Network Formation and Compositional Drift During Photo-Initiated Copolymerization of Dimethacrylate Monomers

Published

July 1, 2001

Author(s)

J W. Stansbury, Sabine H. Dickens

Abstract

Dimethacrylate monomers that differ in structure and viscosity are typically used to generate photocured cross-linked polymers for dental adhesive and restorative applications. In this investigation, the copolymerization of viscous base monomers with a smaller, low viscosity diluent monomer was examined in detail. A combination of partial cure studies with extraction residue analysis was used to provide overall resin activity as well as the individual monomer reactivities over the course of network formation. Photocured cross-linked polymers were prepared with conversion values ranging from approximately 20 % to 80 %. The magnitude and composition of the sol fractions were determined gravimetrically and by FT-IR as a function of conversion. The resin containing a flexible aliphatic urethane dimethacrylate reached a greater maximum polymerization rate and final conversion with a nearly quantitative gel fraction, compared with the resin based on a relatively rigid aromatic dimethacrylate. The reactivity of either of the viscous base monomers was found to be less than that of the diluent comonomer at nearly all stages of the photopolymerization process. The reactivity differential was especially dramatic at the latter stages of the polymerization.

Citation

Polymer

Volume

42

Issue

No. 15

Pub Type

Journals

Keywords

copolymerization, dental materials, kinetics, networks, photopolymerization, resins, sol/gel

Citation

Stansbury, J. and Dickens, S. (2001), Network Formation and Compositional Drift During Photo-Initiated Copolymerization of Dimethacrylate Monomers, Polymer (Accessed September 9, 2024)