Chemical/photochemical functionalization of polyethylene terephthalate fabric: effects on mechanical properties and bonding to nitrile rubber

The aim of this work is to compare the effects of chemical and photochemical functionalization on the mechanical properties of PET fabric and its adhesion to nitrile rubber (NBR). The photochemical functionalization was performed by UV irradiation of PET fabric in the presence of glutaric acid peroxide at a temperature of 60 °C for different exposure times (i.e. 60, 90 and 120 min). The chemical functionalization (i.e. hydrolysis) of PET fabrics was performed by NaOH solution at a temperature of 60 °C for different times (i.e. 60, 120, 240 and 360 min). The tensile properties of the functionalized fibers were also evaluated. The functionalized PETs were evaluated for H-pull and T-peel adhesion to NBR. It was found that both treatment methods created functional groups on the PET surface. However, carboxylation of PET under GAP/UV irradiation generated much more OH groups on the PET surface (i.e. 4.5 times). The hydrolysis of PET in NaOH solution for more than 60 min caused a significant decrement in the tensile strength contrary to carboxylation under GAP/UV irradiation. It was also found that pullout and T-peel adhesions to NBR decreased in the case of hydrolysis of PET while they increased about 33 and 12% for GAP/UV irradiated PET, respectively.