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2013, Volume 27 Issue 10 Publication date: 26 October 2013 Previous Issue Next Issue

Research Progress of Polyaniline/Carbon Nanotube Composites

2013, 27 (10): 1-5 ; DOI: 10.19491/j.issn.1001-9278.2013.10.001

Abstract ( 1567 )

Preparation processes of polyaniline (PANI)/carbon nanotube (CNT) composites by chemical oxidation and electrochemical polymerizations and electrospinning were summarized. The properties of the composites were introduced. Applications of the composites included electrodes in ultracapacitors，sensors for specific chemical or biological species. The future trend of the PANI/CNT composites was prospected.

Research Progress of Intramolecular Hybrid Resin of Benzoxazine

Li Ting Ting

2013, 27 (10): 6-11 ; DOI: 10.19491/j.issn.1001-9278.2013.10.002

Abstract ( 1095 )

This paper reviews recent research progress of intramolecular hybrid benzoxazine resin. The intramolecular hybrid method included inclusion of heteroatoms such as phosphorus, boron, silicon, bromine, and sulphur into benzoxazine monomer to improve the heat resistance and mechanical properties of benzoxazine resin. The design of structure of the monomer and synthesis process was also discussed. The further development of benzoxazine resin was also forecast.

Research Progress in Rare Earth Thermal Stabilizers for PVC

2013, 27 (10): 12-17 ; DOI: 10.19491/j.issn.1001-9278.2013.10.003

Abstract ( 1467 )

Thermal degradation mechanism of PVC and stabilizing mechanism of rare earth thermal stabilizer were introduced. Research progress in rare earth thermal stabilizers was elaborated including inorganic, organic, and organic composite rare earth thermal stabilizers. The prospect of rare earth thermal stabilizer was forecasted.

Synthesis of poly(epoxy ester) and its effect on the compatibility of PC/ABS blends

2013, 27 (10): 18-22 ; DOI: 10.19491/j.issn.1001-9278.2013.10.004

Abstract ( 1193 )

Poly(epoxy ester) was synthesized by bisphenol A epoxy and adipic acid, and it was added to the PC/ABS blends as a new compatilizer. PC/ABS blends with the compatilizer was processed by twin-screw extruder and injection molding machine. The compatibility of the poly(epoxy ester) was evaluated by DSC, SEM and mechanical property, and compared with maleic anhydride grafted polystyrene(SMA). The results showed that the poly(epoxy ester) had a better compatibility with PC, while SMA had a better compatibility with ABS. Poly(epoxy ester) and SMA added into PC/ABS blends simultaneously could significantly improved the compatibility of PC/ABS alloy. The content of poly(epoxy ester) at a low level could led to significant increase in both notched impact strength and tensile strength. The notched impact strength dramaticly decreased with excess poly(epoxy ester) addition. SEM showed that the poly(epoxy ester) compatilizer made the ABS disperse evenly. The size of ABS domains in PC/ABS blends was reduced when the two kinds of compatilizer used simultaneously. The compatibility of PC/ ABS blends was improved correspondingly.

Electrically Conductive Properties of Ultrahigh Molecular Weight Polyethylene/Graphene Nanoplatelets Composites

Jiao-qiang ZHANG

2013, 27 (10): 23-26 ; DOI: 10.19491/j.issn.1001-9278.2013.10.005

Abstract ( 1153 )

Ultrahigh molecular weight polyethylene (PEUHMW)/graphene nanoplatelets(GNPs) composites were prepared through solution blending and ultrasonic dispersion, and their electrical properties were investigated. SEM showed that GNPs were well distributed in PEUHMW, and the composites had a typical percolation behavior with a threshold of 2.8 wt %. With increasing GNPs contents, positive temperature coefficient (PTC) intensity of the composites gradually decreased. Thermal cycles decreased PTC intensity.

Study on Properties of NanoAlN Filled PTFE Composites

2013, 27 (10): 27-31 ; DOI: 10.19491/j.issn.1001-9278.2013.10.006

Abstract ( 1139 )

PTFE/nanoaluminum nitride (nanoAlN) composites were prepared from nanoAlN particles and polytetrafluoroethylene (PTFE) powder by high speed mechanical mixing followed by cold moulding and sintering in air. Effect of nanoAlN content in the composites on crystallization, mechanical, and tribological properties was studied. The worn surface morphology of the composites was characterized and analyzed by scanning electron microscope. It showed that the degree of crystallinity first increased and then decreased as the weight percentage of nanoAlN increased; the mechanical properties and wear resistance of the composites were improved by nanoAlN particles remarkably. The wear resistance of PTFE/4 % nanoAlN composite was increased by two orders of magnitude compared to neat PTFE.

Study on Properties of CPVC/ABS/AS and CPVC/ABS Blends

2013, 27 (10): 32-35 ; DOI: 10.19491/j.issn.1001-9278.2013.10.007

Abstract ( 1178 )

This paper studied the effect of ABS on the mechanical properties, Vicat softening point, and flame retardant performance of CPVC/ABS/AS and CPVC/ABS blends. In the CPVC/ABS/AS system, with the loading of ABS increased from 0 to 30 %, the impact strength was increased from 11.5 to 39.3 kJ/m2. In CPVC/ABS system, with the loading of ABS increased from 0 to 25 %, the impact strength was increased from 11.1 to 52.6 kJ/m2, but the tensile and flexural strengths, Vicat softening point of the blends were reduced. Moreover, the flame retardant performance of the blends was mainly related to the content of CPVC. When CPVC/ABS (or ABS+AS)=6∶4, the limited oxygen index was about 31 %.

Effect of PP-g-AN on Aging Resistance of Polypropylene

2013, 27 (10): 36-39 ; DOI: 10.19491/j.issn.1001-9278.2013.10.008

Abstract ( 1033 )

Polypropyleneacrylonitrile graft compolymer(PPgAN) was grafted onto polypropylene. Aging resistance of PP/PPgAN was studied using SEM and FTIR. QUV was used to speedup aging of the materials for 500, 1000, 1500, 2000, and 2500 h. It showed that PP/PPgAN had an improved aging resistance. When the PPgAN content was 7 %, the tensile strength of modified materials reached a maximum of 19.87 MPa and an impact strength of 60.46 kJ/m2 after accelerated aging 2500 h.

Preparation and Performance of Bismaleimide Resin/Epoxy Resin/NanoSiO2 Composites

2013, 27 (10): 40-45 ; DOI: 10.19491/j.issn.1001-9278.2013.10.009

Abstract ( 1110 )

Effect of nanoSiO2 content on the mechanical properties, thermal behavior and waterabsorbing of BMI/EP/DBA/nanoSiO2 composites was investigated. When the mass fraction of nanoSiO2 content was 2 %, the composites had higher strength and better toughness, compared with BMI/EP/DBA copolymers, and their tensile strength, flexural and notch impact strengths were improved by 22.8 %, 39.0 %, and 37.8 %, respectively. When the mass fraction of nanoSiO2 content was 2 %, the composites had excellent heat resistance; the glass transition temperature, initial degradation temperature, and the maximum degradation temperature were 204, 410, and 451 ℃, respectively.

Preparation of Novel Carboxylates of Modified Ricinoleic Oil and Its Effect in PVC Products

JIANG Ping-Ping Gang Bian

2013, 27 (10): 46-51 ; DOI: 10.19491/j.issn.1001-9278.2013.10.011

Abstract ( 1174 )

Two kinds of novel ricinoleic diacids were synthesized via the reaction of ricinoleic acid with maleic anhydride, or hexahydrophthalic anhydride. And the corresponding metal soaps of ricinoleic diacid were also prepared. Through the method of Congo red test, conductivity test, and thermogravimetry, the thermal stability of the castor oil base metal soaps, calcium isooctanate, and zinc isooctanate were determined. “Zinc burn” was depressed when adding zinc carboxylates of castor oil diacid to PVC. When the zinc ion content was 2 %, the static and dynamic thermal stability times were 9.8 min and 9.2 min, respectively. The best synergistic effect was achieved between calcium isooctanate and zinc carboxylates of castor oil diacid. The thermal stability was changed with the ratio of Ca/Zn.

Preparation of Zn₂SnO₄ and Its Flame Retardant Effect on Flexible Poly(vinyl chloride)

2013, 27 (10): 52-57 ; DOI: 10.19491/j.issn.1001-9278.2013.10.012

Abstract ( 1167 )

Zine stannate (Zn2SnO4) was synthesized through twostep calcining from SnCl4 and Zn(NO3)2, and was used as a flameretardant/smoke suppressant for flexible poly (vinyl chloride). The flame retardacy was characterized by the limited oxygen index test, smoke density test (SDR), and the char yield test. The mechanical properties were also studied. When 15 phr Zn2SnO4 was used, PVC showed excellent flame retardacy and smoke suppression, limited oxygen index was 36.0 %, SDR was 86.2 %, char yield was 29.7 %, tensile strength was 25.47 MPa, and elongation at break was 168 %. Differential thermal analysis, thermogravimetry, and scanning electron microscope showed that Zn2SnO4 decreased the degradation temperature and increased char yield.

Numerical Study on Cycle Time of Rotational Molding Process

2013, 27 (10): 58-64 ; DOI: 10.19491/j.issn.1001-9278.2013.10.013

Abstract ( 1104 )

A new heat transfer theoretical model was established for rotation molding of spherical hollow plastic parts, and a numerical computation was performed using Fluent software. Heat conduction of the mold, heat conduction, melting and crystallization of the plastic layer, and convective heat transfer of internal air were coupled for the solution in the model. Temperatures at outer wall of the mold and of the internal air were obtained by numerical computation, which were in good agreement with those by experiment. In addition, cycle times under different heating temperatures, and convective heat transfer coefficients were calculated so that effect of these parameters on cycle time could be determined. By increasing these parameters the cycle time could be reduced.

Study on Factors Influencing Carbon Black Dispersion and Relationship of Content and Dispersion in Drip Irrigation Pipes or Tapes

LEI Zhen-Kai

2013, 27 (10): 65-68 ; DOI: 10.19491/j.issn.1001-9278.2013.10.014

Abstract ( 1067 )

The effect of carbon black content on its dispersion in drip irrigation pipe was studied. With increasing of carbon black, the dispersion slowly increased. When the content was about （2.25±0.25） %, its dispersion was in grade 1.4~2.6. In addition, the optimal preparation condition was given: the loading weight of 5 kg, the optimum temperature of over 190 ℃, and the time over 1.25 h.

Analysis of Influence of Effect of Strain Rate on Film Posting of Mouse Base on Outside Mold Decoration

2013, 27 (10): 69-72 ; DOI: 10.19491/j.issn.1001-9278.2013.10.015

Abstract ( 1043 )

Mouse shell was outside decorated a polypropylene film, and the forming process was simulated with a finite element method. The film thickness distribution, stress distribution, and its deforming distribution in x, y directions were obtained and analyzed. The influence of strain rate was systematically studied. With increasing strain rate, the thickness and stress of the film were increased, the deforming distribution in x, y direction was hardly influenced. And different loading way had a relatively high impact on forming effect.

Application of Expandable Graphite and Phosphoruscontaining Flame Retardants in Rigid Polyurethane Foams

FENG Fafei

2013, 27 (10): 73-77 ; DOI: 10.19491/j.issn.1001-9278.2013.10.016

Abstract ( 1259 )

The effect of expandable graphite (EG), polyphosphate polyol oligomer (OP550), and diethylN,Nbis(2hydroxyethyl) aminomethylphosphonate WSFR6 on the flame retardancy of rigid polyurethane foam(RPUF) was investigated by means of limited oxygen index and cone calorimeter tests. RPUF exhibited a better charring ability and gave compact residual char layer after ignition in the presence of both OP550 and WSFR6. When the loading of EG in RPUF was 14 %, the limited oxygen index of RPUF system increased to 33.6 %, and the peak value of heat release rate decreased to 106.93 kW/m2.

Synthesis and Application of Environmentally Friendly Plasticizers Di(2ethylhexyl)1,2cyclohexane Dicarboxylate

Xuejia DING

2013, 27 (10): 78-82 ; DOI: 10.19491/j.issn.1001-9278.2013.10.017

Abstract ( 1383 )

In this article di(2ethylhexyl)1,2cyclohexane dicarboxylate (DEHCH) was synthesized by the reaction of hexahydrophthalic anhydride (HHPA) with isooctanol using methanesulfonic acid as a catalyst. The optimal reaction scheme was as follows: n(isooctanol)∶n(HHPA) was 2.6∶1.0, catalyst amount was 0.25 % of the mass of HHPA, reaction temperature was 170 ℃, and reaction time was 2 h. The esterification yield was 97.89 %. In addition, the molecular structure of DEHCH was characterized by IR, 1HNMR, and MS. And the mechanical properties of PVC plasticized by DEHCH were similar to those of PVC plasticized by DEHP. The synthesized DEHCH could be used as an alternative for phthalates.

Application in Flameretardant PBT Based on Metal Salt of Phosphinates with Amide Group

2013, 27 (10): 83-86 ; DOI: 10.19491/j.issn.1001-9278.2013.10.018

Abstract ( 1177 )

The flame retardant abilities of zinc, magnesium, and aluminum salts of β(Nphenyl carboxamide) ethylmethylphosphinate on PBT were compared. It showed that the aluminum salt \[Al(CEMP)\] was better than other two. When the loading of Al(CEMP) was 20 wt %, limited oxygen index of 39.5 % and UL 94 V0 were obtained. TG analysis indicated that Al(CEMP) reduced the thermal decomposition rate and increased the char forming of PBT. FTIR showed that the residue containing phosphorus and carbonrich species, which implies that Al(CEMP) acted in condensed phase.

Application of SPSS in Extrusion Energy Consumption of Meshing Corotating Twinscrew Extruder

Xiuqing MA

2013, 27 (10): 87-92 ; DOI: 10.19491/j.issn.1001-9278.2013.10.019

Abstract ( 1480 )

With the aid of Statistical Product and Service Solutions （SPSS ）, binary linear and nonlinear mathematical model were established for the meshing corotating twinscrew extruder power consumption with screw rotation speed of corotating twinscrew extruder and feeding capacity as the independent variables. Influence of screw rotation speed and feeding capacity on the power consumption was investigated. Experimental and model prediction data were compared, and it was concluded that the binary linear regression model could be used to predict extruder power consumption.

Research of High Accuracy Temperature Control Elements in All-electric Motor Injection Molding Machines

2013, 27 (10): 93-97 ; DOI: 10.19491/j.issn.1001-9278.2013.10.021

Abstract ( 1135 )

In this article, the temperature control system in injection molding machines was introduced. The key elements were illustrated in two main aspects: hardware and software, which affected the accuracy of temperature in the barrel, including PID optimizations of the operating system, measurements of thermocouples and heating coils. Detailed steps for improvements were given to diminish the temperature variation after heating up. Moreover, the presetting of PID parameters optimizes the efficiency of controlling process and reduces overshoot and settling time. Through the measurements of temperature after heating up at stable, the variation of the temperature achieves plus or minus 0.2 degree.

Design of Temperature Measuring Devices for Rotational Molding Molds

Yong-Tong Li

2013, 27 (10): 98-100 ; DOI: 10.19491/j.issn.1001-9278.2013.10.022

Abstract ( 1226 )

A temperature measuring device for rotational molding mold was designed aimed to solving the difficulty in measuring the temperature inside the mould and the quality of plastic products. A spherical carbon brush was designed to keep the conduction in continuous rotation mold. The technology cleverly solved the major problem that the wire would rotate with the mold and selfentangled. The device had a low cost and was easy to install and dismantle. In addition, an install method for the temperature measurement device was also proposed.