DAP ester

Phosphate ester synthesis and properties have been reviewed earlier [1,10-13]. The current treatise will consequently concentrate on manufacturing techniques with special emphasis on recent advances in preparing high monoalkyl phosphate (MAP) and high dialkyl phosphate (DAP) esters. 

The preferred ratio of alcohol (alcohol ethoxylate) to phosphoric anhydride (P40jq) is 5.0 6.2 [25], based on composition and cycle time considerations. In practice, the weight ratio of MAP to DAP ester can be manipulated between 65 35 and 35 65 by adjusting the alcohol or water proportions. This effect can be envisioned by substituting water for a portion of the ROH in the sequence. The product distribution also depends on when the water is added, with or after the alcohol [4,27]. The MAP content is increased by even traces of water in either the phosphoric anhydride or alcohol (alcohol ethoxylate). 

Mixtures of MAP and DAP esters prepared by the reaction of phosphorus oxychloride and lauryl/myristic alcohol [38] have also been describecL However, the methodology is more expensive and not practiced commercially. 

Mixed DAP esters based on this chemistry are important as gellants for enhanced oil recovery [71-73], Phosphoric anhydride is reacted with triethyl phosphate in a hydrocarbon solvent and the slurry heated to 100°C for 1 h. A blend of octanol and decanol is then added in a second step to the intermediate mixture and the reaction is continued for 2 h at 130°C [73], The resulting product is blended with diesel oil and cross-linked to a viscous pumpable gel with aluminum isopropoxide or trivalent metal. The product, by reaction of phosphoric anhydride directly with a blend of ethanol, octanol, and decanol, does not perform because of a much higher MAP content [71], A dialkyl content (mixed ethyl alkyl monobasic ester) of 75-85 mol% is preferred and advantages are reported for use of a hexanol-decanol blend in the finishing step [71],... 

DiaHyl esters find Htde appHcation in lenses. However, DAP and DAIP can be polymerized by high energy radiation in lens molds (74). Coatings of sihca and alumina by vaporization give antiglare, scratch-resistant lenses. 

In studies of the polymerization kinetics of triaUyl citrate [6299-73-6] the cyclization constant was found to be intermediate between that of diaUyl succinate and DAP (86). Copolymerization reactivity ratios with vinyl monomers have been reported (87). At 60°C with benzoyl peroxide as initiator, triaUyl citrate retards polymerization of styrene, acrylonitrile, vinyl choloride, and vinyl acetate. Properties of polyfunctional aUyl esters are given in Table 7 some of these esters have sharp odors and cause skin irritation. 

Small amounts of TAIC together with DAP have been used to cure unsaturated polyesters in glass-reinforced thermo sets (131). It has been used with polyfunctional methacrylate esters in anaerobic adhesives (132). TAIC and vinyl acetate are copolymerized in aqueous suspension, and vinyl alcohol copolymer gels are made from the products (133). Electron cure of poly(ethylene terephthalate) moldings containing TAIC improves heat resistance and transparency (134). 

The resins known as DAP and DAIP, are cross linked allyl esters of phthalic and rsophthalic acid, respectively. They are notable for rigidity and excellent electrical properties at temperatures up to 4.50" F. Allylic resin-impregnated glass cloth is used in aircraft and missile parl.s. Other... 

Work is in progress to validate the MAE method, proposed for EPA, in a multi-laboratory evaluation study. Nothing similar has been reported for additives in polymeric matrices. Dean el al. [452] have reviewed microwave-assisted solvent extraction in environmental organic analysis. Chee et al. [468] have reported MAE of phthalate esters (DMP, DEP, DAP, DBP, BBP, DEHP) from marine sediments. The focus to date has centred on extractions from solid samples. However, recent experience suggests that MAE may also be important for extractions from liquids. 

The enynoic ester 11 is exceptional in that both senses of addition are observed with DAP, exclusively at the substituted triple bond (Scheme 5).7S... 

The methylenepyrazoline 69, formed from cycloaddition between an allenic ester and DAP, rearranges to 70 on slow distillation over glass wool (Scheme 25).115... 

ABA ABS ABS-PC ABS-PVC ACM ACS AES AMMA AN APET APP ASA BR BS CA CAB CAP CN CP CPE CPET CPP CPVC CR CTA DAM DAP DMT ECTFE EEA EMA EMAA EMAC EMPP EnBA EP EPM ESI EVA(C) EVOH FEP HDI HDPE HIPS HMDI IPI LDPE LLDPE MBS Acrylonitrile-butadiene-acrylate Acrylonitrile-butadiene-styrene copolymer Acrylonitrile-butadiene-styrene-polycarbonate alloy Acrylonitrile-butadiene-styrene-poly(vinyl chloride) alloy Acrylic acid ester rubber Acrylonitrile-chlorinated pe-styrene Acrylonitrile-ethylene-propylene-styrene Acrylonitrile-methyl methacrylate Acrylonitrile Amorphous polyethylene terephthalate Atactic polypropylene Acrylic-styrene-acrylonitrile Butadiene rubber Butadiene styrene rubber Cellulose acetate Cellulose acetate-butyrate Cellulose acetate-propionate Cellulose nitrate Cellulose propionate Chlorinated polyethylene Crystalline polyethylene terephthalate Cast polypropylene Chlorinated polyvinyl chloride Chloroprene rubber Cellulose triacetate Diallyl maleate Diallyl phthalate Terephthalic acid, dimethyl ester Ethylene-chlorotrifluoroethylene copolymer Ethylene-ethyl acrylate Ethylene-methyl acrylate Ethylene methacrylic acid Ethylene-methyl acrylate copolymer Elastomer modified polypropylene Ethylene normal butyl acrylate Epoxy resin, also ethylene-propylene Ethylene-propylene rubber Ethylene-styrene copolymers Polyethylene-vinyl acetate Polyethylene-vinyl alcohol copolymers Fluorinated ethylene-propylene copolymers Hexamethylene diisocyanate High-density polyethylene High-impact polystyrene Diisocyanato dicyclohexylmethane Isophorone diisocyanate Low-density polyethylene Linear low-density polyethylene Methacrylate-butadiene-styrene... 

Another example is H-Thr(tBu)-Gln(Trt)-Ile-Asp(OtBu)-Ser(tBu)-Pro-Leu(A -Aloc)-Dap-MBHA-resin, synthesized by the Fmoc strategy.P l Following cleavage of the Aloe group with phenylsilane and tetrakis(triphenylphosphine)palladium, two (aminooxy)acetyl moieties were linked to the a-amino groups of Thr and Dap by reacting the peptide-resin with [(A-Boc-amino)oxy]acetyl A-hydroxysuccinimide ester. 

A microwave-assisted solvent extraction (MASE) method was optimized by Chee et al. to extract phthalate esters from marine sediments, soils, and results were compared with those obtained by the same authors using conventional Soxhlet and sonication techniques. The analysis was performed by GC-ECD or GC-MS. The overall optimal conditions for the extraction of phthalate esters by MASE included the use of 1 1 acetone or hexane at 115°C for 10 min. Recoveries for six individual phthalate esters (DMP, DEP, DAP, DBP, BBP, DEHP) ranged from 71% to 91%, and were better than those obtained with Soxhlet (66% to 90%) or sonication (65% to 89%). The authors stated that advantages of MASE extraction over sonication or Soxhlet are larger sample throughput, lower usage of hazardous solvents, and less laborious cleanup steps. 

Other thermosetting polymers are cyanate esters (CEs), benzoxazines, PU acrylates, bismaleimides (BMIs), dicy-clopentadienes (DCPDs), diallyl phthalates (DAPs), etc. Formulations based on these polymers are used for specific applications where their particular properties are required. For example, DAP has long been the material of choice for electrical components where long-term reliability is required. 

In some cases, carboxylie acid esters were used for o-DAP eyelization, ineluding o-esters. When a mixture of 2,3,4-triaminopyridines and a large exeess of triethyl orthoformate in coneentrated HCl is stored at room temperature for a long time, it affords a mixture of IbPs and IcPs in 97% overall yield (87JMC1746). 

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