Reinforcement of Polyolefins with Polymer-Grafted Cellulose Nanocrystals

To improve their strength, toughness, and other mechanical properties, we have reinforced polyolefins using polyethylene-grafted cellulose nanocrystals. As the most widely used plastics, polyolefins such as polyethylene and polypropylene are extremely diverse. Various structures and molecular weights span a large range of mechanical properties. In order to reinforce polyolefins with a versatile and sustainably-sourced material, we have synthesized polyethylene-grafted cellulose nanocrystals (PE-g-CNC). CNCs are rod-like particles with excellent stiffness and strength, with previously proven potential to reinforce polymers. Asymmetric nanoparticles with high aspect ratio have significant potential for mechanical reinforcement, as demonstrated by clay-platelet dispersed nanocomposites in literature. With surface energy similar to that of polyethylene, these polymer-grafted nanoparticles can be more easily dispersed in polyethylene and similar nonpolar systems. AFM sand X-ray scattering studies revealed the details of CNC structure, dispersion and crystallization aspects of the functionalized polyethylene, while mechanical reinforcement of the films through addition of polyethylene-grafted CNCs was quantified through tensile testing. Ultimately, we will systematically examine the correlation between the molecular parameters of the asymmetric nanoparticles and polyolefins, and the associated macroscopic properties that emerge in such systems.