Phenol-formaldehyde resins synthesis

Figure 6.15 The phenolic curative (methylol terminated, para-alkyl substituted, phenol-formaldehyde resin) synthesis...

The synthesis in 1912 of phenol—formaldehyde resins by Baekeland, which forms the basis of many modern day adhesives. 

Phenol-formaldehyde resins using prepolymers such as novolaks and resols are widely used in industrial fields. These resins show excellent toughness and thermal-resistant properties, but the general concern over the toxicity of formaldehyde has resulted in limitations on their preparation and use. Therefore, an alternative process for the synthesis of phenolic polymers avoiding the use of formaldehyde is strongly desired. 

Wan, P Hennig, D. Photocondensation of o-hydroxyhenzyl alcohol in an alkaline medium synthesis of phenol-formaldehyde resins. J. Chem. Soc., Chem. Commun. 1987, 939-941. 

Recently, several reports of the flame-retardant properties of boron-containing bisphenol-A resins have appeared from Gao and Liu.89 The synthesis of a boron-containing bisphenol-A formaldehyde resin (64 and 65) (Fig. 42) from a mixture of bisphenol-A, formaldehyde, and boric acid, in the mole ratio 1 2.4 0.5, has been reported.893 The kinetics of the thermal degradation and thermal stability of the resins were determined by thermal analysis. The analysis revealed that the resin had higher heat resistance and oxidative resistance than most common phenol-formaldehyde resins. 

The first example in this class of PEMs to be examined was sulfonated phenol-formaldehyde resins (8).i These materials were studied for use in the space program, given the relative ease of the synthesis and sulfonation of the base polymer as well as low cost. However, in common with polystyrene, these systems exhibit low oxidative stability and thus little work has been carried out since the original studies. 

Resin synthesis of OSL-modified phenol-formaldehyde resins. 

Fig. 13. Polymerization chemistry of phenol—formaldehyde condensation synthesis of novolac resin. The phenol monomer(s) are used in stoichiometric excess to avoid gellation, although branching invariably occurs due to the multiple reactive sites on the aromatic ring.

The first synthetic polymers to be of any use were the phenol formaldehyde resins of which the most famous, Bakelite, was discovered by Bakeland at the turn of the century. He combined phenol and formaldehyde in acid solution and got a reaction that starts like the bisphenol A synthesis. 

The institution of fractionated or chemically modified lignin for part or all of the phenol in the synthesis of phenol-formaldehyde resins. This would particularly include the newer forms of lignin recovered with minimum structural alteration and also those representing virtually complete depolymerization to phenylpropane units. 

The substitution of selected and possibly modified carbohydrates for part or all of the phenol in the synthesis of phenol-formaldehyde resins. 

The synthesis of carbon with MCM-48 was also reported by another research group using phenol-formaldehyde resin, following the report on CMK-1 [13]. However, this carbon exhibited the same XRD pattern as CMK-1. 

The potential applications for conducting polymers are enormous and this has stimulated a large amount of research into this area. Not surprisingly, solid-state NMR spectroscopy has been applied to study these amorphous, insoluble and in many cases crosslinked materials [24]. Looking at the CP/MAS spectra of a series conducing polyacenic polymers, some of which were doped with iodine, it was possible to see the effect of the halogen upon conductivity. These resins were prepared by a conventional procedure for the preparation a Novolak-type phenol-formaldehyde resin. After synthesis, the phenol-formaldehyde resin were dissolved and solutions were cast as a film and heat treated to between 590-670°C in a N2 atmosphere to form the polyacenic film. The electrical conductivity of the films was shown to increase... 

Before the advent of oxygenate ethers like MTBE, formaldehyde production was the largest single application of methanol, with at least 16 manufacturers and consuming over 30% of the methanol produced. Formaldehyde is used in the manufacture of urea-formaldehyde resins, phenol-formaldehyde resins, melamine-formaldehyde resins, acetal resins, acetylenic chemicals, etc. The reactions involved in formaldehyde synthesis are ... 

Phenolic polymers and phenol-formaldehyde resins are of great commercial interest for a number of electronic and industrial applications (7). However, there have been serious concerns regarding their use due to various toxic effects of formaldehyde and harsh synthesis environments (2). Peroxidase-catalyzed oxidative polymerization of phenol and substituted phenols provides an alternate route for the synthesis of phenolic polymers (3,4), The increased interest in this type of enzyme-based polymerization is mostly due to its environmental compatibility and potential for producing industrial polymers in high yield (5). 

Uses Intermediate in organic synthesis chemical intermediate for phenol-formaldehyde resins soil sterilant veterinary antiseptic... 

Uses Organic synthesis phenol-formaldehyde resin comonomer copolymerizes with maleic anhydride solvent dye pharmaceutical mfg. Manuf./Distrib. Aldrich http //www.sigma-aldrich.com, Atofina... 

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