不同发泡剂及工艺条件对BR／SBR／NR发泡材料相结构及尺寸稳定性的影响

分别采用一段和两段模压法制备了以顺丁橡胶（BR）／丁苯橡胶（SBR）／天然橡胶（NR）为基体的橡胶发泡材料，研究了三种化学发泡剂N，N＇-二甲基戊次甲基四胺（H）、4，4＇-氧代双（苯磺酰肼）（OBSH）以及H／OBSH（质量比1：1）复配对发泡及硫化特性的影-向，以及3种发泡剂和2种成型工艺对收缩率及相结构的影响。结果表明，发泡剂H对硫化性能影响最大，含发泡剂H的混炼胶在分解过程中释放的热量最多；加入3种发泡剂都具有一种较大的泡孔镶嵌在较小的泡孔丛中的泡孔形态；密度和线收缩率均随着时间的增加而增加，经H／OBSH复配的发泡剂更适合该体系成型，材料线收缩率均比单独使用H和OBSH小，两段模压法可以有效地提高发泡材料的尺寸稳定性，收缩率降低至3．88％，同时发泡剂使用率最多可提高31．67％。

Effect of blowing agents and process technology on morphology and dimensional stability of BR/SBR/NR foams

The blends of 1,4-cis polybutadiene rubbers（BR）, styrene-butadiene rubber（SBR）, and natural rubber（NR）foams were prepared by one-stage and/or two-stage compression molding tech niques. The effects of blowing agent H, OBSH and H/OBSH（mass ratio 1 ：1）on the vulcanization and foaming characteristics of the rubber foams were investigated. In addition, the effects of the three blo- wing agents and the two compression molding techniques on the shrinkage and morphology were also studied. The results showed that the rubber had a great influence on the vulcanization and foaming characteristic with blowing agent H, and the gross rubber including of blowing agent H released the maxium heat quantity. The foam articles have the large ceils inlay among the small cells with the three blowing agents. The density and shrinkage of BR/SBR/NR foams were increasing with time delaying. The blowing agent H/OBSH was suitable for the system to shape, and shrinkage of BR/SBR/NR foams was lower with blowing agent H/OBSH SH. The two-stage compression molding could foams, and shrinkage ratio drop to 3.88%, and 31.67% at most. than those of only filling to blowing agent H and OB- improve on the dimensional stability of BR/SBR/NR the utilization ratio of blowing agent could enhance to