Degradability of radiation crosslinked PCL in the supercooled state under various environments

摘要

Biodegradability in soil and in activated sludge as well as chemical degradation by methylamine solution of gamma-irradiated poly(ε-caprolactone) in the supercooled state (PCL) has been investigated. Biodegradation in soil burial resulted in almost equiva- lent rate for unirradiated PCL and irradiated PCL at 160 kGy (containing 80 of gel). After 6 months, about 60 weight losses were achieved. Aerobic biodegradation using activated sludge for PCL irradiated at l60 kGy shows higher degradation rate com- pared to unirradiated one. Chemical degradation of PCL was carried out using aqueous methylamine 40 at 35℃. The results reveal that crosslinked PCL (80 of gel) has higher degradation rate compared to uncrosslinked one. These are due to crosslinked PCL having smaller crystallites size, which were formed during cooling after molding process and shorter molecular chain formed during irradiation. For soil burial test, since controlling of microbial populations and environment changes by season are difficult, effect of morphology on degradation did not appear clearly. From these findings, it is concluded that biodegradation easily occurs even for PCL introduced crosslinking structure by irradiation.