In Situ Incorporation of Liquid Polysulfide Oligomer Modified MoS₂ into Polysulfide Rubber (PSR) as Solid Crosslinker with Greatly Improved Dispersion Ability and Interfacial Interaction

Abstract

Polysulfide rubber (PSR) is a versatile sealing material, but suffers from poor mechanical properties, which can be solved by increasing the crosslinking density and introducing fillers. In this study, functionalized molybdenum disulfide (MMoS2) by in situ incorporation with different thiol‐containing compounds is obtained. On the basis of the optimum content of 0.5 wt.%, the performance of MMoS2/PSR is systematically studied. The results show that the interfacial interaction between MMoS2 and the matrix is improved. In particular, PSR reinforced by MoS2 modified with polysulfide oligomer (MoS2‐LPO) behaves the most excellently. Its solvent resistance and crosslink density are also improved by 14.2% and 39.4%, respectively. The storage modulus of MoS2‐LPO/PSR is 394% higher than that of the unmodified one. This is attributed to the MoS2‐LPO playing the role of filler and large‐sized solid crosslinker at the same time. Through broadband dielectric spectroscopy (BDS), it is determined that MoS2‐LPO/PSR has the longest relaxation time due to the stronger interfacial interaction. In order to understand the effect of interfacial interaction between MoS2 and PSR on the properties of the composites more clearly, MoS2 modified with other functional groups are also discussed.