Fourier transform infra-red spectroscopy to determine formaldehyde to phenol ratio of phenol formaldehyde resole

A model has been proposed to determine the formaldehyde (F) to phenol (P) ratio [F/P] of resole with the help of Fourier transform infra-red spectroscopy. The study is based on the comparison of IR absorbance of the dominant peaks corresponding to the formaldehyde and phenol contents in the resin. This study can be of much use in adhesive coating industries to employ the F/P ratio as a quality tool as well as for competition resin benchmarking. It can also be utilized for understanding the kinetics of the reactions between phenol and formaldehyde. Detailed qualitative analyses of various resoles with different formulations have been discussed in this paper, which can be of potential help for the standard analysis of the commercial resins. The validation of results confirms that the most fitting model offers an error less than 7%. Interestingly, this model can also be applied with blends of different Phenol formaldehyde resoles.