Phenol combination table

The most widely used antioxidants are sterically hindered phenols and bisphe-nols other additives are combined with phenols mostly in synergistic mixtures. The most recommended structures for stabilization of polyolefins against thermal oxidation and degradation are listed in Table 12.1. 

Another class of stabilizers that is able to reduce hydroperoxides is the thioethers. These stabilizers act mainly as long-term heat stabilizers. In combination with phenolic antioxidants they have a big influence on the long-term heat stability of polyolefins [102] (Table 18.3). 

In the presence of carbon black the phenols and phenol/DLTP combinations are much less effective whilst some phenolic sulphides (e.g. Santonox) show positive synergism with carbon black. Flowever, in general terms the phenol systems tend to be reduced to about the same levels as to those to which the phenol sulphide systems are raised. Some typical figures are given in Table 10.8. 

A cooperative interaction between two or more antioxidants (or antioxidant function) that leads to an overall antioxidant effect greater than the sum of the individual effects of each antioxidant is referred to as synergism. Synergism can be achieved in different ways. It may arise from the combined action of two chemically similar antioxidants, e.g., two hindered phenols (homosynergism), or when two different antioxidant functions are present in the same molecule (autosynergism) the latter is exemplified by many commercial antioxidants (e.g., Irgastab 2002, AO 29 Table lb), which have CB and UVA activity. 

Irg 1076, AO-3 (CB), are used in combination with metal dithiolates, e.g., NiDEC, AO-30 (PD), due to the sensitized photoxidation of dithiolates by the oxidation products of phenols, particularly stilbenequinones (SQ, see reaction 9C) (Table 3). Hindered piperidines exhibit a complex behavior when present in combination with other antioxidants and stabilizers they have to be oxidized initially to the corresponding nitroxyl radical before becoming effective. Consequently, both CB-D and PD antioxidants, which remove alkyl peroxyl radicals and hydroperoxides, respectively, antagonise the UV stabilizing action of this class of compounds (e.g.. Table 3, NiDEC 4- Tin 770). However, since the hindered piperidines themselves are neither melt- nor heat-stabilizers for polymers, they have to be used with conventional antioxidants and stabilizers. 

A series of phosphorus- and bromine-containing FRs were synthesized and studied to understand their role, especially their combined effects. Thus, monocar-danyl phosphoric acid, its bromo derivatives and their formaldehyde condensates and crosslinked products [28,188] were prepared and their properties compared with analogous products made from phenol [28,189]. Table 14 gives the LOI values, char yields (Cy at 600°C), and thermal stability at 50% (T6o) decomposition. 

An interesting combination of enzymatic with non-enzymatic transformation in a one-pot three-step multiple sequence was reported by Waldmann and coworkers [82]. Phenols 125 in the presence of oxygen and enzyme tyrosinase are hydroxylated to catechols 126 which are then oxidized in situ to ortho quinones 127. These intermediates subsequently undergo a Diels-Alder reaction with inverse electron demand by reaction with different dienophiles (Table 4.19) to give endo bicyclic 1,2-diketones 128 and 129 in good yields. 

In summary thermal decomposition of chlorinated phenols does not generally lead to dioxins. There are, however, several conditions which by themselves or combined would favor dioxin formation. First, of all chlorinated phenols either in bulk or in solution, only pentachlorophenol produced measurable amounts of dioxin. Secondly (Table II), only sodium salts in salid state reactions produced dioxins in reasonable yields. In contrast, the silver salt of pentachlorophenol (Figure 8) undergoes an exothermic decomposition at considerably lower temperatures and produced only higher condensed materials. No dioxin was detected. 

TJesticides derived from chlorinated phenols (Table I) are among the most prominent of those currently in worldwide use. Several major herbicides have been applied in large quantities in subtropical locations. Cahfornia used more than 1,200,000 pounds of 2,4-dichlorophenoxyacetic acid (2,4-D) and its derivatives in 1970 (I) Hawaii consumed some 465,000 pounds of pentachlorophenol (PCP) in 1968 (2), and the amount of combined butyl esters of 2,4-D and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) released in one area of Cambodia during two months of 1969 was estimated to exceed 77,000 pounds (3). 

Experimental Procedure. Morwell brown coal was solubilised by reacting with phenol, in the presence of para toluene sulfonic acid, at 1830C, and the reaction product was then separated into four fractions and analysed according to procedures described elsewhere (lj. The structural characteristics of the four fractions as determined by the present work and confirmed by reference to the literature ( ,3) are summarised in Table I. As these characteristics are influenced to some extent by the presence of chemically combined phenol, the content of this in each fraction is also estimated. 

These yields are also given on the basis of 100 g of original dry coal before fractionation. The bottom line of the table shows the mass of each fraction obtained from 100 g of dry coal. For every 100 g of original dry coal an additional 100 g of extraneous material was present. Elemental balances and other evidence (]J showed this to be made up almost entirely of phenol chemically combined with the coal material, with traces present of residual solvent associated with the fractions as a result of the coal preparation and fractionation scheme. Note that with fractions A and B no solid residue was obtained. 

Table IV shows the proton ratios obtained from the nmr spectra on the original fractions A, B and C and all the bottoms products. The proton ratios for the bottoms products have been adjusted to eliminate absorptions due to residual naphthalene. Note that the original fractions contained hydrogen present from combined phenol. Most of this hydrogen appears as monoaromatic hydrogen, but when the phenol-OH is still intact, one proton will appear as OH hydrogen.

The nmr analyses of the bottoms products given in Table IV show the material to have a large aliphatic content. The aromatic/aliphatic ratios of the fractions are higher than for the whole coal because of the presence of combined phenol reaction with Tetralin reduces these ratios considerably, presumably by transfer of much of this material to the solvent-range product, but some of it must remain in the bottoms as the aromatic/aliphatic ratio of the composite bottoms product from the fractions is higher than that from the whole coal. It was not possible to calculate the contribution that the diluents, excess solvent and combined phenol, made to the aromatic H, but the large monoaromatic content of the bottoms product must be due, in part, to these. 

Since probenecid is used extensively as an inhibitor of the urinary and biliary excretion of carboxylic, phenolic and sulphonic acids in many other animals, it was of interest to determine if probenecid would inhibit the urinary and/or biliary transport of phenol red in the shark (Table IV). The plasma levels determined at 4 hrs. after administration of phenol red alone or in combination... 

At just about this time (2), Pearson coined the words Hard and Soft to include, along with other effects, the electrostatic (hard) and covalent (soft) contributions to acid-base interactions. Hard-hard and soft-soft interactions reportedly dominate soft-hard combinations. The above interpretation of the data in Table 2 can be restated in terms of the hard and soft vocabulary. The softer sulphur donors react more strongly with the softer acid iodine and the harder oxygen donors react more strongly with the harder acid phenol. 

Most structural PMCs consist of a relatively soft matrix, such as a thermosetting plastic of polyester, phenolic, or epoxy, sometimes referred to as resin-matrix composites. Some typical polymers used as matrices in PMCs are listed in Table 1.28. The list of metals used in MMCs is much shorter. Aluminum, magnesium, titanium, and iron- and nickel-based alloys are the most common (see Table 1.29). These metals are typically utilized due to their combination of low density and good mechanical properties. Matrix materials for CMCs generally fall into fonr categories glass ceramics like lithium aluminosilicate oxide ceramics like aluminnm oxide (alnmina) and mullite nitride ceramics such as silicon nitride and carbide ceramics such as silicon carbide. 

Figure 3. Extraction with time of phenols from oak chips into red table wine (4-day value = 100%, five levels of chip treatment combined)...

PPS resins must compete with PEI and phenolics. There are two domestic manufacturers of poly(phenylene sulfide) Phillips and Fortron Industries. Worldwide there is currently large overcapacity (Table 15). Four Japanese companies, ie, Toso Susteel, a joint venture of Toso/Hodogaya Chemical Toray Toprene, a joint venture of Toto Kasei/Toren Petrochemical and Kureha Chemical have a combined capacity of 82,500 t. U.S. agents sell their materials in the U.S. markets General Electric sells for Toso Susteel Soltex Polymer, part of Solvay, Belgium, sells for Toprene Hoechst-Celanese sells for Kureha. Prices for PPS resins and compounds range from 8.80/kg for unreinforced resin to 3.30/kg for 65% filled resins. 

A mixture of 1.42 g (0.01 mol) phosphorus pentoxide and 2.5 g of chromatography grade silica gel was placed in a flask and stirred for 30 min. A mixture of equimolar amounts (5 mmol) of the carboxylic acid and phenol was added. Usually an immediate color change was observed. After stirring for 6 h at the temperature indicated in the Table, methylene chloride (50 mL) was added. The mixture was stirred for 1 min and then filtered. The spent reagent was washed twice with methylene chloride (10 mL). The combined organics were washed with aqueous NaOH solution, water and dried over sodium sulfate, and the solvent was removed under reduced pressure. 

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