title: Molecular orientation distributions in a biaxially oriented poly(L-lactic acid) film determined by polarized Raman spectroscopy.
abstract: Molecular orientation distributions in the crystalline and amorphous regions of a biaxially oriented poly(L-lactic acid) film were analyzed fully by polarized Raman spectroscopy. Raman bands at 926 and 875 cm(-1) were chosen for the determination of the most probable molecular orientation distribution functions for the crystalline and amorphous regions in the film. It was revealed that the PLLA molecules were oriented biaxially in both the crystalline and amorphous regions. The orientation distribution normal to the film surface was found to be broader in the amorphous regions than in the crystalline regions. Furthermore, a predominant unidirectional molecular orientation was observed in the crystalline regions, whereas the molecular orientation distribution in the amorphous regions was isotropic in the plane parallel to the film surface. The different behavior of the crystalline and amorphous regions suggests that each region underwent different deformation mechanisms during the film formation.
authors.affiliation: Materials Science Centre, School of Materials, The University of Manchester, Grosvenor Street, Manchester, M1 7HS United Kingdom.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Tanaka
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Young
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D003460:Crystallization; D006868:Hydrolysis; D019344:Lactic Acid / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D015233:Models, Statistical; D008962:Models, Theoretical; D008970:Molecular Weight; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D012984:Software; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D046911:Macromolecular Substances; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)