Allyl ester resins

ALLYL ESTER RESINS. The allyl radical (CH2CH=CH2) is the basis of the allyl family of resins. Allyl esters arc based on monobasic and dibasic acids and are available as low-viscosity monomers and thermoplastic prepolymers. They are used as crosslinking agents for unsaluraied polyester resins and in the preparation of reinforced thermoset molding compounds and high-performance transparent articles. All modem thermoset techniques may be used for processing allyl resins. 

Allylic ester resins possess excellent clarity, hardness, and color stability and thus are used to cast into optical parts. These castings can be either homopolymers or copolymers. The free radical addition polymerization of the allylic ester presents some casting difficulties such as exotherm control, monomer shrinkage during curing, the interaction between the exotherm and the free radical source, and the environmental heat required to decompose the peroxide and initiate the reaction. Cast allylics are noted for their hardness, heat resistance, electrical properties, and chemical resistance. They lack strength, and so their usage is confined to optical parts and some small electrical insulators. (See also allyl.)... 

Jang, J. S., and Yi, J., Curing kinetics of allyl ester resins from differential scanning... 

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... 

Resins 2 and 3 are treated with dichloromethane containg 3% and 1.5% trifluoroacetic acid (lOmL/g resin), respectively, for 18 h. The resin is filtered off and washed twice with dichloromethane (10 mL / g of resin). The filtrate is washed with saturated NaHCCL (5 mL) and brine (5 mL), and the organic phase is separated and filtered through a short path silica gel column to obtain a colourless solution. In the case of polymer-bound allyl esters giving rise to cleavage products of type 5f, the aqueous workup is omitted. The products obtained after removal of solvent under reduced pressure contain small amounts of silanol by-products (note 5), which is to be accounted for in the calculation of cleavage yields. 

Kriston Allyl ester casting resins B.F. Goodrich... 

Cleavage of the phosphonate allyl esters from Abu[PO(OAl)2]-peptide-resins is accomplished by treatment with Pd(PPh3)4 (50 °C, 5 h)[103l followed by acidolytic deprotection of the Abu[PO(OH)2]-peptide from the resin support. The viability of employing allyl phosphonate protection for phosphopeptide synthesis has been demonstrated by the Fmoc solid-phase synthesis (DIC/HOBt couplings) of several 6-9-mer Abu[PO(OH)2]-containing peptides and has been extended to the synthesis of a 19-mer caldneurin-related Abu[PO(OH)2]-peptide.[104 ... 

Allyl chloride is used to make intermediates for downstream derivatives such as resins and polymers. Approximately 90% of allyl chloride production is used to synthesize epichlorohydrin, which is used as a basic building block for epoxy resins and in glycerol synthesis. Allyl chloride is also a starting material for allyl ethers of phenols, bisphenol A and phenolic resins, and for some allyl esters. Other compounds made from allyl chloride are quaternary amines used in chelating agents and quaternary ammonium salts, which are used in water clarification and sewage sludge flocculation (Kneupper Saathoff, 1993). 

Resin-bound (4-acyloxy-2-buten-l-yl)silanes, which can be prepared from resin-bound allylsilanes and allyl esters by cross-metathesis, react with dilute TFA to yield free carboxylic acids (Figure 3.7 [75]). However, the scope of this strategy remains to be explored. Similarly, esters of polystyrene-bound (2-hydroxyethyl)silanes readily undergo acidolysis and have been used as acid-labile linkers (Figure 3.7 [76]). 

Uses Allyl alcohol is used in the manufacture of allyl esters, as monomers and prepolymers for the manufacture of resins and plastics. It has large use in the preparation of pharmaceutical products, in organic synthesis, and as a fungicide and herbicide. Workers engaged in industries such as pharmaceuticals, pesticides, allyl esters, organic chemicals, resins, war gas, and plasticizers are often exposed to this alcohol. 

Preparation of the C-terminal allyl ester protected peptide-resin is carried out by careful introduction of the second and third residues using protocols to minimize DKP formation followed by standard stepwise chain elongation as outlined in Subheadings 3.1.3. and 3.1.4., respectively. 

The C-terminal steroid modified heptapeptides, corresponding to the C-terminus of Hedgehog proteins, were synthesized in a combined solid-phase/solntion approach (41). The synthesis built on the dipeptide Fmoc-SG-OAU that was connected to the trityl resin via the free hydroxyl fnnctionality of the serine. The C -terminal allyl ester was cleaved by noble-metal-mediated... 

Deprotection of the Resin-Bound Glycopeptide Allyl Ester 12 with a Palladium Catalyst and A,iV-Dunethylbarbituric Acid ... 

A similar experiment, performed in soln on the same, but resin-free, glycopeptide allyl ester using the Pd catalyst (0.4 equiv) and iV,iV-dimethylbarbituric acid (5.9 equiv), afforded the deprotected peptide in quantitative 5deld after chromatographic purification. 

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