Süske, E. Scharf, Th.; Schaaf, P.; Panchenko, E.; Nelke, D.; Buback, M.; Kijewski, H.; Krebs, H.-U.
Variation of mechanical properties of pulsed laser deposited PMMA films during annealing
Appl. Phys. A 2004, 79, 1295-1297.
 

The structural and mechanical properties of polymethyl methacrylate (PMMA) thin films produced by pulsed laser deposition in ultra-high vacuum were investigated by infrared spectroscopy, electron microscopy, size-exclusion chromatography and microhardness measurements. After preparation, the film hardness and elastic modulus are found to be increased. This is caused by a reduced chain length of the polymer film to values of 5800 g/mol and by cross links of an amount of about 20% of the polymer, while the chemical structure of the deposited films is comparable to the target material. During annealing, relaxation processes lead to a reduction of the film hardness, without changing the cross-linked part in the samples.