Stabilizers phenolic polymer

Dialkylhydroxybenzyl-N,N-Dimethyl Dithiocarbamates as Intermediates in the Preparation of Phenolic Polymer Stabilizers... 

Additioaal uses for higher olefias iaclude the productioa of epoxides for subsequeat coaversioa iato surface-active ageats, alkylatioa of benzene to produce drag-flow reducers, alkylation of phenol to produce antioxidants, oligomeriza tion to produce synthetic waxes (qv), and the production of linear mercaptans for use in agricultural chemicals and polymer stabilizers. Aluminum alkyls can be produced from a-olefias either by direct hydroalumination or by transalkylation. In addition, a number of heavy olefin streams and olefin or paraffin streams have been sulfated or sulfonated and used in the leather (qv) iadustry. 

Various bisphenol derivatives were also polymerized by peroxidase under selected reaction conditions, yielding soluble phenolic polymers. Bisphenol-A was polymerized by peroxidase catalyst to give a polymer soluble in acetone, DMF, DMSO, and methanol. The polymer was produced in higher yields using SBP as a catalyst. This polymer showed a molecular weight of 4 x 10 and a 7g at 154°C. The HRP-catalyzed polymerization of 4,4 -biphenol produced a polymer showing high thermal stability. ... 

Morphology of the enzymatically synthesized phenolic polymers was controlled under the selected reaction conditions. Monodisperse polymer particles in the sub-micron range were produced by HRP-catalyzed dispersion polymerization of phenol in 1,4-dioxane-phosphate buffer (3 2 v/v) using poly(vinyl methyl ether) as stabihzer. °° ° The particle size could be controlled by the stabilizer concentration and solvent composition. Thermal treatment of these particles afforded uniform carbon particles. The particles could be obtained from various phenol monomers such as m-cresol and p-phenylphenol. 

It is well known that the trimeric phosphonitri-lic chloride can be polymerized, at 200-300°C, to poly(dichlorophosphazene) (1), hereafter this polymer will be referred to as chloropolymer. Since this polymer contains hydrolytically-unstable chlorine groups, these groups are usually replaced with various alcohols, phenols, or amines to import the polymer stability. In our laboratories, the substitution is generally with alcohols or phenols. The reaction scheme is shown in Figure 1. 

The diffusion coefficients and solubility of phenols in polymers play an important role for polymer stabilization also. The values of these parameters can be found in the Handbook of Polymer Degradation [34],... 

Polymer stabilization is another area in which the peroxide-decomposing and chain-breaking antioxidant properties of diorganotellurides has found utUity. Alone or in combination with phenol and phosphate antioxidants, electron-rich dialkylamino-substirnted diaryltellurides and alkylaryltellurides provided greatly enhanced polymer stability for a thermoplastic elastomer and for polypropylene. The effects were unique to the tellurides, with selenides not providing similar protective effects. ... 

Martin, J. R, and Haider, K. (1980). Microbial degradation and stabilization of 14C-labeled lignins, phenols, and phenolic polymers in relation to soil humus formation In Lignin Biodegradation Microbiology Chemistry and Potential Applications, Vol. II. Kent-Kirk, T., Higuchi, T., and Chang, H., eds., CRC Press, Boca Raton, FL, pp. 77-100. 

A number of desirable properties were exhibited in this work, which include ease of monomer synthesis, mild positive electropolymerization potential, polymer stability to continuous potential cycling, and stability to storage under ambient conditions. Unfortunately, the nature of the polymer backbone could not be definitely assigned. Nevertheless, the utility of pendant phenol and aniline groups for anchoring metal complexes to an electrode surface is a method worth further investigation. 

Substitued phenols are commonly applied as commercial anti-oxideuits and the abOTe presented reaction can play a role in the mechanism of polymer stabilization against oxidation. 

Flame Retardance. The most important reason for phenolic foam being an excellent flame retarder is that the phenolic polymer is easily carbonized and the char part formed as a result is highly stabilized. This mechanism of char-formation is considered that of a multi-aromatic ring with chemically stabilized strong bond formed through a dehydrogenation reaction by heating and oxidation. 

In the polymer industry phenolic compounds are important stabilizers they are used to prevent the free-radical induced polymerization of monomers (e.g. methyl methacrylate, styrene) during transit and as stabilizers for polymer systems where radical induced decomposition and decay mechanisms operate. Examples of the latter include polyolefins, such as polyethylenes or polypropylenes, and polyvinyl chlorides. However, these uses of phenols and phenolic polymers are not considered in this chapter (refer to Chapter 12). 

J. Pospisil, Chemical and photochemical behavior of phenolic antioxidants in polymer stabilization-a state of the art report, Part I, Polym. Degrad. Stab. 1993, 40, 217-232. 

Polymer stabilization has been realized by generating a highly reactive carbene species that can insert into the polymer chain. Kaplan et al. described the preparation and use of a phenolic diazooxide that generates a carbene upon heating and that attaches the phenolic group to... 

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