Influence of the thermodynamical quality of the solvent on the properties of polydimethylsiloxane networks in swollen and dry states

Abstract

The dependence of the elasticity modulus and the equilibrium swelling of the endlinked PDMS networks on the thermodynamical quality of the solvent in which the networks are formed and in which they swell is studied. The molar masses of crosslinked oligomers are 800 and 11000. the solvent quality is changed by the increase in the amount of nonsolvent in binary liquids mixture. The correlation between ternary phase diagrams and properties of swollen and dry networks (elasticity modulus, swelling, density) is established. The study of network deswelling in solvents of worsening quality shows that the abrupt collapse proceeds for the networks formed in good solvents at high dilution. The collapse results in an increase of the exponent value of the power law of elasticity modulus concentration dependence.