Alkyne creation in aliphatic polymers: Influence of side groups

作者：Ngono Ravache Yvette^*; Corbin Dominique; Gate Christophe; Melot Mickael; Balanzat Emmanuel

来源：Journal of Physical Chemistry B, 2007, 111(11): 2813-2819.

DOI：10.1021/jp063570f

In this article, we focus on the influence of side groups on terminal alkyne creation, in aliphatic polymers submitted to swift heavy ions, under vacuum. Terminal alkyne creation was compared in polyethylene and in substituted polymers. We selected two classes of side groups: alkyl groups, which differed in their length (polypropylene and polybutene) and allyl groups, which were linear (EPDMh) or cyclic (EPDMn). Irradiated samples were analyzed using Fourier transform IR spectroscopy, in the transmission mode, at room temperature. Alkynes are created when the electronic stopping power, (dE/dx)(e), exceeds a threshold value. This threshold value was moderately influenced by the presence of an alkyl side chain but was clearly reduced in the presence of CC bonds on the side chain. Nevertheless, in all-saturated polymers, below the (dE/dx)(e) threshold, terminal alkyne formation is observed after a latent dose, rather independently of the side-chain length and directly related to the formation of radiation-induced double bonds prior to alkyne formation. Under S ion irradiation, the radiation chemical yield G(0) value obtained in EPDMh was 4 times the value of G(0) in PE. This effect is understandable only if important energy transfers, from the backbone to CC double bonds, are considered.

• 出版日期2007-3-22
• 单位中国地震局