Latex-based butyl acrylate (BA)/acrylic acid (AA)/2-hydroxyethyl methacrylate (HEMA) pressure sensitive adhesive (PSA) films with various microstructures were heated to improve their performance. The treated PSA films showed significantly better performance than original latex-based PSA films with similar polymer microstructures. The effect of the heat treatment depended on the polymer microstructure of the untreated PSA films (or corresponding latices). Decreasing the amount of very small sol polymers (i.e., M-x < 2M(e)) in gel-free untreated PSA films, or both very small (i.e., M-x < 2M(e)) and very large sol polymers (i.e., M-x > 20M(e)) in gel-containing untreated PSA films led to treated PSA films with significantly better performance. (Note: M-e is the molecular weight between two adjacent entanglement points in a polymer material.) In addition, simultaneously increasing the sol polymer molecular weight (M-w) as well as the size of the chain segments between two adjacent cross-linking points (M-c) of the gel polymer in the original PSAs resulted in treated PSA films with better performance. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012