Syntheses and Polymerizations of Unsaturated Dibasic Acid Derivatives
XII. Homopolymerizations of N-(4-substituted phenyl) Maleimides
1969 Volume 26 Issue 290 Pages 393-400
Details
1969 Volume 26 Issue 290 Pages 393-400
The homopolymerizations of N-(4-substituted phenyl) maleimides, _??_(X: OCH3, CH3, H, Cl, OCOCH3, COOC2H5, COCH3) were carried out with azobisisobutyronitrile as an initiator in dimethylformamide.
In the equation which expresses the initial rate of polymerization,
Rp=k[AIBN]x[M]v
the values of x and y were found to be in the range of 0.6-0.9 and 1.0-1.5, respectively, according to the monomer. Also the over-all activation energies and the frequency factors were measured to be 23.8-29.1 kcal/mole and 6.6×1013-6.6×1017.
The relationship between logarithm of initial rate of polymerization (Rp) and σ of Hammett's equation did not give a straight line, the initial rates being greater than expected from the equation for electron releasing substituents and smaller for electron attracting substituents. The above curve was converted to a straight line by applying the Yamamoto- Otsu's equation, which contains a correcting term concerning resonance effects as compared with Hammett's equation. Thus the relationships between the reactivities of N-(4-substituted phenyl) maleimides in the copolymerization with vinyl acetate or methyl methacrylate and those in the homopolymerizations were explained.
The anionic polymerizations of the above monomers were carried out with n-BuLi or C2H5ONa as initiator in tetrahydrofuran. With n-BuLi initiator the polymeryield was high but the reduced viscosity was found to be about 0.07 which corresponded to oligomers.
