FILLERS ON THE SILICA BASE FOR POLYMER COMPOSITES FOR CONSTRUCTIONAL PURPOSES

The finding a filler for the creation of polymer composite (PC) for constructional purposes, which is able not only for improving the level of polymer matrix properties, but also significantly for reducing its price was conducted. It was determined that such fillers are silicas of various modifications, which due to the developed surface and active "silanol" groups on it are capable of physical and chemical interaction with the polymer matrix. The most common industrial brands of silicas, such as aerosil, white soot and silica gel were selected for research. As a result of microscopic investigations it was obtained, that particles of silica of such brands as aerosil and white soot, both in the initial form and in the polymer matrix are actively aggregated, and create agglomerates up to tens of microns. This phenomenon is not observed when using silica gel. Therefore, it is more appropriate to be used as the fillers for PC for construction purposes than other investigated materials. The method of synthesis of silica gel with a high degree of chemical purity was presented. Comparative investigations of the physico-mechanical, thermophysical and tribotechnical properties of constructural polymer composites, based on aromatic polyamide, filled by industrial and synthesized silica gel were performed. It was obtained that PCs with synthesized silica gel have higher level of properties than industrial ones. This is due to the fact that the primes presented in industrial silica gel reduce its reinforcing effect on the polymer matrix and adversely affect the friction process during the friction interaction of the obtained PC with steel.