Study of photo aging of amorphous polymer nano composites

The objects of study were atactic PMMA and polystyrene with molecular weights M = 8 × 104 and 105, respectively, nano carbon materials fullerenes C₆₀ and C₇₀ with a chemical purity of 99.7%, an aromatic solvent bromobenzene (Br B) of ^chemically pure grade. Nano composite films were obtained from mixed solutions of polymers and fullerenes in Br B at 20 deg C, the concentration of fillers in composites was varied in the range C = 0.1-10%, the thickness of films was 15-80 μm. The samples were exposed to double-sided irradiation from a cold UV light source, the sample-source distance was 15 mm, the irradiation time was varied in the interval t = 0-400 h. The state of sample surface, the distribution of nanoparticles in them was studied on a polarizing microscope. UV and IR absorption spectra were recorded on UV-1800 and IR affinity-1 spectrometers, respectively. The weight loss of the initial and composite films under UV irradiation was determined on electronic analytical balance. X-ray diffraction studies of samples were carried out on DRON-2 and KRM-1 installations using nickel-filtered copper radiation. Thermographic studies of composites were carried out on at heating and cooling rate of 10 deg C / min, the mechanical properties of samples were studied on a standard tensile testing machine Rm-1 at a lower clamp movement speed of 12 mm / min. The above methods were used to study changes in the structure and properties of amorphous PMMA and polystyrene nano composites in the field of UV irradiation. It is shown that during photo aging, anomalous changes in the structure, mechanical and thermal properties of composites are observed. (author)