Functionalization of lignin: Synthesis of lignophenol-graft-poly(2-ethyl-2-oxazoline) and its application to polymer blends with commodity polymers

Lignophenol (LP)-graft-poly(2-ethyl-2-oxazoline) (POZO) was prepared to reuse lignin, an industrial waste material, and to produce novel LP-based polymer blends with poly(vinyl chloride) (PVC), poly(bisphenol A carbonate) (PC), polyvinylpyrrolidone (PVP), and polystyrene (PSt) as commodity polymers. The resulting graft polymer was soluble in various types of organic solvents such as chloroform, THF, acetone, and methanol, unlike LP. The miscibility of LP-graft-POZO with commodity polymers was measured by differential scanning calorimetry (DSC) to determine the glass transition temperatures (Tg). In the cases of the blends of LP-graft-POZO with PVC, PC, and PVP, the Tg values decreased during the second scan. Moreover, in the cases of the blends with PVC and PVP, the Tg values were not detected during the third scan. Therefore, it was inferred that LP-graft-POZO was miscible with PVC, PC, and PVP while forming single phases; in particular, the blends of LP-graft-POZO with PVC and PVP exhibited a secondary miscibility because the Tg values were not detected. Furthermore, the blend of LP-graft-POZO with PC exhibited better thermostability than LP and LP-graft-POZO. These results indicated that LP blended with POZO could be used as a polymer additive and as an adhesive to combine different polymers, organicinorganic polymers, etc. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012