STARCH-(METH)ACRYLATE GRAFT COPOLYMER, OIL-ABSORBING EXPANSION MATERIAL AS WELL AS OIL AND WATER-ABSORBING EXPANSION MATERIAL AND PACKER MADE OF SAID MATERIAL

摘要

The invention relates to a kind of starch-(meth)acrylate graft copolymer and its preparation method. Said copolymer is copolymerised from (meth)acrylate monomer and starch in a weight ratio (0.4~8):1. The graft copolymer is grafted with one or more kinds of (meth)acrylate monomer, with the starch macromolecule as the backbone, whose degree of graft is equal or more than 70%. A kind of oil-absorbing expansion material contains the starch-(meth)acrylate graft copolymer as expansion-increasing agent. Oil and water-absorbing expansion material comprises said starch-(meth)acrylate graft copolymer, water absorbent, react monomer, surfactant and matrix. A sealer and a packer, made of said oil-absorbing expansion material as well as oil and water-absorbing expansion material are also provided.