检索结果-南通市图书馆

THE THIXOTROPY-LOOP BEHAVIORS OF AN ldpe MELT:EXPERIMENT AND SIMPLE ANALYSIS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2006年第6期18卷 666-675页

作者： HUANG Shu-xin LU Chuan-jing Department of Engineering Mechanics Shanghai Jiaotong University Shanghai 200030 China

The time-dependent viscoelastic behaviors of an Low-Density-Pdyethyene（ldpe）（PE-FSB-23D022） melt were experimentally investigated using two types of thixotropy-loop test i.e., the triangular- and the trapezoidal-loop shear test. The shear strengthening was noted in the thixotropy-loop tests not only at high shear rate but also at low shear rate, and it was found that the dimensionless stress amplitude of shear strengthening at low shear rate is larger than that at high shear rate. Moreover, the shear strengthening is a time-dependent viscoelastic behavior that is observed during the initial stage of shearing, and it cannot be found when the time interval corresponding to the increase in shear rate is sufficiently long, The remarkable shear-weakening phenomenon was noticed at higher shear rate when shearing time is prolonged. Five types of the triangular thixotropy-loop results were marked in terms of the configurations of the stress-rate curves, which indicate the complex features of the time-dependent viscoelasticity. A simple model was used to describe the thixotropy-loop tests, and the fitted results showed good agreement with the experimental results.

关键词： thixotropy-loop test time-dependent viscoelasticity ldpe shear strengthening shear weakening

Dielectric, Optical and Thermal Properties of ldpe/ZnO Hybrid Film

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2015年第1期30卷 37-42页

作者：任桂华 YU ZhiSong 熊锐 School of Mechanic and Electric Engineering Hubei Polytechnic University College of Physics and Electronic Science Hubei Normal University Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology Wuhan University

The hybrid films of low-density polyethylene （ldpe） embedded with zinc oxide （ZnO） particles were prepared by melt-blending process. X-ray diffraction （XRD） results illustrate that ZnO particles are distributed in the ldpe matrix and FTIR results show that no chemical bonds form between ZnO particles and ldpe matrix. The measurements of the dielectric properties of the hybrid films show that the dielectric constant of the composites reinforces and dielectric loss increases with increasing ZnO weight fraction. Moreover, the thermal properties of the ldpe/ZnO hybrid films are improved and the results of optical properties studied by ultraviolet-visible （UV-Vis） spectrometer show that the inclusion of ZnO particles can improve the anti-UV properties of the films. The improvements of the dielectric, optical and thermal properties demonstrate that the hybrid film will be a promising material in the food package and engineering fields.

关键词： ldpe ZnO XRD FTIR UV-vis TG-DTA dielectric analysis

RHEOLOGIC STUDIES ON CHEMICAL CROSS-LINKING KINETICS FOR ldpe

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2012年第3期30卷 378-386页

作者：杨红梅 Zhi-gang Liu Yong-zhu Yang Qiang Zheng Zhejiang Univ Dept Polymer Sci&EngnHangzhou 310027ZhejiangPeoples R China Minist Educ Key Lab Macromol Synth&FunctionalizatHangzhou 310027ZhejiangPeoples R China

Crosslinking reaction of ldpe resin in the presence of dicumyl peroxide （DCP） was studied by isothermal rheological measurements at different temperatures and non-isothermal differential scanning calorimetry （DSC） technique with different heating rates. The kinetic parameters of crosslinking reaction were calculated by both rheological and DSC measurements. The results reveal that with the increase of DCP contents, the apparent activation energy, Ea, ranges from about 140 kJ/mol to 170 kJ/mol and the order of crosslinking reaction, n, approaches unity. The influence of measurement frequency, on crosslinking reaction was also investigated. It can be found that n does not change with the increase of ωand Ea decreases slightly with the increase of ω

关键词： Crosslinking kinetic ldpe Rheological measurement DSC measurement.

IN SITU COMPATIBILIZATION OF ldpe/NYLON-6 BLEND USING LOW MOLECULAR WEIGHT INTERFACIAL AGENT AS A CHEMICAL COMPATIBILIZER

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 1997年第3期15卷 205-216页

作者：李蓓张瑞丰蔡忠龙 Department of Applied Biology and Chemical Technology Department of Applied Physics the Hong Kony Polytechnic University Hung Hom Kowloon Hong Kong

In situ, compatibilization of low density polyethylene (ldpe) (30%) and nylon-6 (70%) blends through one-step reactive extrusion using t-BuOOH as an initiator and low molecular weight interfacial agents as compatibilizers was studied. The compatibilizer contained a long chain hydrocarbon, double bond and two polar functional groups which was capable of reacting with both ldpe and nylon-6 in the presence of initiator to form a copolymer at the interface of the two polymer phases. The extruded blends exhibited significant enhancement in their compatibility based on morphological, thermal analysis and mechanical studies. The effect of the hydrocarbon chain length and structure of the functional group of the compatibilizer was also examined. It was found that blends prepared by using the compatibilizer containing longer hydrocarbon chain and amide group had better mechanical properties.

关键词： ldpe nylon-6 reactive extrusion compatibilizer

Production of mahogany sawdust reinforced ldpe wood–plastic composites using statistical response surface methodology

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2015年第2期26卷 487-494页

作者： Sofina-E-Arab Md.Azharul Islam Forestry and Wood Technology Discipline Khulna University

We produced wood–plastic composite board by using sawmill wastage of mahogany（Swietenia macrophylla） wood and low density *** used multi-response optimization to optimize the process parameters of composite board production including mixing ratio,fire retardant（%） and pressing time（min）.We investigated the effects of these three process parameters in the mechanical and physical properties of the composite ***,Box–Behnken design was performed as response surface methodology with desirability functions to attain the optimal level of mixing ratio,fire retardant and pressing time（min）.The maximum modulus of elasticity（MOE） and modulus of rupture（MOR） were achieved at the optimal conditions of wood plastic mixing ratio of60：40,pressing time of 9 min and zero fire retardant *** optimized MOR and MOE were 13.12 and1,781.0 N mm-2,respectively.

关键词： Wood plastic composite ldpe Mechanical properties Physical properties Response surface methodology

Irradiation and flame retardant effect of poly[bis(phenoxyphosphazene)] and magnesium hydroxide in ldpe composites

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2015年第3期26卷 57-63页

作者：李建喜张聪陈涛李林繁李景烨 CAS Center for Excellence on TMSR Energy System Shanghai Institute of Applied PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

Poly[bis(phenoxyphosphazene)](PBPP) and magnesium hydroxide(MH) are used as a flame retardant blend with low-density polyethylene(ldpe) for the nuclear cable. This study aims to investigate the effects of PBPP in MH-ldpe blend composites on flame retardance and electron beam irradiation. The structure, morphology,and properties of the blend composites irradiated by an electron beam to different absorbed doses were characterized. The results indicated that PBPP provides lubrication during processing. As the PBPP content in the blend increases the melt flow rate at 20 phr MH, meaning the material is easier to process. The higher the PBPP content, the higher the limiting-oxygen index. The elongation at the break of the PBPP containing composites(at 50 phr MH) was evidently higher than the non-PBPP ones at different absorbed doses by electron beam irradiation. The thermogravimetric analysis results indicated that the improved mechanical property, resulting from electron-beam irradiation, could be attributed to the consumption of PBPP.

关键词：共混复合材料电子束辐照氢氧化镁 ldpe 苯氧基阻燃效果磷腈电子束照射

MORPHOLOGICAL,MECHANICAL,THERMAL AND TRIBOLOGICAL PROPERTIES OF ENVIRONMENTALLY FRIENDLY CONSTRUCTION MATERIALS:RECYCLED ldpe COMPOSITES FILLED BY BLAST FURNACE DUST

在线全文

学校读者我要写书评

暂无评论

Journal of Green Building 2020年第3期15卷 159-175页

作者： Merve Tuna Kayili Gülser Çelebi Abdulmecit Guldas Karabuk University Faculty of ArchitectureDepartment of ArchitectureKarabükTurkey Çankaya University Faculty of ArchitectureDepartment of Interior DesignAnkaraTurkey Gazi University Faculty of TechnologyDepartment of Manufacturing EngineeringAnkaraTurkey

This study focused on developing a sustainable composite material using metallic wastes of the iron-steel industry and plastic wastes of the plastic industry in order to reduce resultant waste from the production processes of various industrial products and to sustain waste management of these *** this study,different amounts of blast furnace dust(BFD),which is the major iron-steel industry waste and is used as filler for recycled low-density polyethylene(ldpe),was mixed with ldpe to produce the composite *** morphology,mechanical,vicat softening temperature thermal conductivity,hardness and wear resistance properties of BFD filled ldpe composites were *** increasing of BFD in recycled ldpe improved the heat resistance,increased thermal conductivity and wear resistance of composite *** addition,it was found that the composite materials had sufficient mechanical properties,when mechanical tests were *** results showed that the produced composite material could be used in buildings as a floor coating material and thereby saving raw materials and resources,as well as potentially reducing environmental problems.

关键词： Blast furnace dust ldpe plastic waste recycling composites mechanical properties floor coating material

ldpe中介入聚合物阻挡层后其交流电场下的电树特性分析

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

高电压技术 2010年第7期36卷 1651-1656页

作者：宋伟张冬杨春韩柏孙志何丽娟王暄雷清泉哈尔滨理工大学电气与电子工程学院哈尔滨150080 工程电介质及其应用省部共建重点实验室哈尔滨150080 上海交通大学电子信息与电气工程学院上海200240 哈尔滨理工大学应用科学学院哈尔滨150080

为了研究低密度聚乙烯(ldpe)的电树老化特性,观察电树在ldpe中的生长情况,以及在频率50Hz交流电压作用下电树老化引起的破坏现象和电树生长过程中的形态变化,采用在ldpe样品的两电极之间介入阻挡层,且阻挡层分别选用不同材质的聚合物薄... 详细信息

为了研究低密度聚乙烯(ldpe)的电树老化特性,观察电树在ldpe中的生长情况,以及在频率50Hz交流电压作用下电树老化引起的破坏现象和电树生长过程中的形态变化,采用在ldpe样品的两电极之间介入阻挡层,且阻挡层分别选用不同材质的聚合物薄膜。对介入了聚合物阻挡层的ldpe与纯ldpe样品电树的生长形态及电树的生长方向进行比对,观察阻挡层对电树的影响情况,并探讨了不同阻挡层对电树阻挡作用的差异。结果表明,当在针-板电极中放入阻挡层时,可以减缓电树的生长,对于增加其击穿时间有一定的研究价值;对击穿时间的影响取决于阻挡层材料本身的性质和结构特点以及空间电荷的作用。

关键词： ldpe 电树枝生长击穿阻挡聚合物膜

纳米二氧化硅填料量对ldpe复合材料局部放电特性的影响(英文)

在线全文

学校读者我要写书评

暂无评论

高电压技术 2011年第11期37卷 2629-2635页

作者： Z.Abdul-Malek A.M.Azzin Y.Z.Arief Aulia K.Y.Lau M.Jaafar UTM Institute of High Voltage & High Current Universiti Teknologi MalaysiaMalaysia School of Materials & Mineral Resources Engineering Universiti Sains MalaysiaMalaysia

Partial discharges(PDs) due to artificial void in samples of ldpe nanocomposite sheet have been investigated in this *** may cause the degradation of insulating materials and may affect the lifetime of high-voltage apparatus. An experimental work using sphere ball-plane electrode system(CIGRE MethodⅡ) and a 1.0 mm ldpe composite sheet was carried *** weight percentages of nanosilica(0%,2%,4%,6%and 8%) were used. PD experimental results,such as PD magnitude and PD number(both PD pulse polarities),as functions of the applied stress duration at a specified applied voltage were *** surface morphology of specimens was also presented and this conforms to the PD *** experimental results show that the PD characteristics of the ldpe generally improve with the introduction of nanosilica,the composite with the highest content of filler,namely the 8%(wt) nanosilica sample has the least partial discharge activities.

关键词： ldpe nanocomposite nanosilica partial discharges