Abstract: Disclosed in the present invention is a benzocrown ether graft polymer with a lithium isotopic separation effect and a preparation method thereof. The polymer is a benzocrown ether graft polymer formed by the linkage of chemical bonds, which takes the main chain of a polymer containing chloromethyl group, chloroformyl group or hydroxyl group as main chain, and takes a benzocrown ether as pendant group.

Abstract: Disclosed in the present invention is a benzocrown ether graft polymer with a lithium isotopic separation effect and a preparation method thereof. The polymer is a benzocrown ether graft polymer formed by the linkage of chemical bonds, which takes the main chain of a polymer containing chloromethyl group, chloroformyl group or hydroxyl group as main chain, and takes a benzocrown ether as pendant group.

Abstract: A composite catalytic membrane applied to catalytic esterification and preparation method thereof are provided. The composite catalytic membrane is porous, and includes nonwoven fabric as base membrane and catalytic coating which is formed on the surface of nonwoven fabric and in the pores and gaps between the nonwoven fabric fibers. The catalytic coating uses solid acid as catalyst and polymer or modified sulfonated polymer as membrane-forming material. The membrane is formed by coating or immersion method, and the composite catalytic membrane is obtained by cross-linking after forming. The greenization and high efficiency of catalytic esterification and preparation of biodiesel can be achieved owing to the microporous structure and huge specific surface area of the composite catalytic membrane. The composite catalytic membrane has high mechanical strength, good reproducibility and stability and easily enables continuous repetitive production of catalytic esterification.