Levulinic acid as a renewable source for novel polymers

PhD ceremony: Mr. M. Chalid, 14.30 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Levulinic acid as a renewable source for novel polymers

Promotor(s): prof. A.A. Broekhuis, prof. H.J. Heeres

Faculty: Mathematics and Natural Sciences

Ligno-cellulosic biomass has been identified as an attractive source for chemical products, which is a promising raw material to substitute the current mainly petrochemical based bulk chemicals. Levulinic acid (LA), which may be obtained from ligno-cellulosic biomass in good yields, is a versatile multi-purpose building block due to the presence of two reactive functional groups. As an attractive derivative of LA, gamma-valerolactone (GVL) is considered as a starting material for the synthesis of bio-based polymers. However, polymerization of GVL is cumbersome due to the low reactivity of GVL and only low molecular weight products are obtained so far. An approach involving the GVL conversion to a more reactive monomer could be a very promising concept to convert GVL to high molecular weight bio-based polymers having good thermal and mechanical properties.

The primary objective of the research is the development of novel synthetic pathways for bio-based polymers derived from LA. A two-step approach has been applied and involves the conversion of LA to novel monomeric building blocks through hydrogenating of LA into GVL and ring-opening of GVL, and the subsequent polymerization (with an emphasis on polyurethanes) to higher molecular weight products.

This research showed that the products are amorphous, thermally stable till 250 °C and have a maximum glass transition temperature of 128 °C. The polyurethane made from TDI and the GVL/1,2-diaminoethane-based precursor which showed the highest molecular weight, i.e. 147 kD with a high elastic modulus (2,210 MPa), brings this bio-based system within the window of commercial polyurethane applications.