Mechanical and Film Properties of Telechelic Methacrylic Polysiloxane with Cycloaliphatic Substituents Groups for UV-Curable Applications
Siloxanes with either methyl, cyclopentyl, or cyclohexyl groups were functionalized with methacrylate groups, then UV-cured using a free radical photo-initiator and a reactive diluent. Hexanediol dimethacrylate (0.1 wt%) was used as the reactive diluent. After curing, the mechanical, the viscoelastic, the coating, and the release properties of the cured films were studied. In addition, the oxygen permeability and the X-ray diffraction scans were evaluated. The crosslink density reduced with increase in siloxane substituent size. The oxygen permeability was dependent on crosslink density, and increased with increasing substituent size. The increase in permeability, and thus free volume, was supported by X-ray studies which showed an increase in d-spacing with increasing alkyl size. The hardness, adhesion, and solvent resistance increased as the size of the substituent increased (methyl to cyclopentyl to cyclohexyl) in the siloxane backbone. The adhesion and re-adhesion forces increased with an increase in size of the backbone substituents. There was also an increase in the advancing and the receding contact angles with the increase in substituent size.
Soucek, Mark, "Mechanical and Film Properties of Telechelic Methacrylic Polysiloxane with Cycloaliphatic Substituents Groups for UV-Curable Applications" (2010). Polymer Engineering Faculty Research. 1872.