The Blending of Poly(glycolic acid) with Polycaprolactone and Poly(l-lactide): Promising Combinations

Poly(glycolic acid) (PGA) holds unique properties, including high gas barrier properties, high tensile strength, high resistance to common organic solvents, high heat distortion temperature, high stiffness, as well as fast biodegradability and compostability. Nevertheless, this polymer has not been exploited at a large scale due to its relatively high production cost. As such, the combination of PGA with other bioplastics on one hand could reduce the material final cost and on the other disclose new properties while maintaining its "green" features. With this in mind, in this work, PGA was combined with two of the most widely applied bioplastics, namely poly(l-lactide) (PLLA) and poycaprolactone (PCL), using the melt blending technique, which is an easily scalable method. FE-SEM measurements demonstrated the formation of PGA domains whose dimensions depended on the polymer matrix and which turned out to decrease by diminishing the PGA content in the mixture. Although there was scarce compatibility between the blend components, interestingly, PGA was found to affect both the thermal properties and the degradation behavior of the polymer matrices. In particular, concerning the latter property, the presence of PGA in the blends turned out to accelerate the hydrolysis process, particularly in the case of the PLLA-based systems.