title: Study on the shape memory effects of poly(L-lactide-co-epsilon-caprolactone) biodegradable polymers.
abstract: The thermal properties, crystalline structure and shape memory effects of poly(L-lactide) (PLLA) and poly(L-lactide-co-epsilon-caprolactone) (PCLA) copolymers are systematically investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and tensile tests. The effects of the deformation strain on the shape recovery rate and recovery stress are also revealed. The polymers have the PLLA crystal and the amorphous phase, which are served as the fixed phase and reversible phase, respectively. The shape recovery rate and the recovery stress are significantly affected by the compositions and the deformation strain. With the increase of the deformation strain, the shape recovery rate decrease and higher shape recovery rate can be obtained in the polymers which have higher epsilon-CL content. However, the variation of recovery stress with the deformation strain is quite different and the maximum recovery stress of all polymers exceeds 3 MPa.
authors.affiliation: Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Lu
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Sun
authors.forename: W
authors.initials: W
authors.lastname: Cai
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Gao
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D001673:Biodegradation, Environmental; D003460:Crystallization; D007773:Lactates / Q000737:chemistry; D008422:Materials Testing; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011312:Pressure; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D013816:Thermodynamics; D023822:Tissue Engineering / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D007773:Lactates; D011091:Polyesters; D011108:Polymers; C512884:poly(epsilon-caprolactone-co-lactide)-poly(ethylene glycol); C088513:poly(lactic acid-ethylene glycol); C016240:polycaprolactone; D011092:Polyethylene Glycols