Accession Number : ADA296660

Title :   Solution and Solid C13 NMR Studies of Polyolacrylate Networks.

Descriptive Note : Technical rept.,

Corporate Author : BOWLING GREEN STATE UNIV OH CENTER FOR PHOTOCHEMICAL SCIENCES

Personal Author(s) : Lungu, Adrian ; Neckers, D. C.

PDF Url : ADA296660

Report Date : 15 JUN 1995

Pagination or Media Count : 45

Abstract : We introduce the use of several C13 NMR techniques to address the problem of the structures of photopolymerized polyolacrylates. We have used these techniques to study both the liquid and solid states of acrylic monomers and oligomers and the network structure formed upon their photopolymerization. High resolution NMR has allowed us to consider the molecular structure of the acrylic groups belonging to each of a series of polyolacrylate monomers. In photopolymerization experiments, by measuring the relative intensity of specific peaks in the carbon spectra as a function of time of irradiation and laser power, it is possible to determine the relative reactivity of monomers/oligomers used in the early stages of polymerization. By monitoring the variation of the proton T1p relaxation time, changes in the cross-link density and in the mobility of the polymeric chains, can be followed throughout the photopolymerization process. The degree of crosslinking is correlated to the relaxation times and increases with an increasing power of the irradiating laser even under conditions where the degree of conversion as measured by quantitative infrared absorption of the 810/cm band of the acrylate is unchanged. jg p. 2

Descriptors :   *PHOTOCHEMICAL REACTIONS, *POLYMERS, *ACRYLATES, CONVERSION, DENSITY, NUCLEAR MAGNETIC RESONANCE, NETWORKS, POLYMERIZATION, STRUCTURES, INTENSITY, REACTIVITIES, ACRYLIC RESINS, CARBON, LASERS, HIGH RESOLUTION, CROSSLINKING(CHEMISTRY), SPECTRA, CHAINS, MONOMERS, MOLECULAR STRUCTURE, RELAXATION, POWER, ABSORPTION, IRRADIATION, INFRARED RADIATION, SOLID STATE CHEMISTRY, OLIGOMERS.

Subject Categories : Polymer Chemistry
      Organic Chemistry
      Physical Chemistry
      Radiation and Nuclear Chemistry
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE