Using cellulose nanocrystals as sustainable additive to enhance mechanical and shape memory properties of PLA/ENR thermoplastic vulcanizates

Abstract

Cellulose nanocrystals (CNC) show great potential in polymers due to their sustainability and excellent mechanical properties, etc. Herein, we used CNC as sustainable additive to improve mechanical and shape memory properties of polylactide (PLA)/epoxidized natural rubber (ENR) thermoplastic vulcanizates (TPVs). A method of combining latex mixing and melt mixing was used to achieve homogeneous dispersion of CNC. With only 5 phr (relative to ENR) CNC, tensile strength, Young’s modulus and dynamic storage modulus at 20 ℃ increased by 22 %, 64 % and 78 % compared with unfilled sample. The shape recovery behavior also improved with the incorporation of CNC, which increased from 87.4 % of unfilled TPV to 91.7 % of sample with 5 phr CNC. Moreover, the decline of Rr in the subsequent cycles also reduced with incorporation of CNC. These results indicate that the enhanced cross-linked rubber network and increased crystallinity of PLA contributed to the enhanced properties.