不同聚硫橡胶对聚硫密封剂耐压缩性能的影响

Influences of different polysulfide rubbers on compressibility of polysulfide sealant

以LP系列液体聚硫橡胶为生胶,二氧化锰(MnO2)为固化剂,制备聚硫密封剂。探讨了生胶的Mr(相对分子质量)和三官能团含量对相应密封剂的拉伸性能和耐压缩性能等影响。结果表明:Mr越大,相应密封剂的压缩强度越低,耐压缩性能变差;三官能团含量越少,相应密封剂的压缩强度越低,交联点数目减少使密封剂的耐压缩性能变好。Mr越大,分子链越柔顺,相应密封剂的断裂伸长率越大,拉伸强度和硬度越低;三官能团含量越少,相应密封剂的断裂伸长率和拉伸强度越大,但硬度越小。密封剂的溶胀指数和压缩强度呈反比关系。

With LP series of liquid polysulfide rubber as raw rubber,MnO2 as curing agent,a polysulfide sealant was prepared.The influences of raw rubber with different Mr（molecular weight） or three functional group contents on tensile properties and compressibility of corresponding sealant were investigated.The results showed that the compressive strength was lower and the compressibility was poorer for corresponding sealant with increasing Mr.The compressive strength of corresponding sealant was lower when the three functional group contents were smaller,but the compressibility was better due number of crosslinking points was less.The elongation at break was larger but tensile strength and hardness were lower for corresponding sealant because the molecular chain segment was more supple with increasing Mr.The elongation at break and tensile strength were larger but hardness was smaller when the three functional group contents were less.The relationship between compressive strength and swelling index of sealant was linear in inverse proportion.