STRUCTURE AND PROPERTIES OF POLY(3-HYDROXYBUTYRATE-CO-4-HYDROXYBUTYRATE) PRODUCED BY ALCALIGENES LATUS

Random copolymers of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4H B) with a wide range of compositions varying from 0 to 83 mol% 4HB wer e produced by Alcaligenes latus from the mixed carbon substrates of 3- hydroxybutyric and 4-hydroxybutyric acids. The structure and physical properties of P(3HB-co-4HB) were characterized by H-1 and C-13 NMR spe ctroscopy, gel-permeation chromatography, and differential scanning ca lorimetry. The isothermal radial growth rates of spherulites of P(3HB- co-4HB) were much slower than the rate of P(3HB) homopolymer. The enzy matic degradation rates of P(3HB-co-4HB) films by a PHB depolymerase w ere strongly influenced by the copolymer composition.