橡胶弹性模型的新进展  

Progress in Model for the Elasticity of Vulcanized Rubber

作　　者：张希[1] Xi Zhang(Department of Chemistry,Tsinghua University,Beijing 100084)

机构地区：[1]清华大学化学系,北京100084

出　　处：《高分子学报》2022年第5期441-444,共4页Acta Polymerica Sinica

摘　　要：传统橡胶弹性模型存在一定的局限性,例如不能真实地反映橡胶的交联网络结构,不能解释多个网络结构参数对橡胶力学性能的影响,也不能很好地描述大变形条件下橡胶的弹性.为了解决上述科学问题,崔树勋等提出了一个新的模型(TCQMG模型),在该模型中橡胶交联网络同时包含顺-1,4-聚异戊二烯和聚硫,并且高分子链的弹性同时包含了熵弹性和焓弹性.研究表明,新的模型不仅可以很好地描述硫化橡胶的弹性,还可以解释硫含量等参数对橡胶性能的影响.考虑到天然橡胶与其他橡胶甚至超分子水凝胶在网络结构上的相似性,新模型也可能用于描述这些材料的力学性能.The main component of raw natural rubber is cis-1,4-polyisoprene(PI).To obtain better mechanical properties,raw natural rubber is usually vulcanized with sulfur to form a crosslinked network.To understand the relationship between the complicated network and the mechanical properties of vulcanized natural rubber(NR),several statistical models have been proposed since the 1940s by the pioneers such as Flory.To make complicated problems simple,two major assumptions were adopted in the models.(1)Only PI chains are considered in the crosslinked network.However,polysulfide chains are not included in the models.(2)Only the entropic elasticity of the network chains is taken into account,but the enthalpic elasticity(arising from variation of bond lengths and angles at large deformation)is ignored.As a result,there are several limitations in the traditional models.First,the traditional models fail to predict the elasticity of NR under large deformation.Second,the effects of sulfur content cannot be explained satisfyingly.To solve the above problems,Shuxun Cui and coworkers have made two modifications to the traditional models.First,the sulfur content is considered in the model.Second,the single chain elasticities(which include both entropic and enthalpic elasticities)of the two main components of NR(PI and polysulfide)are integrated into the model.They found that the new model(called TCQMG model)is clearly superior to the traditional models(e.g.,Gaussian model)in describing the mechanical properties of NR,especially for large deformation.In addition,the effect of sulfur content on the mechanical properties of NR can be explained well.Considering the similarity in network structures between NR and other vulcanized rubbers,it is expected that with more data of single-chain mechanics,this model may be used as a general model for various rubbers.With minor modifications,it is anticipated that the model could be applied in the field of supramolecular hydrogels.

关 键 词：橡胶 弹性模型 单链弹性 新进展 

分 类 号：TQ330.1[化学工程—橡胶工业]