Patent ID: 6838037

Claim:
A method for enhancing the rate of crystallization of a first biodegradable polyhydroxyalkanoate comprising a copolymer of at least two randomly repeating monomer units, wherein the first randomly repeating monomer unit has the structure (I): wherein R 1 is H, or C1 or C2 alkyl, and n is 1 or 2; and the second randomly repeating monomer unit is different from the first randomly repeating monomer unit and comprises at least one monomer selected from the group consisting of the structures (II) and (III): wherein R 2 is a C3-C19 alkyl or C3-C19 alkenyl, and wherein m is from 2 to about 16, and wherein at least about 50 mole % of the copolymer comprises randomly repeating monomer units having the structure of the first randomly repeating monomer unit (I), and further wherein the copolymer has a melting point Tm1, the method comprising solution blending the first biodegradable polyhydroxyalkanoate with a second crystallizable biodegradable polyhydroxyalkanoate comprising at least one randomly repeating monomer unit having the structure (IV): wherein R 3 is H, or C1 or C2 alkyl, and p is 1 or 2; wherein the second biodegradable polyhydroxyalkanoate has a melting point Tm2, wherein Tm2 is at least about 20° C. greater than Tm1; and wherein the second biodegradable polyhydroxyalkanoate is finely dispersed within the bulk of the first biodegradable polyhydroxyalkanoate.