A serials of acrylate monomers containing long conjugated azobenzene groups were prepared and polymerized in N

N-dimethylformamide(DMA)using 2

2'-azobis(isobutyronitrile)(AIBN)as initiator at 70℃．The monomers and polymers were characterized by FTIR

1H-NMR and UV．The molecular weights of polyacrylates were determined by gel permeation chromatography(GPC)．The third-order nonlinear optical properties of these polymers were determined by the Z—sean technique with 8 ns pulses at 532 nm

and the relationship between nonlinear optical properties and the molecular structures of substituted chromophores was investigated．The results revealed that all these polymers possessed well nonlinear absorption

and enlarging π-electron conjugated length and strengthening D-π-A push—pull capacity of side—chain chromophores of polymers will effectively enhance the third-order nonlinear optical properties of polymers．