Thermoplastic PBT-based elastomer created in reactive extrusion
4 Jan 2002
Cyclics Corporation has disclosed that it has polymerized a thermoplastic PBT (polybutylene terephthalate) based elastomer by combining Cyclics' CBT resin and certain other polymers under reactive extrusion conditions.
The advantage of the new technique lies in the fact that a range of soft and hard block copolymers can now be produced directly in the extruder.
The reactive extrusion process allows fast production of thermoplastic copolyester-ether elastomers with wide variation of the hardness while maintaining the high melt temperature of PBT. For example, an 80 Duro Shore A thermoplastic copolyester-ether elastomer with a melting temperature of 215C was produced using the new reactive extrusion process.
'We are excited about our breakthrough ability to both create elastomeric materials with properties not currently attainable and tailor those properties to customer specifications simply by adjusting the ratio of inputs before extrusion,' said John Ciovacco, CEO of Cyclics Corporation. 'We are now actively looking for relationships to assist in commercialisation of our product in this new market.'
Copolyester-ether elastomers are block copolymers composed of alternating hard and soft segments. The hard segments consist of PBT, while the soft segments consist of a polyether gycol. The PBT segments exhibit high heat resistance and good chemical resistance, while the soft segments contribute impact strength and low flexural modulus.
Copolyester elastomers are also commonly used in the industrial product, motor vehicle, wire and cable, construction, and aerospace and other transportation equipment markets. Copolyester elastomer parts may be processed via injection molding, extrusion or compression moulding.
