Considering the difference of shape and dipole of side groups

the modified formulas of mean-square dipole moment and mean-square radius of gyration of the poly(alkyl acrylate) s chains were deduced by the conformational-configurational statistic theory and the generator matrix method

and they were used to investigate the conformational dependent properties of ploy(methyl acrylate)(PMA) and ploy(ethyl methacrylate)(PEMA).It is found that the characteristic ratios of mean-square dipole moment of atactic PMA4(4-state PMA) and PEMA are respectively 0.63 and 0.66

and their temperature coefficients are-0.66 × 10-3 K-1 and 1.72 × 10-3 K-1 respectively.The characteristic ratios of mean-square radius of gyration of atactic PMA4 and PEMA are 1.73 and 1.43 respectively

and their temperature coefficients are-1.05 × 10-3 K-1 and-1.28 × 10-3 K-1 respectively.The obtained results are in agreement with the experiment data.Moreover

the differences of ratios between PMA and PEMA from the change of the chain tacticity and the orientation of ester group dipole are obvious.Especially for the short chains of PMA4

there are maxima of both the dipole moment and its temperature coefficient in the syndiotactic configuration.The results display that the effect of side groups on the conformational properties of poly(alkyl acrylate) s can not be neglected.