老化对NR硫化胶的影响

研究了热空气老化和真空老化对ＮＲ硫化胶结构和性能的影响，采用化学探测剂脱硫的方法测定了老化过程中ＮＲ硫化胶交联密度及交联键分布变化的情况，同时测定了硫化胶的力学性能和动态性能随时间变化的情况。结果显示，热空气老化使硫化胶的交联密度增加，但力学性能损失严重，原因是主链氧化断裂。真空老化使ＮＲ硫化胶交联密度略微降低，但力学性能保持良好，类似于硫化返原。热空气老化使ＮＲ硫化胶的动态性能改善，而真空老化后

Effect of ageing on NR vulcanizates

The effect of thermal and anaerobic ageing on the structure and properties of NR vulcanizates was studied. The crosslinking density and distribution of NR vulcanizates during ageing were determined with the method of devulcanization by using the chemical probes,and the physical and dynamic properties were also determined. The results showed that the crosslinking density of NR vulcanizates after thermal ageing increased, but physical properties were deteriorated severely due to main chain oxidization and fraction. The crosslinking density of NR vulcanizates after anaerobic ageing firstly increased then decreased and physical properties decreased slightly same as reversion. The dynamic property of NR vulcanizates after thermal ageing increased, while decreased slightly after anaerobic ageing.