A series of preformed polymers containing amphiphilic side chains and hydrophilic spacer groups in the backbone have been investigated by grazing incidence reflection and transmission infrared spectroscopy. In the former the electric field vector is normal to the film surface whereas in the latter, it is parallel to the surface. The two measurements taken collectively have provided information about the orientation of the ordered amphiphilic side groups and the partially disordered polymer backbone. The results indicate that there is a definite preferred orientation of the side chain axis normal to the substrate surface. The extent of this side chain order is affected by both the concentration of backbone spacer groups and the temperature of the Langmuir-Blodgett (LB) layers. These effects on the long-term aging of these polymeric multilayers will be discussed. © 1989, American Chemical Society. All rights reserved.