Abstract: Considering side group structures of poly(organosilanes),unified basic formula are derived with method of configurational-conformational statistics in rotational-isomeric-state model.Characteristic ratios of mean-square radius of gyration for atactic poly(silastyrene)(PSS),polysilapropylene(PSP),poly(methylphenylsiloxane)(PMPS),poly(dimethylsilmethylene)(PDMSM) and poly(dimethylsilylene)(PDMS) chains are obtained.They are 1.45,0.63,0.97,0.69 and 1.99,and ratios of mean-square dipole moment are 2.49,0.99 0.61,0.48 and 0.27,respectively.It is found that effect of temperature,conformational energy,polymerization degree and tacticity of chains on ratios of PSS and PMPS is quite obvious.However,dependences of basic quantity of PSP and PDMSM on side groups,conformational energy and temperature are inappreciable.Dipolar large side groups in analysis flexibility and polarity of poly(organosilanes) is significant.

Key words: poly(organosilanes), configuration-conformation, side groups, mean-square radius of gyration, dipole moment