Effect of PLA Crystallization on the Thermal Conductivity and Breakdown Strength of PLA/BN Composites

Lu Bai

Shaodi Zheng

Ruiying Bao

Zhengying Liu

Mingbo Yang

Wei YangEmail

College of Polymer Science and Engineering, Sichuan University, State Key Laboratory of Polymer Materials Engineering, Chengdu, 610065, Sichuan, China

Abstract

Polylactide (PLA), whose crystallinity could be easily tuned, was selected to examine the effect of polymer crystallization on thermal conductivity (TC) of the polymer composites. Compression-molded PLA/boron nitride (BN) were heat-treated at 120 °C to fabricate highly crystalline samples. It demonstrated crystallization of the PLA significantly affects TC of the PLA/BN composites. With increased BN content, the improvement of the TC of PLA/BN composites via crystallization is more obvious. TCs of the crystalline PLA/BN composites with 5 wt% and 40 wt% BN are increased by 23 % and 47 % in the in-plane direction and are increased by 21 % and 54 % in the through-plane direction compared to those of amorphous PLA/BN, while TC of pure PLA is increased by 17 % via crystallization. When BN content is 40 wt%, the in-plane and through-plane TCs of the crystalline PLA/BN are 4.7 W/mK and 0.8 W/mK, respectively. Both the amorphous and crystallized PLA/BN exhibit high breakdown strengths.

Effect of PLA Crystallization on the Thermal Conductivity and Breakdown Strength of PLA/BN Composites