preparation and properties of biodegradable nanocomposite foams based on pla/pbat/nanoclay

In order to reduce environmental pollution, polylactic acid (pla) is one of the suitable alternatives for synthetic polymers. this is despite the fact that the use of this polymer in various industries, such as packaging, faces limitations like brittleness. in this study, this weakness of pla has been modified using 25wt.% ​​polybutylene adipate-co-terephthalate (pbat), which is a flexible biodegradable synthetic polymer. also, clay nanoparticles (cloisite 20a) ​​(0, 1 and 3 phr)  and chain extender (adr 4368) ​​(0 and 0.5 phr) were used to improve the compatibility between two phases and mechanical properties of the nanocomposite. in the next step, the composition of optimal percentages of nanocomposite was selected and the foaming process was carried out using a twin-screw microcompounder. the results of tensile test and izod impact strength showed that nanocomposite has better mechanical properties than pure blend, also better compatibility can be observed. it is evident in the sem images that in the presence of nanoparticles and chain extender, the number of foam cells has increased and more uniform cells have been obtained. cell expansion ratio was also calculated and foam cell density was obtained from sem images.