Designing biodegradable multiblock PCL/PLA thermoplastic elastomers.
A series of poly(epsilon-caprolactone)/poly(L-lactic acid) (PCL/PLA) biodegradable poly(ester-urethane)s, was synthesized and characterized. The first step of the synthesis consisted of the ring opening polymerization of L-lactide, initiated by the hydroxyl terminal groups of the PCL chain, followed by the chain extension of these PLA-PCL-PLA triblocks, using hexamethylene diisocyanate (HDI). The trimers comprised PCL2000 flexible segments, while the length of each PLA block covered the 550-6000 molecular weight range. The morphology of the copolymers gradually changed, as the length of the PLA blocks increased. The multiblock copolymers produced displayed enhanced mechanical properties, with ultimate tensile strength values around 32 MPa, Young's modulus as low as 30 MPa and elongation at break values well above 600%. The longer the PLA block, the slower the in vitro degradation of the material, with all copolymers degrading faster than the respective homopolymers.
Cohn
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Casali Institute of Applied Chemistry, Hebrew University of Jerusalem, Gival Ram Campus, Jerusalem 91904, Israel.
Salomon
A Hotovely
AH
D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry*; D004548:Elasticity; D020724:Elastomers / Q000737:chemistry; D008422:Materials Testing; D008970:Molecular Weight; D010969:Plastics / Q000737:chemistry; D011091:Polyesters / Q000032:analysis / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength
D001672:Biocompatible Materials; D020724:Elastomers; D010969:Plastics; D011091:Polyesters; C062968:lactide-caprolactone copolymer