The Preparation And Properties Of Modified Polyurea Elastomer

Polyurea elastomer is a polymer which is made by the reaction between isocyanate prepolymers and amino compounds. It has excellent wear resistance, anti-slippery, anti-corrosion and other excellent physical and chemical properties. In the paper, we studied on the modified polyurea elastomer,mainly including:Spray polyurea elastomer had the bubble problem during the production, we used the chemical and physical methods to consume bubbles. Being tests, the performances of the spray polyurea elastomer after being defoamed have been improved.In order to improve the comprehensive properties, expand its scope of application and break through the limitations of the material, the paper prepared MWNTS/polyurea nanocomposites by in situ polymerization, mainly using the excellent mechanical properties of MWNTS to make up polyurea's shortage in this area.First, we used mixed acid to oxidate MWNTS to generate an amount of hydroxyl groups on the surface of MWNTS. Polyacrylic acid was covalently grafted onto the surface of MWNTS through esterification of polyacrylic acid with hydroxyl groups on the surface of acid-modified MWNTS. Through FTIR, TG, XPS,we know that amino was successfully grafted onto the surface of MWNTS.The two kinds of carbon nanotubes, raw carbon nanotubes and amino-functioned carbon nanotubes,were dispersed in amino polyether by ultrasound. Then the mixer was reacted with the isocyanato prepolymer to achieve the nanocomposites. After determination of the gel content, tensile strength test and SEM, we know that amino-functioned carbon nanotubes can be dispersed evenly in polyurea, the tensile strength of the nanocomposites increased with amino-functioned carbon nanotubes increased, and when MWNTS content was 0.7wt%, the maximum value was 58.7MPa which was 40% more than pure polyurea. The raw MWNTS can't be dispersed evenly in polyurea, the tensile strength of the nanocomposites decreased with the raw MWNTS increased. Because the amino reacted with the isocyana to produce the covalent bonds to form a interface between amino-functioned MWNTS and polyurea, and enhanced the adhesion between the carbon nanotube and polyurea. After been modified by the amino- functioned MWNTS, the mechanical propertie of the polyurea has been greatly improved and it can be used more widely.