Allylamine plasma-polymerization on PLLA surface evaluation of the biodegradation

Biodegradation of poy(L-lactide) (PLLA) films and filaments recovered with hydrophilic layer (contact angle = 14°, surface energy s = 70.9 mJ m-2) from allylamine plasma polymerization was investigated under aerobic conditions in sludge. XPS and FTIR-ATR analysis of the plasma layer showed 14.4% N and 16.6% O mainly as amide group. Optical microscopy showed much bacteria colonies on treated PLLA surface than on untreated one. Weight loss and oxygen consumption after 65 days were 4-5% and 4 mg h-1 per gram polymer respectively. The fact that biodegradation lag-phase for treated PLLA was released quicker (7 days) than untreated one (14 days), could be related to the presence of hydrophilic plasma layer that improved swelling-dissolution of hydrolyzed molecular fragments