Pulsed-Laser Polymerization Measurements of the Propagation Rate Coefficient for Butyl Acrylate

• Published in: Macromolecules 1996-03, Vol.29 (6), p.1918-1927
• Main Authors: Lyons, Robert A, Hutovic, Jelica, Piton, Mark C, Christie, David I, Clay, Paul A, Manders, Bart G, Kable, Scott H, Gilbert, Robert G
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Physicochemistry of polymers; Polymerization; Polymers and radiations
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma950747n

The results are reported for a series of measurements of the propagation rate coefficient (k p) of butyl acrylate obtained from pulsed-laser polymerization (PLP). Previous attempts reported in the literature to use PLP for this monomer have failed because the data did not satisfy the internal consistency tests afforded by PLP. The problem was obviated by carrying out measurements at very low temperatures and with very short times between laser pulses. Data for k p were obtained over the range −65 to −7 °C which satisfy PLP consistency tests (invariance of the apparent k p value to laser pulse frequency, etc.). The results fit k p (dm3 mol-1 s-1) = 107.2 exp(−17.3 kJ mol-1)/RT); the confidence ellipse for these parameters is provided. These data extrapolate to a value of k p = 2.7 × 104 dm3 mol-1 s-1 at 50 °C. The higher value of the frequency factor of butyl acrylate compared to that of butyl methacrylate can be rationalized in terms of hindered rotations in the transition states.