Chemical changes in irradiated polypropylene studied by X-ray photoabsorption and advanced EPR/ENDOR spectroscopies

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• 作者：I. Caretti^a ; ^{caretti@icmm.csic.es" class="auth_mail} ; I. Jimé ; nez^a ; S. Van Doorslaer^b
• 关键词：Polypropylene ; Irradiation ; Plasma treatment ; Electron Paramagnetic Resonance (EPR) ; X-ray absorption near edge structure (XANES)
• 刊名：European Polymer Journal
• 出版年：April, 2014
• 年：2014
• 卷：53
• 期：Complete
• 页码：223-229
• 全文大小：627 K

文摘

Pulsed and Continuous-wave (CW) Electron Paramagnetic Resonance (EPR) in combination with X-ray absorption near edge structure (XANES) analysis is used to study the bulk and surface modification of isotactic polypropylene (i-PP) conducted by X-ray irradiation and O₂, Ar and N₂ plasma treatments. In all cases, a midchain peroxy radical is the major species detected by CW-EPR, with little delocalization onto the i-PP main chain, as revealed by X-band Mims electron nuclear double resonance and hyperfine sublevel correlation. Besides, surface functionalization of plasma treated i-PP is discussed on the light of XANES results with emphasis in the more complex case of N₂ plasma modification. The article gives a comprehensive picture of the chemical changes that occur in irradiated i-PP, with implications in sterilization, surface activation, and adhesion enhancement procedures.