Medical textiles are among the fastest growing sectors in the textile industry, with rapid progression especially in wound healing and implantable devices. Considerable attention is paid to the development of new fibre-based absorbable polymer implants because they reduce or eliminate the need for additional surgery to remove implanted structures. For bioabsorbable implants, the rate, mechanism and products of degradation must be carefully controlled to ensure the material functions as intended. Specifically, the degradation rates of the product should ideally be in alignment with the formation of new tissue, and the degradation products must be non-toxic and have minimal interference with the surrounding tissue and the body. 

Polyhydroxyalkanoates (PHAs) are a group of thermoplastic, biobased and biodegradable polyesters, showing promising potential for the use in medical textiles. This is because of their favourable degradation properties, which are considered superior to those of currently used biomaterials. However, PHAs like poly(3-hydroxybutyrate) entail challenges regarding their melt processability, due to the closeness of their thermal degradation temperature to the melting temperature and secondary crystallisation, which results in material embrittlement. 

This thesis investigates the melt spinnability of different PHAs, in particular a semi- crystalline and amorphous blend of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), using different processing methods. There was also an aim to improve the bioactivity of the filaments by adding bioceramics during filament production. 

It was possible to melt spin rather amorphous fibres from the semi-crystalline and amorphous polymer blend that showed similar mechanical properties to bone and could be processed into knitted and woven textile structures, which demonstrates the PHA filament’s potential to be used for medical textiles.