Enhanced Extrusion\nProcessability of PLA Blends through\nRheology Control Using Biodegradable PLA-based Graft Polymers

Owing\nto the increasing global emphasis on the eco-friendliness\nof materials, significant progress has been made toward the development\nof polymer blends containing biodegradable polylactic acid (PLA).\nOver the past few decades, research on PLA has primarily focused on\nenhancing its physical properties and processability for advantageous\nindustrial applications. In this study, we leveraged the unique rheological\nproperties of bottlebrush polymers (BBPs) to improve the processability\nof PLA and verified their applicability as processing aids. Cellulose\nacetate butyrate (CAB)-based PLA-grafted polymers (CAB-<i>g</i>-PLA) were designed to mimic the characteristics of BBPs. Moreover\nCAB-<i>g</i>-PLAs were synthesized by grafting PLA onto\ncellulose-based biodegradable polymers to produce blends with PLA\nwithout compromising their biodegradability. The biodegradable CAB-<i>g</i>-PLAs were characterized through GPC, FT-IR spectroscopy,\nand SEM. The rheological and mechanical properties of the PLA blends\nwith the CAB-<i>g</i>-PLAs were compared by adjusting the\nmolecular weights of the backbone and side-chains of the CAB-<i>g</i>-PLAs. The role of CAB-<i>g</i>-PLAs as processing\naids was analyzed by examining the melt tension and drawing resonance\nphenomena during the extrusion process, demonstrating the improved\nprocessability of the PLA blends. Our results facilitate the broader\nindustrial adoption of biodegradable polymers, enabling industries\nto achieve eco-friendly goals without compromising material performance.