摘要 |
<p>A polyester composition comprises at least one first semi-crystalline or crystallisable polyhydroxyalkanoate (PHA-X) and at least one second polyhydroxyalkanoate (PHA-Y) in semi-crystalline or crystalline form and having a higher crystalline melting point than said PHA-X. The PHA-Y is prepared by an annealing treatment in which the crystalline melting point is raised preferably by at least 5 °C compared to the PHA-X and preferably by at least 3 °C compared to the PHA-Y prior to the annealing treatment. The PHA-X and PHA-Y are preferably selected from polyhydroxybutyrate and polyhydroxybutyrate-co-valerate.</p> |