Special Applications

Abstract

Synthetic copolymers have both molecular weight (MW) and chemical composition distributions. Copolymer molecules of the same molecular size, which are eluted at the same retention volume in SEC, may have different MWs in addition to different compositions. This is because separation in SEC is achieved according to the sizes of molecules in solution, not to their molecular weights. Therefore, determination of accurate values of MW averages and a molecular weight distribution (MWD) for a copolymer by SEC is limited to cases where the copolymer has a homogeneous composition across the whole range of molecular weights.