Preparation and Mechanical, Thermal and Oil-resistance Properties of Acrylic Rubber Nanocomposites Reinforced with Cellulose Nanocrystals

Abstract

Acrylic rubber (ACM) nanocomposites reinforced with cellulose nanocrystals (CNCs) were prepared and the properties were characterized. CNCs were produced by hydrochloric acid hydrolysis of microcrystalline cellulose powder and used without further chemical modification of the surfaces. The CNCs were already aggregated in aqueous suspension. However, their aggregated sizes and uniform distribution in the ACM did not change with increase in the concentration of CNC. This result suggested good compatibility of the CNC with ACM. Fourier-transform infrared/attenuated total reflection spectroscopy revealed that the good compatibility could be attributed to attractive interactions between CNC and ACM. The good compatibility led to an increase in breaking stress of the ACM/CNC nanocomposites, up to about 10 MPa at a high concentration of 24 phr of CNC. Thermal decomposition of the nanocomposites occurred due to first the CNC followed by the ACM. More weight residues of the nanocomposites were found above 400 °C with increase in the concentration of CNC. The char produced by the decomposition of CNC is suggested the act as a flame retardant for ACM. In addition, the swelling ratio of the ACM/CNC nanocomposites against hydrophobic solvents decreased with increase in the concentration of CNC. The hydrophilic properties of the unmodified CNC from the surface hydroxyl groups increased the oil-resistant properties of the ACM.