挤出牵引速度对聚乙烯/金属锡导电复合材料性能的影响

采用高温挤出热拉伸-低温注射成型的加工工艺,制备了聚乙烯/金属锡（PE/Sn）导电复合材料,研究了挤出造粒时不同切粒机转速（即热牵引速度）和Sn用量对其微观结构、导电性能及力学性能的影响。结果表明,当切粒机的转速由常规的35 r/min提高到50 r/min时,Sn在PE基体中成纤更细更长,PE/Sn复合材料导电所需的Sn的最低含量由常规时的9.2 %（质量分数,下同）降低到6.2 %,即导电逾渗值降低,且复合材料的力学性能略有上升。     

片材挤出用导电聚碳酸酯工程塑料的研制

采用熔融共混法制备了导电炭黑/聚碳酸酯(PC)片材挤出用导电复合材料,研究了炭黑、增韧剂等对复合材料的表面电阻率、力学性能、剥离强度和外观的影响。结果表明:将炭黑添加到PC中制得的导电复合材料可挤出合格的用于载带制造的片材,可以满足芯片包装的各项要求,适宜的炭黑加入量为16%~23%;甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)、丙烯腈-丁二烯-苯乙烯共聚物(ABS)均可作为导电PC复合材料的增韧剂,但以两者共混时的焊接剥离强度最为稳定,片材的外观良好,适宜用量为5%~7%。     

PET/PE/CB导电母料的研制

采用分离喂料技术在聚对苯二甲酸乙二酯(PET)/聚乙烯(PE)共混物中加入导电炭黑(CB),通过布斯往复式脉动挤出机熔融共混、挤出造粒,制备了综合性能较好的纤维级PET/PE/CB导电母料。研究发现,以PET/PE不相容共混物代替PET作母料的基体树脂,能以较低的CB用量获得较好的导电性能;CB的质量分数为15%时,母料的体积电阻率随PET用量的增加呈先减小后增大的趋势,在PET与PE的质量比为60∶40时,母料的体积电阻率最低。     

熔融挤出制备HDPE/纳米石墨薄片导电塑料研究

采用苯乙烯-丙烯腈共聚(AS)树脂对纳米石墨薄片(GN)进行包裹改性,制备成GN母料,并将它与高密度聚乙烯(HDPE)树脂进行混合挤出,制备了HDPE/GN复合材料,其渗滤阀值质量含量为14%。讨论分析了复合体系在加工过程中导电性能及其变化特征,研究了所制备的复合材料力学性能与石墨含量的关系。     

润滑剂对PE木塑复合材料力学性能和加工性能的影响

本文讨论了两种润滑体系在PE木塑复合材料中的应用，测试了材料的力学性能和加工性能。结果发现，润滑剂需用量要约2％、并保持物料较快塑化、形成较大的挤出压力，才能使PE木塑复合材料获得较高的挤出速度和较好的外观质量，产品的力学性能则基本不受润滑剂品种的影响。     

润滑剂对PE木塑复合材料力学性能和加工性能的影响

本文讨论了两种润滑体系在PE木塑复合材料中的应用，测试了材料的力学性能和加工性能。结果发现，润滑剂需用量大约2％、并保持物料较快塑化、形成较大的挤出压力，才能使PE木塑复合材料获得较高的挤出速度和较好的外观质量，产品的力学性能则基本不受润滑剂品种的影响。     

可剥离氯化聚乙烯绝缘屏蔽材料的研制

以橡胶型氯化聚乙烯为主体材料,过氧化物(DCP)作为主要硫化剂制备半导电橡胶.研究了该混炼胶的导电性能、力学性能、老化性能、半导电橡胶与其他橡胶共同挤出硫化后的可剥离性能.     

抗氧剂对PE滴灌带热氧老化性能的影响

研究了滴灌带用聚乙烯(PE)混配料中加入抗氧剂,经多次挤出后产物的熔体流动速率、羰基指数及拉伸性能的变化,分析了抗氧剂对回收滴灌带用PE热氧老化性能的影响。结果表明:加入抗氧剂可降低滴灌带用PE的热氧化反应速率;添加抗氧剂比未添加抗氧剂的PE微观化学性能和宏观力学性能都有明显提高。     

国内外信息

LDPE/PA6共混阻透薄膜江苏石油化工学院研制成将LDPE(低密度聚乙烯 ) ,PA6 (尼龙 6 )和PE - g -MAH(马来酸酐接枝聚乙烯 )等混合后加入单螺杆挤出机内 ,经熔融挤出吹塑制成LDPE/PA6共混阻透薄膜 ,其阻透性能比纯LDPE膜提高了 10倍以上。PE吹塑转光膜徐州塑料一厂在PE中添加转光母料及转光粉制成PE吹塑转光膜。据介绍 ,转光膜在保持PE膜的外观质量和物理力学性能的同时 ,具有明显的增温效应 ,可促进农作物早熟 ,提高作物质量。(以上由常州市和平北路 9号　汪焕心供稿 )工程塑料低温抗冲改性剂据“AdditivesforPolymers” ,2 0…     

钛化合物填充的聚合物导电复合材料的PTC特性及微观结构

以高密度聚乙烯 (PE HD)及热固性环氧树脂为基体 ,钛的硼化物、碳化物、氮化物或碳氮化物为导电粒子 ,研究了PE HD/钛化合物、环氧树脂 /钛化合物导电复合体系的逾渗行为、PTC/NTC现象及微观结构行为。结果表明 ,PE HD/钛化合物及环氧树脂 /钛化合物导电复合体系均具有强PTC开关特性 ,其逾渗阀值为 3 5 %～ 65 % (体积分数 ) ;电阻温度系数高达 (5 5 .7%～ 64 .3 % )·℃ -1。钛化合物导电颗粒以粒度不等的非均匀分布分散在聚合物基体中 ,其中在PE HD基体中颗粒之间在室温下紧密接触导通 ;而在环氧树脂基体中颗粒之间易产生团聚。     

The synergistic effects on enhancing thermal conductivity and mechanical strength of hBN/CF/PE composite

In this work, a simple and novel method was applied to prepare polymer composites by taking the advantage of melt flow shear force driving orientation of the fillers. By using this method, hexagonal boron nitride/polyethylene (hBN/PE) and hexagonal boron nitride/carbon fibers/polyethylene (hBN/CF/PE) composites were fabricated to be possessed of high thermal conductivity and mechanical properties. A high thermal conductivity of 3.11 W/mK was realized in the composite containing 35 wt% hBN and 5 wt% CF, which was over 1,200% higher than that of unfilled PE matrix. Under this component, the compressive strength and modulus of hBN/CF/PE composite were determined to be 30.1 and 870.9 MPa, respectively, which were far higher than that of unfilled PE accordingly. The bending performance was also somewhat enhanced. Meanwhile, the bulk resistivity of the composite material reached 2.55 × 10¹¹ Ω·cm, which was basically the same as that of pure PE. The novel composites with high thermal conductivity, excellent mechanical properties, and controllable electrical insulation could be a potential thermal management material for electrical and electronics industries.     

LDPE／炭黑导电复合材料电学及力学性能研究

研究了炭黑种类及用量、极性共聚物（Ｅ－ＡＥ－ＭＡＨ）、润滑剂种类及用量和交联剂（ＤＣＰ）对ＬＤＰＥ／炭黑导电复合材料电学及力学性能的影响。结果表明,ＨＧ－４型炭黑导电性最好,ＡＣＥＴ炭黑导电性较差。极性共聚物能提高复合材料的导电性和力学性能。高分子蜡改善复合材料电学及力学性能的效果优于液体石蜡。交联剂使复合材料导电性变差,但力学性能提高     

Thermal,electrical, and mechanical properties of polyethylene–graphene nanocomposites obtained by in situ polymerization

In this study, we investigated the thermal, dynamic mechanical, mechanical, and electrical properties of polyethylene (PE)–graphene nanosheet (GNS) nanocomposites, with GNS amounts from 0 to 20 wt %, prepared by in situ polymerization. The thermal stability was evaluated by thermogravimetric analysis (TGA) and showed that the addition of GNSs to the polyolefin matrix increased the onset degradation temperature by 30°C. The electrical conductivity, measured by the impedance technique, presented a critical percolation threshold of 3.8 vol % (8.4 wt %) of GNS. A slight decrease in the tensile strength was found. On the other hand, dynamic mechanical analysis showed an increase in the storage modulus of the nanocomposites compared with that of neat PE. The glass‐transition temperature value increased from ?111°C (neat PE) to ?106°C (PE/6.6 wt % GNS). All of these results show that PE became stiffer and thermally more stable and could be transformed from an insulator to a semiconductor material in the presence of GNSs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Polyethylene multiwalled carbon nanotube composites

Polyethylene (PE) multiwalled carbon nanotubes (MWCNTs) with weight fractions ranging from 0.1 to 10 wt% were prepared by melt blending using a mini-twin screw extruder. The morphology and degree of dispersion of the MWCNTs in the PE matrix at different length scales was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and wide-angle X-ray diffraction (WAXD). Both individual and agglomerations of MWCNTs were evident. An up-shift of 17 cm⁻¹ for the G band and the evolution of a shoulder to this peak were obtained in the Raman spectra of the nanocomposites, probably due to compressive forces exerted on the MWCNTs by PE chains and indicating intercalation of PE into the MWCNT bundles. The electrical conductivity and linear viscoelastic behaviour of these nanocomposites were investigated. A percolation threshold of about 7.5 wt% was obtained and the electrical conductivity of PE was increased significantly, by 16 orders of magnitude, from 10⁻²⁰ to 10⁻⁴ S/cm. The storage modulus (G′) versus frequency curves approached a plateau above the percolation threshold with the formation of an interconnected nanotube structure, indicative of ‘pseudo-solid-like’ behaviour. The ultimate tensile strength and elongation at break of the nanocomposites decreased with addition of MWCNTs. The diminution of mechanical properties of the nanocomposites, though concomitant with a significant increase in electrical conductivity, implies the mechanism for mechanical reinforcement for PE/MWCNT composites is filler-matrix interfacial interactions and not filler percolation. The temperature of crystallisation (T_c) and fraction of PE that was crystalline (F_c) were modified by incorporating MWCNTs. The thermal decomposition temperature of PE was enhanced by 20 K on addition of 10 wt% MWCNT.     

Graphene/polyethylene nanocomposites: Effect of polyethylene functionalization and blending methods

Since its recent successful isolation, graphene has attracted an enormous amount of scientific interest due to its exceptional physical properties. Graphene incorporation can improve electrical and mechanical properties of polymers including polyethylene (PE). However, the hydrophobic nature and low polarity of PE have made effective dispersion of nano-fillers difficult without compatibilization. Graphene was derived from graphite oxide (GO) via rapid thermal exfoliation and reduction. This thermally reduced graphene oxide (TRG) was blended via melt and solvent blending with linear low density PE (LLDPE) and its functionalized analogs (amine, nitrile and isocyanate) produced using a ring-opening metathesis polymerization (ROMP) strategy. TRG was well exfoliated in functionalized LLDPE while phase separated morphology was observed in the un-modified LLDPE. Transmission electron micrographs showed that solvent based blending more effectively dispersed these exfoliated carbon sheets than did melt compounding. Tensile modulus was higher for composites with functionalized polyethylenes when solvent blending was used. However, at less than 3 wt.% of TRG, electrical conductivity of the un-modified LLDPE was higher than that of the functionalized ones. This may be due to phase segregation between graphene and PE, and electrical percolation within the continuous filler-rich phase.     

Durable compliant electrode based on graphene and natural rubber

A compliant electrode is a stretchable electronic device that retains good conductivity under stretching or bending. It has been used in various electro‐actuating applications which require large deformations under electrical field. The objective of this work was to fabricate a compliant electrode possessing high electrical conductivity and good mechanical properties. Due to the excellent mechanical properties of natural rubber (NR), it was used as a matrix for the compliant electrode. Graphene was used as a new and innovative conductive filler to provide excellent electrical conductivity. The mechanical properties and electrical properties were investigated by using a rheometer in the tension mode. Both mechanical and electrical properties were improved drastically by introducing graphene into the matrix. The highest electrical conductivity of 0.61 S/cm was obtained from the 35.0 %vol/vol graphene/NR composite, two orders of magnitude higher than that of the commercial compliant electrode. The 5.0 %vol/vol graphene/NR composite was shown and identified here as a promising material for using as a compliant electrode. POLYM. ENG. SCI., 57:129–136, 2017. © 2016 Society of Plastics Engineers     

导电型室温硫化硅橡胶的研究

研究了炭黑的结构和配合量对室温硫化硅橡胶导电性能和力学性能的影响, 以及室温硫化硅橡胶基胶摩尔质量对导电性能的影响。结果表明： ７ 份乙炔炭黑能赋予室温硫化硅橡胶良好的导电性, 当乙炔炭黑用量为１０ 份时, 室温硫化硅橡胶的体积电阻率达到６０ Ω·ｃｍ ; 摩尔质量较低的硅橡胶导电性能更佳; 同时, 乙炔炭黑能提高硅橡胶的拉伸强度和硬度。     

具有原位导电微纤网络的CB/PET/PE复合材料的力学性能

在前期热塑性塑料原位成纤研究的基础上，尝试利用原位成纤方法制备炭黑(CB)／聚对苯二甲酸乙二醇酯(PET)／高密度聚乙烯(HDPE)原位导电微纤网络复合材料(CEMN)，以期增强复合体系的力学强度。通过对CEMN体系与CB／PE体系的力学性能测试发现，CEMN体系的拉伸强度低于普通CB/PE复合物。为增强复合体系的力学性能，应改变加工过程及降低体系中CB的用量。     

Structure,properties, and applications of polyacrylonitrile/carbon nanotube (CNT) fibers at low CNT loading

Bi-component, polyacrylonitrile (PAN)/carbon nanotube (CNT) fibers were processed, at different core-sheath area ratios, by gel spinning. A percolated CNT network at 10 wt% CNT in the sheath enhanced electrical conductivity as compared to the neat PAN fiber, while PAN polymer in the core contributed to the good mechanical properties. Fibers with relatively thin sheath allowed overall CNT loading as low as 3.7 wt% to be made with good electrical conductivity, and PAN stabilization by Joule heating was demonstrated. Such fibers with combined good mechanical properties and electrical conductivity can also potentially be used for electrical heating of fabrics, for making smart textiles, and for electromagnetic interference shielding.