A molecular dynamics study of the effects of silane and cellulose nanocrystals at a glass fiber and epoxy interphase

Due to commonly observed adhesive fracture, the interphase regions between fibers and matrix have often been considered a critical design factor in polymer matrix composites. This study uses molecular dynamics simulation to explore the effects of two modifications at a glass fiber and epoxy interphase by adding a silane sizing and a cellulose nanocrystal particle. The interphase thickness increases by 1 nm and by 3.8 nm, respectively, when silane coating, a combination of silane and a 36-chain cellulose nanocrystal are added. Furthermore, the shear modulus and strength of the interphase increase by around 120% and 415% in the case of silane and by about 70% and 240% in the case of a cellulose nanocrystal. When both cellulose nanocrystal and silane are added at interphase, the shear modulus and strength increase by approximately 125% and 265%, respectively. The cellulose nanocrystal particle is physically absorbed on the glass fiber surface without silane, and it is physically confined in a region created by covalent bonds between silane and epoxy when silane is present. In both cases, a cellulose nanocrystal particle increases the nanoscale roughness at a glass fiber surface, leading to improved shear properties at the interphase.

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s10570-024-06170-7