Poly(1,4-butylene isophthalate)s containing sodium sulfonate groups were prepared from dimethyl isophthalate, 3,5-bis(carbomethoxycarbonyl) benzenesulfonate (5SIPNa) and 1,4-butanediol. Polymers of fairly high molecular weight were obtained with a content of ionic comonomeric units up to 16.7 mol%; however, increasing amounts of 5SIPNa led to a decrease in the molecular weight and to an increase in the COOH/OH terminal-group ratio. The ionomer samples were characterized for chemical structure, terminal groups, the concentration of sulfonate groups, solubility and their thermal properties. Results from different methods of terminal-group and sulfonate-group analysis were compared. Solubility was found to be strongly affected by the introduction of sulfonate groups, and samples containing 16.7 mol% of SO3Na groups were water dispersible. D.s.c. studies on samples containing sulfonate groups, either in the free acid or sodium salt form, suggested that the effects on glass transition temperature and crystallization were due to the introduction of bulky sulfonate groups into the polymer backbone rather than to ionic interactions. Thermogravimetry showed that SO3H groups decreased the thermal stability significantly, while SO3Na groups had only a limited effect with respect to pure poly(1,4-butylene isophthalate).
Посилання на статтю:
Ion-containing polymers: 1. Synthesis and properties of poly(1,4-butylene isophthalate) containing sodium sulfonate groups / F. Pilati*, P. Manaresi, M. G. Ruperto, V. Bonora and A. Munari // Polymer. – 1993. – Vol 34. – P. 2413-2421.