene terephthalate)/Acrylonitrile-styrene-acrylic Copolymer

2014, 28 (05): 42-47 ; DOI: 10.19491/j.issn.1001-9278.2014.05.008

Abstract ( 394 )

Blends of poly（trimethylene terephthalate）/acrylonitrile-styrene-acrylic copolymer were prepared through melt extrusion. The morphology, rheology, thermal aging, and mechanical properties of the blends were investigated using the scanning electrole microscopy, universal material testing machine, and a capillary rheometer. It was found that ASA and PTT were partially miscible in the blends. When ASA content was 50 %, a binary continuous phase formed. The blend’s fracture surface became rough with increasing ASA content. ASA component improved the impact strength but depressed the tensile strength of the blends. The apparent viscosity increased with increasing ASA content and the latter improved the processing property of the blends. The blend’s pseudoplasticity increased with increasing ASA content. Moreover, PTT/ASA blend had better thermal aging resistance than that of PTT/ASA blend.

Effect of PP-g-MAH on Mechanical Property of Linen Fiber-reinforced PE-HD Composites

2014, 28 (05): 48-53 ; DOI: 10.19491/j.issn.1001-9278.2014.05.010

Abstract ( 391 )

High density polyethylene（PE-HD）/linen fiber composites were prepared by a twin-screw extruder. When maleic anhydride grafted polypropylene（PP-g-MAH）was introduced, the mechanical properties of the composites were greatly enhanced. The maximum values of tensile, bending, and impact strengths, 32.75 MPa, 37.21 MPa, and 43 kJ/m2, respectively, were observed when the content of PP-g-MAH between 5 % and 10 %. Dynamic mechanical test showed that the introducing of PP-g-MAH enhanced the heat resistance and reduced the mechanical loss of the composites.

Effect of Halloysite Nano-Tubes on Properties and Phase Morphology of PA66/TLCP In Situ Composites

2014, 28 (05): 54-58 ; DOI: 10.19491/j.issn.1001-9278.2014.05.011

Abstract ( 336 )

PA66/TLCP/HNTs composites were prepared by melt blending. Dynamic mechanical thermal properties, crystallization behavior and morphology of the composites were investigated. DSC test showed that small part of TLCP promoted the crystallization. When the content of HNTs increased to 40 %, the storage modulus of the composites was increased by 188 %. SEM observation of the cryogenically fractured surface showed that HNTs and TLCP micro-fibrils were well dispersed in PA66 matrix.

Effect of Alkali Treated Bamboo Fiber on the Structure and Properties of Polyamide 6

2014, 28 (05): 59-63 ; DOI: 10.19491/j.issn.1001-9278.2014.05.012

Abstract ( 368 )

Bamboo fibers（BFs）were treated with 10 % NaOH solution, and polyamide 6/bamboo fiber（PA6/BFs）composites were prepared by a twin screw extruder and an injection molding, and analyzed by SEM, DSC, XRD, TG, and mechanical testing. It demonstrated that BFs provided a larger surface area for leaching out the cementing materials during alkali treatment, which improved the mechanically interlocking between bamboo fibers and the PA6 matrix. BFs had good interfacial adhesion with PA6 matrix without obvious gaps. The presence of BFs resulted in more crystal imperfection of the PA6 component, and the increased stiffness of PA6/BFs composite accompanied by a decrease of impact strength, melt flow index, and thermal stability. The combination of reasonably good melt flow index and thermal stability of PA6/BFs composites ensured the processability of the composites during extrusion and injection molding.

Three-dimensional Non-isothermal Numerical Simulation of Die Swell and Deformation in L-shaped Profile Coextrusion

2014, 28 (05): 64-69 ; DOI: 10.19491/j.issn.1001-9278.2014.05.013

Abstract ( 285 )

A three-dimensional non-isothermal viscoelastic numerical simulation nodel with Phan-Thien and Tanner（PTT）constitutive equation was established for two-layer L-shaped coextrusion profile. Arrhenius equation was used to relate the viscosity with temperature. The coextrusion processes of polypropylene（PP）and polystyrene（PS）were investigated by finite element method. The distribution of velocity and shear rate at die exits, die swell, and deformation was discussed in different proportions of the two materials. Calculation results revealed that the die swell and deformation were affected by viscosity ratio as well as the cross section of the die. The deflection from the lower viscous PP to the higher viscous PS was observed and the PP trends to encapsulate the PS. The die swell and deformation when the lower viscous PP was in the inner side were larger than that of PP in the outer side, and the died swell and deformation gap between this two situations increased with increasing viscosity ratio.

Injection Mold Design for Disassembly Evaluation Algorithm Under Remanufacturing Perspective

2014, 28 (05): 70-74 ; DOI: 10.19491/j.issn.1001-9278.2014.05.014

Abstract ( 347 )

According to the requirement of injection mold remanufacturing, an evaluation system for mold disassembly was established, and each single factor was quantitatively described. Having studied the evaluation process of the molded parts and researched the correlation and interaction among various factors, based on the correlation matrix of indicators and mathematical graph theory, an evaluation algorithm model of mold disassembly design was established. Taking an injection mold design as an example, the validity of the evaluation algorithm was examined.

Pressure Changes During the Processing of High Molecular Weight Polyethylene /Paraffin Oil System

2014, 28 (05): 75-80 ; DOI: 10.19491/j.issn.1001-9278.2014.05.015

Abstract ( 505 )

Rheological behavior of high molecular weight polyethylene/paraffin oil blends was studied by a constant speed high pressure capillary rheometer. The influence of molecular weight, paraffin oil content, and temperature on the pressure was analyzed. It was observed that the higher the molecular weight, the lower the critical shear rate, and the higher the extrusion pressure oscillation frequency and amplitude. The lower the paraffin oil content, the higher the extrusion pressure at a same shear rate. When the oil content was 30 %, the extrusion pressure became stable, i.e., the extrusion pressure oscillation disappeared when the shear rate changed. With increasing extrusion temperature, the extrusion pressure decreased, the frequency and amplitude of pressure oscillation also decreased.

Research on Cutting Performance and Tool Selection of Aramid Fiber Composites

2014, 28 (05): 81-84 ; DOI: 10.19491/j.issn.1001-9278.2014.05.016

Abstract ( 456 )

The paper discussed the structural characteristics of the aramid fiber composites such as anisotropy, heterogeneity, discontinuity, and low interlaminar strength, which resulted in high cutting force, low conductivity of the cutting heat, severe wear of the cutting tool, easy formation of defects, and unstable quality. Some principles in selection of cutting tool materials were proposed, carbide or diamond tools became preferable. The structure and geometrical parameters of cutting tools in turning, milling, and drilling processes were also suggested.

Synthesis of Hexallyloxycyclophosphazene and Its Application in Sheet Molding Compounds of Unsaturated Polyester

2014, 28 (05): 85-90 ; DOI: 10.19491/j.issn.1001-9278.2014.05.017

Abstract ( 451 )

A novel unsatursate cyclophosphazene, hexallyloxy-cyclophosphazene（HACP）was synthesized from hexachlorocyclotriphosphazene（HCCP）and allyl alcohol, with irs structure characterized by FTIR, MS, 1H-NMR, and elemental analysis. The obtained HACP was introduced as a flame retardant into sheet molding compounds of unsaturated polyester, the effect of HACP on the flame retardancy and mechanical properties was researched by limiting oxygen index, scanning electron microscopy, etc. It was found that, with the addition of 15 %HACP, the limiting oxygen index valve of the unsaturated polyester was increased to 36.0%, and the flammability class reached V-0. The carbon residue was increased. The bending strength was 214.63 MPa, and the impact strength was 106.23 kJ/m2.

Synthesis of a Novel α-Nucleating Agent and Its Influence on the Properties of Isotactic Polypropylene

2014, 28 (05): 91-96 ; DOI: 10.19491/j.issn.1001-9278.2014.05.018

Abstract ( 468 )

With anthracene. maleic anhydride and hydrazine hydrate as raw materials, a novel α-nucleating agent（AMHD）for isotactic polypropylene（iPP）was synthesized. Its thermal stability was characterized using thermogravimetric analysis（TG）. The influence of the nucleating agent on the crystalline morphology, crystallization behavior, mechanical properties, and Vicat softening temperature（VST）of iPP was investigated with X-ray diffraction（XRD）, polarized light microscopy（PLM）, differential scanning calorimetry（DSC）,etc. It showed that AMHD enhanced the crystallization temperature（Tc）and crystallinity（Xc）of iPP. The mechanical properties and the heat resistant temperature of iPP improved greatly. Compared with neat iPP, the Charpy impact strength, tensile strength, and flexural strength increased by 1.27 times, 18.02 %, and 10.76 %, respectively.

Study on Migration Behavior of Acetaldehyde from PET Bottles

2014, 28 (05): 97-101 ; DOI: 10.19491/j.issn.1001-9278.2014.05.019

Abstract ( 487 )

An analytical method using gas chromatography mass spectrometry（GC-MS）has been developed for the quantification of acetaldehyde migration from PET bottles into liquid food. The effect of time, temperature and food stimulant（the aqueous stimulant, the acid stimulant and the alcoholic stimulant）has been tested on the migration of acetaldehyde. The results showed storage time and temperature were positively correlated with migration of acetaldehyde in all stimulants. Different food stimulants led to different levels of acetaldehyde migration at the same storage temperature. The migration level of acetaldehyde in the alcoholic stimulant was much higher than the one in the acid stimulant and the aqueous stimulant.

Design of Overall Structure Outside Mold Decoration

2014, 28 (05): 102-106 ; DOI: 10.19491/j.issn.1001-9278.2014.05.020

Abstract ( 378 )

The overall structure of outside mold decoration was designed, which was composed of heating, changing, and posting sections, and equipped with a single stage air-cooling reciprocating air compressor（TA-65）and a water ring vacuum pump（2BV）. The system of heating servo feed was analyzed and corrected, with the transient and steady state characteristics of the system obviously improved.

Comparative Study on Mixing Performance of Different Rotors in Two-rotor Continuous Mixer

2014, 28 (05): 107-110 ; DOI: 10.19491/j.issn.1001-9278.2014.05.021

Abstract ( 355 )

Slotted and stepped screw rotors were designed in order to study the effect of rotor configuration on the mixing performance. Numerical simulation was carried out on the mixing sections of the three rotors using the polymer processing analysis software Polyflow, and the mixing performance of the slotted, stepped, and common screw rotors was compared. It was concluded that the slotted screw rotor had the best dispersive and distribution mixing performance, the dispersive mixing performance of the stepped screw rotor was between the common and the slotted screw rotor. The dispersion of materials in the slotted screw rotor depended more strongly on the stretching than the other two rotors.

Design of Injection Mould for a Pair of Louver Heads

2014, 28 (05): 111-114 ; DOI: 10.19491/j.issn.1001-9278.2014.05.022

Abstract ( 494 )

Based on the analysis of the louver head part, the overall structure of an injection mold was designed. The mold was featured with a module containing two cavities, a side fees gate, and a side core-pulling mechanism of the slanted guide pillar. The inner and outer were formed by assembled blocks. The mold structure was prove reasonable, the operation was reliable, and the quality of plastic parts met requirements.

Hot Runner System Design of Injection Molds with Side-sliders for Transparent Shell-like Covers

2014, 28 (05): 115-118 ; DOI: 10.19491/j.issn.1001-9278.2014.05.023

Abstract ( 251 )

The article analysizes the structure of a hot runner mold with side-sliders according to the shell-like cover part used ofr car dashboard. Especially the mold design and molding process were have described; and the needed power of the manifold and the expansion of the system were have also calculated. In this mold, the gate wave design and heat insulation were adopted. The mold is exact and compact, which can efficiently save material, and improve the part quality and work automatically.