THIN-FILM BEHAVIOR OF POLY(METHYL METHACRYLATES) .2. AN FT-IR STUDY OF LANGMUIR-BLODGETT-FILMS OF ISOTACTIC PMMA

The structure of Langmuir-Blodgett films of isotactic PMMA transferred to substrates was investigated with FT-infrared techniques. From the results it is argued that at high surface pressures, the isotactic PMMA is transferred in a crystalline-like conformation, presumably as double helices. The films built of this type of Langmuir-Blodgett layers can easily be crystallized further, in contrast with films of amorphous isotactic PMMA. Infrared techniques were also used to deduce the orientational characteristics of the crystalline structures. These were found to be strongly dependent on the molecular weight and mono-layer history. Very strongly oriented, highly crystalline thin films could be prepared starting from Langmuir-Blodgett multilayers.