In addition, the application properties of those compound can reportedly be tuned as required.
The controversial use of bisphenol A
Bisphenol compounds are included in the composition of different polymers (polycarbonates, polyesters, polyurethanes, etc.). Inexpensive, they have the advantage of endowing these matrices with thermo-mechanical, plasticizing and/or antioxidant properties, which are notably sought for packaging applications. Their principal drawback is their proven toxicity to humans and more globally to the environment. In the long term, a tightening of the EU REACH regulations may merely ban their use, and particularly that of bisphenol A (BPA) in products destined to come into contact with food and human body (packaging, cosmetics and health sectors, etc.).
Using plant phenols for the ecological production of a range of replacement compounds with tunable properties
The methodology developed by the scientists specifically uses plant based raw materials:
- platform molecules resulting from the conversion of cell wall polysaccharides,
- ferulic acid from lignocellulose, and
The first two stages of this synthesis are chemical transformations that are widely applied in industry and have a limited environmental impact. The third stage is a bio-catalytic condensation process which involves a commercial lipase. This process does not require either the use of chemical protection/deprotection reactions, or the use of of solvents. The method is highly flexible because it enables the condensation of a ferulic acid derivatives with different compounds (such as polyols or polyamines) in order to produce a broader range of compounds with tunable properties.
The new bisphenolic compounds thus obtained exhibit excellent thermal stability up to a temperature of 250 °C. They can be used as antioxidants/anti-free radical substances and/or as biosourced plasticisers which display no endocrine disrupting activity.
An innovative application: the synthesis of new bio-sourced “plastic materials”
Because of their properties, these new bisphenols could be used in replacement of bisphenol A to make food packaging. They could also be employed as monomers for the synthesis of new polyesters or polyurethanes. After a phase of further functionalization, they can also be used as monomers for the synthesis of polyamides or polyolefins. The range of potential applications is consequently very large.