Environmentally Friendly High‐Performance Polydimethylsiloxane Composites Reinforced with Renewable Cellulose Nanocrystals Based on Dynamic Silyl Ether Linkages

Abstract

AbstractEnvironmentally friendly high‐performance composites made from either reprocessable polymer matrix or renewable fillers have become increasingly significant in order to reach a sustainable future. Herein, polydimethylsiloxane/modified cellulose nanocrystals (PDMS/mCNC) composites showing outstanding mechanical and reprocessable properties via silyl ether linkages are prepared. With only 1 wt% mCNC, the PDMS/mCNC composite exhibits the tensile strength of 2.96 MPa, which is twice that of the pure PDMS elastomer, while the toughness can achieve 7.32 MJ m−3. Remarkably, the reprocessing efficiency can be as high as 100% even for triple reprocessing process. Additionally, the favorable effect of mCNC on constructing hybrid filler network within vitrimers is explored for the first time. Selection of boron nitride nanosheet (BNNS) as the functional filler, 40 wt% BNNS is uniformly dispersed by only a small amount of mCNC and a homogeneous thermally conductive network is built, with the thermal conductivity of the PDMS/mCNC@BNNS composite increasing remarkably to 2.901 W m−1 K−1. In a word, this work paves the way to develop sustainable, mechanically strong, and reprocessable composites with mCNC as a renewable bio‐filler.