Kinetics study of an acrylic tetrapolymer: Poly(IBMA-MMA-MAA-TBMA)

In this study, the polymerization kinetics and the molecular structure of t he tetrapolymer poly[isobornyl methacrylate (IBMA)-methyl methacrylate (MMA )methacrylic acid (MAA)-tert-butyl methacrylate (TBMA)] were investigated. The relationships among the tetrapolymer composition, monomer conversion, a nd reaction time were studied. Kinetic equations of the four-component copo lymerization related to the mean sequence length, the run number, the react ivity ratio, and the monomer concentration were derived. The mean sequence length of the monomer IBMA increases with the reaction time and monomer con version. However, those of the other three monomers remain an insignificant variation. Furthermore, the run number decreases rapidly at the end of pol ymerization. These results suggest that the slow polymerization rate of IBM A is due to its bulky side group. The mean sequence lengths of IBMA, MMA, M AA, and TBMA at the end of polymerization are 1.772, 1.304, 1.169, and 1.22 9, respectively. On the other hand, the run number of the prepared tetrapol ymer is 70.25. The results of the mean sequence length, run number, and the single glass transition temperature suggest that the prepared tetrapolymer is a random copolymer. The molecular weight distribution of the prepared t etrapolymer is significantly affected by polymerization conditions. (C) 200 0 John Wiley & Sons, Inc.