Poly(ether-b-ester) Copolymers, Blends, Composites, and Their Applications
I. INTRODUCTION Poly(ether-fr-ester) copolymers (PEE-fr-EC) belong to the group o f multiblock thermoplastic elastomers characterized by high elasticity and good mechanical properties combined with thermoplastic properties. This unique combination o f properties is due to the specific chemical structure and distribution o f the seg ments along the macromolecule. In these systems, the hard segments o f high Tg are easily crystallizable blocks that form domain structures, whereas the soft seg ments o f low Tg contribiute to the formation o f the amorphous continuous matrix. This immiscibility o f segments and their two-phase microstructure results in a unique behavior o f the multiblock elastomers. In PEE-fr-EC, the hard segments are oligoester chains o f various molecular weights (MW ), whereas the soft seg ments are usually aliphatic oligoethers o f M W ranging from 300 to 6000. The chemical nature o f the hard segments imparts a good mechanical strength, hard ness, and high temperature and solvent resistance to the material. The nature o f the soft segments is responsible for hydrolysis resistance, elastic properties, and be havior at low temperatures o f PEE-b-EC. Compounds with electrical and a vari ety o f other properties are also available. Because o f the unique combination o f properties, PEE-&-EC have found several commercial applications in the automo tive, machine, wire, and cable industries and other areas, despite their high price, ca. three times that o f styrenic elastomers (1,2).