Bisphenol F resin

Bisphenol F Resin. Bisphenol F [2467-02-9] epoxy resin is of the same general stmcture as the epoxy phenol novolaks. Bisphenol F is 2,2Emethylene bisphenol. Whereas the epoxy phenol novolaks vary from viscous Hquids to soHd materials, the bisphenol F resin has a low viscosity (ca 4 Pa-s (40 P)) and 165 epoxy equivalent weight. Its n value (degree of polymerization) is about 0.15 and crystallization, often a problem with low viscosity conventional bisphenol A resins, is reduced with the bisphenol F resin. 

Bisphenol F Resins. Diglycidyl ether resins based on bisphenol F (DGEBF) have been developed to provide cured epoxy resins with greater flexibility and lower softening temperatures than conventional DGEB A epoxy resins. The preparation of bisphenol F resins is from formaldehyde and phenol. Three isomers are possible because substitution can occur at the ortho-, meta-, or para- positions. The proportion of isomers depends upon the pH of the reaction medium. 

FIGURE 2.7 Chemical structure of bisphenol F resin (4,4 isomer). 

Bisphenol F resins are often mixed with conventional DGEBA epoxy resins because of the relatively high cost of the bisphenol F product. When mixed with bisphenol A resins, the two form crystallization-free resins of moderate viscosity. 

For adhesive systems, the liquid epoxy resins most widely used with LP-3 polymers are liquid unmodified and diluent-modified bisphenol A resins and liquid blends of bisphenol A and bisphenol F resins. Solid bisphenol A, multifunctional, and aliphatic diepoxy resins have also been used. Ratios of liquid polysulfide polymer to epoxy are in the range of 1 2 to 2 1. The effect of various degrees of polysulfide on cure properties of a DGEB A epoxy is shown in Table 7.7. An increase in elongation and impact strength is the result of increased amounts of the liquid polysulfide polymer. 

CTBN modified bisphenol F resin (EPON 58003) Elastomer modified bisphenol A resin 25 100 ... 

EPON 58003 285-330 1,500-3,000 at 52°C CTBN elastomer modified bisphenol F resin Resolution... 

The lowest member of the series (n=o), the so-called Bisphenol-F resin, after glycylidation with epichlorohydrin, provided a low viscosity (4-6000 cP) liquid resin with slightly higher functionality and a more chemically resistant system after curing with... 

Being a glycidyl ether of a novolac type phenol formaldehyde resin, epoxy phenol novolac resins (Figure 2.39 (a)) are the polymeric multifunctional counterpart of bisphenol F resin. They are supplied as highly viscous through semisolid to solid resins. They are generally prepared by reacting epichlorohydrin with novolac type phenol formaldehyde resins. 

Owing to relatively low viscosity, these resins offer advantages for 100% soHds (solvent-free) systems. Higher filler levels are possible because of the low viscosity. Faster bubble release is also achieved. Higher epoxy content and functionaHty of bisphenol F epoxy resins can provide improved chemical resistance compared to conventional epoxies. 

Bisphenol F epoxy resins are used in high-soHds-high-build systems such as tank and pipe linings, industrial floors, road and bridge deck toppings, stmctural adhesives, grouts, coatings, and electrical varnishes. Bisphenol F epoxy resins are manufactured in Europe and Japan. 

Liquid epoxy resin based on the reaction product of epichlorohydrin and bisphenol A or bisphenol F mild to moderate irritants mild to moderate sensitizers low volatility, exposure unlikely unless heated, sprayed, or spread over large unventilated surface low toxicity... 

The products of the chemical degradation of PETP with triethylene tetramine and triethaneolamine can be used as epoxy resin hardeners, it is demonstrated. Products of PETP aminolysis with triethylene tetramine and aminoglycolysis with triethanolamine, were characterised using NMR and rheometric measurements. Characteristics of the crosslinking process for the system epoxy resin/ PETP/amine degradation product, and epoxy resin/TETA for comparison were investigated by DSC. Three classes of liquid epoxy resins based on bisphenol A, bisphenol F and epoxy novolak resins were used in the experiments. 16 refs. 

Bisphenol A resins, 10 5-6 Bisphenol A terminated hardeners, 10 406 Bisphenol F epoxy resin, 10 368-369 Bis(phenolic) developers, 19 346-347 Bisphenol resins, formulation of,... 

Bisphenol F (BPF) is a mixture of three isomers 2,2 -, 2,4 -, and 4,4 -dihydroxydiphenylmethane, in the ratio 15%, 50% and 35%, respectively. It has also found application in the manufacture of epoxy resins, but as a fully crosslinked polymer it is rarely used in food-contact materials. Residues of... 

Hisphenol F Resin. Bisphenol F epoxy resin is of the same general structure as the epoxy phenol novolaks. Bisphenol F is 2.2 -tnelhylene hisphenol... 

As industrial relevant Friedel-Crafts reaction, the synthesis of Bisphenol-F, a material for epoxy resin, from phenol and formaldehyde was chosen [57]. This reaction involves formation of higher order condensates such as tris-phenols. To minimize the latter, the molar ratio of phenol to formaldehyde is set to a very high value (30-40), which is more than 15 times larger than the amount theoretically necessary. Three types of micromixers were used. These are a T-shaped mixer with 500 pm inner diameter, a multilaminating interdigital micromixer with 40 pm channels and a so-called self-made K-M micromixer with center collision mixing. 

In addition to the DGEB A resins, there are several other types of epoxy resins of commercial significance. The most common of these are epoxy novolacs, glycidyl ether of tetraphe-nolethane, bisphenol F-based resins, and aliphatic and cycloaliphatic resins. 

Bisphenol F-based epoxy resins (Fig. 2.7) are analogous to DGEB A-based epoxy resins in most respects. They use the same curing agents and reaction mechanisms. Bisphenol F epoxies are often used in blends with DGEBA resins to lower the viscosity or to modify certain properties. 

Bisphenol F epoxy resins are produced by condensing phenol with formaldehyde, resulting in a mixture of isomers and higher-MW condensation products. Bisphenol F epoxy resins have lower viscosity then DGEB A epoxy resins for the same molecular weight (or number of repeating units n). Cured bisphenol F epoxy resins also have increased solvent resistance. 

Bisphenol F based epoxy resins. Instead of reacting bisphenol A with epichlorohydrin to form a liquid resin, a similar reaction can be conducted with bisphenol F (Figure 2.2). Bisphenol F is composed of a mixture of isomers - ortho-ortho, ortho-para and para-para linkages -whereas bisphenol A is composed mainly of para-para linkages. If n is less than about 0.2, the resins are called bisphenol F epoxides. If n is higher they are referred to as epoxy phenol novolac (EPN) resins (Helfad, 1996). 

The repeat unit of bisphenol F epoxy resins (Figure 2.3) or epoxy novolac resin does not significantly increase the epoxy equivalent weight although viscosity and functionality do increase (Helfad, 1996). 

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