AbstractAn automated, solid‐state small‐angle light scattering apparatus has been constructed for the investigation of polymers; the main features of this system are a bidimensional CCD (charge coupled device) detector with 12‐bit resolution and custom‐made, user‐friendly software for the acquisition and treatment of the scattering data. The miscibility and phase separation kinetics of several bisphenol‐A polycarbonate/poly(methyl methacrylate) blends have been investigated using this apparatus. It was found that the rate of phase separation can be altered significantly by replacing part of the polydisperse poly(methyl methacrylate) (PMMA) in the blends by monodi