POLY(OXYETHYLENE)S TERMINATED AT BOTH ENDS WITH PHOSPHONIUM ION END-GROUPS .2. PROPERTIES

Poly(oxyethylene)s with number-average degrees of polymerization (DPn) ranging from approximate to 6 to approximate to 80, terminated at bot h ends with phosphonium ion end groups (diionic poly-EO), have been pr epared and characterized as described in the preceding paper. Viscosit ies of diionic poly-EO were measured, both in solution and in bulk. In chloroform solution, at low concentration (< 1 g/100 mL), the viscosi ty of diionic poly-EO was lower than the viscosity of nonionic (termin ated with HO-groups) poly-EO of the same DPn. At higher concentrations , the viscosity of diionic poly-EO exceeded that of nonionic poly-EO a nd increased sharply with increasing concentration. At the constant we ight concentration of approximate to 4 g/100 mL, the viscosities of sh ort-chain diionic poly-EO were higher and those of longer chain diioni c poly-EO were lower than the viscosities of the nonionic poly-EO of t he same chain lengths. These results were attributed to a predominant intramolecular aggregation of terminal ionic groups at low concentrati on of ionic groups in solution and predominant intermolecular aggregat ion at higher concentration of ionic groups. The results of bulk visco sity measurements as well as the results of differential scanning calo rimetry measurements of the dependence of the glass transition tempera ture on the DPn of diionic poly-EO indicated that in bulk physically c ross-linked networks were formed, due to intermolecular aggregation of terminal ionic groups.