Nuclear magnetic resonance relaxation studies of nylon 11 solution

CORC > 武汉物理与数学研究所 > 中国科学院武汉物理与数学研究所 > 2011年以前论文发表（包括2011年）

	Nuclear magnetic resonance relaxation studies of nylon 11 solution
	Gao, HC; Li, CG; Mao, SZ; Yuan, HZ; Du, YR
刊名	ACTA POLYMERICA SINICA
	2004-02-01
期号	1 页码:78-83
关键词	nylon 11 hydrogen bonding NMR relaxation entanglement
英文摘要	An unambiguous assignment of the main H-1 and C-13-NMR resonance's of nylon 11 in trifluoroacetic acid solutions has been carried out by using a combination of 1D and 2D NMR heteronuclear techniques( HMQC) The spin-spin relaxation time measurements at different temperatures and different concentrations provide information about the detailed structure and the relative arrangement of the nylon chains in solution. The results show that the temperature dependence of the relaxation behavior of nylon 11 solution is obviously different from that of ordinary polymer solutions. With increasing temperature, the solvation is strengthened, i.e. the interaction between nylon 11 chain segments and solvent molecules is gradually strengthened. This leads to the dissociation of the hydrogen bonding among the nylon 11 chain segments,and the interaction among main chain of nylon 11 is then weakened. As a result the phenomenon of cohesional entanglement of the main chains due to hydrogen bonding among them gradually disappeared. In these cases the solvent molecules come to bind the dissociated free CO and NH groups of nylon 11 molecules. The main chains are coiled and aggregated with a shape of random clew with a part of the solvent molecules included, making the motions restricted along with the a methylene protons of the CO groups staying in the interior of this random clew structure. The dependence of the relaxation process of nylon 11 solution on concentrations shows biexponential behavior, which suggests the existence of two states of the polymer. The fast relaxation component rapidly increases with increasing concentration,it corresponds to the increase of the cohesional entanglement of the main chain due to hydrogen bonding among the nylon 11 chains. This behaviour is related to the increase of the cohesional entanglement points in a unit volume. With the increase of the concentration, the nylon 11 solution gradually becomes soft-solid-like.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Polymer Science
研究领域[WOS]	Polymer Science
关键词[WOS]	CHAIN SEGMENTAL MOTION ; N-15 NMR ; CROSS POLARIZATION ; SOLID-STATE ; C-13 ; POLYAMIDES ; SPECTROSCOPY ; COMPOSITES ; H-1
收录类别	SCI
语种	英语
WOS记录号	WOS:000188968000016
公开日期	2015-12-08
内容类型	期刊论文
源URL	[http://ir.wipm.ac.cn/handle/112942/8959]
专题	武汉物理与数学研究所_2011年以前论文发表（包括2011年）
作者单位	Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China
推荐引用方式 GB/T 7714	Gao, HC,Li, CG,Mao, SZ,et al. Nuclear magnetic resonance relaxation studies of nylon 11 solution[J]. ACTA POLYMERICA SINICA,2004(1):78-83.
APA	Gao, HC,Li, CG,Mao, SZ,Yuan, HZ,&Du, YR.(2004).Nuclear magnetic resonance relaxation studies of nylon 11 solution.ACTA POLYMERICA SINICA(1),78-83.
MLA	Gao, HC,et al."Nuclear magnetic resonance relaxation studies of nylon 11 solution".ACTA POLYMERICA SINICA .1(2004):78-83.