金属铜离子配位交联丁腈橡胶的压缩Mullins效应

Compression Mullins effect of cross-linked nitrile rubber with copper ions

采用氯化亚铜(CuCl)、乙酸铜(C4H6CuO_(4))、硫酸铜(CuSO_(4))和氯化铜(CuCl_(2))对丁腈橡胶(NBR)进行配位交联制得硫化胶,考察了不同铜盐对硫化胶的硫化特性、力学性能、交联密度及压缩模式下Mullins效应的影响。结果表明,通过配位反应在NBR中形成了以铜盐为交联点的三维网络结构。相比于CuCl/NBR、C4H6CuO_(4)/NBR、CuSO_(4)/NBR而言,CuCl_(2)/NBR硫化胶的交联密度最大。在单轴循环压缩过程中,不同铜离子配位交联NBR硫化胶均产生了明显的Mullins效应,且Mullins效应随硫化胶交联密度的增加而明显减弱。在相同应变下,硫化胶的最大压缩应力随加载-卸载次数的增加而下降,但瞬时残余应变则随应变和加载-卸载次数的增加而增大。

Nitrile rubber(NBR)vulcanizates were prepared by coordination crosslinking of cuprous chloride(CuCl),copper acetate(C4H6CuO_(4)),copper sulfate(CuSO_(4)),and copper chloride(CuCl_(2)).The effects of different copper salts on the curing characteristics,mechanical properties,crosslinking density,and Mullins effect under compression mode of the vulcanizate were investigated.The results showed that a three-dimensional network structure with copper salt as the crosslinking point was formed in the coordination reaction of NBR.Compared to CuCl/NBR,C4H6CuO_(4)/NBR,and CuSO_(4)/NBR,CuCl_(2)/NBR vulcanizates had the highest crosslinking density.During the uniaxial cyclic compression,various copper ion coordination cross-linked NBR vulcanizates caused significant Mullins effects,and the Mullins effect significantly weakened with the increasing crosslinking density of the vulcanizate.At the same strain,the maximum compressive stress of the vulcanizate decreased with the increasing number of loadings and unloads,but the instantaneous residual strain increased with the increasing strain and number of loadings and unloads.