LET effect on cross-linking and scission mechanisms of PMMA during irradiation
1999; Elsevier BV; Volume: 55; Issue: 3 Linguagem: Inglês
10.1016/s0969-806x(99)00184-x
ISSN1879-0895
AutoresE.H Lee, Gopal R. Rao, L.K. Mansur,
Tópico(s)Diamond and Carbon-based Materials Research
ResumoMechanisms of scission and cross-linking are investigated for poly(methyl methacrylate) subjected to various irradiation sources, such as low LET radiation sources (MeV e-beams, Co60 γ-rays) and high LET ions (MeV He+, Ar+). PMMA properties were degraded upon irradiation by e-beam and γ-rays, but were improved upon bombardment with high energy ion beams (HEIB) as a result of cross-linking. The results indicate that high LET produces a high concentration of free radicals over many neighboring molecular chains, facilitating track overlap and enhancing cross-linking over scission, while low LET affects only a single molecular chain, leading to chain scission.
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