The concentration dependence of the molecular association of 2,4,6-trihydroxymethylphenol (THMP) as a model compound for phenol-formaldehyde resin was studied. 13C-NMR spin-lattice relaxation time (T 1) measurements indicated that the molecular interactions were influenced by the concentration of THMP. Plots of T1 versus the concentration revealed an inflection point around 1.2 mol/L. Molecular orbital calculations of the THMP molecules implied the following features of the molecular interactions: in the concentration range below 1.0 mol/L, THMP existed as a single molecule, and then at a higher concentration, self-association started. At concentrations higher than 1.5 mol/L, almost all the THMP molecules were bimolecularly associated, and the formation of larger clusters was initiated.
All Science Journal Classification (ASJC) codes
- Surfaces, Coatings and Films
- Polymers and Plastics
- Materials Chemistry