Jump to main content
Jump to site search

Issue 15, 2018
Previous Article Next Article

Pronounced effects of the densities of threaded rings on the strain-dependent Poisson's ratio of polyrotaxane gels with movable cross-links

Author affiliations

Abstract

The density of threaded ring molecules (fCD) in polyrotaxane (PR) chains has pronounced effects on the strain-induced swelling of PR gels where the cross-linked ring molecules are slidable along the network strands. The equilibrium Poisson's ratio (μ), which is a measure of the strain-induced volume change, for the PR gel increases with an increase in elongation (λ) at moderate λ but becomes a constant value (Image ID:c8sm00257f-t1.gif) at sufficiently large λ. When the modulus exceeds a threshold value (Ec), the λ dependence of μ disappears due to the loss of the slidability of the cross-links. The fraction fCD significantly influences the values of Image ID:c8sm00257f-t2.gif and Ec. When fCD is sufficiently small (<14%), Image ID:c8sm00257f-t3.gif (≈0.25) agrees with the values of μ for the classical gels in good solvents. When fCD is high (>25%), Image ID:c8sm00257f-t4.gif varies over a wide range (0.22 < Image ID:c8sm00257f-t5.gif < 0.33) depending on fCD and the cross-link concentration in a complicated way. The modulus Ec at fCD = 25% is more than twice as high as that at fCD = 5% due to the finite contribution of the larger amount of uncross-linked ring molecules via combinatorial entropy in the axial polymers. The origin of the markedly small values of μ (less than 0.1) at small λ is also considered on the basis of the magnitude of the accompanying force reduction caused by the slidable function of the cross-links.

Graphical abstract: Pronounced effects of the densities of threaded rings on the strain-dependent Poisson's ratio of polyrotaxane gels with movable cross-links

Back to tab navigation

Publication details

The article was received on 05 Feb 2018, accepted on 14 Mar 2018 and first published on 22 Mar 2018


Article type: Paper
DOI: 10.1039/C8SM00257F
Citation: Soft Matter, 2018,14, 2808-2815
  •   Request permissions

    Pronounced effects of the densities of threaded rings on the strain-dependent Poisson's ratio of polyrotaxane gels with movable cross-links

    A. Tanaka, K. Kato, K. Ito and K. Urayama, Soft Matter, 2018, 14, 2808
    DOI: 10.1039/C8SM00257F

Search articles by author

Spotlight

Advertisements