A comparison of the film forming ability of methyl methacrylate (MMA)/butyl acrylate (BA) latex copolymers stabilised by either a reactive or a non-reactive steric stabiliser are reported. The study indicates the effects of constraining the stabiliser and change of the length of the hydrophilic ethylene oxide chain on the coalescence process. Segregation and diffusion of the stabiliser from the interfacial layer into the surrounding media influences both the rate of the coalescence process and the final physical properties of the films formed. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) are used to indicate the mechanism of the coalescence process and identify differences between the behaviour of these two systems. The final surface structure of the films was investigated using atomic force microscopy (AFM) and revealed the extent to which coalescence of the latex particles in the surface had occurred.