M. Gazzano et al., X-RAY-INVESTIGATION ON MELT-CRYSTALLIZED BACTERIAL POLY(3-HYDROXYBUTYRATE), Macromolecular chemistry and physics, 198(1), 1997, pp. 71-80
Films of bacterial poly(3-hydroxybutyrate), obtained by crystallizatio
n from the melt at different temperatures up to 120 degrees C, were in
vestigated by powder X-ray diffraction analysis and optical microscopy
. With increasing crystallization temperature (T-c) the diffraction pa
tterns differed more and more from that of the ''as received'' powder
in both relative intensity of the reflections and peak width. The rela
tive peak intensities also varied in response to temperature changes o
f the melt from which the polymer was quenched to a selected T-c. The
differences in the X-ray diffraction patterns were correlated with cha
nges of average spherulite size (0.1 mm to 2 mm) in films with limited
thickness. When the spherulites were large the lamellar crystals were
strongly oriented parallel to the film plane. Full profile Rietveld a
nalyses allowed to quantify the preferred orientation effect and to ex
tract additional morphological and structural informations.