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2015, Volume 29 Issue 01 Publication date: 26 January 2015 Previous Issue Next Issue

The Flame Retardant effects of nano filler layered double hydroxides on the polymers

2015, 29 (01): 1-6 ; DOI: 10.19491/j.issn.1001-9278.2015.01.001

Abstract ( 446 )

The effect of layered double hydroxide (LDH) nanofillers on properties of polyethylene grafted maleic anhydride (PE-g-MAH) and epoxy resin (EP) based composites was reviewed. The preparation of PEgMAH/LDH and EP/LDH was introduced in detail. The thermal stability and flame retardancy of the composites were discussed. In addition, the mechanism of nano LDP in flame retardancy and as a synergistic component of ammonium polyphosphate(APP) was explored.

Properties and Investigation Methods of Microrheology

2015, 29 (01): 7-11 ; DOI: 10.19491/j.issn.1001-9278.2015.01.002

Abstract ( 1123 )

This paper introduced the characteristics of micro-flow such as low Reynolds number，wall slip，viscoelasticity and so on．The main testing methods of the microrheology such as magnetic bead manipulation，quasi-elastic light scattering, atomic force microscopy were also introduced．Finally，the application and development of microrheology was prospected.

Technology Development for XPS Foam and Its Market Situation

2015, 29 (01): 12-18 ; DOI: 10.19491/j.issn.1001-9278.2015.01.003

Abstract ( 436 )

In this article, research progress in alternative technologies for HCFCs foaming of extruded polystyrene (XPS) in China, USA, EU, and Japan was reviewed. The properties of XPS foam, blowing agents, and extrusion foaming equipments were discussed. Finally, the market was analyzed based on the developing trend of HCFCs foaming and fire protection requirements in China.

Application of Phenyl Silicone Oil and Titanium Dioxide in Polypropylene Intumescent Flame Retardant

2015, 29 (01): 19-22 ; DOI: 10.19491/j.issn.1001-9278.2015.01.004

Abstract ( 671 )

In this paper, a masterbatch was prepared by introducing phenyl silicone oil and titanium dioxide into a blend of polypropylene and an intumescent flame-retardant SR-50A (PP/IFR) through extrusion. When the content of masterbatch in polypropylene was 20 wt%, the limited oxygen index value of the system reached 35.6 %, and all the samples reached UL 94 V-0 grade. Thermal gravimetric analysis showed that the addition of phenyl silicone oil promoted the decomposition of flame retardant in the initial stage and reduced the thermal decomposition rate of PP. Titanium dioxide promoted the char formation. The addition of phenyl silicone and titanium dioxide had little influence on the mechanical properties of the composites.

Thermal Conductivity of Epoxy/Modified Multiwall Carbon Nanotube Nanocomposites

2015, 29 (01): 23-28 ; DOI: 10.19491/j.issn.1001-9278.2015.01.005

Abstract ( 671 )

Multiwall carbon nanotubes (MWCNTs) were modified in three ways, namely, oxidizing with HNO3, filling with Ag, and grafting with hexamethylene diamine. Epoxy/modified MWCNTs composites were prepared and its thermal conductivity was tested. TEM images showed that the modified MWCNTs were dispersed in the epoxy matrix homogeneously. The thermal conductivity was improved obviously. As the modified MWCNTs was 2.2 %, the thermal conductivity of the composites containing Opened MWCNTs or Ag-filled MWCNTs reached 0.20 W/(m·K), 33.3 % higher than that of neat epoxy resin.

Study on Toughening Modification of Poly(lactic acid)/Acorn Starch Blends Using Dimer Fatty Acid

2015, 29 (01): 29-34 ; DOI: 10.19491/j.issn.1001-9278.2015.01.006

Abstract ( 603 )

Composites of poly(1actic acid) (PLA), acorn starch(AS), and dimer fatty acid(DA) were prepared by melt extrusion. Keeping the mass ratio of PLA to AS at 60/40, the effect of DA content on the mechanical, hydrophobic, thermal properties and melt flowability of the composites was studied by tensile test, flexural test, melt index analysis, contact angle analysis, scanning electron microscope, dynamic thermomechanical analysis and thermogravimetric analysis. It showed that the hydrophobic property and melt flowability of the composites increased, while the tensile and flexural strength decreased with increasing DA content. DA could not only improved the toughness of PLA matrix, but also reduced the glass transition temperature and the early thermal stability of composites.

Tribological Behavior of PA66/PVDF Reinforced with Different Whiskers of Potassium Titanate and Calcium Sulphate

2015, 29 (01): 35-41 ; DOI: 10.19491/j.issn.1001-9278.2015.01.007

Abstract ( 655 )

The tribological behavior of blends of polyamide (PA66)/poly (vinylidene fluoride) （PVDF） reinforced with two different whiskers, potassium titanate (PTW) and calcium sulphate (CSW) was studied in this article. The effect of the different whisker content on the friction and wear property of the PA66/PVDF blends was investigated. The morphology of the microstructure, worn surface and transfer film of polymer material were analyzed using a scanning electron microscope. The chemical change of the blends before and after friction was analyzed by FTIR spectrometer. It was found that the self-lubricating and anti-wear property of the blends were lowered by the addition of PTW, the tribological property of the blends was enhanced by the addition of CSW. An obvious plastic deformation and adhesion were shown on the worn surface of the blend with PTW; lots of debris was adhered on the surface of counter steel ring. For the blend with CSW, lots of debris was adhered on the worn surface acting as lubricant under the shear action. Before and after friction, no chemical change occurred on the worn surface.

Mechanical Properties of ABS/Wood Powder Composite Prepared by a Twin-screw Extruder with Subcritical Water

2015, 29 (01): 42-47 ; DOI: 10.19491/j.issn.1001-9278.2015.01.008

Abstract ( 490 )

In this article ABS/wood powder composites were prepared by a twin screw extruder in presence of a small amount of water or subcritical water. The acetone extract of the composite was analyzed with FTIR, from which the effects of extrusion temperature and additive agents were investigated. And the fractured surface morphology of the composite was also observed. It was found that water swelling promoted the interface reaction between wood fiber and ABS or ABS-g-MAH, leading to an improvement of the interface bond strength and the mechanical properties of the composite. When the extruding condition was in the optimum value (at 200 ℃ and with 5 % of ABS-g-MAH) and in the presence of subcritical water, the tensile, flexural, notched and non-notched impact strengths of the ABS/wood powder composite reached 45.3 MPa, 72.4 MPa, 1.5 kJ/m2, and 6.5 kJ/m2 respectively.

Study on Antistatic PBT Composite Based on Phosphorus-nitrogen Synergism Flame Retardant System

2015, 29 (01): 48-52 ; DOI: 10.19491/j.issn.1001-9278.2015.01.009

Abstract ( 513 )

A antistatic PBT material was prepared by blending it with a compound flame retardant, AlPi and MPP(mass ratio 2∶1), and carbon black. The thermal stability and anti-static properties of the PBT material were studied. It provided a UL 94 V-0 rating，an increased the limited oxygen index value (31 %)，a carbon black percolation threshold of 12 phr and a volume resistivity (104 Ω·cm) when the quantity of carbon (CB) reached 20 phr. TG showed that an improvement in thermal stability was from the flame retardant and carbon black. SEM showed that after continuous combustion a porous carbon surface was formed.

Influence of Different Fillers on Thermal Conductivity and Crystallization Behavior of PLA-based Composites

2015, 29 (01): 53-57 ; DOI: 10.19491/j.issn.1001-9278.2015.01.010

Abstract ( 604 )

In this work, four thermal conductive fillers (Fe, Cu, Al and Al2O3 powders) were used to prepare the poly (lactic acid) (PLA)-based composites via melt extrusion. Effects of the type and amount of the fillers on the thermal conductivity, solidification kinetics as well as crystallization behavior of the prepared composites were studied. The coefficient of thermal conductivity of the composites increased by 89 % with the addition of 5 wt% fillers. The addition of 10 wt% Al2O3 improved the impact strength by 55 %. No obvious effect of the filler type and content on Shaw hardness was detected. The 2d-Tait equation and P-V-T relationship of PLA were adopted to explore the influence of different fillers on the crystallization kinetics of the PLA composites. It showed that the addition of 5 wt% and 10 wt% fillers could improve the crystallization rate by 83 % and 79 %, respectively. The possible reason was probably due to the limited space (or excessive packing) for crystal growth.

Effect of Interface Modification on the Structure and Properties of Poly(lactic acid)/Lyocell Fiber Composites

2015, 29 (01): 58-63 ; DOI: 10.19491/j.issn.1001-9278.2015.01.011

Abstract ( 485 )

Lyocell fiber-reinforced poly(lactic acid) (PLA) composites were prepared by melting blending and injection molding in this work. The effects of silane coupling agent (KH550) and hexamethylenediisocyanate (HMDI) on the structure and properties of the composites were investigated by means of mechanical property test, DSC, Vicat softening temperature test, and SEM. It showed that interface modification of the HMDI was better than KH550. With the increasing content of HMDI, the mechanical properties of the composites increased firstly, then decreased. Compared with the composite without coupling agent, the composite containing 1 wt% coupling agent gave rise to a 5.1 ℃ higher Vicat softening temperature and better mechanical properties, with tensile strength, tensile modulus, flexural strength, flexural modulus, and notched impact strength being 57.1 %, 10.5 %, 32.3 %, 19.5 % and 23.7 % higher, respectively.

Effect of EPDM Graft Copolymer on Properties of MXD6/PA6/EPDM Blends

2015, 29 (01): 64-70 ; DOI: 10.19491/j.issn.1001-9278.2015.01.012

Abstract ( 538 )

In this paper, EPDM was grafted with maleic anhydride and introduced into blends of poly(m-xylene adipamide)/polyamide 6 (MXD6/PA6） as a reactive compatibilizer forming a ternary blend (MXD6/PA6/EPDM). The compatibility of blended components was analyzed by Molau test. The rheological property, melting and crystallization behavior, and heat resistance of MXD6/PA6/EPDM blends were studied by HAAKE torque rheometer, differential scanning calorimetry, polarized light microscopy, and thermal gravimetric analysis. It was found that the addition of EPDM-g-MAH increased the balance torque of the blend system and the interfacial adhesion between MXD6 and PA6 was improved. EPDM-g-MAH lowered the nucleation density and the crystallization rate. The glass transition temperature and melting point of the blends decreased with increasing EPDM content，however, the thermal stability of blends was improved.

Heat Transfer Analysis of Non-metallic Roller Supporting Rotary Bodies

2015, 29 (01): 71-74 ; DOI: 10.19491/j.issn.1001-9278.2015.01.013

Abstract ( 472 )

For the thermal destruction of non-metallic rollers, a selection method of roller material was designed. The mechanical property of six materials was tested, and their compression-strain curves were obtained. Using the finite element software ANSYS, the plastic deformation energy of the roller under compression was simulated. Applying proper heat load and boundary conditions, the radial temperature profile and maximum temperature under pressure were estimated.

Study on Addition-curable Allylic Novolac Resin

2015, 29 (01): 75-79 ; DOI: 10.19491/j.issn.1001-9278.2015.01.014

Abstract ( 718 )

Allyl ether novolac (AEN) was synthesized by allyl chloride and novolac, then the AEN was changed into allylic novolac (AN) by Claisen rearrangement rule at high temperature, that made the curable type from condensation to addition. The allylic degree, curing process, transition mechanism and heat resistance were investigated. It was found that the novolac with high allylic degree, prepared by different allyl chloride consumption, were cured fast than low one. The addition-curable resin was rearranged at 245 ℃ and cured at 330~350 ℃, and the heat resistance was better than condensation-curable resin because of less inter defects.

Optimization of Pressure in Bi-color Molding Through a Hybrid of Back Propagation Neural Network and Genetic Algorithm

2015, 29 (01): 80-84 ; DOI: 10.19491/j.issn.1001-9278.2015.01.015

Abstract ( 472 )

A method of combining back propagation neural network (BP neural network) and genetic algorithm was proposed to optimize the pressure curve in order to improve the volume shrinkage at ejection and the warping of bi-color products. Using the method, the optimal pressure curve could be obtained: PP holding pressure 55 MPa, holding time 12.5 s, ABS holding pressure 75 MPa，holding time 3.5 s. Finally, the CAE simulation was simulated under the optimized parameters. The target variable was 4.411，less than the experimental scheme. And the warpage of bi-color products was reduced from 1.696 to 0.7427 mm.

Modification of o-Crosel Formaldehyde Epoxy Resin by Carbon Nanotubes-polyamide Fiber

2015, 29 (01): 85-89 ; DOI: 10.19491/j.issn.1001-9278.2015.01.016

Abstract ( 526 )

Multi-walled carbon nanotube (MWCNTs) was treated by a concentrated acid, then the acidified carbon nanotubes was co-spun with polyamide (PA66) to prepare MWCNTs-PA66 fiber membrane. An o-CFER/MWCNTs-PA66 composites was prepared through co-cured with the o-cresol formaldehyde epoxy resin (o-CFER), and the microstructure, mechanical and thermal properties were characterized. The diameter of PA66 fiber was increased with the addition of acidified MWCNTs. The impact strength and tensile strength of the composites increased firstly and then decreased with increasing content of carbon nanotubes. When the MWCNTs mass fraction was 0.5 % (based on the mass of PA66), the impact and the tensile strengths reached their maximum value 0.29 kJ/m2 and 1.96 MPa, respectively. The impact strength increased by 23.2 % compared with o-CFER resin, and increased 16.3 % compared with PA66/o-CFER composites. Tensile strength increased by 74 % compared with that of o-CFER resin. The thermal performance was improved when the MWCNTs-PA66 fibers membrane was added.

Influence of Processing Parameters on Short Glass Fiber Reinforced PP Injection Part Warpage

2015, 29 (01): 90-94 ; DOI: 10.19491/j.issn.1001-9278.2015.01.017

Abstract ( 535 )

In this article, the computer aided engineering (CAE) and orthogonal design experimental was combined to study the warpage of injected parts of glass fiber reinforced polypropylene. Taking the car liner as an example, the warpage related parameters such as melt temperature, mold temperature, injection time, injection speed/pressure were investigated. It showed that the fiber content and mold temperature were two important factors affecting the warpage, which could be optimized to values giving minimum warpage.

Preparation of a novel nucleating agent and its representation

2015, 29 (01): 95-99 ; DOI: 10.19491/j.issn.1001-9278.2015.01.018

Abstract ( 465 )

With o-phthalic acid and aluminium isopropoxide as raw materials, a new salt of phthalic acid hydroxy aluminium was prepared, which was used as a nucleating agent for isotactic polypropylenes (iPP) and was denoted as OXA. Thermal stability of OXA was characterized by using thermogravimetric analysis technology (TG). The influence of OXA on the crystal form, crystalline morphology, and crystallization behavior of iPP were investigated using X-ray diffraction, polarized light microscopy, and differential scanning calorimetry. When the content of OXA was 0.3 wt%, the crystallization temperature (Tc) was 13.26 ℃. In addition, OXA increased the degree of crystallinity from 52.49 % to 58.37 % and refined spherulites were observed. The flexural strength was increased from 46.19 to 50.89 MPa.

Heat Stabilization of Organotin Carboxylates on PVC：Progressive Change Law of Performance and Mechanism

2015, 29 (01): 100-103 ; DOI: 10.19491/j.issn.1001-9278.2015.01.019

Abstract ( 770 )

The heat stabilization of dialkyltin carboxylates on PVC was studied. It was found that the stronger the electron-withdrawing of the group linked to carbonyl C atom in the stabilizer, the more stable of PVC resin. For the dialkyltin carboxylate, the stabilizing ability was originated from the electrophilic reaction between PVC and the electrophilic centers of the carbonyl C atom in the carboxylate radical and/or dialkyltin ion. For this reason, the traditional Frye and Horst’s theory on mechanism of heat stabilization of heat stabilizers did not apply to dialkyltin carboxylates.

Effect of Screw Metering Section Geometric Parameters and Processing Conditions on Energy-saving Performance of Plastics Extruders

2015, 29 (01): 104-107 ; DOI: 10.19491/j.issn.1001-9278.2015.01.020

Abstract ( 658 )

The calculation formulas for unit consumption were given by analyzing the extrusion theory and energy thermal balance of the plastic extruder. Relationship between the unit consumption and geometry parameters of screw and processing conditions was discussed with a Φ65 mm plastic single-screw extruder base as the study object, and the software Origin was employed. The study results showed that in the curve of relationship of influence factors on the unit consumption there was a best value for the plastic extruder, which made the unit consumption minimal under the high productivity.