Polyphosphonate esters

Another rule of thumb concerns the oxidation tendency of polymers. Carbonates and phosphates with the C02 and 0P03 moieties are already largely oxidized. Thus portions of polymers that contain the carbonate and phosphate molecules do not contribute to combustion. In fact, polyphosphate and polyphosphonate esters... 

A significant number of works are concerned with the development of new membranes for the separation of mixtures of aromatic/alicyclic hydrocarbons [10,11,77-109]. For example, the following works can be mentioned. A mixture of cellulose ester and polyphosphonate ester (50 wt%) was used for benzene/cyclohexane separation [113]. High values of the separation factor and flux were achieved (up to 2 kg/m h). In order to achieve better fluxes and separation factors the attention was shifted to the modification of polymers by grafting technique. Grafted membranes were made of polyvinylidene fluoride with 4-vinyl pyridine or acrylic acid by irradiation [83]. 2-Hydroxy-3-(diethyl-amino) propyl methacrylate-styrene copolymer membranes with cyanuric chloride were prepared, which exhibited a superior separation factor /3p= 190 for a feed aromatic component concentration of 20 wt%. Graft copolymer membranes based on 2-hydroxyethyl methylacrylate-methylacrylate with thickness 10 pm were prepared [85]. The membranes yielded a flux of 0.7 kg/m h (for feed with 50 wt% of benzene) and excellent selectivity. Benzene concentration in permeate was about 100 wt%. A membrane based on polyvinyl alcohol and polyallyl amine was prepared [87]. For a feed containing 10 wt% of benzene the blend membrane yielded a flux of 1-3 kg/m h and a separation factor of 62. 

The reactions between Y-(co-haloalkyl)phthalimides and sodium dialkyl phosphite were reported as early as 1949 by Chavane in the successful sytheses of several (co-aminoalkyl)phosphonic diesters. The advantage over the Michaelis-Arbuzov reaction in the preparation of (2-aminoethyl)phosphonic diesters with Y-alkyl or Y-silvl substituents is worth recalling, and several reports of its successful use may be noted, including the preparation of nitrogen-functionalized polyphosphonic esters (Scheme 17). Other substrates for the reaction have included l,3-bis(bromomethyl)benzene and 4-(co-bromoalkyl)arenes ... 

Polyphosphonic acids are conveniently esterified by treatment with orthoformate esters with distillation of the lower-boiling alcohol. This procedure worked well for the acid (74), which readily dimerizes, and was also used to establish the structure of the dimer (75). ... 

Apart from their behaviour as ligands in metal catalyst systems, studies of the reactivity of phosphites towards a wide variety of other substrates have attracted attention. New aspects and applications of the classical Michaelis-Arbuzov reaction and its variants continue to appear. Evidence of the thermal disproportionation of methyltriaryloxyphosphonium halides formed in the reactions of triarylphosphites with alkyl halides, together with the formation of P-O-P intermediates, has been reported. The Michaelis-Arbuzov reaction has been used in the synthesis of phosphonate-based styrene-divinylbenzene resins and polyphosphonated chelation therapy ligands.Treatment of electron-rich benzylic alcohols dissolved in triethylphosphite with one equivalent of iodine affords a low-temperature one-pot route to the related benzylic phosphonates, compounds which are otherwise difficult to prepare. Upper-rim chloromethylated thiacalix[4]arenes have also been shown to undergo phosphonation on treatment with a phosphite ester in chloroform at room temperature. The nickel(II)-catalysed reaction of aryl halides with phosphite esters in high boiling solvents, e.g., diphenyl ether, (the Tavs reaction), has also... 

Reports of examples of arylphosphonates include those of water-soluble phosphinic-polyphosphonic acids, e.g. 132, and the phosphonate 133 which when coupled to alcohols, to give e.g. 134, act as linkers to proteins in experiments intended to generate antibodies to catalyse cationic cyclisation reactions.Novel water-soluble phosphonate-substituted phthalocyanines have been prepared.The phosphonate esters 135 are insoluble in water but can be hydrolysed by hydrochloric acid to give the water-soluble phosphonic acids 136. Aromatic phosphonate-phosphines 137, and their air-stable complexes, have been obtained from the reaction of 4-halogeno-substituted phenylphosphonates with lithium diphenylphosphide. ... 

This is an area in which the syntheses of functionalized acids (as their esters) has predominated (Chapter 3, Sections VI and VII). Nevertheless, the procedure is not without its uses in non-functionalized systems, and it has also received attention as a means for the synthesis of polyphosphonic acids (as their esters). 

Addition of hydrogenphosphonates to the 1,4-quinonemethides 383 to give the 4-hydroxyphenyl polyphosphonic acids as their esters 384 is well established , and that of hydrogenphosphonates to / -benzoquinone itself is reported to give the 2,5-dihydrox-yphenyl-l,4-bisphosphonic acid derivative. ... 

The earliest report on the nonbiological s tithesis of polyphosphonates and polyphosphate ester was by Arvin. (Arvin, 1936). Much of the earlier work in the synthesis of polyphosphate ester was carried out by Millich et al, (Millich, 1969, 1974). One of the earliest re iews in the interfacial s)tithesis of polyphosphonates, polyphosphates and polyphosphites by Millich et al, (Millich, 1977) is highly recommended. 

Millich, E and C.E. Carraher, J. (1969) Interfacial syntheses of Polyphosphonate and Polyphosphate esters. I. Effects of alkaline medium./. Polyrn. Sci Part A-1, 7, 2669-2678. 

Because of the commercial availability of phenylphosphonyl dichloride flben-zene phosphorus oxydichloride, BPOD), much work has been done on this intermediate to make polymeric phosphonates as flame-retardant thermoplastics or as additives for thermoplastics. In an early study, Toy (90) carried out the polycondensation of BPOD and dihydric phenols in a melt. Coover and McConnell added the use of an alkaline earth halide catalyst (91). For enhancement of the flame-retardant effectiveness as flber additives, tetrabromobisphenols were used to make polyphosphonates (92). Various cocondensed polyesters with both phosphonate ester units and dicarboxylic ester units have been described and patented. 

Insertion of a Diepoxide into a Phosphonate Ester. The insertion reaction of bisphenol A diglycidyl ether with diaryl aryl- or alkylphosphonates was shown to give polyphosphonates of moderate molecular weight (114). 

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