六方氮化硼/丙烯酸酯橡胶复合材料的制备、性能及γ射线辐射效应  

Hexagonal boron nitride/acrylic rubber composites:preparation,thermal and mechanical properties,and effect of γ-radiation

作　　者：王佳健 姜志文 葛志青 潘祖雄 汪谟贞[1] 葛学武[1] WANG Jiajian;JIANG Zhiwen;GE Zhiqing;PAN Zuxiong;WANG Mozhen;GE Xuewu(CAS Key Laboratory of Soft Matter Chemistry,Department of Polymer Science and Engineering,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院软物质化学重点实验室中国科学技术大学高分子科学与工程系,合肥230026

出　　处：《辐射研究与辐射工艺学报》2022年第6期1-14,共14页Journal of Radiation Research and Radiation Processing

基　　金：国家自然科学基金(51973205、51773189);中国科大-延长石油新能源联合实验室基金;中央高校基本科研业务费专项资金(WK9110000066、WK3450000005、WK3450000006)资助。

摘　　要：耐高温、耐辐射橡胶复合材料的开发是未来先进橡胶材料的研发方向之一。本工作将乳液聚合制备的丙烯酸酯类橡胶(ACM)生胶和三种(平均粒径为0.25μm、1.00μm和10.00μm)六方氮化硼粒子(BN-0.25、BN-1和BN-10)分别进行熔融共混,再原位硫化,成功制备了一系列BN/ACM复合材料。研究了BN含量、粒子尺寸以及γ射线辐射对BN/ACM复合材料的热稳定性、导热系数、电阻率和力学性能的影响。结果表明:在BN质量分数不高于40%时,复合材料的热稳定性、导热系数和电阻率随BN质量分数和粒径而增加。当BN-10质量分数为40%时,BN-10/ACM复合材料的导热系数高达1.438 W/(m·K),超过高导热高分子材料所要求的导热系数(>1 W/(m·K))。而力学性能方面,如拉伸强度和断裂伸长率,虽然随BN含量而增加,但却随BN粒径减小而增大。BN质量分数达40%时,由于粒子间的团聚导致分散性变差,复合材料整体力学性能变差。进一步对ACM和BN/ACM复合材料的γ射线辐射效应研究表明,当吸收剂量达200 kGy时,ACM和BN/ACM复合材料的热稳定性和导热系数提高,电阻率则有所下降,但仍与辐照前保持在同一数量级上。γ射线辐照使纯ACM基体有交联硬化的趋势;而BN/ACM复合材料经辐照后,力学性能变差。但由于BN粒子的增强作用,在BN质量分数低于20%的情况下,复合材料辐照后的拉伸强度和断裂伸长率仍然比辐照后的纯ACM要高。这说明要制备耐辐射稳定性好的高导热的ACM橡胶复合材料,可以通过填充粒径10μm的BN粒子,质量分数控制在30%左右。本工作为用于高温油封、电子元件热界面材料和高能辐射环境领域的高导热、耐辐射ACM橡胶复合材料的开发具有理论和实际意义。The development of heat-and radiation-resistant rubber composite materials is a key future research direction for advanced rubber materials. In this work, raw acrylic rubber(ACM) prepared via emulsion polymerization was first melt-blended with hexagonal boron nitrite(BN) particles with average particle sizes of0.25 μm, 1.00 μm, and 10.00 μm(which were correspondingly labeled as BN-0.25, BN-1, and BN-10) and then in situ cured to obtain a variety of BN/ACM composites. The effects of mass fraction and particle sizes of BN fillers, as well as γ radiation on thermal stability, conductivity, electrical resistivity, and mechanical properties of BN/ACM composites were investigated. The results showed that when the mass fraction of BN was less than 40%, the thermal stability, conductivity, and electrical resistivity of BN/ACM composites increased with mass fraction and particle sizes of BN. At a mass fraction of BN-10 of 40%, the thermal conductivity of BN-10/ACM composites was as high as 1.438 W/(m·K), which exceeds that for high thermal conductivity polymer materials(>1 W/(m·K)). The mechanical properties, such as tensile strength and elongation at break, also increased with the increase of the mass fraction and the decrease of the particle sizes of BN. When the mass fraction of BN reached 40%, the overall mechanical properties of composites worsened due to the agglomeration of BN particles. The γ radiation effect on ACM and BN/ACM composites was studied. The results showed that when the absorbed dose reached 200 kGy, the thermal stability and conductivity of ACM and BN/ACM composites were improved, while electrical resistivity slightly decreased. Pure ACM matrix showed a tendency of hardening under γ radiation through crosslinking,resulting in decreased tensile strength of BN/ACM composites. However, the tensile strength and elongation at a break of the BN/ACM composites irradiated by γ-ray remained as high as those of the pure ACM, when the mass fraction of BN was less than 20%. Our results indicated that a

关 键 词：丙烯酸酯类橡胶 六方氮化硼 导热系数 耐辐射性能 

分 类 号：TL13[核科学技术—核能科学]