Crosslinking of poly(beta-caprolactone) by radiation technique and its biodegradability

Poly(epsilon-caprolactone), PCL, (melting temperature, 60 degrees C) was ga mma-irradiated in the solid state at 30-55 degrees C, the molten state, and the supercooled state (irradiation at 45-55 degrees C after melting, 80 de grees C) under vacuum to improve its heat resistance. Irradiation of PCL in the supercooled state led to the highest gel content and this polymer has high heat resistance. On the other hand, relatively smaller doses such as 1 5 and 30 kGy were effective to improve processability of PCL by formation o f branch structure during irradiation. (C) 2000 Elsevier Science Ltd. All r ights reserved.