Development of green/biodegradable polymers for water scaling applications

Abstract

The usage of green polymers are widely increased from day-to-day as detergent builders, paper-sizing agents, flocculants, thickeners, emulsifiers, and scale inhibitors due to their friendly nature with the water systems. Minimizing the formation of inorganic scale deposits in processing industrial waters presents a challenge for water treatment systems. In the present investigation, we have developed water soluble green polymers based on malic acid (MA) and citric acid (CA) through a bulk-melt condensation process and applied as water scaling inhibitors. The copolymer of poly(malic acid-citric acid) (PMC) was synthesized by varying the ratio of MA and CA monomers with 1:3, 1:1, and 3:1, and studied their descaling property with carbonate, sulfate and phosphate ions. The scale inhibition property of the homopolymers was also investigated and compared with the copolymers. As the ratio of CA was increased in the copolymer formation, there was a greater influence on the scale inhibition. Interestingly, copolymers showed the highest phosphate inhibition (98%) and have no significant change with its homopolymers. The results indicate that the synthesized green copolymers PMC were water soluble, biodegradable, non-toxic and hence, have a good water descaling property without disturbing the taste, quality and purity of water. Characterization techniques such as Fourier Transform Infrared Spectroscopy (FTIR) analysis and Thermal Gravimetric Analysis (TGA) were performed in order to understand its thermal properties and copolymer confirmation.