Reactive compatibilization of poly( l ‐lactide)/poly(butylene succinate) blends through polyester maleation: from materials to properties

The melt blending of poly( l ‐lactide) ( PLLA ) with biodegradable poly(butylene succinate) ( PBS ) is considered with a view to fine‐tuning its mechanical properties and its degradability. For this purpose, both maleic‐anhydride‐grafted PLLA ( PLLA ‐ g ‐ MA ) and maleic‐anhydride‐grafted PBS ( PBS ‐ g ‐ MA ) were prepared and used as reactive compatibilizers. The influence of PBS melt viscosity on the morphology and mechanical properties of PLLA / PBS blends was studied. Interestingly, the blending of low viscosity PBS with PLLA allows PLLA to be toughened while the use of high viscosity PBS led to PLLA / PBS blends exhibiting co‐continuous morphology. The nanostructure of the co‐continuous blends may be tuned through the joint action of organo‐modified clays and reactive compatibilizers. The effect of PBS on PLLA degradability was also investigated. The accelerated weathering testing of blends reveals that such combination of biodegradable polymers allows their degradability rate to be tailored. It is found that the addition of 20 wt% PBS to PLLA allows the molar mass loss fraction to be doubled after 425 h of testing.