abstract
Post-consumer poly(ethylene therephthalate) (PET) obtained from milled w ater bottles was chemically
degraded by glycolysis, using suitable amounts of diethylene glycol (DEG) and Ca/Zn stearate as catalyst
system. The process was carried out by employing a melt mixer as the chemical reactor, which is the
facility generally used for plastic compounding. The degraded PET products were first characterized from
structural and thermal point of view by Fourier transform infrared spectroscopy (FTIR), Proton nuclear
magnetic resonance (
1
H NMR), Size exclusion chromatog raphy (SEC) Differential scanning calorimetry
(DSC) and Thermogravimetric analysis (TGA), and thereafter used alone or together with
di(2-ethylhexyl) phthalate (DEHP) in poly(vinyl chloride) PVC formulations. The plasticization was, in
fact, accomplished by using a binary system consisting of DEHP as primary plasticizer and a degraded
PET product as secondary plasticizer (SP). The obtained materials were characterized through the main
methods used to assess flexible PVC compounds: hardness in Shore A scale, thermal properties and
quantitative migration of the plasticizer. The solid secondary plasticizer obtained from post-consum er
PET improves both the proce ssing characteristics and the thermal stability of the final flexible PVC
compounds while maintaining their hardness within the top values of the Shore A scale. In addition, a
considerable reduction of the plasticizers migration (23%) was obtained by optimizing the formulation.