Characteristics of Cellulose Acetate-g-Poly(L-lactic Acid) (CA-g-PLA) and Its Application as a Compatibilizer for CA/PLA Blends

In order to improve the compatibility of immiscible blends of cellulose acetate (CA) and poly(L-lactic acid) (PLA), CA-g-PLA having the properties of both CA and PLA polymers was synthesized and it was investigated whether it acts as a compatibilizer for CA/PLA blends. The characteristics of CA-g-PLA with various graft yields were examined by infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. Mechanical properties and morphologies of the CA(50)/PLA(50)/CA-g-PLA blend films prepared by adding a certain amount of CA-g-PLA having different graft yields or by adding different amounts of CA-g-PLA having a constant graft yield were analyzed. CA-g-PLA acted as a compatibilizer for the CA/PLA blends, judging from the results that both the stress and strain at the break of the blend films increased and the phase separation in the blends decreased as the graft yield or the added amount of CA-g-PLA increased.