62. [Journal of Polymer Science, Part B: Polymer Physics] The Effect of Methyl Group on the Mechanical Properties of Hydrophobic Association Hydrogel
writer：Song Gu, Yang Gao, Xiuyan Ren, Jianhong Yu, Lijie Duan, Guanghui Gao
keywords：hydrogels; hydrophobic association; mechanical property; methyl group; structure-property relations; toughness
source：期刊
Issue time：2018年
ABSTRACT: Hydrophobic association hydrogels were fabricated
via micellar copolymerization of acrylamide and hydrophobic
monomers lauryl (meth)acrylate (LA or LMA) in an aqueous
solution of sodium dodecyl sulfate. The effect of methyl groups
of hydrophobic monomers on the crosslinking network structure
and mechanical behavior of the gels was investigated on the
basis of rubber elastic theory. It was found that the LMA-gel
exhibited higher effective crosslink density and elastic modulus.
The methyl groups of hydrophobic monomers limited the flexibility
of the methacrylate backbone in the association domain,
which resulted in the increment of chains constraints. With the
increase of stretch rate, the dissipated energy of LMA-gel
increased more highly than that of LA-gel. In addition, the
methyl group hindered the movement of polymer chains, leading
to the lower recovery efficiency of dissipated energy for
LMA-gel. In contract, the LA-gel exhibited a rapid response to
external force, and possessed better elasticity and self-recovery
property.