Reactive mono- and di-epoxy-functionalized poly(3-hydroxybutyrate)s. Synthesis and characterization

This work describes universal transformation method of low molar mass crotonate-terminated poly(3-hydroxybutyrate)s (PHB), obtained by anionic ROP of β-butyrolactone and controlled degradation of high-molar mass bacterial PHB, into mono- and di-epoxy-functionalized reactive poly(3-hydroxybutyrate)s via oxidation of crotonate end groups to α-3-methyloxirane-2-carboxylates, while carboxylate terminal groups were functionalized by simple alkylation with epibromohydrin. Combining these two methods resulted in telechelic structures: α-3-methyloxirane-2-carboxylate-ω-glicydyl PHB. Moreover, the reactivity of 3-methyloxirane groups of a functional aPHB, was confirmed in experiment with primary amine and primary alcohol, revealing very high yield in reaction with alcohol, while degradation of polymer backbone was noticed during reaction with amine.