A novel amphiphilic dendron-coil macromonomer3

4

5-tri( n -hexadecyloxy)benzoyloxy polyoxyethylene methacrylate was synthesized by esterification of polyoxythylene (molecular weight M=1000) with 3

4

5-tri(n-hexadecyloxy)benzoyl chloride and followed by methacrylic chloride.The compound was then characterized by means of NMR and FTIR

elementary analysis.Moreover

a new kind of hydrophobically modified alkali-soluble emulsion copolymer (DHASE) was synthesized by emulsion copolymerization of amphiphilic macromonomer 6 with mathacrylic acid and ethyl acrylate.As a comparison

an alkali-soluble emulsion copolymer (MAAEA) of mathacrylic acid and ethyl acrylate was synthesized also.The rheological properties of DHASE and MAAEA aqueous solutions under different solid contents and pH values were studied using controlled stress rheometer.It was found that DHASE aqueous solutions had outstanding alkali-thickening and thixotropy properties and larger zero shear rate viscosity than MAAEA aqueous solutions when pH 6.8 and the solid content of copolymer 1.0 wt%.At the same time

the storage modulus G' was always larger than the loss modulus G over the entire range of frequencies for DHASE aqueous solutions

suggesting formation of physical network structure due to hydrophobic associations of dendron alkyl trails in DHASE aqueous solutions.On the contrary

the MAAEA aqueous solution exhibited Newtorian fluid behavior and its G was always smaller than G' under the same condition.The results demonstrated the potential of this novel amphiphilic dendron-coil macromonomer in hydrophobically modified alkali-soluble emulsion copolymers and associative thickeners in the future.