Synthèse de composé photoréticulables, 9. Modification du polybutadiène carboxytéléchélique par des monomères acryliques

The addition of mercaptoacetic acid upon radical initiation onto carboxytelechelic polybutadienes (1) which have an average mass Mn = 4400 gives polyacids having about twelve carboxylic groups. The reaction is followed by 13C NMR, 1H NMR and by GPC. The thiol disappears according to a first order law. Besides, the value of the modification rate obtained from acido-basic titration confirms that obtained from NMR. In a second step, 2,3-epoxypropyl methacrylate is added to the acid groups to obtain an insaturated and carboxylated polydienic oligomer 5. An application of these oligomers processed with a reactive diluter shows their high cross-linking ability under UV irradiation and confirms the improvement of the flexibility properties compared to those of traditional insaturated oligomers.