Molecular weight changes induced in an anionic polydimethylsiloxane by gamma irradiation in vacuum

作者：Satti Angel J^*; Andreucetti Noemi A; Ciolino Andres E; Vitale Cristian; Sarmoria Claudia; Valles Enrique M

来源：Radiation Physics and Chemistry, 2010, 79(11): 1137-1143.

DOI：10.1016/j.radphyschem.2010.07.003

• Polydimethylsiloxane
• Gamma irradiation
• Mathematical model
• Anionic synthesis
• Crosslinking

An anionic almost monodisperse linear polydimethylsiloxane (PDMS) was subjected to gamma irradiation under vacuum at room temperature. The molecular weight changes induced by the radiation process have been investigated using size exclusion chromatography (SEC) 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.
The analysis of the data indicates that crosslinking reactions predominated over scission reactions. The results obtained by an SEC-RI have confirmed the presence of small, but measurable amounts of scission.
A previously developed mathematical model of the irradiation process that accounts for simultaneous scission and crosslinking and allows for both H- and Y-crosslinks, fitted well the measured molecular weight data. This prediction is in accordance with the experimental data obtained by (29)Si-Nuclear Magnetic Resonance spectroscopy (NMR) and previously reported data for commercial linear PDMS (Satti et al., 2008).

• 出版日期2010-11