Linear all‐<i>ortho</i> oligomers of phenol–formaldehyde resins. I. Preparations, characterizations, and solution properties

Abstract

Abstract Three kinds of all‐ ortho methylene‐linked phenolic oligomers, i.e., 4‐ tert ‐butylphenol (BP), phenol (AO), and O‐methylated BP (BPM), were prepared with good yields and their dilute solution properties were studied. In acetone, all of these oligomers are highly solvated and molecularly dispersed. In chloroform, however, AO and BP molecules strongly form hydrogen bonds among themselves. By intramolecular and intermolecular hydrogen‐bondings, a large portion of the dimers and the trimers of AO and BP associate to form bimolecular aggregates in chloroform, assuming pseudo‐cyclic conformations analogous to calix [4] arene and calix [6] arene, respectively. By intramolecular hydrogen‐bonding, the tetramers and the hexamers also form pseudo‐cyclic conformations by themselves in chloroform. © 1993 John Wiley &amp; Sons, Inc.