Phenolic resin spectra

Polyethylene separators offer the best balanced property spectrum excellent mechanical and chemical stability as well as good values for acid availability and electrical resistance have established their breakthrough to be the leading traction battery separator. Rubber separators, phenolic resin-resorcinol separators, and mi-croporous PVC separators are more difficult to handle than polyethylene separators their lack of flexibility does not allow folding into sleeves or use in a meandering assembly in addition they are more expensive. 

We have studied demulsifier association by the electron spin resonance (ESR) technique. The spin label is covalently attached (Figure 5a) to the demulsifier. Normally, the ESR spectrum of a freely tumbling nitroxyl radical consists of three sharp peaks (Figure 5b). However, the spectrum for a tagged ethoxylated nonyl phenol resin (Figure 6a or 6b) shows only a single broad peak. 

In the polymer industry, packing material, laminates including multilayer films, pellets or molded products can be analyzed by NIR. Even polymer latex particles with up to 99 % water content may be analyzed. NIR provides information about reaction mechanisms, polymerization, crystallinity, orientation, water content and hydrogen bonding, even during the process of polymer manufacture. For example the disappearance of the double bonds in polyethylene and polypropylene can be monitored. In the NIR spectrum C=C bonds lead to a combination band at about 4740 cm and a first overtone at about 6170 cm NIR spectroscopy is applied to characterize ester-, nitrile-, or amide-based acrylic and methacrylic polymers. Other examples are the identification of polyvinylchloride, polyvinyl alcohol and polyvinyl acetates or the analysis of polymerization in epoxy and phenolic resins. 

Using flow charts for paints the type of resin employed can be identified, and in some cases, for example, alkyl and phenolic resins, quantitative determination of resins can be made from the relative areas of the spectrum peaks. 

Alkaline Catalysts, Resoles. Resole-type phenolic resins are produced with a molar ratio of formaldehyde to phenol of 1.2 1 to 3.0 1. For substituted phenols, the ratio is usually 1.2 1 to 1.8 1. Common alkaline catalysts are NaOH, Ca(OH)2, and Ba(OH)2. While novolak resins and strong acid catalysis result in a limited number of structures and properties, resoles cover a much wider spectrum. Resoles may be sohds or liquids, water-soluble or -insoluble, alkaline or neutral, slowly Cluing or highly reactive. In the first step, the phenolate anion is formed by delocahzation of the negative charge to the ortho and para positions. Alkaline catalysts are also effective in the polymerization-depolymerization of methylene... 

Fig. 6 Infrared spectrum of a typical phenolic resin air-cured for 3 hr at 120 C. [Reprinted from W. M. Jackson and R. T. Conley, J. Appl. Polym. Sci. 8, 2163 (1964). Copyright 1964 by the Journal of Applied Polymer Science. Reprinted by permission of the copyright owner.]...

An example of this approach is illustrated in Fig. 19. The difference spectrum (d) is the result of subtraction of the spectra (a) of an oxidized carbon fiber and (b) of a phenolic matrix from the total spectrum (c) of the fiber and matrix coupled with a titanium alkoxide coupling agent (TOT=tetrakis(2-ethylhexyl)ti-tanate) 151). The difference spectrum is characteristic of the -O-TiRi-O- group which might be formed by reaction of the titanium alkoxide with both the oxidized fiber surface and the phenolic resin according to the scheme. 

Figure 19. Illustration of the method of extracting the valence-band spectrum of the buried interface between an oxidized carbon fiber and a phenolic resin, with an intermediate titanium alkoxide agent, (a) Valence-band spectrum of oxidized carbon fiber alone, (b) valence-band spectrum of phenolic matrix alone, (c) valoncc-band spectrum of the composite, and (d) difference. spectrum—the result of subtracting spectra (a) and (b) from (c). Spectrum (d) represents the desired valence-band spectrum of the interface. (From Ref. 51.)...

The original spectrum of the adhesive is largely the sum of the spectra of the phenolic resin and neoprene. The last fraction was obviously at a low concentration, and its presence would not have been detected without carrying out the separation procedure described. 

The polymeric phenolic phosphites are excellent heat and processing stabilizers and can contribute significantly to photostability. These broad-spectrum stabilizers offer possibilities for simplifying polypropylene stabilizer systems. They may allow one to use lesser amounts of other additives, and they open up a new area for potential cost savings in formulating polypropylene resins. 

The phenol/glucose/urea resin, to which formaldehyde was later to be added, showed the usual sequence of products formation, but by the end of the acidic reaction stage, there were no distinct glucose or glucosyl ureide species identifiable by 13C-NMR or HPLC. After neutralization and addition of formalin, signals for formalin immediately showed in the 49 to 55 ppm (methoxy) and 82 to 90 ppm (hemiformal and hemiacetal) regions of the spectrum. After the end of an hour of reaction with formaldehyde, the 13C-NMR spectrum of the reaction mixture showed that the signals due to phenolic species had reduced in size relative to the sulfolane internal reference, but their number had multiplied... 

Figure 2. 13C-NMR spectrum (in CDCI3) of peracetylated glucose-urea-phenol-based acid stage resin.

As has been shown by Quest International [31], lipoxygenases also accept a relatively broad spectrum of phenolic compounds as substrates. Of interest to the flavour industry are the lipoxygenase-catalyzed conversions of isoeugenol and coniferyl benzoate from Siam resin to vanillin (4-15% peld. Fig. 7.12). At present, the commercialization of these biotransformations is hampered by the... 

The chemical nature of amber is complex. Amber consists of complex mixtures of sesquiterpenoids, diterpenoids, and triterpenoids that have undergone polymerization and molecular reorganization during fossilization. Phenolic units may also be present. Baltic coast deposits, which contain about 8% succinic acid, are often called succinite. Amber is amorphous, and its infrared spectrum closely resembles those of nonvolatile resins from extinct pine trees. It is believed not to be a high polymer, the resinous state being accounted for by the complexity of materials present. Amber also serves as a repository for a variety of extinct species of insects. 

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