Nitroxide‐mediated radical polymerization of 4‐vinylpyridine and its application on modification of silicon substrate

The poly(4-vinylpyridine) with hydroxyl end group and narrow polydispersity was synthesized by polymerization of 4-vinylpyridine by the use of nitroxide initiator based on 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl and azobisisobutyronitrile. The effects of different initiator amounts and reaction time on polymerization rate, molecular weight, and molecular weight distribution of the poly(4-vinylpyridine) were investigated at bulk polymerization. The experimental results have shown that the polymerization of 4-vinylpyridine is a controlled living free-radical polymerization; the molecular weight is proportional to reaction time; and the molecular weight and molecular weight distribution are affected by molar ratios of [4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl]/[azobisisobutyronitrile]. By varying the ratio of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl to azobisisobutyronitrile, the poly(4-vinylpyridine) with narrow polydispersity can be obtained. X-ray photoelectron spectroscopy results show that the synthesized poly(4-vinylpyridine) can be tethered on the surface of silicon wafer through the reaction between hydroxyl end of poly(4-vinylpyridine) and native silicon oxide layer on the wafer surface. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2687–2692, 2002