Unplasticised (U-PVC) and modified (M-PVC) pipes used in irrigation and infrastructure applications, nominal diameter DN 300 (outside diameter 326 mm and wall thickness 13.1 mm) were evaluated according to various methodologies, including fracture toughness (KIC and GIC), essential work of fracture (EWF) and C-ring toughness. The pipes were also evaluated for the quality of processing (degree of gelation) via DSC and tensile strength. The formulations of these PVC compositions, in the case of the Brazilian market, are differentiated only by the presence of impact modifiers in the case of M-PVC pipes, added in smaller quantities than in the case of other countries that adopt this technology such as Australia, New Zealand and South Africa.
The results show that, even with impact modifiers added in minor quantities, the differences in behavior against fracture propagation are sensitive when comparing the results between the different types of pipes, opening up new possibilities for testing this product. This possibility is particularly interesting in the case of the degree of gelation evaluation, since the dichloromethane method still in use tends to be replaced by alternative methodologies due to chemical exposition factors.