Plastics, ISCR highlighted in "En direct des labos" @ CNRS INC Actualités

Towards new biodegradable and modular plastics
Plastics, ISCR highlighted in "CNRS En direct des labos" @ CNRS INC News

Polyhydroxyalkanoates are natural, biodegradable polymers that represent a sustainable alternative to plastics of fossil origin. They occupy an important place in the market of eco-materials (packaging, cosmetics, etc.) thanks to their diversified chemical nature resulting in a wide range of properties. An array that scientists from the Rennes Institute of Chemical Sciences (ISCR, CNRS / University of Rennes 1 / ENSC Rennes / INSA Rennes) have extended upon chemically grafting the polymers with new substituents, thereby granting plastics with innovative thermal, mechanical properties or even biodegradability. Results to be found in the journal Polymer Chemistry (*).

Polyhydroxyalkanoates (PHAs), polyesters found in nature, are produced by the fermentation of sugars (sucrose, glucose, etc.), starches or lipids (glycerin, triglycerides) by bacteria. They offer a wide range of physicochemical properties which depend essentially on the chemical nature of the side groups distributed on either side of the chains that compose them. PHAs represent a sustainable alternative to plastics of fossil origin with, in particular, the marketing of the most common of the PHAs, poly (3-hydroxybutyrate) (PHB), used in food packaging, in cosmetic formulations or in the (bio) medical environment. The non-natural but chemically synthesized PHAs should make it possible to further broaden the range of their properties and applications, in particular by grafting in a controlled manner new functional side groups different from those encountered in natural PHAs. Researchers at ISCR have been developing such synthetic PHAs for several years. With the help of a specific catalyst ** to control the polymerization, they recently produced new families of PHAs, and especially "syndiotactic" ones that feature a specific microstructure ***. Some of the new side substituents, of the CH2ZPh type (Z = O, S, CH2OCH2), which the teams have managed to graft onto the chains, can for instance transform the initially hydrophobic PHAs into polymers which are soluble in water. Others, biocompatible and capable of binding molecules of biological interest, should facilitate their transport in living environments. This work was the subject of a publication selected as "HOT Article" in the special issue on "Sustainable polymers and polymer chemistry" published in Polymer Chemistry.

  •  (*) On the occasion of a special issue of the journal entitled "Sustainable polymers" dedicated to the valorization of bioresources
  • (**) Yttrium diamino- or amino-alkoxy-bis (phenolate) amide catalyst
  • (***) The substituents are distributed stereoregularly, alternately on one side and the other of the chain

Learn more


Rama M. Shakaroun, Hui Li, Philippe Jéhan, Marielle Blot, Ali Alaaeddine, Jean-François Carpentier & Sophie M. Guillaume
Stereoselective ring-opening polymerization of functional β-lactones: influence of the exocyclic side-group
Polym. Chem. 2021, DOI: 10.1039/d1py00669j,


  • Sophie Guillaume, Univ Rennes, CNRS, ISCR-6226, F-35000 Rennes, France
    sophie [dot] guillaumeatuniv-rennes1 [dot] fr
  • Jean-François Carpentier, Univ Rennes, CNRS, ISCR-6226, F-35000 Rennes, France
    jean-francois [dot] carpentieratuniv-rennes1 [dot] fr


Published September 14, 2021