Post-Synthetic Enzymatic and Chemical Modifications for Novel Sustainable Polyesters

Abstract

Because of their biodegradability, compostability, compatibility and flexible structures, biodegradable polymers such as polyhydroxyalkanoates (PHA) are an important class of biopolymers with various industrial and biological uses. PHAs are thermoplastic polyesters with a limited processability due to their low heat resistance. Furthermore, due to their high crystallinity, some PHAs are stiff and brittle. These features result sometimes in very poor mechanical characteristics with low extension at break values which limit the application range of some natural PHAs. Several in vivo approaches for PHA copolymer modifications range from polymer production to enhance PHA-based material performance after synthesis. The methods for enzymatic and chemical polymer modifications are aiming at modifying the structures of the polyesters and thereby their characteristics while retaining the biodegradability. This survey illustrates the efficient use of enzymes and chemicals in post-synthetic PHA modifications, offering insights on these green techniques for modifying and improving polymer performance. Important studies in this sector will be reviewed, as well as chances and obstacles for their stability and hyper-production.

Novel Biodegradable Nanoparticulate Chain-End Functionalized Polyhydroxybutyrate–Caffeic Acid with Multifunctionalities for Active Food Coatings

“…To illustrate, they do not possess biological activities due to the lack of essential functional groups in their structure. 38 For this reason, the three hydroxyl groups of PHB-DEA were substituted with CafA molecules to enhance the polymer functionalities. Alkene and aliphatic carboxylic acid groups are the two main functional groups of caffeic acid as a cinnamic acid derivative.…”

“…Despite the positive features of PHAs in numerous applications, they are inactive polymers. To illustrate, they do not possess biological activities due to the lack of essential functional groups in their structure . For this reason, the three hydroxyl groups of PHB-DEA were substituted with CafA molecules to enhance the polymer functionalities.…”

The Hyperproduction of Polyhydroxybutyrate Using Bacillus mycoides ICRI89 through Enzymatic Hydrolysis of Affordable Cardboard

“…Under nutrient-restricted environments, microbial polyesters accumulate with surplus carbon and polymerize as inclusion bodies [ 48 ]. To mimic such conditions, 1 L filtrate of cardboard hydrolysate was supplied with all components of MSM except glucose and (NH 4 ) 2 SO 4 , where the cardboard hydrolysate would be the carbon and nitrogen sources.…”

Advances in Polyhydroxyalkanoate (PHA) Production, Volume 3

“…Post-synthetic modification of microbial PHA to generate novel, functional materials becomes of increasing significance for improvement of performance of these bioproducts [ 33 ]. Brelle and colleagues prepared a novel class of mcl -PHA-based gels by using ionic interactions.…”