MECHANICAL CHARACTERISTICS OF SEALANTS BASED ON POLYURETHANE LIGNIN POLYBLENDS

Previously, different characteristics such as curing, morphology, misc ibility and swelling have been evaluated in studies of polyurethane-li gnin polyblends. In the present paper the mechanical properties of the same polyblends are investigated and compared with those of polyureth ane filled with some mineral fillers. The effect of these fillers and lignin on the polyurethane sealant curing kinetics and the effect of t heir packing characteristics on the mechanical properties are consider ed and discussed. The research showed that the addition of mineral fil lers or different kinds of lignins increases the Young modulus. The en hancement of the mechanical characteristics is more evident for Sillit in/Titanox (clay/TiO2) filled polyurethane than for lignin filled poly urethane. This mineral filler combination increases both stress and st rain, which is attributed to its finer average particle size.