Preparation and Properties of Thiol-ene UV-cured Nanocomposites with Methacrylate-grafted Cellulose Nanocrystals as Fillers

In this study, we grafted free radical polymerizable methacrylate groups on the surface of cellulose nanocrystals (CNCs) using 3-methacryloxypropyltrimethoxysilane (MPTMS) as a silane coupling agent. We prepared nanocomposites using pristine CNCs and MPTMS modified CNCs (MPTMS-CNCs) as fillers in UV-curable resin by thiol-ene step-growth photopolymerization. The effects of pristine CNC and MPTMS-CNC fillers on thermal stability, tensile strength, elastic modulus, and dispersion state of fillers in nanocomposites were measured by Fourier transform infrared spectrometer (FTIR), thermogravimetric analyzer (TGA), universal testing machine (UTM), dynamic mechanical analyzer (DMA), and field emission scanning electron microscope (FE-SEM). The MPTMS-CNC filler was more effective in increasing tensile strength and elastic modulus of nanocomposites than CNC.