Research And Application Of Aerospace Plexiglass Polyurethane Wear-resistant Protective Layer

The plexiglass(PMMA),as the main material for the transparent parts of the aircraft cockpit,is the key transparent functional structural part in the aviation aircraft.When the transparent parts of the aircraft cockpit are used in windy and sandy areas,serious wind-sand erosion occurs,which causes a decrease in transparency,and seriously affects the pilot's view and threatens the flight safety.Since the wind-sand erosion first acts on the surface of the material,the wear resistance of the plexiglass is improved by coating a high-performance polymer protective coating on the surface of the plexiglass.The transparent polyurethane material with good optical properties,heat resistance and wear resistance was selected as the protective layer material.This article is divided into two technical schemes to study the aviation glass protective layer.(1)Synthesizing high-transparent polyurethane adhesive,pasting high-transparent polyurethane film,and using it as a wind-sand resistant protective layer at the front windshield of the transparent cockpit.(2)Synthesizing polyurethane coating,adopting spray method for wind-sand resistant coating on other parts of the cockpit transparent parts.In this paper,the dicyclohexylmethane diisocyanate(HMDI),isophorone diisocyanate(IPDI),polyether glycol and polyester trihydric alcohol are selected to synthesize a highly transparent polyurethane resin with excellent optical properties,and the light transmittance can reach 92.01%.The 52Y72 resin is used as a highly transparent polyurethane adhesive to paste a transparent polyurethane film to make a protective layer,the light transmittance is91.82%.The protective layer has excellent optical properties and abrasion resistances,and the light transmittance of the protective layer remains 79.2% after the sand blowing test.And the protective layer also has excellent UV aging resistances,water resistances and humidity and heat aging resistances.The 52Z11 resin is used as the coating film-forming resin and by adding diluents,leveling agents,defoaming agents,etc.,a highly transparent polyurethane coating is prepared with a light transmittance of 91.97% is prepared.The highly transparent polyurethane coatings have excellent optical properties and abrasion resistances,and the light transmittance of the coating can still reach 75.9% after the sand blowing test.The coating has good adhesions,excellent UV aging resistances,water resistances and humidity and heat aging resistances.