Acid Photo Etching Effect of Epoxidized Natural Rubber (ENR) and Polyvinyl Chloride (PVC) as Polymer Binder

Abstract

Epoxidized natural rubber (ENR) and polyvinyl chloride (PVC) were used as polymer binders in immobilizing TiO2 on glass substrate by using the dip-coating technique. Acid photo etching process was applied to the immobilized TiO2/ENR/PVC (TEP) samples to determine the reaction and surface transformation with the presence of hydrochloric acid (HCl). The photocatalytic activity of the prepared immobilized TiO2/ENR/PVC samples was examined on the degradation of reactive red 4 (RR4) dye under a 65 W compact fluorescent lamp. All immobilized TiO2/ENR/PVC samples under the acid photo etching process (TEP A) expressed higher photoactivity in comparison with to photo etching process (TEP P). TEP A50 (acid photo etching for 50 h) sample has shown the highest photocatalytic degradation where the pseudo 1st order rate constant (k) value was ca. 0.0694 min-1. However, it is not considered as an optimum sample due to the peel-off effect. Therefore, the optimum sample for the acid photo etching process was TEP A40 (acid photo etching for 40 h) with 0.0553 min-1. TEP A40 is 2 times faster as compared with the photoetched immobilized TiO2/ENR/PVC (TEP P), which is primarily due to the surface transformation and formation of C-OH bond from crosslinking reaction of the polymer binder with the HCl as verified from the FESEM and FTIR analysis.