Valorisation of glycerol and CO2 to produce biodegradable polymer nanoparticles with a high percentage of bio-based components

The biodiesel industry has grown rapidly in the last years, leading to the production of 88 000 tons of waste glycerol in 2018. Glycerol is a bio-derived molecule already exploited in pharmaceutical and cosmetic industries for its beneficial emollient and antimicrobial properties, safety and low cost. However, since its production is increasing year by year, many efforts are being done to find new ways to exploit it and to produce new valuable bio-based molecules. In particular, glycerol carbonate is a versatile molecule that can be produced from glycerol and another waste product, CO2. Despite its potentialities in further functionalization, harsh reaction conditions are often required for the synthesis of glycerol carbonate and its exploitation is often challenging. Therefore, an industrially scalable reaction to convert glycerol into high added-value compounds is urgently needed. Here, the aim is to demonstrate a feasible conversion of glycerol to glycerol carbonate-based vinyl monomers that can be conveniently incorporated in amphiphilic block copolymers by reversible addition-fragmentation chain transfer (RAFT) polymerization. These block copolymers can be self-assembled in water to obtain nanoparticles with a bio-based content as high as 70% w/w. Since both glycerol and glycerol carbonate are approved by the Food and Drug Administration (FDA) and considered as safe, the possibility of exploiting these bio-based nanoparticles for the controlled drug release was explored.