Biphenolate

Du Pont s Zenite range of LCPs have been reintroduced. These materials are also LCP polyesters based on HBA copolymers with, it is beheved, various amounts of 4,4 -biphenol, terephthaUc acid, and naphthalene-2,6-dicatboxyhc acid (NDA) as comonomers. Their compositions are thus similar to those of XYDAR with added NDA to further reduce the melting point (235,236). 

NMP are examples of suitable solvents for PES and PPSF polymerizations. Chlorobenzene or toluene are used as cosolvents at low concentrations. These cosolvents form an azeotrope with water as they distill out of the reaction mixture, thereby keeping the polymerization medium dehydrated. Potassium carbonate is a suitable choice for base. The synthesis of PES and PPSE differ from the PSE case in that the reaction is carried out in a single-step process. In other words, the formation of the dipotassium salt of the bisphenol is not completed in a separate first step. Equations 2 and 3 represent polymerizations based on the dipotassium salts of bisphenol S and biphenol to make PES and PPSE, respectively. 

The resins are made by batch processes employing Friedel-Crafts reactions or nucleophilic aromatic substitution. Udel resin and Radel R resin are produced by the nucleophilic displacement of chloride on 4,4 -dichlorodiphenyl sulfone by the potassium salts of bisphenol A and 4,4 -biphenol, respectively (97) ... 

Chemically all the currently commercial materials are linear aromatic esters. Xydar (3) is a terpolymer of, -biphenol, -hydroxyben2oic acid, and terephthahc acid. Vectra (4) is a copolymer of -hydroxyben2oic acid and 6-hydroxy-2-naphthoic acid. 

Maximum chemical resistance of polyester mortars is obtained from cements made from isophthalic or biphenol resins. The biphenolic resins are preferred for alkaline and hypochlorite solutions. 

The biphenol polyesters, being considerably more expensive than isophtha-leics, have better chemical resistance to strong alkaline solutions and oxidizing solutions. For about the same price as the biphenols, the... 

Palladium may also show exceptional selectivities. as in the conversion of o,o -biphenol to o-(2-hydroxycyclohexyl)phenol (55), or p-phenylphenol to p-cyclohexylphenol (90%). If this latter reduction is continued in methanol solvent, the main product is not 4-cyclohexylcyclohexanol, but rather 4 cyclohexylcyclohexyl methyl ether (84%) (5d). 

Paraformaldehyde (7.5 g) (0.25 mol) and 18.3 g (0.25 mol) of diethylamine are mixed in 25 cc of alcohol and warmed until a clear solution Is obtained. The solution is cooled and mixed with 26.6 g (0.10 mol) of 3,3 -diallyl-4,4 -biphenol in 25 cc of alcohol. After standing several hours, the solution is warmed for one hour on the steam bath, allowing the alcohol to boil off. The residue is then taken up in ether and water, the ether layer separated and washed with 2% sodium hydroxide solution and finally with water. The washed ether solution is dried over solid potassium carbonate, and filtered. After acidifying with alcoholic hydrogen chloride, the ether is distilled off and the alcoholic residue diluted with an equal volume of acetone. The crystalline hydrochloride is filtered off, triturated with alcohol, diluted with several volumes of acetone, filtered and dried MP 209°-210°C. 

However, many salts such as the hydroquinone or biphenol salt are so insoluble diat they do not work well by this procedure. Furthermore, a stoichiometric amount of base used for die reaction is critical to obtain high-molecular-weight polymers. Moreover, die sd ong base may undesirably hydrolyze the dihalides to afford deactivated diphenolates, which upset the stoichiometry. Clendining et al. reported that potassium carbonate or bicarbonate could be used in these reactions instead of corresponding hydroxides.60 McGrath and co-workers were the first to systematically study die use of the weak base K2C03 instead of a strong base to obtain phenolate salts.8,61,62 Potassium carbonate was found to be better than... 

Robeson and Matzner were the first to report the synthesis of the sulfonation of DCDPS.205 This work makes it possible to synthesize sulfonated poly(arylene ether sulfone) with well-controlled structures. Ueda et al. used this monomer (Scheme 6.27) as a comonomer of DCDPS to react with bisphenol A and high-molecular-weight bisphenol-A-based copolymers with up to 30 mol % sulfonation achieved.206 Biphenol-based copolymers with up to 100 mol % sulfonation were recently reported by Wang et al.207... 

Shohba et al. reported a sulfonated BFPPO monomer.209 The sulfonated BFPPO was used as a comonomer of BFPPO to react with biphenol. Fairly high molecular... 

Biomedical applications, 27 Bionolle, 28, 42, 43 Biopol polyesters, 28, 41 Bioresorbable polyesters, 27 synthesis of, 99-101 Biphenol-based copolymers, 356 Bis(aryloxy) monomers, polymerization of, 347... 

In order to make polymers behave as liquid crystals it is necessary to introduce some structural rigidity. A typical polymer which has the required rigidity is poly(phenylenetetraphthalamide) (10.7). This material belongs to a class of polymer known as the aramids. Other liquid crystalline polymers are the thermotropic polyesters derived from /7-hydroxybenzoic acid, p, p -biphenol and terephthalic acid (10.8). 

Biaryl derivatives bearing reactive groups have become increasingly important in industry. Uses for this class of compounds are constantly being developed in the production of high performance polymers. Materials such as 3,3, 4,4 -biphenyl-tetracarboxylic dianhydride 1 and 4,4 -biphenol 2 are monomers employed in the manufacture of high performance polyimides or polyesters. Applications for this family of molecules have also been found both in the dye industry and in the pharmaceutical industry. 

Previous studies by Sorokin with iron phthalocyanine catalysts made use of oxone in the oxidation of 2,3,6-trimethylphenol [134]. Here, 4 equiv. KHSO5 were necessary to achieve full conversion. Otherwise, a hexamethyl-biphenol is observed as minor side-product. Covalently supported iron phthalocyanine complexes also showed activity in the oxidation of phenols bearing functional groups (alcohols, double bonds, benzylic, and allylic positions) [135]. Besides, silica-supported iron phthalocyanine catalysts were reported in the synthesis of menadione [136]. 

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. ... 

Glucose transport in the erythrocyte is also potently inhibited by a series of biphenolic compounds, including diethylstilboestrol and related compounds, and phloretin, whose structures are shown in Fig. 1. Diethylstilboestrol inhibits transport with a K of about 5 [35] and phloretin inhibits with a K of about 2 /rM [36]. 

In one example described in the paper,44 irradiation of biphenol 57 in the presence of EVE gives the bisquinone methide-EVE adduct 58 in 22% yield (Eq. 1.15). The... 

Tris-spiro compounds have been generated from hexachlorocyclotriphosphazene by substitution with dihydroxyby-pyridine derivatives (Equation 31) <1999IC5457>. Treatment of hexachlorocyclotriphosphazene with 2equiv of biphenol or binaphthol yields only the / >-compounds 25 and 176. Enantiomerically pure cyclotriphosphazenes were generated from the (R)- or (Tl-forms of binaphthol (Equation 32) <1999EJI1673>. 

Several aluminum biphenolate complexes have been investigated as initiators for the ROP of PO.810,935 Unlike the TPP and salen-based systems, a cis coordination site is realistically accessible and in theory an alternative cis-migratory mechanism to the backside attack pathway might operate. However, NMR analyses on the resultant PPO show that stereochemical inversion still occurs when the biphenolate initiators are used (Scheme 22). It has also been confirmed that the same process occurs with the Union Carbide calcium alkoxide-amide initiator for both PO and CHO.810... 

Chisholm et al. synthesized organozinc compounds with bulky biphenolates as catalysts for the ring-opening polymerization of lactides.196 The protonolysis of diethyzinc by the biphenols, in the presence of diisopropylmethanol, afforded the polycyclic, trimetallic zinc-di(ethylzinc) pre-catalyst 135, which polymerizes /m -lactide to polylactide, enriched in isi- and. sir-tetrads (Scheme 85). 

Enantioselective additions of dialkylzincs and diphenylzinc to enones and related compounds were accomplished using catalytic amounts of Gu salts and optically active ligands, including biphenol-based phosphoramidites301-304... 

---