Preparation and degradation of salts of poly(methacrylic acid). I. Lithium,sodium, potassium,and caesium salts

The polymers of lithium, sodium, potassium, and caesium salts of methacrylic acid have been prepared by free radical polymerization of the respective monomers in methanol solution. The degradation behavior of the polymers has been investigated by thermal volatilization analysis, thermogravimetry, and product analysis. These materials are stable to about 350°C under programmed heating at 10°C/min in vacuo. The principal degradation products are monomer, the corresponding isobutyrate, carbonate, oxide, carbon dioxide, and a fraction of liquid volatiles that is complex and contains a variety of aldehydes and ketones. The mechanism of degradation is discussed in detail.