title: Perpendicularly oriented lamellae in poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) blended with an amorphous polymer: ultra-thin to thick films.
abstract: The oppositely oriented lamellae in ridge and valley bands of ring-banded spherulites in biodegradable poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) interacting with amorphous poly(vinyl acetate) (PVAc) were examined using polarized-light optical, scanning electron, and atomic-force microscopy techniques (POM, SEM, AFM). Solvent-etching and fracturing were utilized for probing the interior morphology of the large-size ring-banded spherulites in PHBV/PVAc (70/30) blend [T(c) = 110 °C] films or thick bulk of various thicknesses. SEM analysis revealed that dual ridges of two opposite-oriented lamellae correspond to two-color bands (yellow and blue) of successive rings in POM micrographs. Fracture of thick blend samples further exposed that interior 3D spherulites were composed of sheath-kebab (similar to corrugated board) lamellae of two mutually perpendicular orientations.
authors: Department of Chemical and Materials Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Nan-Tzu Dist., Kaohsiung, 811, Taiwan. ccsu@nuk.edu.tw
authors: Chean-Cheng
authors: CC
authors: Su
authors: Eamor M
authors: EM
authors: Woo
authors: Ya-Ting
authors: YT
authors: Hsieh
mesh_terms: D003460:Crystallization; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D011091:Polyesters / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties; D000094122:Polyhydroxybutyrates
chemical_list: D011091:Polyesters; D012997:Solvents; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates