Patent ID: 7417101
Filing Date: 2008-08-26
Classification: C08F

Abstract:
1. A thermal responsive, water-soluble copolymer, which is copolymerized by the following monomers: 0.5˜20 wt % of N-isopropyl acrylamide (NIPAAm); 0.5˜20 wt % of 1-vinyl-2- pyrrolidinone (VPD); 0.01˜10 wt % of acrylic acid (AA); and 80˜90 wt % of acrylamide, wherein the copolymer comprises the structure as shown in formula (I): in which, x, m, n, z are independently an integer greater than 1, and the weight concentration ratio of x:m:n:z is 0.03˜0.06:0.005˜0.19:0.005˜0.19:0.8˜0.9; and the viscosity of the copolymer is 60 to 300 cp when the thermal responsive temperature is at room temperature, and the viscosity of the copolymer is 5000 to 11000 cp when the thermal responsive temperature is increased to 70° C.