Fully-biodegradable poly(3-hydroxybutyrate)/poly(vinyl alcohol) blend films with compositional gradient.
Fully-biodegradable bacterial poly(3-hydroxybutyrate) (PHB)/chemosynthetic poly(vinyl alcohol) (PVA) blend films with compositional gradient from one surface to the other surface of the films were prepared by a dissolution-diffusion technique. Three kinds of PVA samples, high- and low-molecular weight atactic PVA and highly syndiotactic PVA (s-PVA), were used in order to investigate the effects of molecular weight and tactic structure on the generation of compositional gradient. The solution of PHB in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), which is also a good solvent for PVA, was cast on the PVA film and then the solvent HFIP was evaporated. By selecting the optimum volume of solvent and the evaporation rate, the PHB/PVA blend film with compositional gradient was obtained. The formation of compositional gradient was confirmed by FT-IR microscopy and ATR-FT-IR analysis. The 50%/50% PHB/s-PVA blend film with a nearly ideal compositional gradient, that is, the composition of PHB (or PVA) in the film changing gradually from 100% at one surface to 0% at the other surface of the film was obtained by casting PHB/HFIP solution on to the s-PVA film. Positional dependence of the absorbance of C==O and OH stretching bands along the film thickness direction for the PHB/S-PVA cast films.
Department of Biomolecular Engineering, Tokyo Institute of Technology, Nagatsuta 4259-B-55, Midori-ku, Yokohama 226-8501, Japan.
Li
L
Zhao
Katsunori
K
Tsuchiya
Yoshio
Y
Inoue
D000042:Absorption; D001673:Biodegradation, Environmental; D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D006885:Hydroxybutyrates / Q000737:chemistry*; D008422:Materials Testing; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D000094122:Polyhydroxybutyrates
D006885:Hydroxybutyrates; D011091:Polyesters; D011142:Polyvinyl Alcohol; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates