Anionic synthesis and characterization of alkyl methacrylate containing polymeric systems
The anionic synthesis of alkyl methacrylates has received sparse attention in comparison to the synthesis of nonpolar hydrocarbon monomers such as styrene or the dienes. The two major reasons for the sluggish synthetic development of this class of polar monomers are the protic impurities present in most commercially available grades of monomer and the inherent side reactions associated with the ester functionality during anionic polymerization. However, by very carefully controlling various synthetic parameters and utilizing rigorously purified monomers, one can take advantage of the "living" nature of this polymerization to synthesize a variety of well-defined polymeric materials.
Small variations in polymerization conditions drastically affect the properties of the polymers obtained. However, the effects depend largely upon the size of the ester alkyl group involved. The subtle relationships among such variables as ester alkyl group size, polymerization temperature, polymerization solvent and initiator have been explored and are discussed. Extensive thermal, microstructural and mechanical characterization reveal very interesting effects on the resulting polymer properties.
Styrene-acrylic, acrylic-acrylic and diene-acrylic block copolymers have been synthesized demonstrating predictable molecular weights, narrow molecular weight distributions and controlled composition. These novel block copolymers preparation selective also serve as of acid- and hydrolysis excellent precursors for the ion- containing polymers. By of certain labile poly(alkyl methacrylate) esters and subsequent neutralization, metal carboxylates were introduced into a variety of block copolymers. In addition to the preparation of surfactant-like macromolecules and blend compatibilizers, novel ion-containing block copolymers were synthesized.