I don't work in polymer science, so I don't know the state of the field or who the really big names are. But, I work across the hall from the McNeill and Matzger research groups at the University of Michigan. McNeill has won several awards for her research on gradient copolymers and her students are doing well. Matzger is a little bit more solid-state, working on metal-organic frameworks and energetic materials (explosives), but his science is very closely related to polymer science (MOFs are 3-dimensional "coordination polymers").
My advice to you in looking for a graduate program is to find one that has at least one other area you'd like to work in. Labs can sometimes get competitive, and if you come to a school that has only one lab you're even remotely interested in and then you don't get in, you're stranded. Just something to consider. Good luck!