ДОСЛІДЖЕННЯ ЕКСПЛУАТАЦІЙНОЇ СТІЙКОСТІ, ВОГНЕБЕЗПЕКИ ТА ТЕХНОЛОГІЧНОСТІ ГІБРИДНИХ СИНТАКТНИХ КОМПОЗИТІВДЛЯ МАЛОТОННАЖНОГО СУДНОБУДУВАННЯ

o comprehensively assess the durability, fire-safety performance, chemical resistance, and manufacturability of hybrid syntactic composites based on an elastic polyurethane matrix containing mineral (expanded perlite) and organic (expanded polystyrene) fillers, and to substantiate their application in small-vessel structures. Method. A comparative experimental study of the physicochemical and service properties of the composites was performed. Continuous UV irradiation was used to assess atmospheric ageing; prolonged exposure to aggressive media to evaluate chemical resistance; and direct exposure to an open flame to determine self-extinguishing behaviour and the nature of the residual protective framework. Manufacturability was assessed through high-speed CNC milling, mechanical fastening tests, and contact moulding with ED-20 epoxy resin. Results. The elastic polyurethane matrix was found to form a protective surface skin that limits UV degradation, while perlite provides an additional shielding effect. All investigated formulations demonstrated high resistance to salt water and alkalis. The mineral-filled composite exhibited virtually complete inertness to hydrocarbons, whereas in the polystyrene-filled composites the polymer shell prevented direct contact between gasoline and the filler. Fire tests showed the formation of a protective char layer and self-extinguishing behaviour in the organic-filled formulations; the high perlite content formed a non-combustible mineral framework. Mechanical machining caused no significant filler chipping, while strong adhesion to ED-20 enabled the fabrication of monolithic sandwich panels. Scientific novelty. For the first time, a causal relationship was established between filler type in an elastic polyurethane matrix and the functional survivability of the composites under the synergistic action of aggressive marine-environment factors. Practical importance. The results substantiate differentiated use in small-vessel construction: organic-filled formulations are suitable for lightweight, highly elastic hull elements, whereas the mineral-filled formulation is recommended for insulating inter-hull spaces in machinery and boiler rooms, fuel compartments, and adjacent barrier zones.