The autocatalytic model of photopolymerization of dimethacrylates.
Polimery 2001, No 7-8, 549
SummaryThe aim of the work was to analyze photopolymerization kinetics of a series of homologous alkylene dimethacrylates according to the autocatalytic model. The model parameters k, m and n (where k is the rate constant at temperature T, p is fractional conversion after time t, m is the autocatalytic exponent, and n is the reaction order exponent) were determined for the polymerization of six monomers under argon at six temperatures (40, 50, 60, 70, 80, and 90oC). The investigation of a series of dimethacrylates differing only in the number of -CH2- groups in the spacer group allowed the effect of the length of the monomer molecule on these parameters to be studied. The experimental method was based on differential scanning calorimetry (DSC). The parameters k, m and n were calculated from a best fit between model prediction and data points of the experimental curves polymerization rate versus conversion degree. Statistical analysis showed a very good fit of the model to the experimental data. It was found that k values increase with the number of -CH2- groups in the monomer molecule and with the polymerization temperature. The values of m and n show a tendency to decrease with increasing temperature. The values of the parameters for all the monomers lie in the range of 0.031-0.054 s-l (k), 0.44-0.70 (m) and 1.44-1.75 (n).