Ethylene Copolymers

Abstract

Copolymerization of ethylene (E) and styrene (S) has been enabled by developments in metallocene catalysts. An overview of copolymerization chemistry shows that catalyst structure and polymerization conditions have major influences on the production efficiency, product composition, and copolymer microstructure. Copolymers produced have included those with alternating (ES) n sequences; when these sequences are stereoregular, they can crystallize. Ethylene and styrene have been copolymerized with additional monomers, including dienes and α‐olefins. Ethylene–styrene copolymers have been primarily produced via solution polymerization techniques. To date, the copolymers of major interest are essentially atactic, and contain up to about 50 mol% styrene. These copolymers range from highly crystalline to essentially amorphous, dependent upon comonomer composition ratio. The structure–property relationships presented include thermal properties, viscoelastic behavior, mechanical properties, and rheology/processability. Materials engineering is important regarding the utility of poly(ethylene‐ co ‐styrene). The copolymers are compatible with bitumens, plasticizers, and tackifiers. Blend systems with copolymers as components and copolymer/filler composites are discussed. Potential markets/applications for poly(ethylene‐ co ‐styrene) have been identified from literature sources, and include foams.