聚丁二烯胶乳敏化辐射交联研究

Irradiation vulcanization of polybutadiene latex appended n-BMA and n-BA

在^(60)Coγ射线辐照下,以甲基丙烯酸丁酯(n-BMA)和丙烯酸丁酯(n-BA)作为敏化剂对聚丁二烯胶乳(PBL)进行辐射硫化,探讨敏化辐射交联机理和交联行为。研究了敏化剂和吸收剂量对聚丁二烯橡胶的交联、力学性能及动态力学性能的影响,并采用红外吸收光谱对辐照交联产物分子结构予以表征。结果表明,随交联密度增加,玻璃化转变温度(T_g)升高,室温弹性模量(E')和损耗模量(E'')增大,抗张强度和杨氏模量增大,但断裂伸长率降低。提示n-BMA和n-BA均对聚丁二烯胶乳具有交联敏化作用,且偏离Charlesby-Pinner关系式,不符合无规交联规律。

Irradiation vulcanization of polybutadiene rubber latex （PBL） in the presence of radiation sensitizer n-butyl methacrylate （n-BMA） and n-butyl acrylate （n-BA） by 60Co γ-rays was studied. The crosslinking mechanism and kinetics of irradiation vulcanization were investigated. The effect of absorbed doses and the sensitizer contents on the gel fraction was evaluated, and the micro structure, mechanical and dynamic mechanical properties of latex films were characterized by means of FTIR and DMA, etc. The results indicated that both of n-BMA and n-BA showed vulcanization enhancement for PBL. With increment of crosslink density, the tensile strength and Young＇s modulus increased while elongation at break decreased. Moreover, as heavy crosslinking restrained the movement of chains the glass transition temperature （Tg） increased, and the storage modulus （E＇） and loss modulus （E＂） at room temperature increased as well. The deviation from the Charlesby-Pinner equation revealed PBL enhancement vulcanization, which didn＇t fit well with kinetic randomly.