Phenol-formaldehyde and allied resins. V.-Synthesis of a bridged decanuclear novolak and a case of hardening by way of meta-substitution

✍ Scribed by Hunter, R. F. ;Turner, C.

• Book ID: 102329277
• Publisher: Wiley (John Wiley & Sons)
• Year: 2007
• Weight: 390 KB
• Volume: 7
• Category: Article
• ISSN: 0021-8871
• DOI: 10.1002/jctb.5010070909

✦ Synopsis

Abstract

The bridged decanuclear novolak (V) has been synthesized rationally as a non‐crystalline chemical individual from 2: 6‐bis‐2′‐hydroxy‐5′‐methylbenzyl‐4‐bromophenol (I) by way of the dimethylol derivative (II) which on reaction with 2: 4‐xylenol furnished 2: 6‐bis‐2′‐hydroxy‐3′‐(2″‐hydroxy‐3″: 5″‐dimethylbenzyl)‐5′‐methylbenzyl‐4‐bromophenol (III) which was debrominated to the pentanuclear novolak (IV). On reaction with an equivalent of formaldehyde in acetic acid, using sulphuric acid as catalyst, the latter gave the required bridged decanuclear novolak (V). In the presence of excess of acid formaldehyde, both the pentanuclear and the decanuclear novolaks were readily converted into hardened products whose infra‐red absorption spectra indicated the formation of methylene bridges in meta‐position to the hydroxyl groups.