Abstract
Two cyclic oligomers, which are by-products of p-t-butyl phenol resin (BPR), have been analyzed by means of 1H NMR, 13C NMR and mass spectrometry.
One of them, white crystalline precipitate (UK-1) which was isolated from resol type BPR (A) toluene solution, was determined to be the cyclic tetramer of p-t-butyl phenol (BP) having one dimethylene ether bridge and three methylene bridges as shown in Fig. 6.
The other, white amorphous precipitate (UK-II) which was obtained from n-hexane soluble components of BPR (B) condensated under non catalyst, was identified to be the cyclic trimer of BP having only dimethylene ether bridge as shown in Fig. 12.
It was found that 1H NMR, 13C NMR and mass spectra were available to distinguish between the linear oligomer and the cyclic oligomer, especially mass spectra, as shown in Fig. 6 and Fig. 7, were very useful for the microanalysis of the oligomers which have strong molecular ion peak.
