Poly(Acrylic Acid)-Bound Piperonyl/3,4-Dihydroxybenzyl Units: Metallic Adsorption And pH-Metric StudiesAuthor(s): Saad Moulay, Nadjia Khalfaoui
Optimization of the esterification of poly (acrylic acid) (PAA) with piperonyl alcohol (PA) was undertaken in dioxane. Degrees of esterification (DE) were found higher in an open system than in a closed one, 28 versus 24%, under the following conditions: [PA] [PAA] molar ratio of 1, temperature of 110°C and time of 3h. A degree of esterification of 72% was obtained for the former system at a time of 5.5 h, but only 32% was reached for the latter system, for [PA]/[PAA] of 4. Treatment of the piperonyl-modified PAA with PCl5 followed by hydrolysis afforded a copolymer of 3,4-dihydroxybenzyl acrylate and acrylic acid. pH-metric studies of PAA and modified PAA, and their corresponding systems containing Cu2+ and Cd2+ were performed using 0.1N NaOH. The adsorption extents of these two heavy metallic ions by PAA and PA-modified PAA were experimentally estimated.