Effect of organically modified montmorillonite (OMMT) on biodegradation of PS:PLA and PS:PLA:OMMT using Phanerochaete chrysosporium

The environmental issues of synthetic polymers have been resolved using biodegradation under controlled conditions. The degradation study of polymeric composites of (a) polystyrene (PS) and poly(lactic acid) (PLA) (PS:PLA), and (b) PS:PLA filled with organically modified montmorillonite (OMMT) (PS:PLA:OMMT) was carried out using Phanerochaete chrysosporium. PLA was synthesized using l‐lactic acid under controlled ultrasound cavitation technique, dried and added to a solution of PS. Surface of montmorillonite (MMT) was modified using column chromatographic technique to improve d‐spacing up to 31.5 Å. The sheets of PS:PLA and PS:PLA:OMMT were subjected to degradation study in minimal medium using P. chrysosporium micro‐organism under controlled conditions up to 28 days. The growth of micro‐organism and fractures inside the polymer matrix before and after degradation was observed using scanning electron microscope. Change in extracellular protein content, biomass production, and % degradation with respect to time of incubated samples have been also studied. It was found that the PS:PLA:OMMT (at 5 phr OMMT content) and PS:PLA (at 30% PLA) composites show an increment in degradation. The presence of OMMT leads to faster degradation of PS:PLA:OMMT nanocomposites, which decreases in mechanical property by 30% of PLA and 5 wt% of OMMT content. POLYM. COMPOS., 38:1292–1301, 2017. © 2015 Society of Plastics Engineers