Poly(lactic acid) (PLA) brushes prepared by the ring opening of lactide were thicker when polymerized at a lower temperature (25 degrees C) than was typically used for polymerization in solution. The molecular weight of solution polymerized lactide was also higher when lactide was polymerized at 25 degrees C compared with polymerization at higher temperatures. However, the yield of PLA was low at this temperature. These results highlight the different requirements for solution polymerization and brush growth. In the former case, both percentage of conversion and molecular weight are important considerations. In the latter case, however, percentage of conversion is unimportant as a brush represents a very small amount of polymer. It was also shown during the course of these studies that the native hydroxy groups on silicon substrates and silanols in solution were equally good initiators when compared with hydroxy terminated self-assembled monolayers on gold and alcohols, respectively. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3362-3367, 2010