GAMMA-STERILIZATION EFFECTS AND INFLUENCE OF THE MOLECULAR-WEIGHT DISTRIBUTION ON THE POSTIRRADIATION RESISTANCE OF POLYPROPYLENE FOR MEDICAL DEVICES

MARTAKIS, N; NIAOUNAKIS, M; PISSIMISSIS, D

dc.contributor.author	MARTAKIS, N	en
dc.contributor.author	NIAOUNAKIS, M	en
dc.contributor.author	PISSIMISSIS, D	en
dc.date.accessioned	2014-03-01T01:42:48Z
dc.date.available	2014-03-01T01:42:48Z
dc.date.issued	1994	en
dc.identifier.issn	0021-8995	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/23949
dc.subject.classification	Polymer Science	en
dc.subject.other	ANTIOXIDANTS	en
dc.subject.other	DEGRADATION	en
dc.subject.other	POLYOLEFINS	en
dc.title	GAMMA-STERILIZATION EFFECTS AND INFLUENCE OF THE MOLECULAR-WEIGHT DISTRIBUTION ON THE POSTIRRADIATION RESISTANCE OF POLYPROPYLENE FOR MEDICAL DEVICES	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1994	en
heal.abstract	In the present study, the dose-rate effects of gamma-irradiation in air on two isotactic polypropylene grades of different molecular weight distribution, used for medical devices, were investigated. The thermal, mechanical, rheological, and photometric properties of these materials were examined using DSC, stress-strain measurements, MFI, and a yellow index. At low dose rates (0.12 Mrad/h), the oxygen diffusion parameter prevailed. At high dose rates (2.84 Mrad/h), the thermal degradation became dominant. However, at high dose rates, an increase in sample temperature was monitored. This temperature rise is thought to increase the oxygen diffusion rate, peroxide decomposition, and radical migration. As a result, intermediate dose rates (in the region of 0.72 Mrad/h) gave the lowest changes in physical properties in both samples. Furthermore, it was found that the polypropylene grade of broader molecular weight distribution and lower M(n) had a higher gamma-irradiation and postirradiation resistance. (C) 1994 John Wiley & Sons, Inc.	en
heal.publisher	JOHN WILEY & SONS INC	en
heal.journalName	JOURNAL OF APPLIED POLYMER SCIENCE	en
dc.identifier.isi	ISI:A1994MM15000014	en
dc.identifier.volume	51	en
dc.identifier.issue	2	en
dc.identifier.spage	313	en
dc.identifier.epage	328	en