Thiol-functionalized cellulose nanocrystals for applications in rubber

Abstract

This invention relates to improved cellulose nanocrystal fillers for rubber compositions and more specifically with the grafting of disulfide and thioesters onto cellulose nanocrystals for improved performance as a filler in rubber compositions. At least one embodiment describes a method to graft thiols or disulfides on CNC surfaces via esterification exemplified by 3-mercapto-propionic acid (MPA), 3-(acetylthio)propionic acid (APA), or dithiodipronanoic acid (DTDPA). The reaction may be carried out on CNCs highly dispersed in a suitable solvent and improved reaction conditions to achieve a favorable degree of substitution, DS. The embodiment further discloses how surface thiol groups can then be protected, in a second step, as thioesters or asymmetric disulfides to tune the hydrophobicity of CNCs to improve compatibility with styrene-butadiene, SBR, or natural rubbers.

Dependencies are inferred from the claim text.