SYNTHESIS AND PROPERTIES OF FIBER-GRADE POLY(TRIMETHYLENE TEREPHTHALATE)

Poly(trimethylene terephthalate) was synthesized on a semi-technical s cale following the trans-esterification route. Ester exchange as well as polycondensation were catalyzed by titanium tetrabutylate. The poly mer formed shows a remarkable degree of whiteness, contrary to poly(et hylene terephthalate) when synthesized with the aid of titanium compou nds. Polymers having molar masses up to 70000 (weight average) were ob tained suitable for melt spinning. The Mark-Houwink parameters for sol utions in 1,1,2,2-tetrachloroethane/phenol (1:1, w/w) were determined using static light scattering as a calibration, The melt volume index (235 degrees C, 1.2 kg) was typically in the range 20-30 mL/10 min for a polymer having a weight-average molar mass of 50 000 - 60 000 g mol (-1).