Effects of solvent and temperature on the copolymerizations of 2-acryloyloxyethyl diethyl phosphate with methyl methacrylate and styrene

✍ Scribed by C.P. Reghunadhan Nair; G. Clouet

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 486 KB
• Volume: 25
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(89)90227-9

✦ Synopsis

Radical copolymerlzations of 2-acryloyloxyethyl diethyl phosphate (ADP) with methyl methacrylate (MMA) and with styrene were carried out under various conditions. The reactivity ratios were determined by the method of Fineman-Ross. Under a given set of conditions, the reactivity of the acrylate terminated radical towards styrene was found to be much higher than that towards MMA. In their reaction with ADP, the polymer radicals were more reactive when terminated with MMA than with styrene. The reactivity ratios of the two pairs were determined at various temperatures and in solvents of differing polarity. An increase in r t and a corresponding decrease in r 2 for the ADP-MMA pair with rise in temperature revealed a higher activation energy for the addition of the radicals to ADP than to MMA, a result which is consistent with the potential energy concepts in the respective transition states. The slight decrease in both r I and r 2 with increasing temperature for the ADP-ST pair suggests that the cross propagations need slightly higher activation energies than the homopropagations. Changing the solvent polarity did not greatly affect the relative reactivities of ADP, except when a hydrogen bonding solvent was used. A substantial decrease in the relative reactivity of ADP in 2-methoxyethanol indicated a solvent-induced shift in the electron redistribution on the intramolecular bonds of ADP, through H-bonding. Examination of the glass transition temperatures revealed the influence of the monomer sequence distribution on the copolymer T~'s. Their variation with composition was explained by the equation of Johnston.