ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Degradability of cross-linked polyurethanes based on synthetic polyhydroxybutyrate and modified with polylactide

Joanna Brzeska, Magda Morawska, Wanda Sikorska, Agnieszka Tercjak, Marek Kowalczuk, and Maria Rutkowska

Gdynia Maritime University, Gdynia, Poland

E-mail: j.brzeska@wpit.am.gdynia.pl

Abstract: In many areas of application of conventional non-degradable cross-linked polyurethanes (PUR), there is a need for their degradation under the influence of specific environmental factors. It is practiced by incorporation of sensitive to degradation compounds (usually of natural origin) into the polyurethane structure, or by mixing them with polyurethanes. Cross-linked polyurethanes (with 10 and 30%wt amount of synthetic poly([R,S]-3-hydroxybutyrate) (R,S-PHB) in soft segments) and their physical blends with poly([d,l]-lactide) (PDLLA) were investigated and then degraded under hydrolytic (phosphate buffer solution) and oxidative (CoCl₂/H₂O₂) conditions. The rate of degradation was monitored by changes of samples mass, morphology of surface and their thermal properties. Despite the small weight losses of samples, the changes of thermal properties of polymers and topography of their surface indicated that they were susceptible to gradual degradation under oxidative and hydrolytic conditions. Blends of PDLLA and polyurethane with 30 wt% of R,S-PHB in soft segments and PUR/PDLLA blends absorbed more water and degraded faster than polyurethane with low amount of R,S-PHB.

Keywords: Degradable polymers; Cross-linked polyurethanes; Synthetic polyhydroxybutyrate; Polymer blends; Polylactide

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-017-0216-6

Chemical Papers 71 (11) 2243–2251 (2017)