Phenyl phosphite

In addition to stabilisers, antioxidants and ultra-violent absorbers may also be added to PVC compounds. Amongst antioxidants, trisnonyl phenyl phosphite, mentioned previously, is interesting in that it appears to have additional functions such as a solubiliser or chelator for PVC insoluble metal chlorides formed by reaction of PVC degradation products with metal stabilisers. Since oxidation is both a degradation reaction in its own right and may also accelerate the rate of dehydrochlorination, the use of antioxidants can be beneficial. In addition to the phenyl phosphites, hindered phenols such as octadecyl 3-(3,5-di-tcrt-butyl-4-hydroxyphenyI)propionate and 2,4,6-tris (2,5-di-rcrt-butyl-4-hydroxybenzyl)-1,3,5-trimethylbenzene may be used. 

Rose and Lepper found that phosphites, especially o-substituted phenyl phosphites, enhance the catalytic activity of Pd(acac)2 or Pd(OAc)2 and affect the ratio of 47 to 48 (52). When Pd(OAc)2 and PPh3 (1 1) were used at 50°C for 1.5 hours, the yield was 20% and the ratio of 47 to 48 was... 

Chart 6.2 Intermediates in the tris (2-tert-butyl-4-methyl phenyl) phosphite modified Rhodium catalyzed hydroformylation. 

F. UNDECACARBONYLTETRAHYDRIDO[TRIS(4-METHYL-PHENYL) PHOSPHITE]TETRARUTHENIUM, Ru4H4(CO)u[P(OC6H4Me-/>)3]... 

PRu4C12H25, Ruthenium, undecacar-bonyl-tetrahydrido[tris(4-methyl-phenyl)phosphite]tetra-, 26 277 OijP2Ru CjIHij, Ruthenate(2-), prcar-bido-tetradecacarbonylpenta-bis[p,-nitrido-bis(triphenylphosphorus)-(1+)], 26 284... 

PO]4Ru4C32H25, Ruthenium, undecacar-bonyl-tetrahydrido-[tris(4-methyl-phenyl)-phosphite]tetra-, 26 277 POsSC5 H47, Osmium(II), dihydrido(thio-carbonyl)tris(triphenylphosphine), 26 186... 

Ammonium salts of sulfonated phenyl phosphites, which are surprisingly resistant to hydrolysis, have been prepared (25). The compounds are more water stable than triphenyl phosphite, but they decompose completely within 24 h. 

In order to check for the possibility of primary electron transfer, hydroperoxides were allowed to react with the donors that contained the stabilizing groups, namely, 4,4 -di(ani-syl) sulfide or l,2-dihydroxyphenyl-bis 2,4,6-tri(/m-butyl)phenyl phosphite. The ESR method revealed the formation of corresponding cation radicals. 

A number of ortho hindered alkyl-substituted phenyl phosphites and phosphonites were found to be effective process stabilizers for polypropylene and high density polyethylene combining more effective stabilization activity at high temperatures with good storage stability at relatively elevated humidity and ambient temperature, as well as resistance to discoloration. 

The possibility that R-0 fission may occur in advance of attack by halide ion has been demonstrated in the reactions of dineopentyl phenyl phosphite or neopentyl diphenyl phosphite with alkyl halides. In these cases the Michaelis-Arbuzov intermediates cannot be isolated but the neopentyl halides which are formed are contaminated with varying amounts of rearrangement product (t-pentyl halide) (Table IV). These results may explain the formation of mixtures of isomeric halides (9,10,11) in certain applications of Rydon s method for alkyl halide preparation (12). S i fission of the R-0 bond appears to be encouraged by the electron-attracting effect of phenoxy-substituents (Figure 3). 

The steric hindrance introduced by bulky ligands [e.g., tri(o-phenyl-phenyl)phosphite] has the effect that the ethylene molecule is unable to coordinate to the nickel atom and mainly COD is formed. 

The most predominant volatile compound identified was dibutyl adipate which is a decomposition product of DOA. The second predominant volatile compound was 4-nonyl phenol which is again a decomposition product of the antioxidant tris-nonyl phenyl phosphite. Most short-chain phthalates were considered to be either decomposition or transesterification products of DOP, which indicated that the type and the amount of additives could be a major cause of off-odor problem. 

Representative compounds of importance in polypropylene stabilization are tris( mixed nonyl phenyl) phosphite and dilauryl thiodipropionate-(DLTDP). The aryl phosphite is used in film grade resins and in other... 

DLTDP + 0.1% tris(nonyl-phenyl) phosphite (tris) 18... 

Abou-Donia, M.B. (1992). Tri-phenyl phosphite a type II organophosphoras compound-induced delayed neurotoxic agent. In Organophosphates Chemistry, Fate, and Effects (J.E. Chambers, P.E. Levi, eds), pp. 327-51. Academic Press, San Diego. 

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