Polymers from renewable resources: Bulk ATRP of fatty alcohol-derived methacrylates

Abstract

Copper-mediated atom transfer radical polymerization (ATRP) of lauryl methacrylate (LMA) and other long-chain methacrylates was investigated in bulk at 35 degrees C by using CUCl/N,N,N',N',N ''-penta- methyldiethylenetriamine (PMDETA)/tricaprylylmethylammonium chloride (Aliquat (R) 336) as the catalyst system and ethyl 2-bromoisobutyrate (EBIB) as the initiator. The investigated monomers can be derived from fatty alcohols and are therefore an important renewable resource for a sustainable development of our future. The amounts of ligand, Aliquat (R) 336 and CICl were optimized and the effect of their concentrations on the control of the polymerization and the observed conversions were investigated. It was found that a molar ratio of EBIB/CUCl/Ligand/Aliquat (R) 336 of 1 : 1 : 3 : 1 provided the highest conversions of LMA and the best controlled polymerizations. These optimized conditions allowed for the synthesis of poly(lauryl methcarylate)s with different targeted DP (25, 50, 75, 100, 120 240, and 500) including high-molecular-weight polymers with narrow molecular weight distributions. In addition, methacrylate monomers were prepared from fatty alcohols (capric, myristic, palmitic, stearic) and polymerized using the developed procedure to obtain polymers With the same DP and different chain lengths (C-10, C-12, C-14, C-16, and C-18) of pending alkyl groups. Finally, the thermal properties of these polymers were examined by differential scanning calorimetry and thermogravimetric analysis.