A convenient route to PHB macromonomers via anionically controlled moderate‐temperature degradation of PHB

• Published in: Journal of Polymer Science Part A: Polymer Chemistry
• Main Authors: kawalec, Michał, Sobota, Michał, Scandola, Mariastella, Kowalczuk, Marek, Kurcok, Piotr
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2010
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1002/pola.24357; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fpola.24357; https://onlinelibrary.wiley.com/doi/pdf/10.1002/pola.24357

Abstract The degradation of poly(3‐hydroxybutyrate)s in homo‐ and heterogeneous mixtures with selected salts of organic and mineral acids was investigated. Nonvolatile degradation products, of processes conducted at moderate temperatures (150–170 °C), were analyzed using 1 H NMR. Analysis of results revealed a significant decrease in poly([ R ]‐3‐hydroxybutyrate) (PHB) thermal stability in the presence of acetic acid and carbonic acid salts of alkali metals (Cs, K, Li) as well as a less substantial effect with respect to bivalent metal (Ca, Mg, Zn) salts. This significant decrease in PHB thermal stability in the presence of salts of weak Bronsted‐Lowry acids can be explained in terms of an anionic degradation reaction proceeding via an E1cB mechanism. Furthermore, continuous poly(3‐hydroxybutyrate) controlled degradation was developed by a moderate‐temperature process using carbonic acid salts as “initiators” of anionic degradation. Foamed PHB macromonomers, bearing one crotonate terminal group, were obtainable via a reactive extrusion process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010