کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5204614 1381966 2007 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mössbauer, NMR and ATR-FTIR spectroscopic investigation of degradation in RTV siloxane foams
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Mössbauer, NMR and ATR-FTIR spectroscopic investigation of degradation in RTV siloxane foams
چکیده انگلیسی
The combination of experimental techniques allowed for a comprehensive study of aging processes occurring in RTV siloxane foams. 119Sn Mössbauer spectroscopy demonstrated that tin residues are composed of Sn(II) and Sn(IV) species. The 27-year-old foams showed only Sn(IV) species with a quadrupole-splitting parameter larger than that observed for SnO2. Solid-state 29Si NMR differentiated between the various functional linkages in the foams, and showed no significant change of the di- to trifunctional linkage ratios. High-resolution NMR, on solvent extract of foams, showed the presence of water, catalyst, plasticizer, and some silicone oligomers. ATR-FTIR demonstrated changes near the surface of the foam when aged with water and with the presence of the tin catalyst. Gamma irradiation at a low dose had little effect on compression sets. The main changes observed for artificially aged and aged in service foams were related to the presence of the tin catalyst.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 92, Issue 3, March 2007, Pages 414-424
نویسندگان
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