喷雾干燥法制备粉末橡胶及其硫化性能研究

Preparation of powdered NR by spray drying method and study on its curing behaviour

以超声分散的炭黑悬浮液填充天然胶乳,采用喷雾干燥法制备粒径小于5μm的粉末橡胶。结果表明,对于固形物质量分数约为0.1的炭黑/天然胶乳悬浮液,当喷雾干燥机的浆料进口温度约180℃、进给量约15%、吸气量为100%时,粉末橡胶制备过程较为顺利且制得的粉末橡胶颗粒细小、尺寸均匀;在相同的硫化条件下,与机械混炼法相比,喷雾干燥法制得的粉末橡胶硫化性能显著改善,硫化曲线的转矩峰值提高约1倍;粉末橡胶对氧化锌、硬脂酸、硫黄、促进剂CZ和DM的需求量更大,当以上小料用量均提高至普通机械混炼胶料2倍时,粉末橡胶硫化曲线的转矩峰值大幅度提高,由约30 N.m提高至约60 N.m,比普通机械混炼胶料提高约3倍。

A powdered NR with particle size smaller than 5μm was prepared from NR latex filled with supersonically dispersed suspension of carbon black（CB） by spray drying method and its curing behaviour was studied. The results showed that a powdered NR with even and smaller particle size could be successfully prepared when 0.1 solid content of CB/NR latex suspension, 180℃ temperature at paste entrance of spray dryer, 15% feed rate and 100% air breathing amount were used;the curing behaviour of the powdered NR prepared by spray drying method improved significantly under the same curing conditions as used for the mechanically mixed NR compound,and the peak torque value of curing curve increased nearly by 100%;the powdered NR required more zinc oxide,stearic acid,sulfur, CZ and DM,and when the double addition level of these additives was used in the powdered NR based on that in the mechanically mixed NR,the peak torque value raised from 30 N · m to 60 N · m.