FLUORESCENCE PROBE STUDIES OF UV LASER-INDUCED POLYMERIZATION OF POLYOLACRYLATES - THE POST-POLYMERIZATION PROCESS

We describe an analysis of the post-polymerization process [i.e., the polymerization reactions that occur after the cessation of radiation b y a UV laser, of a polyolacrylate, trimethylolpropane triacrylate (TMP TA)]. We use a new fluoroprobe, 2-dimethylaminonaphthyl-5-sulfonyl-n-b utylamide (DASB), designed and synthesized for the specific purpose of monitoring the evolution of polymer in real time. On the basis of der ived analytical expressions for fluorescence response of DASB in the c ourse of transient dark process, we estimate the effective rate consta nts for linear termination radicals in the course of the dark polymeri zation of TMPTA, the contraction coefficients for the formed TMPTA pol ymer, and the fraction of dark reaction for bulk laser-induced polymer ization of TMPTA. Results indicate that the dark polymerization is les s important in highly crosslinked polymers formed from TMPTA than in l ess crosslinked systems.