Phenolics polymers

Polar solvent extraction of sapwood, heartwood, or rhytidome (outer bark) yields a pale tan- to brown-colored solid, which is insoluble in water and in less polar solvents such as diethyl ether or dichloromethane. Proximate analysis, methoxyl content, color reactions, and infrared spectra (32) are so close to those of lignin to have lead F. E. Brauns and others in the 1940s to believe that this material was a low molecular weight fraction of lignin. Later on, Hergert (21) showed that this material was present in relatively large amounts in heartwood and only in very small quantities in sapwood. It must, therefore, be formed biosynthetically in the same way as other heartwood extractives since solubility characteristics alone would preclude translocation from the sapwood or the cambium. 

One of the troubling aspects of these polymers is that they appear to have lignans which are characteristic of the species from which they are isolated, incorporated into the polymeric chain. Heartwood lignans are invariably optically ac- 

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If formaldehyde is replaced by furfural, the furfural - phenol polymer (U.S.A. Durite) results. The above polymers are largely used for moulding purposes. 

The PVF is made by acidic reaction between poly(vinyl alcohol) (PVA) and formaldehyde. The poly(vinyl alcohol) is, in turn, made by hydrolysis of poly(vinyl acetate) or transesterification of poly(vinyl acetate). Thus, residual alcohol and ester functionality is usually present. Cure reportedly occurs through reaction of phenolic polymer hydroxyls with the residual hydroxyls of the PVA [199]. The ester residues are observed to reduce bond strength in PVF-based systems [199]. This does not necessarily extend to PVF-P adhesives. PVF is stable in strong alkali, so participation of the acetals in curing is probably unimportant in most situations involving resoles. PVF is physically compatible with many phenolic resins. 

Chemical Name 4-( 1,1,3,3-tetramethylbutyl)phenol polymer with formaldehyde and ethylene oxide... 

R. Antony, Synthesis, Characterization and Thermal Behaviour of Chemically Modified Phenolic and Substituted Phenolic Polymers, Ph.D thesis. Regional Research Laboratory, Trivandrum and Kerala University, Trivandrum, India (1993). 

Oxidoreductases Transferases Hydrolases Lyases Isomerases Ligases Phenolic polymers, polyanilines, vinyl polymers Polysaccharides, cyclic oligosaccharides, polyesters Polysaccharides, polyesters, polycarbonates, poly(amino acid)s, polyphosphates... 

Enzymes are generally classified into six groups. Table 1 shows typical polymers produced with catalysis by respective enzymes. The target macromolecules for the enzymatic polymerization have been polysaccharides, poly(amino acid)s, polyesters, polycarbonates, phenolic polymers, poly(aniline)s, vinyl polymers, etc. In the standpoint of potential industrial applications, this chapter deals with recent topics on enzymatic synthesis of polyesters and phenolic polymers by using enzymes as catalyst. 

Phenol-formaldehyde resins using prepolymers such as novolaks and resols are widely used in industrial fields. These resins show excellent toughness and thermal-resistant properties, but the general concern over the toxicity of formaldehyde has resulted in limitations on their preparation and use. Therefore, an alternative process for the synthesis of phenolic polymers avoiding the use of formaldehyde is strongly desired. 

The peroxidase-catalyzed polymerization of m-alkyl substituted phenols in aqueous methanol produced soluble phenolic polymers. The mixed ratio of buffer and methanol greatly affected the yields and the molecular weight of the polymer. The enzyme source greatly affected the polymerization pattern of m-substituted monomers. Using SBP catalyst, the polymer yield increased as a function of the bulkiness of the substituent, whereas the opposite tendency was observed when HRP was the catalyst. 

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. ... 

A bi-enzymatic system (glucose oxidase -I- HRP) was also used to catalyze the synthesis of phenolic polymers. The polymerization of phenol, albeit in moderate yield, was accomplished in the presence of glucose avoiding the addition of hydrogen peroxide (Scheme 2 ), which was formed in situ by the oxidation of glucose catalyzed by glucose oxidase. 

New positive-type photoresist systems based on enzymatically synthesized phenolic polymers were developed. The polymers from the bisphenol monomers... 

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. 

Blends of enzymatically synthesized poly(bisphenol-A) and poly(p-r-butylphenol) with poly(e-CL) were examined. FT-IR analysis showed the expected strong intermolecular hydrogen-bonding interaction between the phenolic polymer with poly(e-CL). A single 7 was observed for the blend, and the value increased as a function of the polymer content, indicating their good miscibility in the amorphous state. In the blend of enzymatically synthesized poly(4,4 -oxybisphenol) with poly(e-CL), both polymers were miscible in the amorphous phase also. The crystallinity of poly(e-CL) decreased by poly(4,4 -oxybisphenol). 

R. S. Buriks, A. R. Fauke, and D. J. Poelker. Vinyl phenol polymers for demulsification of oil-in-water emulsions. Patent CA 2031122,1991. 

Tyloxapol 4-(l,3,3-Tetramethylbutyl)-phenol polymer with formaldehyde and oxirane... 

Shindo H, Huang PM (1984) Catalytic effects of manganese (IV), iron (III), aluminum, and silicon oxides on the formation of phenolic polymers. Soil Sci Soc Am J 48 927-934... 

Reihmann, M. and Ritter, H. Synthesis of Phenol Polymers Using Peroxidases. Vol. 194, pp. 1-49. 

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