Effects of Binding Energy of Bioinspired Sacrificial Bond on Mechanical Performance of cis-1,4-Polyisoprene with Dual-crosslink  

作　　者：Sheng Wang Zheng-Hai Tang Jing Huang Bao-Chun Guo 

机构地区：[1]Department of Polymer Materials and Engineering, South China University of Technology

出　　处：《Chinese Journal of Polymer Science》2018年第9期1055-1062,共8页高分子科学（英文版）

基　　金：financially supported by the National Basic Research Program of China(No.2015CB654700(2015CB654703));the National Natural Science Foundation of China(Nos.51673065,51703064,51473050 and 51333003);Fundamental Research Funds for the Central Universities(No.2017PY006)

摘　　要：Although bioinspired sacrificial bonds have been demonstrated to be efficient in improving the mechanical properties of polymer materials, the effect of binding energy of a specific dynamic bond on the ultimate mechanical performance of a polymer network with dual-crosslink remains unclear. In this contribution, diamine and sulfur curing package are introduced simultaneously into a sulfonated cis-1,4-polyisoprene to create dually-crosslinked cis-1,4-polyisoprene network with sulfonate-aminium ionic bonds as the sacrificial bonds. Three diamines （primary, secondary and tertiary） with the same spacer between the two nitrogen atoms are used to create the ionic bonds with different binding energies. Although the binding energy of ionic bond does not affect the glass transition temperature of cis-1,4-polyisoprene （IR）, it exerts definite influences on strain-induced crystallization and mechanical performance. The capabilities of diamine in dissipating energy, promoting strain-induced crystallization and enhancing the mechanical performance are in the same order of secondary diamine 〉 primary diamine 〉 tertiary diamine. The variations in mechanical performances are correlated to the binding energy of the ionic bond, which is determined by pKa values.Although bioinspired sacrificial bonds have been demonstrated to be efficient in improving the mechanical properties of polymer materials, the effect of binding energy of a specific dynamic bond on the ultimate mechanical performance of a polymer network with dual-crosslink remains unclear. In this contribution, diamine and sulfur curing package are introduced simultaneously into a sulfonated cis-1,4-polyisoprene to create dually-crosslinked cis-1,4-polyisoprene network with sulfonate-aminium ionic bonds as the sacrificial bonds. Three diamines （primary, secondary and tertiary） with the same spacer between the two nitrogen atoms are used to create the ionic bonds with different binding energies. Although the binding energy of ionic bond does not affect the glass transition temperature of cis-1,4-polyisoprene （IR）, it exerts definite influences on strain-induced crystallization and mechanical performance. The capabilities of diamine in dissipating energy, promoting strain-induced crystallization and enhancing the mechanical performance are in the same order of secondary diamine 〉 primary diamine 〉 tertiary diamine. The variations in mechanical performances are correlated to the binding energy of the ionic bond, which is determined by pKa values.

关 键 词：cis-1 4-Polyisoprene Ionic bond Sacrificial bond Binding energy Strain-induced crystallization 

分 类 号：TQ333.3[化学工程—橡胶工业]