title: Uncatalyzed synthesis, thermal and mechanical properties of polyurethanes based on poly(epsilon-caprolactone) and 1,4-butane diisocyanate with uniform hard segment.
abstract: Polyurethanes based on poly(epsilon-caprolactone) (PCL) (750-2800 g/mol) and 1,4-butane diisocyanate (BDI) with different soft segment lengths and constant uniform hard segment length were synthesized in absence of catalysts for the production of a degradable meniscus scaffold. First the polyesterdiols were endcapped with BDI yielding a macrodiisocyanate with a minimal amount of side reactions and a functionality of 2.0. Subsequently, the macrodiisocyanates were extended with 1,4-butanediol in order to obtain the corresponding polyurethane. The polyurethanes had molecular weights between 78 and 160 kg/mol. Above molar masses of 1900 g/mol of the polyesterdiol crystalline PCL was found while the hard segment showed an increase in melting point from 78 to 122 degrees C with increasing hard segment content. It was estimated that the percentage crystallinity of the hard segment varied between 92 and 26%. The Young's modulus varied between 30 and 264 MPa, the strain at break varied between 870 and 1200% and tear strengths varied between 97 and 237 kJ/m2.
authors.affiliation: Department of Polymer Chemistry, Faculty of Mathematics & Natural Sciences, University Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands.
authors.forename: Ralf G J C
authors.initials: RG
authors.lastname: Heijkants
authors.forename: Ralph V
authors.initials: RV
authors.lastname: van Calck
authors.forename: Tony G
authors.initials: TG
authors.lastname: van Tienen
authors.forename: Jacqueline H
authors.initials: JH
authors.lastname: de Groot
authors.forename: Pieter
authors.initials: P
authors.lastname: Buma
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Pennings
authors.forename: Reen P H
authors.initials: RP
authors.lastname: Veth
authors.forename: Arend Jan
authors.initials: AJ
authors.lastname: Schouten
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry*; D002073:Butanes / Q000032:analysis / Q000737:chemistry*; D002384:Catalysis; D019245:Compressive Strength; D004548:Elasticity; D006244:Hardness; D008422:Materials Testing; D008970:Molecular Weight; D009570:Nitriles / Q000032:analysis / Q000737:chemistry*; D011091:Polyesters / Q000032:analysis / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D044366:Transition Temperature
chemical_list: C502324:1,4-butane diisocyanate; D001672:Biocompatible Materials; D002073:Butanes; D009570:Nitriles; D011091:Polyesters; C016240:polycaprolactone