Unsaturated polyester resin from glycolysed waste polyethyleneterephthalate : synthesis and comparison of properties and performance with virgin resin

Recycling of polyethyleneterephthalate (PET) bottles for soft drinks is accomplished by
depolymerization through glycolysis. Obtained intermediates are reacted with mixtures of
saturated and unsaturated acids to obtain unsaturated polyesters (UP) suitable for use as
a matrix for fibre-reinforced thermosetting composites. The influence of chemical structure
of glycols on the chemo-rheological behaviour of resins, has been verified. By using
di-ethylene glycol, the behaviour of the resulting UP closely resembles that of UP obtained
from virgin monomers. Moreover, composite sheets containing UP developed in the present
research, show enhanced toughness if compared with the analogous composite made of
virgin UP resin.