Determination of volumetric properties for polycarbonate at different temperature and pressure conditions

Značilnost polimernih materialov je, da so njihove lastnosti časovno odvisne. Temeljna procesa, ki se odvijata ob konstantni obremenitvi materiala, sta lezenje in relaksacija. Časovno odvisne lastnosti so pri enoosni in strižni obremenitvi za različne polimere dokaj dobro znane, malo informacij pa je na voljo o časovno odvisnih volumskih lastnostih materialov. V diplomski nalogi so obravnavane volumske lastnosti izbranega polimernega materiala polikarbonata. Meritve so bile izvedene na laboratorijski merilni napravi CEM Measuring System, kjer so bile merjene časovno odvisne volumske lastnosti pri različnih temperaturah in tlakih. Iz meritev smo določili termični koeficient linearnega raztezka, specifični volumen in volumsko voljnost materiala.One of the interesting features of polymeric materials is that their properties are time dependent. When constant load is applied to the material, two fundamental processes occur, creep and relaxation. Time dependent properties for diverse polymers are fairly known in case of single axis and shear load, however, little information is available on time dependent volumetric properties of materials. The thesis discusses volumetric properties of the selected polymeric material polycarbonate. Measurements were performed on an apparatus, called CEM Measuring System, where time dependent volumetric properties were measured at various pressures and temperatures. Thermal coefficient of linear expansion, the specific volume and bulk creep compliance were determined by analyzing and processing measurement data