Phosphoric Acid → Terephthalic Acid

Participants

Reaction Steps

A 1-liter resin kettle was provided with a Jiffy Mixer stirring agitator with an Electro-Craft Motomatic constant speed controller, a heater, a thermocouple, condenser and nitrogen sweep. To this kettle was added 0.2 g of the TiO1.5 catalyst, 115 ml of ethylene glycol, 6.23 μl of concentrated H3PO4, 0.3 wt % passivated TiO2 delusterant and 400 g of a low molecular weight ethylene terephthalate oligomer formed from ethylene glycol and terephthalic acid. The mixture was stirred at 280° C. at 60 rpm and vacuum of less than 1 torr (133 Pa) for 120 minutes at which time the supply voltage to the vessel's agitator control, an indication of the torque applied to the agitator and therefore of the viscosity of the reactants, reached a limiting value of 150 mv, upon which the polymer was poured into cold water to quench the polymerization. The polymer solid was annealed for crystallization at 150° C. for 12 hours and ground to pass through a 2 mm filter screen for color measurement using a Hunter calorimeter. The polymer color numbers were 69.48 L, -0.91a, 3.08b. The polymer inherent viscosity is 0.58 dL/g, the weight average molecular weight is 27,100 and the Z-average molecular weight is 41,500.

Provenance & Evidence