WENG Yun-xuan, NIU Li-jie, XU Guo-zhi
Abstract (
3190 )
The paper reviewed different types of biodegradable plastics including
petroleum based and renewable resource based biodegradable plastics
and their blends. The current status and development tend of biodegradable
plastics were introduced. Some suggestions including the measures that
should be taken and the relevant policy of governments were also made
for further development of the biodegradable plastics.
LI Yi, YIN Bo, YANG Ming-bo, YANG Wei, XIE Bang-hu
Abstract (
2019 )
In this paper, the microencapsulation of ammonium polyphosphate (APP) was introduced according to the capsule material (melamine, melamine formaldehyde resin, isocyanate polymers, silicone oil and thermoplastic resin). While melamine or melamine formaldehyde resin encapsulation may improve the waterproof and fire retardancy of the APP, silicone oil encapsulation increased its hydrophobicity. When the encapsulated APP was introduced into polypropylene, the fire retardancy of the system was obviously enhanced compared with those based on neat APP.
FAN Xiao-hong, CAI Chao-hui, WU Yao-gen, YE Shu-zhan, XU Bing
Abstract (
3270 )
In this paper, the main function and performance, research and present situation of home and overseas of microporous membranes made of polyolefin materials are summarized, which are used in Li-ion battery as separators. The principles, process of dry and wet methods are emphasized. The modification and new type of battery separator are also discussed. At last, the development trend of separator is predicted.
WANG Rong-fei, GAO Lei, SHEN Kai-zhi
Abstract (
3250 )
This paper reports the effect of high-molecular-weight polyethylene (PE-HMW) on the crystal morphology of high-density polyethylene (PE-HD) specimen. The PE-HD specimen containing a small amount of PE-HMW prepared via dynamic packing injection molding was found to be obviously reinforced. The tensile strengths were increased from 28 MPa to 76 MPa in machine direction and to 32 MPa in transverse direction, the impact strength of them increased from 2.0×105 kJ/m2 to 8.7×105 kJ/m2 in machine direction. Electron microscopy micrograph indicated that there were abundant interlocking shish-kebab crystals present in shear layers. DSC confirmed the formation of central long shish structure and thickened kebabs which exhibit a higher thermal stability.
LUAN Fu-jin, CHENG Min-lian, WANG Shi-yin
Abstract (
3208 )
The compatibility, thermal properties, mechanical properties and barrier properties of the blends of PP/poly (ethylene-co-vinyl alcohol) (EVOH) containing three kinds of compatilizers(PP-g-AA, PP-g-ITA and PP-g-MAH) were investigated. Infrared spectra analysis indicated that the improvement of compatibility was resulted from the formation of ester bonds and hydrogen bonds between compatilizers and EVOH. Scanning Electron Microscopy observations showed that the presemce of compatilizers in the PP/EVOH blends reduced the size of the dispersed phase. Differential scanning calorimetry analysis showed that the compatilizers lowered the crystallization temperature of dispersed EVOH phase, but increased that of PP phase. Compared with the uncompatibilized blends, the tensile strength of the compatibilized blends was increased by10 MPa, and the oil absorption rate was decreased by 0.8 %.
LI Wei, LV Qun, YANG Hai-tang, HE Tian, LAI Guo-qiao
Abstract (
2297 )
High wood-flour-content filled PE composites were manufactured via extrusion, with a recipe of 70 wt% wood flour, 27 wt% PE-HD plus maleic anhydride grafted PE (PE-g-MAH), and 3 wt％ lubricant. The mechanical properties and water absorption of the PE/wood flour composites were investigated. The addition of PE-g-MAH increased the flexural strength, toughness, and tensile strength of the composites significantly, which were increased from 30.0 to 60.0 MPa, 3.94 to 14.1 kJm-2, and 12.5 to 34.7 MPa, respectively. Water absorption was decreased from 2.51 to 0.04 wt%. FTIR indicated that ester bonds were formed between wood flour and PE-g-MAH.
WANG Huan-feng, LI Bin
Abstract (
3127 )
A polysiloxane modified β-cyclodextrin (CDS) was synthesized from tetramethyl dihydro disiloxane, allyl glycidyl ether, and β-cyclodextrin (β-CD). FTIR showed that β-CD was grafted to the chain ends of polysiloxane. The prepared CDS was employed in a flame retarding polypropylene system containing also an intumescent flame retardant (IFR), and compared with unmodified β-CD in the thermal and mechanical properties using thermogravimetric analysis (TGA), limiting oxygen index (LOI), scanning electron microscopy (SEM), etc. It showed that CDS had a synergistic effect with IFR, which promoted the formation of stable, continuous and compact char structure at high temperature. When the content of CDS was 1.5 wt%, the LOI was 35.0 %, pass the UL94 V-0 test. The tensile, flexural, and impact strength were 8. 6 %、16.8 % and 70.7 % higher, respectively, than those based on β-CD.
HU Jian-feng, SITU Yue, XU Li, CHEN Huan-qin
Abstract (
3193 )
Phenolic resin was modified with epoxidized soybean oil (ESO) and organic-montmorillonite (OMMT) in order to improve its mechanical properties. The grafting of phenolic resin with ESO via etherification resulted in toughening, and the mechanical properties of modified phenolic resin was further enhanced with inorganic nanoparticles. After adding 40 wt% ESO, the impact strength of the phenolic resin was increased by 72 %, bending strength and elongation at break reached 94 MPa and 4.5 %, respectively. By introducing 2 wt%OMMT into the ESO toughened phenolic resin, the impact strength increased by 42.2 %, bending strength tensile strength, and elongation at break reached 111 MPa, 30.8 MPa, and 40 %, respectively.
WANG Xiao-dong, QIAN Jia-sheng
Abstract (
3116 )
PPS/nano-Si3N4 composites were prepared via melt blending. The tensile and impact properties were significantly enhanced by filling nano-Si3N4.With the addition of 0.8 wt% Si3N4, the tensile strength of the composite was increased by 22 % based on neat PPS. As the content of Si3N4 increased, both un-notched and notched impact strengths each exhibited a maximum at 1.2 wt%, was increased by 33 % and 41 %, respectively, based on neat ones. As Si3N4 powder increased the activation energy of PPS segment relaxation, the storage modulus of PPS/nano-Si3N4 composites reduced, loss modulus increased.
LI Ya-dong, QIANG Ke-gang, LIU Zhi, ZHANG Zhi-jun
Abstract (
3210 )
Ethylene-co-tetrafluoroethylene(ETFE)/nano-SiO2 composite coatings were prepared via flame spray. The degradation behavior of the composite coating was characterized using Fourier transform infrared spectroscopy, which confirmed that no oxidation nor degradation occurred during the flame spray. The non-isothermal crystallization and melting behavior were investigated using differential scanning calorimeter. It showed that the SiO2 particles promoted the heterogeneous nucleation and the crystallization temperature was increased by 2 oC, the melt point was also increased.
XUE Ping, MAO Xu-lin, DING Wen-ying
Abstract (
2448 )
A new extrusion technique, solid state extrusion was adopted for molding ultra high molecular weight polyethylene(PE-UHMW). The product by solid state extrusion was smoother, more transparent, and with a higher density than those based on regular extrusion. The microstructure of the products were studied using scanning electron microscope (SEM), and the effects of extrusion temperature and extrusion draw ratio on products’ thermal property were investigated using differential scanning calorimetry (DSC). It was found that a large quantity of micro-fiber was produced in the products of solid state extrusion. Compared with those by regular extrusion, it possessed a greater degree of molecular orientation, higher degree of crystallinity, and higher melting point. Besides, the tensile strength and modulus increased by 4 and 40 times based on regular extrusion ones.
WANG Dong-yan, FU Qiang
Abstract (
3123 )
A set of injection mould was designed for the PMMA artwork ‘Bird nest’. According to the analysis of the structure and injection process, the contracted core with eight inserts and the twice - parting mechanism with pendulum hook were adopted to make the injecting and stripping of this set of mould work well. This article offered one efficient and reasonable idea for the mould design of the hollow plastic work pieces.
YANG Hua-lin, GAO Ji-tao, DENG Fang, SHI Jun-you
Abstract (
4615 )
Under the circumstances of plastic material’s diversity and the difficulty of material selection, the material data classification method and the relation of material property and the plastic part are studied, and a general database which including material property, melt plastic flow behavior, plastic configuration, and pigmentation libraries is set up. “Material property – plastic structure factor” mapping mechanism is created according to the material property influence on the plastic product. The mapping tool can automatically solve the mutual influence and requirement between material property and plastic structure factor. The general inquiry navigator is developed to search the associated information of the material selected, and export the selected information to several formats for share. It showed that this system can solve the problem of multipurpose plastic material selection fairly well.
LI Wei, GUO Kui, CHEN Hong, YANG Wei-min
Abstract (
2153 )
By virtue of visualization equipment in injection molding, three kinds of cavities were constructed. Under certain conditions, the forming process of weld line defect was observed. Via studying the forming mechanism, the weld line defect was eliminated or reduced by improving packaging pressure, melt temperature, and injection velocity. The study results could provide theoretical basis for investigating and avoiding product defects in injection molding process.
LIU Dong-lei, XIN Yong
Abstract (
1814 )
Based on a deeper understanding and a reasonable analysis on the rapid heat cycling molding (RHCM) technology, the process quality index including wrap age, sink index, and volumetric shrinkage were selected as predictive index of plastic part manufactured by RHCM technology. The main process parameters including mold temperature, melt temperature, injection pressure, pressure at v/p switch-over point, and packing pressure were defined as predictive variances as well. An efficient multifactor comprehensive predictive model was created between molding quality predictive index and main process parameters by coupling with CAE analysis, Taguchi method, and multivariable liner regression methodology. Although the dimension theory did not referred to, it was used during the former research. The comprehensive quality predictive model was interfaced with an effective updated GA to find the optimum process parameters values. A case results showed that the model was effective and feasible.
CHEN Bin-yi, Wang Xiang-dong, LIU Ben-gang, CHEN Shi-hong, ZHANG Yu-xia
Abstract (
2746 )
PP/nano-clay composites were prepared based on two different PP and various contents of compatibilizer PP-g-MAH on a twin-screw extruder.XRD curbes showed that the resultant composites exhibited intercalation structure,and PP matrixes and contents of the compatibilizer PP-g-MAH affected their intercalation structure.Sag resistance experiment indicated that the sag resistance of the composites changed with the intercalation structure.Neither large layer space nor small layer space of the clay is 2.90~3.00 nm,the sag resistance of the PP/nano-clay composite reached its highest value.
LU Lin-gang, YANG Shou-sheng, HUANG Xiao-dong, ZHANG Yan, DONG Xi-lin
Abstract (
2739 )
A novel phosphorus fire retardant, 1,2,3-tri(5,5-dimethyl-1,3, -dioxaphosphorinanyl-2-oxy)benzene (FR), was synthesized from 1,2,3-tri(hydroxy)benzene, neopentyl glycol, and phosphorus oxychloride, and was employed in epoxy resin system. The flame retarding effect on limited oxygen index (LOI) and UL-94 was studied. It showed that FR was effective on the flame retardancy of epoxy resin at a content of 20 %, UL94 V-0 rating and an LOI of 27.8 % were reached. The cone experiment showed that the av-HRR and av-SEA of the FR-containing epoxy resin were 77.0 % and 82.8 % lower than neat resin, respectively. SEM observation revealed that a continuous, dense, strong, and closed charred layer was formed.
LIU Ji-chun, FU Meng-yue, LI Qing-yuan, ZHANG Yu-qing
Abstract (
2229 )
PS resin, organically modified montmorillonite (OMMT), and surface modified magnesium hydroxide (MH) were melt blended forming a composite. The structure of the composites was analyzed using X-ray diffraction. The flame-retardant property of the composites was investigated by employing horizontal burning, oxygen index, and high temperature treatment. It was found that the interlayer space of OMMT was increased from 1.46 nm to 3.30 nm after melt blending with PS, indicating a structure of intercalation occurred. The introduction of MH did not affect the formation of the intercalation structure. The coexistence of OMMT and MH decreased the melt dripping and smoke emitting of the composites during burning. The PS/MH/OMMT composite exhibited better stability and flame retardancy than its PS/MH counterpart. As a result, the amount of flame retardants could be greatly decreased.
ZHANG Ning, DAI Wei-min, XU Kun-peng, LIU Min
Abstract (
2881 )
The mechanical properties of polypropylene/waste tire power composites were studied. The compatibility between the components was improved by shucking off sulfur and free radical reaction. It was found that the tensile strength and elongation at break were decreased with increasing tire power. When the tire content was 70 wt%, the tensile strength decreased from 37 MPa to 7 MPa, the elongation at break from 108 % to 35 %. Impact strength increased first and then decreased as content of tire power increased. When the content was 20 %, impact strength was 14 kJ/m2. When modified tire power was employed, these mechanical properties were improved. When the tire powder content was 30 wt%, the impact strength and elongation at break were 18.5 kJ/m2 and 320 %, respectively.
GE Xiao-hong, WU Shao-lan, LI Hui, LIU Ya-dan, YANG Hui-huang
Abstract (
2495 )
In processing the transparent and complicated PMMA handles, hot runner injection mould was introduced so that the hot runner system was shared in the optimal combination of the mould bases, the inserts and the beryllium-copper alloy cored cooling system to create an effective general structure model of hot runner injection mould of handles. CAE analysis and production validation of a handle mould was carried out and the test results proved to meet the requirements for the operations to have high quality, cost-efficiency and shortened mould cycles.
