硫调型氯丁橡胶乳液聚合速率的影响因素

Effect of Some Facters on Emulsion Polymerization Rate of Sulfur-Modified Meoprene

考察了硫调型氯丁橡胶合成中,氧气、氨水、碱、乳化时间、引发剂用量及加入方式等对氯丁二烯乳液聚合速率(R_p)的影响。结果表明,氧在聚合前与单体接触对R_p影响不大,但在聚合中接触则有很强的阻聚作用。聚合前加入少量氨水可大大缩短反应诱导期,并加快R_p配方中碱用量以NaOH/松香摩尔比为1.5即pH=10.5时R_p最高。乳化时间取30-40分钟较为适宜。引发剂的反应级数为0.75。如引发剂分批加入,可根据需要控制R_p。

The influences of some facters such as oxygen, aqueous ammonia, sodium hydroxide, emulsion time and the amount of initator as well as its addition method on polymerization rate ( R ) in emulsion polymerization of sulfur - modified neoprene were studied. The R was little affected if the oxygen had contacted monomer before polymerization, while it was greatly handicapped during polymerization. The R was speeded up rnd the induction period was remarkably shortened by adding aqueous ammonia prior to the polymerization. The Rpwas greatest if the molar ratio of NaOH rosin = 1. 5 or the pH value of the system = 10. 5. The emulsion efficiency was higher provided that the preferable emulsion time was 30～40 minutes. The initiator was the order of 0.75 and the Rpwas steadily controlled the by fractionnal addition of initiator.