Phenol-formaldehyde polymers properties

Polymers. Quinoline and its derivatives may be added to or incorporated in polymers to introduce ion-exchange properties (see Ion exchange). For example, phenol—formaldehyde polymers have been treated with quinoline, quinaldine, or lepidine (81) (see Phenolic resins). Resins with variable basic exchange capacities have been prepared by treating Amherlites with 2-methylquinoline (82). 

Of all organic polymers used to produce insulation materials, glyptal and phenol-formaldehyde polymers are the most thermal resistant. They can function for a long time in electrotechnical devices at temperatures up to 130 °C. At higher temperatures insulation from organic polymers bums. Its dielectric properties considerably decrease, because the carbon formed is a good conductor. 

Copolymers of furfural with phenol or phenol-formaldehyde polymers have been available commercially for many years. Since the acid-catalyzed reaction of furfural and phenol has been difficult to control, most industrial applications involve the use of alkaline catalysts. Furfural-phenol resins are used for their alkali resistance, enhanced thermal stability, and good electrical properties compared to phenol-formaldehyde resins. 

Tyloxapol, 4-11,1,3,3-Teiramethytbutyl)phenol polymer with formaldehyde and oxirane oxyethylated tertiary octylphenol formaldehyde polymer oxyethylated tertiary octyl phenol-poly methylene polymer p-isooctylpolyoxyeth-y ten e phenol formaldehyde polymer tyloxypal Aleva ire Superinone Triton A-20 Triton WR-1339. Nonionic detergent with surface-ten si on-reducing properties. Prepn Bock, Rainey, U.S. pat. 2.454,541 (1948 to Rohm Haas) Cornforth et at.. Nature 168, 150 (19SI). 

Synonyms Formaldehyde, phenol polymer Formaldehyde, polymer with paraformaldehyde and phenol Paraformaldehyde, formaldehyde, phenol polymer Paraformaldehyde, phenol polymer Phenol-formaldehyde copolymer Phenol, formaldehyde polymer Phenol, polymer with formaldehyde Phenol, polymer with paraformaldehyde Classification Thermosetting polymer Definition Reaction prod, of phenol with aq. 37-50% formaldehyde with basic catalyst chief class of phenolic resin Formula (CeHeO (CH20)x)x Properties Gray to bik., hard, infusible solid when cured resist, to moisture, soivs., heat to 200 C dimensionally stable good elec, resist. noncombustible... 

Phenol-formaldehyde resins are widely used in industry and, consequently, studies on their thermal properties are of great technical importance [1]. Phenol-formaldehyde polymers heated for 1 hour up to 300, 430 and 840 °C lose 7%, 10% and 50% of their mass, respectively. 

Two families of phenolic-based adhesives are to be found in industry those formulated with phenolic resoles and those with novolacs. Although the starting chemistries for both resins are very similar, both are phenol/formaldehyde polymers, the different manufacturing routes leading to resins with significantly dissimilar properties. This article is concerned with resoles novolacs are considered in Phenolic adhesives two-stage novolacs. 

The final products of cast phenol-formaldehyde polymers have a number or exceptional properties, including high tensile and compressive strengths, good electrical insulating capabilities, and excellent adhesive qualities. Also, they can be polished and machined. Finally, the presence of very small water droplets in the material gives the surface a superb appearance. 

Table 12.1. Typical values for various properties of cured phenol-formaldehyde polymers, unfilled and filled [13]. 

General Properties. Phenolic resins generally are aqueous solutions of alkaline-catalyzed phenol-formaldehyde polymers. A typical resin would be about 40% solids, containing phenol, formaldehyde, and sodium hydroxide in molar ratios of about 1 2 0.75, and might average 10-50 phenol units linked together. These can be spray dried for application as a dried powder. Phenol-formaldehyde resins are cured with heat under pressure. The resultant bond is highly water resistant and heat resistant. The durability and weatherability of phenolic-bonded wood composites enables them to be rated for exterior use. 

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. 

It has been demonstrated that red oak OSL could be used to replace 35% to 40% of the phenol (or phenolic resin solids) in phenol-formaldehyde resins used to laminate maple wood and to bond southern pine flake boards (wafer-board and/or strandboard) without adversely affecting the physical bond properties. While this pulping process and by-product lignin do not commercially exist at this time in the United States, lignins from such processes are projected to cost 40% to 50% less than phenol as a polymer raw material. 

The importance of crosslinked polymers, since the discovery of cured phenolic formaldehyde resins and vulcanized rubber, has significantly grown. Simultaneously, the understanding of the mechanism of network formation, the chemical structure of crosslinked systems and the motional properties at the molecular level, which are responsible for the macroscopic physical and mechanical properties, did not accompany the rapid growth of their commercial production. The insolubility of polymer networks made impossible the structural analysis by NMR techniques, although some studies had been made on the swollen crosslinked polymers. 

Usually, phenolphthalein-derived polymers are polymerized through the hydroxyl groups, thus destroying their well-known indicator properties. There is one example in which phenolphthalein and o-cresolphthalein 284 have been polymerized with formaldehyde to form phenol/formaldehyde type polymers, for example, 285. These polymers retain the indicating properties of the monomers with potential application in pFl test strips and optical pH sensors <2005PSA1019>. 

Blending of inert materials with ion-exchange resins to an extent that the desirable properties such as thermal stability and exchange capacity are not affected can partially replace the polymer content thereby reducing the production cost. Vasudevan et al. reported the preparation of phenol-formaldehyde composite ion-exchange... 

The synthesis of phenolic-formaldehyde and melamine-formaldehyde resins in the presence of fumed silica allows obtaining porous organic materials with a differentiated porous structure and surface properties. The pore characteristics of the studied resins in dry state were determined from nitrogen adsorption isotherms. The differences in surface character of the synthesized polymers were estimated satisfactorily by XPS spectra showing the presence of various functional groups. The adsorption/desorption mechanism of water and benzene on the investigated porous polymers was different due to differentiated hydrophobicity of the bulk material. 

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