AMIDE-MODIFIED POLY(BUTYLENE TEREPHTHALATE) - POLYCONDENSATION

The synthesis of poly(ester amide) copolymers (PBTA) based on poly(but ylene terephthalate) (PET) and nylon-4,T with the diamide of butanedia mine and dimethyl terephthelate (N,N'-bis(p-carbomethoxybenzoyl)butane diamine) has been carried out. Different melt and solid state condensa tion reactors ro of amide units (PBTA20/PBTA25) were used. The polycon densation of PET and PBTA with 20-25 mol% was carried out in the melt at 255-265 degrees C under high vacuum. The inherent viscosity eta(inh ) the amino and carboxylic acid endgroup concentrations and the meltin g temperature (T-m) were determined. The influence of diamide purity a nd concentration of Ti catalyst (0.02-0.28 mol%) was studied. The conc entration of Ti catalyst had little effect. The purity of the diamide had an effect on eta(inh) but also on T-m. Postcondensation in the sol id phase, 20 degrees-30 degrees C below T-m, was most effective after short melt polymerization times. Copyright (C) 1996 Elsevier Science L td.