Improving performance of polylactic acid by renewable modified butadiene rubber

Abstract

The manuscript described the modification of polylactic acid (PLA) through melt blending, using butadiene rubber (BR) and epoxidized butadiene rubber (EBR) as toughening agents, dicumyl peroxide (DCP) as the crosslinking agent and acetyl tributyl citrate (ATBC) as the plasticizer for the first time to prepare high‐performance BR/PLA‐S and EBR/PLA‐S composites, and the optimal formulation was identified. The results showed that the optimal composition of modified‐BR/PLA was that the mass ratio of PLA/BR (or EBR)/DCP/ATBC was 80/20/0.15/4. The impact strength and elongation at break of the BR/PLA‐S and EBR/PLA‐S were 8.73 kJ/m ² and 155.6%, 11.18 kJ/m ² and 157.9%, respectively, enhancing the toughness of PLA, and the toughening effect of EBR was better than that of BR. The peak intensity of the CC bond (3006 cm ⁻¹ ) in the FTIR spectra of the modified‐BR/PLA weakened, and the peak area of the CH ₂ bond (2918 cm ⁻¹ ) increased, occurring a cross‐linking reaction between BR (or EBR) and PLA. Tg, Tc, and Tm of the BR/PLA‐S, and EBR/PLA‐S were 58.44°C, 92.53°C and 170.13°C; 55.0°C, 87.5°C, and 169.66°C respectively, lower than Tg and Tc of PLA, and higher than Tm of PLA, suggesting that modified‐BR improved processability, cross‐linking reaction and thermal stability of PLA composites. This work provided a feasible pathway for the sustainable application of renewable bio‐based polymer composites.