Polymerization and viscoelastic behavior of networks from a dual-curing, liquid crystalline monomer

Abstract

The network formation and viscoelastic behavior of a liquid crystalline monomer, whose structure includes both acrylate and acetylene reactive groups, have been studied. By combining both photo and thermal polymerization, the networks can be formed in two separate steps, with the initial photopolymerization dominated by acrylate crosslinking and subsequent thermal polymerization dominated by acetylene crosslinking. In addition, the monomer exhibits a liquid crystalline phase. Photopolymerization while in the liquid crystal phase locks in the molecular ordering. Dynamic mechanical analysis shows that networks formed from the liquid crystalline phase have lower crosslink densities and narrower distributions of molecular weights between crosslinks when compared to networks formed from the isotropic phase (and at higher polymerization temperatures). After thermal postcure at 250°C, the networks formed from the isotropic monomer have a 23% higher dynamic mechanical storage modulus (in the glassy state) than the networks formed from the liquid crystalline monomer. The thermally postcured networks have unusually high glass‐transition temperatures, which exceed 300°C. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1183–1190, 1999

Dual-curable fluorinated poly(methacrylate) copolymers for optical adhesives

“…In this article, dual-curable [8][9][10][11][12] acrylic oligomers (AOs) having alkoxy silane group, fluorine atoms and vinyl group as a pendent group were synthesized by two-stage reactions. The dual curing behaviors, e.g.…”