Polylactide porous biocomposites with high heat resistance by utilizing cellulose template-directed construction

With the world’s focus on environmental and sustainability problems, bio-based polymer porous materials have achieved tremendous attention. Here, light weight and biodegradable cellulose/polylactic acid (PLA) porous biocomposites with outstanding mechanical and heat resistance properties are fabricated based on a novel template-directed strategy. The cellulose/PLA porous biocomposites exhibit densities as low as 0.09 g/cm³ and specific moduli as high as 288.9 MPa g⁻¹ cm³. More importantly, the biocomposites possess a high service temperature of 221.3 °C after a thermal treatment, ascribing to the exclusive formation of stereocomplex crystals (SCs) in PLA with a high crystallinity of 0.5. In situ wide-angle X-ray diffraction observations reveal that cellulose templates significantly accelerate the nucleation of SCs without suppressing the growth, and thus greatly facilitate SC crystallization. The stimulation of SC nucleation lies in the interfacial hydrogen bonding interactions between cellulose templates and PLA molecules, which promote the formation of precursor racemic helical pairs. The current work provides further inspiration on fabricating bio-based polymer porous materials in a greener and more sustainable way.