Development of novel polar thermoplastic vulcanizates based on ethylene acrylic elastomer and polyamide 12 with special reference to heat and oil aging

Thermoplastic vulcanizates (TPVs) based on ethylene acrylic elastomer (AEM) and polyamide 12 (PA12) have been developed by the dynamic vulcanization process, in which selective cross‐linking of the elastomer phase (AEM) during melt mixing with the thermoplastic phase (PA12) has been carried out simultaneously. TPVs at varied blend ratios (50 : 50, 60 : 40, 70 : 30) of AEM/PA12 were prepared at 185°C at a rotor speed of 80 rpm up to 5 min of mixing. Di‐(2‐tert‐butyl peroxy isopropyl) benzene (DTBPIB) was chosen as the suitable cross‐linking peroxide to carry out the dynamic vulcanization. Morphology study reveals the development of continuous agglomerate of rubber network in case of all the TPVs took place and the average dimension of the rubber particles are in the range of 30–40 nm. TPV based on 50 : 50 AEM/PA12 shows better physicomechanical properties, thermal stability, and dynamic mechanical behavior among all the TPVs. For aging test, TPVs were exposed to air, ASTM oil 2 and 3. Air aging tests were carried out in hot air oven for 72 h at 125°C, while the oil aging tests were carried out after immersion of the samples into the oils in an aging oven. After aging, there are only slight deterioration of physicomechanical properties of the TPVs. Particularly in case of 50 : 50 blend of AEM/PA12, the retention of the properties even after aging was found excellent. The recyclability of these new TPVs is also found to be excellent leading to find potential application in automotives. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42655.     

NBR/PA6 TPV的制备与性能研究

文中对由丁腈橡胶（NBR）和尼龙6（PA6）制成的全动态硫化热塑性弹性体（TPV）的硫化体系进行了探索,就不同硫化体系考察了动态硫化NBR/PA6热塑性弹性体的性能。通过加入羧基丁腈橡胶（XNBR）提高了两相的相容性,对橡胶相和塑料相分别使用了高密度氧化聚乙烯蜡（AC-316A）和正丁基苯磺酰胺增塑剂,讨论了硫化体系、增容组分、增塑剂对热塑性弹性体材料微观相结构、宏观力学性能、流变性能、尼龙相结晶和动态力学性能的影响。     

A review on the mechanical and electrical properties of graphite and modified graphite reinforced polymer composites

Carbon materials particularly in the form of sparkling diamonds have held mankind spellbound for centuries, and in its other forms, like coal and coke continue to serve mankind as a fuel material, like carbon black, carbon fibers, carbon nanofibers and carbon nanotubes meet requirements of reinforcing filler in several applications. All these various forms of carbon are possible because of the element's unique hybridization ability. Graphene (a single two-dimensional layer of carbon atoms bonded together in the hexagonal graphite lattice), the basic building block of graphite, is at the epicenter of present-day materials research because of its high values of Young's modulus, fracture strength, thermal conductivity, specific surface area and fascinating transport phenomena leading to its use in multifarious applications like energy storage materials, liquid crystal devices, mechanical resonators and polymer composites. In this review, we focus on graphite and describe its various modifications for use as modified fillers in polymer matrices for creating polymer-carbon nanocomposites.     

TPV及其微发泡复合材料的非等温结晶动力学研究

以热膨胀发泡微球为发泡剂,采用双螺杆挤出机及模压法制备了微发泡三元乙丙橡胶(EPDM)/聚丙烯(PP)复合材料。利用差示扫描量热法(DSC)研究了该热塑性硫化胶(TPV)及其微发泡复合材料的非等温结晶动力学。结果表明:TPV及其发泡复合材料的非等温结晶过程与Ozawa动力学方程不符,但可用Jeziorny和莫志深(Mo)动力学方程描述。微发泡复合材料的起始结晶温度、最大结晶温度在同一降温速率下均比相应的TPV高,这表明发泡微球具有一定的成核作用;另外,表征结晶速率的半结晶时间(t1/2)明显延长,说明发泡微球的加入对TPV结晶有一定的延缓作用,而复合物较大的空间体积结构所导致的位阻效应是延缓TPV结晶的主要原因。     

动态硫化制备聚烯烃弹性体/三元乙丙橡胶/聚丙烯热塑性硫化胶的性能

讨论了三元乙丙橡胶、硫化剂(TX-29)及聚丙烯用量对聚烯烃弹性体/三元乙丙橡胶/聚丙烯热塑性硫化胶硫化特性和力学性能的影响。结果表明,随着三元乙丙橡胶生胶用量的增加,热塑性硫化胶的交联程度逐渐降低,胶料的拉伸强度、撕裂强度、定伸应力、硬度和高温压缩永久变形都呈减小趋势,而扯断伸长率和扯断永久变形变大。随着硫化剂用量的增加,胶料的拉伸强度、撕裂强度和定伸应力先增大后减小,高温压缩永久变形和扯断伸长率逐渐减小。随着聚丙烯用量的增加,胶料的流动性和力学性能改善,高温压缩永久变形呈现先增大后减小的趋势。     

挤出工艺对POE/PP热塑性硫化胶性能的影响

采用双螺杆挤出机制备茂金属聚烯烃弹性体(POE)/聚丙烯(PP)热塑性硫化胶(TPV),研究螺杆转速和硫化温度对TPV微观结构和物理性能的影响。结果表明,POE/PPTPV中POE为分散相,PP为连续相;当挤出机螺杆转速为400r.min-1、硫化温度为190～200℃时,TPV的综合物理性能良好。     

硫化胶常温脱硫机理研究

利用甲苯－醋酸－氯化锌在常温睛脱除硫化胶中的橡胶结合硫，使之转化为H2S放出，判断此脱硫过程为Friedel-Crafts反应。     

提高FKM硫化胶耐热性能的研究

为了提高氟橡胶（FKM）硫化胶的耐热性能，采用平行实验法、优选实验法（黄金分割法）设计出几十个配方；通过物理性能（扯断强度、扯断伸长率、硬度）和耐老化实验的测试，找到了氟橡胶硫化胶所应用的最佳助剂及最为合理的配方。测试结果表明：各项性能完全符合国家橡胶测试标准的规定（在200℃的条件下），耐热温度达到275℃。     

钢丝绳芯胶带及硫化胶结技术在安钢2 200 m3高炉的应用

介绍了钢丝绳芯胶带在安钢2 200 m3高炉上料主带式输送机中的应用及在INBA法炉渣处理系统中替代普通帆布胶带的效果,并简单概述硫化胶结技术的在安钢应用特点及具体措施.