Sustainability, Compostability, and Specific Microbial Activity on Agricultural Mulch Films Prepared from Poly(lactic acid)

Abstract

Agricultural mulch film of poly­(lactic acid) (PLA) has been prepared under industrial conditions by the extrusion blown film method with modified properties using poly­(hydroxibutyrate) (PHB) and reactive compatibilizer maleic anhydride (MA). Processing parameters and blend composition have been optimized based upon processability and mechanical properties of the final materials. Because PLA is a biopolymer, evaluation of service life period of the mulch film is very much important. Sustainability of the film has been analyzed by keeping the films in a weatherometer, which can create accelerated weather conditions, followed by mechanical testing at regular intervals. Similarly, variation in compostability has been analyzed as per the American standard for test method, ASTM D 5988, using vermi-compost. In addition, specific microbial action on the mulch films also has been analyzed using bacteria <i>Berkholdaria cepacia</i> (<i>B. cepacia</i>), which is selective in particular toward PLA degradation and in mixed fungal inoculums