Carboxylate-induced degradation of poly(3-hydroxybutyrate)s.
This communication shows that thermal degradation of poly(3-hydroxybutyrate)s (PHBs) is induced by carboxylate groups via a newly proposed E1cB mechanism. In PHBs with end groups in the form of carboxylic acid salts with Na+, K+, and Bu4N+ counterions, the proposed mechanism explains the dependence of thermal stability on the size of the counterion. The degradation via intermolecular alpha-deprotonation by carboxylate is suggested to be the main PHB decomposition pathway at moderate temperatures. The results of the present study show the ability to control the degradation and stability of poly(3-hydroxybutyrate)s as well as of their blends via chemical structure and concentration of the carboxylate polymer end groups.
Kawalec
Michal
M
Centre of Polymer Chemistry, Polish Academy of Sciences, 34, M. Curie-Sklodowska Street, 41-819 Zabrze, Poland.
Adamus
Grazyna
G
Kurcok
Piotr
P
Kowalczuk
Marek
M
Foltran
Ismaela
I
Focarete
Maria Letizia
ML
Scandola
Mariastella
M
D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D006885:Hydroxybutyrates / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry; D012680:Sensitivity and Specificity; D013696:Temperature; D013818:Thermogravimetry; D000094122:Polyhydroxybutyrates
D002264:Carboxylic Acids; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates