Molecular weight changes induced in PDMS by gamma and electron beam irradiation

SATTI, ANGEL J; RESSIA, JORGE A; ANDREUCETTI, NOEMÍ A; SARMORIA, CLAUDIA; VALLAT, MARIE FRANCE; VILLAR, MARCELO; VALLÉS, ENRIQUE M

Gramado

Congreso; X International Macromolecular Colloquium; 2005

Comité Organizador

Two commercial linear polydimethylsiloxanes (PDMS) of different molecular weights and were subject to gamma irradiation under vacuum and in air, as well as to accelerated electron beam radiolysis (EB). Both processes of irradiation were done at room temperature. The molecular weight changes induced by the radiation processes have been investigated using gel permeation chromatography (GPC) with refraction index (RI) and multi angle laser light scattering (MALLS) detectors to obtain the number and weight average molecular weights of the irradiated samples. Although crosslinking was always predominant, the magnitude of these reactions washigher under vacuum conditions. The effects of irradiation time exposures were investigated. A mathematical model of the irradiation process was developed, which gave good predictions of the measured values.