BIOSTABLE VEGETAL COMPOSITE FOR THERMAL INSULATION

Abstract

Composites of different composition and structure have been obtained on the basis of crushed porous stems of Sosnovsky's hogweed modified with borazote for biostability with the use of organopolymer binders. The particle size of the plant material varied from 1 to 10 mm. Polyvinyl acetate, polyurethane, and casein were used as binders. The ratio of the components (vegetable raw material: polymer) in the composites was 3:1 by mass. Biostability and thermophysical properties of the composites obtained were investigated by applying appropriate GOST methods. It was established that the preliminary modification of vegetable raw material particles with monoethanolamine (NB)-trihydroxyborate provides 100% biostability of composite materials based on used raw materials and organopolymer binders. The use of the above modifier is equally effective for all composites obtained using different types of binders: polyurethane, polyvinyl acetate, and casein. The composites obtained on the basis of modified plant raw materials and organopolymer binders are heat-insulating materials characterized by appropriate coefficients of thermal conductivity and density. Composites based on polyurethane binders have lower thermal conductivity compared to composites based on polyvinyl acetate and casein binders and belong to class A. The polyurethane binder provides the resulting composites with a particle size of 5 mm with an increased compressive strength as compared to the composites based on polyvinyl acetate and casein binders. Thus, the optimal composition of biostable heat insulating material is the composition based on modified plant raw materials with a particle size of 5 mm and polyurethane binder.