高腈橡胶序列结构与加工硫化特性

Sequence Structure and Curing Properties of High Nitrile Rubber

对乳液聚合法制备的丙烯腈含量40%以上的丁腈橡胶,使用核磁共振氢谱对其序列结构进行表征,使用差示扫描量热仪对其玻璃化转变温度(T_(g))进行分析,使用凝胶渗透色谱仪和门尼黏度仪分别对其相对分子质量和门尼黏度进行测试,研究了不同丙烯腈含量的丁腈橡胶的序列结构规律及序列结构与加工硫化特性的关系。结果表明,丙烯腈含量40%以上的高腈丁腈橡胶中开始出现低腈橡胶所没有的BAA序列,且随着结合丙烯腈含量的增加呈现上升的趋势。而其他序列结构含量的改变对丁腈橡胶的加工硫化特性也有所影响,例如BAB序列含量升高会缩短焦烧时间,BBB序列含量升高会改善丁腈橡胶的分子链柔顺性,且会缩短正硫化时间。综合来看,文中制备的丁腈橡胶已优于市场一线产品的性能。

The sequence structure of nitrile butadiene rubber with the acrylonitrile content of more than 40%prepared by emulsion polymerization was characterized by hydrogen magnetic resonance spectroscopy,the glass transition temperature(T_(g))was characterized by differential scanning calorimeter,and the molecular weight and Mooney viscosity were characterized by gel permeation chromatograph and Mooney viscometer,respectively.The sequence structure of nitrile butadiene rubber with different acrylonitrile contents and relationship between sequence structure and curing characteristics were studied.The results show that BAA sequence began to appear in high acrylonitrile butadiene rubbers with more than 40%acrylonitrile content,which was not found in low acrylonitrile rubbers,and shows an increasing trend with the increase of acrylonitrile content.However,the changes of other sequence structure contents have impact on the curing characteristics of nitrile butadiene rubber.For example,the increase of BAB sequence content will shorten the char time,and the increase of BBB sequence content will improve the molecular chain compliance of nitrile butadiene rubber and shorten the positive curing time.In summary,the performance of nitrile butadiene rubber prepared in this laboratory is superior to that of first-line products in market.