Effect of the initial oligoglycol molecular weight and filling with powdered silica on the visco-elastic properties and supermolecular structure of network polyurethanes

Abstract

An investigation to determine visco-elastic properties has been carried out for a series of polyurethanes which were prepared using polyoxypropylene glycols of differing MW, toluylene-2,4-diisocyanate and trimethylolpropane, along with those filled with different amounts of powdered silica (aerosil). The results were examined and compared with supermolecular structure. It was found that an increase both in MW of an initial oligoglycol and in the filler content resulted in the formation of a smaller globular and more uniform structure which in a regular way alters the viscoelastic properties of the polymers examined. The results obtained have been interpreted in the light of concepts concerning different rigidities of interglobular phase and globular formations, in view of which the latter may be regarded as a filler.