Trisurfactantomethylol melamines: Synthesis, structural characterization and physicochemical properties of aqueous systems

Abstract

Trimethylol melamine (TMM) trifunctional core was prepared to synthesize TSMM (Trisurfactantomethylol melamine) with cationic (CTAB {Hexadecyltrimethylammonium bromide}, CPC {Hexadecylpyridinium chloride}) and nonionic (polysorbate-40 and 60) surfactants as branching material. Melamine (Me), Formaldehyde (F), Surfactant (S) in 1:3:3 ratios were used for TSMMs synthesis via condensation reaction through nucleophilic addition. TSMMs were characterized with FTIR, FT-NMR, FT-RAMAN, and TGA to depict -CH2-CH- covalent bond formation between methylol of TMM and α-C of surfactants on releasing H2O molecule. The 1001 cm−1 stretching frequency with CTAB and CPC both, and 996, 992 cm−1 stretching frequencies with polysorbates-40 and 60 for Me-NH-CH2–CH-S bond are supported by 1023 cm−1 Raman frequency and 16–27% weight loss on TGA from 190 to 405 °C. TCTMM (TriCTABmethylol melamine), TCPMM (TriCPCmethylol melamine), TP4MM (Tripolysorbate-40methylol melamine) and TP6MM (Tripolysorbate-60methylol melamine), a series of TSMMs varied with an alkyl chain (AC) of C-15 to 17 with variable head groups to attain adequate hydrophobicity and hydrophilicity. Thereby, their hydrophobic and hydrophilic interactions in aqueous solutions at 298.15 K have illustrated the structural activities of their head groups and AC with their physicochemical properties. Structural constituents of TSMMs with adequate tentropy on account of their several localized electronic sites have acted as interacting coordinates for encapsulating/conjugating activities to explore a host and guest chemistry.