Catalytic strategies to novel bio-based alpha-hydroxy acid building blocks for polyester polymers.

Plastics lie at the heart of modern day comfort and find use in nearly all aspects of human activity. There are however two main drawbacks concerning the current generation of polymers. For one, they are derived from diminishing fossil resources with associated greenhouse gas emissions. Secondly, most of these polymers are non-degradable and contribute to a huge environmental waste problem after disposal. Polymers obtained from renewable and overly abundant ligno- and hemicellulose derived sugars offer potential to replace current commodity polymers and can be used in tailored applications as well. Especially polyesters hold promise in this respect, since they are biodegradable and renewable. More specifically, lactic acid is the major building block of a range of such polyester plastics. There are however certain structural problems with this polymer but these can be overcome by incorporating co-monomers or via the synthesis of novel look-alike polyesters. This project therefore aspires the synthesis of novel alpha-hydroxy acid molecules, their incorporation in polylactic acid, and their exploitation for designing novel polymers and superabsorbents. The use of two available sugar resources for the direct synthesis of these building blocks are proposed: pentoses and glycol aldehyde. The followed strategy will involve the use of catalysis for elaborating these novel routes as well as delivering fundamental insight into the catalytic and organic reactions occurring.