A. Cao et al., COMPOSITION FRACTIONATION AND THERMAL CHARACTERIZATION OF POLY(3-HYDROXYBUTYRATE-CO-3-HYDROXYPROPIONATE), Polymer Journal, 28(12), 1996, pp. 1096-1102
The compositional distribution has been investigated for poly(3-hydrox
ybutyrate-co-3-hydroxypropionate) [P(3HB-co-3HP)]s, which were microbi
ally synthesized by Alcaligenes latus with 3-hydroxypropionic acid, su
crose or 3-hydroxybutyric acid as the sole carbon source. With a chlor
oform/n-heptane mixed solvent, they were found to be fractionated into
several fractions with different comonomer composition. It was conclu
ded that the as-produced bacterial P(3HB-co-3HP) samples have a broad
distribution of comonomer composition. Using the fractions with a narr
ower comonomer composition distribution, the composition dependence of
thermal properties and isothermal spherulite growth behavior were inv
estigated. One of as-produced unfractionated P(3HB-co-3HP) showed the
DSC melting behavior reflecting that of only minor fractions with 3HP
content differed remarkedly from average 3HP content of original unfra
ctionated P(3HB-co-3HP). It was concluded that each of the fractions a
ffects thermal properties of the original P(3HB-co-3HP).