Oxidative degradation of poly(3-hydroxybutyrate). A new method of synthesis for the malic acid copolymers

Abstract

Herein was presented by the first time the green way to obtain poly(3-hydroxybutyrate-co-3-malic acid) from natural origin poly(3-hydroxybutyrate).

Review of recent advances in the biodegradability of polyhydroxyalkanoate (PHA) bioplastics and their composites

“…88,89 Thermal or oxidative degradation is non-selective, occurring to all polymers, and introduces thermal or chemical stressors that scission the chains of polymers into smaller units of oligomers, acids, alcohols, esters, and radicals. 90,91 For example, PHAs are less thermally stable than PLA and PCL due to the different thermal degradation mechanisms of random chain scission instead of unzipping depolymerization, and thermal degradation results in a reduced molecular weight along with the esters and alcohol end groups. 92 However, thermal energy can also enhance most if not all other forms of degradation, through disproportionally increasing the high energy collisions between reactants or enzymes and reactants.…”

“…15 Simplified main pathways and optimal conditions for PHB degradation and bioassimilation in natural environments. 91,226,[253][254][255] Green Chemistry…”

Polyhydroxyalkanoate-based drug delivery systems

“…Moreover the increasing number of functional β‐lactones presented in the literature gives hope for the development of synthetic functional PHAs as alternatives to microbial‐originated PHAs . Novel functionalized PHAs and the introduction of methods like ‘click’ chemistry in PHA functionalization also open the possibility for the preparation of nanoparticles without any surfactants or polymeric additives as well as attachment of targeting or imaging molecules on the multifunctional particle surfaces. These developments in combination with the generally excellent biocompatibility of PHA materials are expected to further increase the interest in PHA‐based drug delivery systems.…”

Bioactive oligomers from natural polyhydroxyalkanoates and their synthetic analogues

“…It was also found that oligomers consisted of 3-hydroxybutyrate 3-malic acid units can be synthesized via thermal treatment of poly(3-hydroxybutyrate) (PHB) in oxygen/ ozone mixture. Nuclear magnetic resonance (NMR) and multi-stage mass-spectrometry (MS) characterization revealed random distribution of 3-malic acid units in oligomeric products as well as content of the malic acid units dependent on oxidation conditions [13].…”