Strain Hardening and Strain Softening of Reversibly Cross-Linked Supramolecular Polymer Networks

	Strain Hardening and Strain Softening of Reversibly Cross-Linked Supramolecular Polymer Networks
	Xu DH ; Craig SL
刊名	macromolecules
	2011
卷号	44 期号:18 页码:7478-7488
关键词	AMPLITUDE OSCILLATORY SHEAR ASSOCIATIVE POLYMERS RHEOLOGICAL PROPERTIES MECHANICAL-PROPERTIES THICKENING BEHAVIOR TRANSIENT NETWORKS AQUEOUS-SOLUTIONS DYNAMICS FLUIDS VISCOELASTICITY
ISSN号	0024-9297
通讯作者	xu dh
中文摘要	the large amplitude oscillatory shear behavior of metallosupramolecular polymer networks formed by adding bis-pd(ii) crosslinkers to poly(4-vinylpyridine) (pvp) in dimethyl sulfoxide (dmso) solution is reported. the influence of scanning frequency, dissociation rate of cross-linkers, concentration of cross-linkers, and concentration of pvp solution on the large amplitude oscillatory shear behavior is 2 explored. in semichlute unentangled pvp solutions, above a critical scanning frequency, strain hardening of both storage moduli and loss moduli is observed. in the semidilute entangled regime of pvp solution, however, strain softening is observed for samples with faster cross-linkers (k(d) similar to 1450 s(-1)), whereas strain hardening is observed for samples with slower cross-linkers (k(d) similar to 17 s(-1)). the mechanism of strain hardening is attributed primarily to a strain-induced increase in the number of elastically active chains, with possible contributions from non-gaussian stretching of polymer chains at strains approaching network fracture. the divergent strain softening of samples with faster cross-linkers in semidilute entangled pvp solutions, relative to the strain hardening of samples with slower cross-linkers, is consistent with observed shear thinning/shear thickening behavior reported previously and is attributed to the fact that the average time that a cross-linker remains detached is too short to permit the local relaxation of polymer chain segments that is necessary for a net conversion of elastically inactive to elastically active cross-linkers. these and other observations paint a picture in which strain softening and shear thinning arise from the same set of molecular mechanisms, conceptually uniting the two nonlinear responses for this system.
收录类别	SCI收录期刊论文
语种	英语
WOS记录号	WOS:000295058400047
公开日期	2012-06-08
内容类型	期刊论文
源URL	[http://ir.ciac.jl.cn/handle/322003/44337]
专题	长春应用化学研究所_长春应用化学研究所知识产出_期刊论文
推荐引用方式 GB/T 7714	Xu DH,Craig SL. Strain Hardening and Strain Softening of Reversibly Cross-Linked Supramolecular Polymer Networks[J]. macromolecules,2011,44(18):7478-7488.
APA	Xu DH,&Craig SL.(2011).Strain Hardening and Strain Softening of Reversibly Cross-Linked Supramolecular Polymer Networks.macromolecules,44(18),7478-7488.
MLA	Xu DH,et al."Strain Hardening and Strain Softening of Reversibly Cross-Linked Supramolecular Polymer Networks".macromolecules 44.18(2011):7478-7488.