甲基硅羟基封端硅树脂的合成及固化性能

将甲基三氯硅烷和二甲基二氯硅烷分别与二苯基二羟基硅烷反应得到1,1,5,5-四氯-1,5-二甲基-3,3-二苯基三硅氧烷(A)和1,1,5,5-四甲基-1,5-二氯-3,3-二苯基三硅氧烷(B)。按一定比例将(A)和(B)水解缩合得到完全是甲基硅羟基封端树脂(Ⅰ)。将甲基三氯硅烷和甲基三乙酰氯基硅烷分别处理一般共水解法硅封端树脂可得到另外两种甲基硅羟基封端树脂(Ⅱ)和(Ⅲ),将树脂Ⅰ、Ⅱ、Ⅲ与一般共水解法得到的具有相同R/Si和Ph/R(R代表甲基和苯基)的树脂(Ⅳ、Ⅴ、Ⅵ)进行固化试验,结果表明,甲基-硅羟基封端树脂(Ⅰ—Ⅲ)的固化速度为共水解法制得的以苯基硅羟基封端树脂(Ⅳ—Ⅵ)固化速度的两倍以上。

SYNTHESIS OF METHYLSILANOL-TERMINATED SILICONE RESINS AND THEIR THERMOSETTING PROPERTIES

1, 1, 5, 5-tetrachloro-1, 5-dimethyl-3, 3-diphenyltrisiloxane(A) and 1,1, 5, 5-tetrame-thyl-1, 5-dichloro-3, 3-diphenyltrisiloxane(B) Were obtained by the reactions of methylt-richlorosilane and dimethyldichlorosilane with diphenyldichlorosilane, respectively. The wholly methylsilanol-terminated silicone resin(Ⅰ) was prepared from (A) and (B) in proper proportion. Also, two another kinds of methylsilanol-terminated silicone resins (Ⅱ) and (Ⅲ) were produced by the reactions of methyltrichlorosilane and methyltria-cetoxyisilane, respectively, with the phenylsilanolterminated silicone resins prepared by the usual cohydrolysis method. The methylsilanol-terminated silicone resins (Ⅰ, Ⅱ, Ⅲ) can be cured more than two times faster than the phenylsilanol-terminated silicone resins prepared by the usual cohydrolysis method.