Poly(tert-butyl methacrylate) (PBMA) macromononer with one vinyl end group per polymer chain was synthesized by using free radical polymerization in the presence of 2-mercaptethanol and end capping reaction with p-chloromethyl styrene．The PBMA macromonomer was selected as reaction stabilizer to prepare core-shell polymeric microspheres. The PBMA grafted polyacrylamide (PAm-g-PBMA) microspheres were obtained by dispersion copolymerization of acrylamide (Am) with PBMA macromononer using 2

2′-azobis (N

N′-dimethyl-eneisobutyramidine) (VA) as a free radical initiator in the presence of N

N′-bismethyleneacrylamide (Bis-A) as crosslinking agent in the different ethanol／water mixed solvents at 60℃ for 24 h．Also

the poly(methylacrylic acid) graft polyacrylamide (PAm-g-PMAA) microspheres were obtained by hydrolysis of PAm-g-PBMA microspheres in HCl. The monodisperse polymeric microspheres were studied by using transmission electron microscopy (TEM) and laser light scattering (LLS)．It was found that the microspheres have a hydrophilic core and a hydrophobic shell based on the analysis results of X-ray photoelectron spectra. The morphology and diameter of the microspheres can be controlled by changing reaction conditions such as the volume ratio of ethanol to water

the molecular weight of PBMA macromononer

the mole ratio of Am to PBMA macromononer and Bis-A concentration in feed. lt was found that the PAm microspheres can be swollen in water greatly and their size distribution remains narrow.