HIGH-RESOLUTION LATEX-STATE 13C-NMR SPECTROSCOPY FOR NATURAL RUBBER VULCANIZATES
HIGH-RESOLUTION LATEX-STATE 13C-NMR SPECTROSCOPY FOR NATURAL RUBBER VULCANIZATES
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天然橡胶硫化橡胶的高分辨率乳胶态 13C-NMR 光谱
DOI：
10.5254/1.3539414
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发表时间：
2007
影响因子：
1.5
通讯作者：
Yoshinobu Isono
中科院分区：
文献类型：
--
作者：
S. Kawahara;Jinta Ukawa;J. Sakai;Yoshimasa Yamamoto;Yoshinobu Isono
Crosslinking junctions of natural rubber vulcanizates were characterized by high-resolution latex-state 13 C-NMR spectroscopy. Vulcanized natural rubber latex was prepared by two methods: i.e., vulcanization of the rubber latex and cryogenic crushing of a rubber sheet vulcanized on a hot press. High-resolution latex-state 13 C-NMR spectroscopy was attained even after vulcanization of the rubber latex, as is evident from no background in spectrum and narrow half width of signals independent of vulcanization time. Small signals at 44 ppm and 57 ppm in the aliphatic carbon region were assigned by measurements of both Distortionless Enhancement by Polarization Transfer (DEFT) and Attached Proton Test (APT) to secondary and tertiary carbons of crosslinking points. The assignment was proved by high-resolution solution-state NMR spectroscopy of vulcanized liquid cis-1,4-polyisoprene as a model, in which DEPT, APT, 2-dimensional 1 H- 1 H correlation (H-H COSY), 2-dimensional 1 H- 13 C correlation (H-C COSY) and 2-dimensional heteronuclear multiple bond correlation (HMBC) measurements were applied.
