WAXD and FTIR studies of electron beam irradiated biodegradable polymers
Carregando...
Data
Data de publicação
2009
Orientador
Título da Revista
ISSN da Revista
Título do Volume
É parte de
É parte de
É parte de
É parte de
INTERNATIONAL TOPICAL MEETING ON NUCLEAR APPLICATIONS AND UTILIZATION OF ACCELERATORS, 9th
Exportar
Resumo
Poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL) have been receiving much attention lately
due to their biodegradability in human body as well as in the soil, biocompatibility, environmentally friendly
characteristics and non-toxicity. Morphology of biodegradable polymers affects the rate of their biodegradation.
A polymer that has high degree of crystallinity will degrade at a slower rate due to the inherent increased
stability. PCL homopolymer cross-linking degree increases with increasing doses of high energy radiation. On
the other hand, the irradiation of PLLA homopolymer promotes mainly chain-scissions at doses below 250 kGy.
In the present work, twin screw extruded films of PLLA and PCL biodegradable homopolymers and 50:50 (w:w)
blend were electron beam irradiated using electron beam accelerator Dynamitron (E = 1.5 MeV) from Radiation
Dynamics, Inc. at doses in the range of 50 to 1000 kGy in order to evaluate the effect of electron beam radiation
on the homopolymers and blend. Wide-angle X- ray diffraction (WAXD) patterns of non irradiated and irradiated
samples were obtained using a diffractometer Rigaku Denki Co. Ltd., Multiflex model; and FTIR spectra was
obtained using a NICOLET 4700, ATR technique, ZnSe crystal at 45°. By WAXD patterns of as extruded non
irradiated and irradiated PLLA it was observed broad diffusion peaks corresponding to amorphous polymer.
There was a slight increase of the mean crystallite size of PCL homopolymer with increasing radiation dose. PCL
crystalline index (CI) was 68% and decreased with radiation dose above 500 kGy. On the other hand. PLLA CI
was 10% and increased with radiation dose above 750 kGy. On the other hand, PLLA presence on the 50:50
blend did not interfere on the observed mean crystallite size increase up to 250 kGy. From 500 kGy to 1 MGy the
crystallite size of PCL was a little bigger in the blend than the homopolymer. Also it could be observed that the
PLLA peak increase at 14.2° was affected by PCL presence on the blend above 750 kGy. In contrast, FTIR
results have shown that this technique was not sensitive enough to observe the degradation promoted by ionizing
radiation of the studied homopolymers and blends, and neither on the miscibility of the blends.
Como referenciar
KODAMA, Y.; LIMA, N.B.; GIOVEDI, C.; MACHADO, L.D.B.; CALVO, W.A.P.; NIAKAYAMA, K. WAXD and FTIR studies of electron beam irradiated biodegradable polymers. In: INTERNATIONAL TOPICAL MEETING ON NUCLEAR APPLICATIONS AND UTILIZATION OF ACCELERATORS, 9th, May 4-8, 2009, Vienna, Austria. Proceedings... Disponível em: http://repositorio.ipen.br/handle/123456789/16035. Acesso em: 30 Dec 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.