Mesylated lignin, preparation

Reaction of the mesylated lignin prepared in step 1 (Fig. 1) with the polystyryl carbanion (living polystyrene) from step 2 (Fig. 2). The carbanion displaces the mesylate groups on the lignin in a nucleophilic displacement reaction with the formation of the polystyrene-lignin graft copolymer (Fig. 3). 

Preparation of the Living" Polystyrene. 18 g of the living polymer was prepared by standard anionic polymerization using n-butyl lithium. The reaction was carried out by the dropwise addition of 20 ml of styrene to 5 ml of the initiator solution in 150 ml of neat THF at -78°C. The styrene drip was adjusted to take approximately 30 min for completion and then the reaction was allowed to stir for two hours before the grafting reaction with mesylated lignin was carried out. The number average molecular weight of the polystyrene, as determined by HPSEC, was 9500 with polydispersity of 1.2. 

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