The aim of the work is to develop a scientific basis for the directed synthesis of polymers. This goal is achieved by solving the following tasks: obtaining epoxy oligomers based on diphenylolpropane; modification of phenolformaldehyde oligomers (PFOs) with thiocarbamide; combination of epoxy oligomers with modified phenolformaldehyde oligomers and obtaining paint and varnish materials based on them. IR analysis shows that when the ratio of modified PFO to epoxy oligomer is 40:60, a significant change in the absorption frequencies of phenolic hydroxyls is observed, which indicates chemical interaction when combining oligomers. The DTA method shows that in the curve of epoxy oligomer with modified novolac are observed 2 peaks (at 60 and 100 °C), the first of which is due to the interaction of the epoxy oligomer with the modifier, and the second one with the novolac PFOsTherefore, due to the interaction of epoxy oligomer with modified PFOs, the modified epoxy novolac oligomers are formed ‒ solid, brittle materials that to a certain degree of completeness of the process retain the ability to melt and dissolve in various organic solvents and due to their polyfunctionality, they are thermosetting and transfer to a crosslinked state with further heating. Phenolformaldehyde novolac oligomers have been modified with thiourea The optimal ratio of the initial components phenol: formaldehyde: thiourea is 0.47:0.37:0.1 mol, respectively. The physicochemical characteristics of modified novolacs have been determined. - By combining epoxy oligomers with modified PFOs at 120 °C for 1.5-2.5 hours epoxy novolac oligomers have been obtained and the optimal ratio of epoxy oligomers with modified novolacs has been determined 60:40, respectively. The formation of modified thermoset ENOs is indicated by a change in the properties of the products obtained during the process. On the basis of the synthesized epoxy novolac oligomers paints and varnishes have been prepared and subjected to tests (Table 2). It has been shown that paints and varnishes based on epoxy-novolac oligomers are distinguished by good covering powder, adhesion, elasticity, weatherability and can be applied in various industries (aeronautical engineering, rocket technology, space technique, shipbuilding, automobile construction, building and construction, etc.).
Volume 12 | 02-Special Issue