无喷霜硫化体系中硫黄用量对三元乙丙橡胶/白炭黑硫化胶性能的影响

Effect of sulfur amount on properties of ethylene-propylenediene monomer / white carbon black vulcanizates with non-blooming sulfur cure system

采用无喷霜硫黄硫化体系,考察了硫黄用量对三元乙丙橡胶（EPDM）/白炭黑（WcB）混炼胶硫化特性及硫化胶物理机械性能、耐热老化性能、动态力学性能和压缩永久变形的影响.结果表明,在硫黄用量为0.5 ～1.5份的条件下,随着硫黄用量的增加,EPDM/WCB混炼胶的硫化速率减慢,硫化胶的拉伸强度先升高后下降,当硫黄用量为1.00份时达到最大值（22.4 MPa）,同时扯断伸长率和永久变形逐渐下降,邵尔A硬度升高;热空气老化后,硫化胶的拉伸强度、撕裂强度和硬度均提高,但扯断伸长率下降幅度较大;随着硫黄用量的增加,硫化胶的玻璃化转变温度向高温方向移动,损耗因子峰值先升高后下降,储能模量增大,压缩永久变形略有减小.

Based on a non-blooming sulfur cure system, effects of sulfur amount on curing character- istics of ethylene-propylene-diene monomer（EPDM）/ white carbon black（WCB） compounds, and mechan- ical properties, heat aging resistance, dynamic me- chanical properties and compression set of EPDM/ WCB vulcanizates were investigated. The results showed that with increasing sulfur amount from 0. 5 phr to 1.5 phr, the curing rate of EPDM/WCB compounds decreased, tensile strength of vulcani- zates increased firstly and then decreased, and reached the maximum （ 22.4 MPa） when sulfur was 1.00 phr, meanwhile, elongation at break and per-manent set decreased, and Shore A hardness in- creased. After hot air aging, the tensile strength, tear strength and Shore A hardness of vulcanizates increased, but elongation at break decreased signifi- cantly. With increasing sulfur amount, the glass transition tempetature of the vulcanizates shifted to higher temperature, loss factor peak value increased firstly and then decreased, storage modulus in- creased and compression set decreased slightly.