Abstract
Viscosity characteristics of isotactic polystyrene were compared with those of atactic polystyrene taking account of a partly free draining effect on the intrinsic viscosity-molecular weight relationships.The results obtained were as follows.
1) A parameter Δ of isotactic polystyrene was larger than that of atactic one, where Δ was a parameter proposed in this paper as a measure of a free draining effect on an exponent a in Mark-Houwink equation.
2) A parameter (1/2-1-a1) of isotactic polystyrene was less than that of atactic polystyrene, where (1/2+a1) was a parameter proposed in this paper as a measure of an effect of volume exclusion.
3) The fact that the constants of the Mark-Houwink equation obtained for atactic polystyrene in good solvent was the same as that obtained for atactic polystyrene, which has been experimentally confirmed by many investigators, was explained taking account of the effects of free draining and volume exclusion the constants in the Mark-Houwink equation.
4) The difference in expansion factor a between isotactic and atactic polymer was due to that in thermodynamic parameter (Φ1-k1) as well as chain extension parameter (r02/M).
5) Various molecular constants of solution properties, for example those in the Mark-Houwink equation, were calculated from the theory proposed in this paper and they were compared with those in literatures.
