The purpose of this research was to evaluate how the presence of oxygen can affect irradiation-induced degradation reactions of PEGd,lPLA and PEG-PLGA multiblock copolymers submitted to gamma irradiation, and to investigate the radiolytic behaviour of the polymers. PEGd,lPLA, PEG-PLGA, PLA and PLGA were irradiated by using 60Co irradiation source, in air and under vacuum. The irradiated products underwent a stability study. Gel permeation chromatography was used to evaluate the possibile change in polymer Mw due to irradaition. Polymer thermal and radiolytic behaviour was investigated by differential scanning calorimetry and electron paramagnetic resonance respectively. The results obtained contribute to clarify the radiolytic mechanism of these biodegradable polymers and show that both the irradiation and storage conditions siginificantly affect polymer reaction to gamma rays.
GAMMA-IRRADIATION OF PEGd,lPLA AND PEG-PLGA MULTIBLOCK COPOLYMERS: EFFECT OF OXYGEN AND EPR INVESTIGATION
DORATI, ROSSELLA;COLONNA, CLAUDIA;GENTA, IDA;MODENA, TIZIANA;FAUCITANO, ANTONIO;BUTTAFAVA, ARMANDO;CONTI, BICE
2008-01-01
Abstract
The purpose of this research was to evaluate how the presence of oxygen can affect irradiation-induced degradation reactions of PEGd,lPLA and PEG-PLGA multiblock copolymers submitted to gamma irradiation, and to investigate the radiolytic behaviour of the polymers. PEGd,lPLA, PEG-PLGA, PLA and PLGA were irradiated by using 60Co irradiation source, in air and under vacuum. The irradiated products underwent a stability study. Gel permeation chromatography was used to evaluate the possibile change in polymer Mw due to irradaition. Polymer thermal and radiolytic behaviour was investigated by differential scanning calorimetry and electron paramagnetic resonance respectively. The results obtained contribute to clarify the radiolytic mechanism of these biodegradable polymers and show that both the irradiation and storage conditions siginificantly affect polymer reaction to gamma rays.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
