Molecular structure and its influence on the properties of phenolic resins

✍ Scribed by Megson, N. J. L.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1948
• Weight: 657 KB
• Volume: 67
• Category: Article
• ISSN: 0368-4075
• DOI: 10.1002/jctb.5000670409

✦ Synopsis

Abstract

From a consideration of molecular dimensions and bond angles, it is deduced that a Novolak resin must consist of highly kinked, asymmetrical molecules. As a result, it is concluded that such a resin, when hardened with “hexa, “ will contain much less than the theoretically possible number of methylene cross‐links. A hardened resin will have a sponge‐like structure which can explain, partially, certain physical and chemical properties. Phenol‐methylene resins derived from formaldehyde are contrasted with phenol‐ethylene resins, which can have a symmetrical structure. An explanation is given of the good “tack” producing properties of Koresine, based on this symmetry. It is advocated that attention should be given to the synthetic method, as opposed to the analytical procedure hitherto used in investigating Novolaks. The importance of the synthetic approach is stressed, because of the comparative lack of information on crystalline intermediates. Finally, other methods of attack are outlined, including the desirability of determining the fine structure of simple phenol‐formaldehyde condensation products.