Biobased Polymer Recycling: A Comprehensive Dive into the Recycling Process of PLA and Its Decontamination Efficacy

The recycling process and the presence of contaminants play important roles in alimentary security. In this research, poly(lactic acid) (PLA) samples were contaminated using an FDA-defined framework by immersing them in a cocktail of five surrogates (benzophenone, tetracosane, heptane, chloroform, and toluene). Migration tests were then conducted on the samples after different recycling stages by using two food simulants and varying conditions. To this end, it was used SPME–GC–MS and GC–MS techniques in order to evaluate the efficiency of the recycling technology. The contaminants in PLA samples decreased after they were submitted to the total recycling cycle. Compounds such as tetracosane, heptane, and toluene showed decreased values between 73 and 80%, much higher than those obtained when the sample went through only washing or mechanical recycling. The theoretical molecular volume of contaminants, the type of food simulants, the temperature of the test, and the interactions between the polymer and surrogates influence the input and output of contaminants. The interaction energy values estimated from electronic structure calculations prove to be useful for predicting and analyzing global interaction trends between contaminants and the polymer. Consistency was observed between the results obtained from the Hansen sphere analysis and the theoretical approach.