Room temperature curing polyurethane encapsulating material and preparation method thereof

The invention discloses a room temperature curing polyurethane encapsulating material and a preparation method thereof. According to the invention, hydroxyl components are distributed in two components, and a hydroxyl-terminated polybutadiene polyurethane encapsulating material is prepared by using a compound chain extender, wherein the chain extender is a mixture of two or more of ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, 3,5-dimethyl thio-toluene diamine, N,N'-di(2-hydroxypropyl) aniline, and 2,4-diamino-3,5-dimethylthio chlorobenzene, and the like, the tensile strength is over 14 MPa, and in salt fog and hygrothermal environments, the retention ratio of mechanical properties is high. According to the invention, the method adopts a half pre-polymerization process, so that the viscosities of two components are similar, and the two components are mixed more easily; and the encapsulating material is simple in preparation process, quick in forming, good in flowability, and less in surface blowholes of products.