Enhancing Mechanical Properties of Polyurethane with Cellulose Acetate as Chain Extender

Polyurethanes (PUs) are a class of versatile engineering materials synthesized by the reaction between polyol, isocyanate, and chain extender as the hardener. Among various cellulose derivatives, cellulose acetate (CA) possessed unique features such as excellent mechanical properties, good thermal stability, tailorable surface chemistry, and can be used as hydroxyl providers to enhance the properties of PUs. Our goal is to develop a simple method to prepare PUs by using varying weight ratio of CA as the chain extender or crosslinking agent. PUs modified with varying weight percentage of CA (5 %, 10 %, and 30 %) (based on total parts per weight of poly(tetramethylene oxide) (PTMO) and isocyanate) were compared with PUs modified with 1,4-butanediol (BD), acting as the control. The morphological, chemical structural, thermal stability, and mechanical properties of the modified PU CA polymer were investigated thoroughly. The findings from this study found that modified PUs with CA possessed higher thermal stability. The PUs with 10 % of CA as chain extender was found to be the optimal percentage for the preparation of PUs with the highest tensile strength and elongation properties. However, the utilisation of higher weight percentage of CA reduced the elongation property of the modified PUs due to excessive crosslinking effect.