Investigation of Thermoplastic Elastomer Properties for Microfeature Replication

Preliminary investigation has shown that the relative amount of hard and soft segments in block copolymer elastomers affected the molding window and replication of injection molded parts with microstructured surfaces.  In this work, two different types of block copolymers, polyester block copolymers (COPEs) and polyether block amide copolymers (PEBAs) were compared for molding window and replication.  Materials with a moderate hardness had the widest processing window and PEBAs showed slightly wider processing window than COPEs.  The depth the molded micro features were only slightly influenced by COPE and PEBA hardness, but the softer elastomers exhibited sharper edged features.   PEBA also exhibited a tendency to adhere to the tooling surface, and so, was molded with lower mold temperatures.