Unique leafy morphology of poly(lactic acid) monoliths controlled: Via novel phase separation technology

Abstract

This work reports the unique leaf-like morphology and physical properties of plant-based poly(lactic acid) (PLA) monoliths designed by a novel thermally induced phase separation (TIPS) technology. PLA monoliths with micron to nano scale frameworks and a leaf-like morphology were successfully produced via TIPS with ternary solvent using 1,4-dioxane as a good solvent, water as a non-solvent, and 2-butanone as a mid-solvent which controls phase separation. It was revealed for the first time that the addition of mid-solvent significantly affects the morphology and crystallization of PLLA, which leads to a precise controllability in morphology and high porosity (90-93%). A ternary phase diagram of the solvents was proposed for the TIPS, which successfully explained the present results. It was demonstrated that the newly developed, amazingly simple TIPS is ideal for the synthesis of PLA monoliths compared to the most commonly used TIPS with binary solvent.