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