Thermal Insulation Materials Based on Polyurethane Foam Filled With Basalt Fiber

The paper presents research aimed at increasing the thermal insulation properties, as well as reducing the flammability of polyurethane foams through the use of basalt fiber treated with a water-polyurethane dispersion. The content of basalt fiber was selected, as well as the parameters for its processing with a water-polyurethane dispersion, providing an optimal set of physical and mechanical properties, as well as reducing the flammability of rigid polyurethane foam samples. It was revealed that modification of the surface of basalt fiber leads to an increase in the adhesion of the filler to the polymer matrix. When using modified crushed basalt fiber, the strength of polyurethane foam increases, the compressive stress remains at the level of polyurethane foam with unmodified basalt fiber. Modification of basalt fiber using a water-polyurethane dispersion makes it possible to increase the filler content in the polymer without reducing the strength properties. Also, treating basalt fiber with a water-polyurethane dispersion has a positive effect - the burning rate decreased from 387 (for an unfilled analogue) to 70 mm/min (30% wt. filling with basalt fiber, treated with a water-polyurethane dispersion). Also, when using modified basalt fiber, the moisture absorption of the heat-insulating composition is reduced. It has been established that samples of rigid polyurethane foam with basalt fiber in an amount of 20 wt.% have the best complex of physical and mechanical properties. The strength properties of the material increase with a slight increase in its density. Basalt fiber reduces the flammability of materials using it by 4.7 times (with a basalt fiber content of 30% wt.) and, unlike fire retardants, does not produce toxic combustion products while maintaining a set of technological and physical-mechanical characteristics of rigid polyurethane foam. Modification of basalt fiber using a solution of water-polyurethane dispersion improves technological properties - ease of introducing basalt fiber into the composition, lack of sticking and clumping. At the same time, the strength indicators, fire resistance and water absorption of rigid polyurethane foam are slightly increased. The resulting polyurethane foams filled with basalt fiber from 10 to 30% wt. have high physical and mechanical properties and a relatively high degree of fire protection. The best fire resistance indicators are found in samples filled with basalt fiber in an amount of 30% wt.