丁腈羟聚氨酯密封胶的制备与性能

Preparation and Properties of Polyurethane Sealant Based on Hydroxyl-Terminated Butadiene-Acrylonitrile Copolymer

以丁腈羟 (HTBN)、N ,N 二羟丙基苯胺 (BHPA)和多亚甲基多苯基多异氰酸酯 (PAPI)反应 ,制备了聚氨酯弹性体。讨论了异氰酸酯指数 (R值 )、固化温度和扩链剂用量对密封胶机械性能的影响 ,并对密封胶耐水、耐油性进行了实验。结果表明 ,当R值为 1.0、BHPA与HTBN的摩尔比为1.0时 ,密封胶在 10 0℃固化 2 4h后制得的弹性体物性较好 ,拉伸强度、剪切强度、永久变形分别为6 .5MPa、8.2MPa及 0 ;随着扩链剂BHPA用量的增加 ,弹性体的硬度、拉伸强度及粘接强度增加 ,但伸长率下降、永久变形增加 ;粘接试样在水中浸泡一个月剪切强度保留率大于 90 % ,在油中浸泡一个月剪切强度保留率大于 85%。该体系可用于密封胶。

s: A polyurethane sealant was prepared from hydroxyl terminated butadiene acrylonitrile copolymer (HTBN),bis hydroxypropyl phenyl aniline (BHPA) and polyaryl polyisocyanate.The effects of NCO/OH ratio(R),curing temperature and the amount of chain extender BHPA on the properties of the sealant were discussed.The water and oil resistance of the sealant was examined.The results show that the optimal properties were gained when cure 24 h at 100℃;and when molar ratio of BHPA to HTBN is 1.0 and R value of the sealant is 1.0,the optimal properties is gained;the physical properties of the tensile strength,shear strength and permanent set of the elastomer is 6.5 MPa,8.2 MPa and 0,respectively;the physical properties increase with the amount of BHPA;the retention rate of shear strength are more than 90% and 85% respectively after the glued sample dipped in water and oil one month.