Influence of pH/Salt Concentrations on Tuning Lower Critical Solution Temperature of Poly(NIPAAm-co-DMAA-co-DTBAVA) Multi-Environmentally Terpolymer

New series of thermo-pH multi-responsive terpolymers were fabricated. Cationic acrylate monomer was synthesized and named by [2-((ditert-butylamino)methyl)-4-formyl-6-methoxyphenyl acrylate] and abbreviated as (DTBAVA). H-1 NMR and C-13 NMR investigated the new compounds and FT IR. The new terpolymers were fabricated by the free radical polymerization of N-isopropylacrylamide NIPAAm, 10 mol% N, N-dimethylacrylamide and 5, 10, and 20 mol% DTBAVA. The investigation process involved the chemical method such as H-1 NMR and FT IR; physical methods for the solid terpolymers as glass temperature by DSC, polymer degradation by TGA, and polymer crystallinity via XRD. GPC was performed for molecular weights and dispersity; contact angles for identifying the hydrophilic or hydrophobic terpolymers solutions. The lower critical solution temperatures T-c,T-s and cloud points C-p 's of terpolymers were recorded considering the impact of pH solutions and the concentrations of different sodium salts of (SO4-2, Cl-1, and SCN-1) in the Hofmeister series; turbidity measurements were used via UV/vis spectroscopy and micro-DSC. In a new optimization study, we will use these terpolymers in the post-polymerization with biomolecules such as chitosan, protein, and amino acids via Schiff base. [GRAPHICS] .

Automated summary

A new series of thermo-pH multi-responsive terpolymers were synthesized by free radical polymerization. The terpolymers were characterized using various techniques including H-1 NMR, C-13 NMR, FT IR, DSC, TGA, XRD, GPC, contact angle measurement, UV/vis spectroscopy, and micro-DSC. The impact of pH solutions and different sodium salts on the properties and phase transition behavior of the terpolymers was investigated. The terpolymers were also used in post-polymerization reactions with biomolecules such as chitosan, protein, and amino acids.