Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5182784 | Polymer | 2012 | 6 Pages |
Abstract
When silica/polybutadiene and silica/styrene-butadiene are submitted to γ irradiation at 77 K a scavenging of the silica radiolytic species by absorbed vinyl units takes place at the surface with concomitant grafting and crosslinking of the polymers. Key intermediate in such reactions are SiO2-bonded radicals of structure SiO2-Câ¢(CH3)CH(R)(Râ²). The role of silica is rationalized in terms of the following steps: a) absorption of the radiation energy in the bulk of the silica particles followed by exciton migration at the surface; b) reactions of excited groups (silanols) with absorbed vinyl units giving SiO2-bonded radicals; c) crosslinking of the polymers initiated by grafted radicals.
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Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
D. Dondi, A. Buttafava, A. Zeffiro, L. Conzatti, A. Faucitano,