An amiphiphilic phosphorylcholine based copolymer (PMC) bearing hydrophilic phosphorylcholine (PC) and hydrophobic cholesteryl (Chol) side groups was designed and prepared by free radical polymerization. It was used to modify the hydrophilic feature of the surface of microporous polypropylene hollow fiber (PPHF) membrane using another phosphorylcholine based copolymer PML (containing n-dodecyl hydrophobic side groups) as control.1H-NMR and DSC were used to determine the chemical structure of the obtained phosphorylcholine based copolymer. The surface chemical composition was measured by X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance infrared spectroscopy (ATR-IR). The hydrophilicity of the modified membranes and reorganization behavior of surface functional groups were characterized by static and dynamic contact angle

respectively. The results showed that the ratio of the monomer units in the amphiphilic random copolymers were similar to the ratios in feed. The melting temperature of PMC (190.5 ℃) was much higher than that of PML (90.3 ℃). Compared with the virgin PPHF membrane surface

the static water contact angle of PMC-PPHF was greatly decreased from 117 to 44. Moreover

when PMC-PPHF was heated at 100 ℃ for 2 h and placed in air at room temperature for 8 months

respectively

the water contact angle and the relative amount of P element almost did not change

which indicated the improved surface stability in comparison with PML-PPHF.