Construct of heterogeneous crosslinked networks and the reversible bonds for TPV toward the combination of excellent reinforcement and extensibility

Abstract

Introducing heterogeneous network or reversible bonds is one kind of useful non-filling methods to improve the properties of elastomers. Perhaps the combination of the two methods could have a better effect on the elastomer. However, there are few reports about combining these two methods employing to improve the performance of thermoplastic vulcanizates (TPVs). Herein, a TPV based on PA6/NBR, with both heterogeneous network and reversible bond, has been prepared by melt blending. For this TPV, the deformation of short chains for heterogeneous rubber network could alleviate the stress concentration of PA6 ligament during the stretching process. And the reversible bonds have been successfully generated between PA6 and NBR interface to improve the compatibility between PA6 and NBR, which could make the stress transfer from the matrix to the heterogeneous rubber network better. In addition, the reversible dissociation/association of reversible bonds could avoid the premature destruction of the matrix. Compared with commercial TPVs based on PA6, this TPV has reached the higher strength and elongation at break. Thus, a TPV based on PA6/NBR combining excellent reinforcement and extensibility have been realized.