Чем и как растворить Полиэтилентерафталат (ПЭТФ)?...

При комнатной температуре - НИ В ЧЕМ.. .
При температурах выше 100 °C полиэтилентерефталат гидролизуется растворами щелочей (наиболее распространенный в промышленности способ) , растворим в фенолах и их алкил- и хлорзамещенных, анилине бензиловом спирте, хлороформе, пиридине, дихлоруксусной и хлорсульфоновой кислотах и др. А при 200 °C ПЭТФ гидролизуется даже водой...

Вот нашел, что при 25 град в какой-то бяке растворяется.

Encyclopedia of Polymer Science & Technology (Wiley):
As a step-growth polymer made under equilibration conditions, PET has a molecular weight distribution very close to the theoretical value of 2.0. The Mark–Houwink equation relates the intrinsic solution viscosity [] to the molecular weight as [] = KMv, where Mv is the viscosity average molecular weight and K and are the Mark–Houwink coefficients determined experimentally for individual solvents. The usual solvents historically used for PET are 60/40 w/w phenol/tetrachlorethane (P/TCE) and 2-chlorophenol (OCP). Neither solvent system is entirely satisfactory and better results have been obtained using either hexafluoroisopropyl alcohol (HFIP) or a 50/50 v/v mixture of HFIP and pentafluorophenol (PFP) at 25°C (63). Although expensive, these acidic fluorinated solvents readily dissolve even highly crystalline samples of PET at moderate temperatures, thus avoiding the degradation problems commonly encountered with the older solvents at high temperatures. Thus the results are more likely to be reliable, since degradation under normal conditions is minimal.