Electrospun hyperbranched polylactic acid-modified cellulose nanocrystals/polylactic acid for shape memory membranes with high mechanical properties

The polylactic acid (PLA) nanofiber membranes reinforced with hyperbranched PLA-modified cellulose nanocrystals (H-PLA-CNCs) were prepared by electrospinning. The H-PLA-CNCs and the nanofiber membranes were researched by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The outcomes embodied that the cellulose nanocrystals (CNCs) could be successfully improved by the hyperbranched PLA, which would offer powerful CNCs/matrix interfacial adhesion. Thus, the mechanical and shape memory properties of PLA can be improved by adding the H-PLA-CNCs. In particular, when the addition of H-PLA-CNCs was 7 wt%, the tensile strength and an ultimate strain of PLA composite nanofiber membranes was 15.56 MPa and 25%, which was 228% and 72.4% higher than that of neat PLA, respectively. In addition, the shape recovery rate of the PLA/5 wt% H-PLA-CNCs composite nanofiber membrane was 93%, which was 37% higher than that of neat PLA. We expected that this present study would provide unremitting efforts for the development of more effective approaches to prepare biology basic shape memory membranes with high mechanical properties.