| abstract |
Compositions of P4HB (poly-4-hydroxybutyrate) and copolymers thereof, have been developed for pultrusion, as well as processes to produce profiles from these compositions by pultrusion. These pultrusion processes provide profiles without causing structural damage to the surface of the profile. The profiles may be used in medical applications. These compositions include P4HB, and copolymers thereof, having intrinsic viscosities less than 3.2 dl/g but greater than 0.8 dl/g. The profile may be formed using conditions such as: pull rate of 0.1 to 100 mm/min, die temperature of up to 95° C., rod stock temperature up to 95° C., draw ratio of up to 100×, pulling force of greater than 10 MPa, and clamping pressure at least 10% higher than the pulling force. Preferably, the profile is formed by pulling the rod stock through a series of dies placed at intervals with the hole sizes decreasing in diameter by 0.1 to 10 mm. |