Lightweight and insulation polylactide/poly(butyleneadipate-co-terephthalate) foam with good cushioning performance prepared by supercritical CO2

Abstract

Herein, biodegradable polylactide (PLA) foams were prepared by supercritical CO₂. To address the foaming challenges posed caused by the low crystallization rate and the weak melt strength of PLA, the blending of PLA and poly(butyleneadipate-co-terephthalate) (PBAT) was adopted in this work, the diphenylmethane diisocyanate (MDI) was utilized to boost the compatibility and rheological features of the PLA/PBAT combination. The effects of MDI and PBAT on the crystallization and rheological of the blends were studied. In PLA/PBAT foam, the density prepared was adjustable from 0.02 to 0.025 g/cm³, and the heat-conductivity was a minimum of 0.028 W/(m·K). In addition, the effect of PBAT on PLA cushioning performance was studied, the PLA/PBAT foam prepared has good mechanical properties, which can be used for cushioning packaging and heat insulation. The hardness of the PLA/PBAT blend foam slowly reduced as the PBAT increased, and the elasticity gradually increased. Notably, with 10 phr of PBAT, the compressive strength of the blend foam at 25 ℃ and 60 ℃ was 57 KPa and 55 KPa, respectively. This work broadens the application prospect of PLA and has a positive impact on promoting the high-value utilization of biobased polymers.