Synthesis of polystyrene microgel with glucose as hydrophilic segment via controlled free-radical polymerization

4-Vinylbenzyl glucoside peracetate (1) was copolymerized with divinylbenzene (DVB) using I-phenyl-1-(2',2',6',6'-tetramethyl-1'-piperidinyloxy)ethane (2) as an initiator in in-xylene at 138 degrees C for 20h ([DVB]/[2]=28; [DVB]=0.62mol L-1). The copolymerizations were performed using the mole fraction of I in the total feed of I and DVB (F-1: [1]/[1] + [DVB]) ranging from 0.11 to 0.38 that produced the polystyrene (PSt) microgel with acetyl glucose, 3, in 46-53% yields. Dynamic laser light scattering (DLS) measurements showed that 3 was stably suspended in toluene as particles with average diameters (d's) ranging from 12 to 22 nm. A static laser light scattering (SLS) measurement gave the average molar mass, M-w,M-SLS, of 3 that ranged from 9.69 X 10(4) to 6.96 X 10(5). The numbers of the 1, 2, and DVB units in 3 (N-1, N-2, and N-DVB, respectively) were from I I I to 238, from 17 to 208, and from 350 to 45 10, respectively. The deacetylation of 3 was achieved by treatment with sodium methoxide in dry 1,4-dioxane to produce the PSt microgel with glucose as the hydrophilic segment, 4. The solubilities of 4 in toluene, CHCl3, THF, 1,4-dioxane, pyridine, DMF, DMSO, and H2O, and the mixture of H2O and 1,4-dioxane were examined, indicating that a hydrophilic property had been effectively introduced into 4. (c) 2006 Elsevier Ltd. All rights reserved.