The effect of the polymer network structure on methanol transport dynamics in glassy polymers was investigated in both dry and plasticized disks of poly(methyl methacrylate) (PMMA) through gravimetric integral sorption studies. PMMA was synthesized by a controlled free radical polymerization mechanism, crosslinked in bulk with ethylene glycol dimethacrylate, and swollen in methanol under a variety of conditions. In the Case II transport regime, control over the transport rate was shown to depend on the glassy-state properties of the polymer, and the Case II front velocity was found to be proportional to the square root of the crosslinking density. Similarities were observed in the penetrant transport behavior of both dry and plasticized samples at high degrees of crosslinking, and the activation energy of methanol transport at low degrees of crosslinking was found to be similar for both Fickian and Case II mechanisms. (c) 2011 American Institute of Chemical Engineers AIChE J, 2012