Epoxy aliphatic esters

The most common types of plasticizer are the phthalic acid esters of Cg, Cio alcohols citric acid esters and epoxy aliphatic esters. 

Chlorinated paraffins, which contain up to 60-70% chlorine, are low in cost and are used as secondary plasticizer in PVC wire and cable insulations. Perchlorobicyclopentadiene has little plasticizing action and is used in polyethylene. Some of the more expensive bromine-containing fire retardants which have been used in the ratio of 5 p.p.h. in polystyrene foam, may be reduced to 0.5 p.p.h. by adding synergists such as peroxides or nitroso compounds. The reaction-type retardants, such as chlorendic acid and anhydride, hydroxy-terminated phosphonated esters, and specific brominated aliphatic esters, are admixed to rigid and flexible polyurethane foams, reinforced polyesters, phenolics, and epoxy resins. 

Aliphatic esters are diesters of adipic, sebacic or azelaic acids and offer greater resistance to low temperatures than phthalates, but at a higher cost Epoxy ester plasticizers have limited compatibility with PVC so are used at low concentrations. The most widely used epoxy ester plasticizer is epoxidized soya bean oil (ESBO). ESBO resists extraction, does not migrate readily and acts also as a heat stabilizer. Other plasticizers in this group include epoxidized linseed oil and tall oil. 

Over half of all the world s phthalic anhydride is used to make phthalate plasticisers. Aliphatic esters (adipates, sebacates etc.) are the second most important plasticiser category after phthalates, followed by the polymeries and the trimellitate and epoxy esters. 

A = bisphenol A epoxy—aliphatic amine hardener 1 -B = bisphenol A epoxy—aromatic amine hardener 1 -C = bisphenol F epoxy (epoxy novolac) 2-D = polyester resin—chlorendic acid type 2- E = polyester resin—bisphenol A fumarate type 3- F = vinyl ester resin 3-G = vinyl ester novolac resin ... 

Epoxy vinyl ester, phenolic, methacrylate, styrene-divinylbenzene, cyanafe ester, and dicyclopentadiene (DCPD) resins have been made in Pittman s laboratory in which various POSS macromers have been chemically incorporated. For example, a low-viscosity aliphatic epoxide resin was blended with macromer 32 (Fig. 15) and aliphatic triamine curing agents, and these blends were cured in five stages to both 120°C and 150°C. The incorporation of 5 and 25 wt % of 32 into these epoxy resins gave an increase in the storage modulus versus that of the neat epoxy. " The... 

A reiterative application of a two-carbon elongation reaction of a chiral carbonyl compound (Homer-Emmonds reaction), reduction (DIBAL) of the obtained trans unsaturated ester, asymmetric epoxidation (SAE or MCPBA) of the resulting allylic alcohol, and then C-2 regioselective addition of a cuprate (Me2CuLi) to the corresponding chiral epoxy alcohol has been utilized for the construction of the polypropionate-derived chain ]R-CH(Me)CH(OH)CH(Me)-R ], present as a partial structure in important natural products such as polyether, ansamycin, or macro-lide antibiotics [52]. A seminal application of this procedure is offered by Kishi s synthesis of the C19-C26 polyketide-type aliphatic segment of rifamycin S, starting from aldehyde 105 (Scheme 8.29) [53]. 

The best performing coatings were the vinyl ester, the bisphenol A epoxy cured with an aliphatic amine, and a novolac epoxy cured with a mixed aromatic/cycl oal i phati c amine. The saturated polyester, and a bisphenol A epoxy cured with a polyamide amine showed significant deterioration of the coating material in the acid, and corrosion of the underlying steel. Two types of novolac epoxies cured with aromatic amines showed intermediate performance. 

Cycloaliphatic Epoxy Resins. This family of aliphatic, low viscosity epoxy resins consists of iwo principal varieties, cyclouleliils epoxidi/.cd with peracetic acid anil diglvcidyl esters of cyclic diearboxvlic acids. 

Polyunsaturated aliphatic alkohols, aldehydes, ketones, and esters occur as fragrance components in fats, oils, fruits and plants 158). As an example the synthesis of ethyl (2 ,4Z)-2,4-decadienoate (232, pear ester ), which is responsible for the aroma of bartlett pears 161) is given. 2,4-Diunsaturated ester 232 may be obtained by a number of highly stereoselective syntheses, a lot of them making use of the Wittig reaction. Ohloff and Pawlak condensed 4,5-epoxy-( )-2-pentenal 228 with the ylide generated from 229 (butyllithium/ether) to the alkadiene epoxide 230 which was oxidized with periodic acid to the 2,4-decadienal 231. 231 is subsequently converted with MnOj/NaCN in ethanol to the pear ester 232162) [75 % (Z)-amount of the C-4 double bond] (Scheme 44). 

The condensation of aldehydes and ketones with ethyl chloroacetate in the presence of sodium ethoxide or sodium amide produces a,/3-epoxy esters (Darzens). The scope, limitations, typical experimental procedures, and examples have been given. Briefly, aliphatic and aromatic ketones, and aromatic aldehydes react satisfactorily, whereas aliphatic aldehydes give poor yields. a-Halopropionic and a-halobutyric... 

Chemical resistance. Unmodified epoxy resins have excellent resistance to dilute acids, alkalis and certain solvents. The incorporation of an LP component into the epoxy resin extends this resistance to a wide variety of oils, aromatic and aliphatic hydrocarbons, esters and ketones. Coatings and adhesives based on polysulphide-epoxy resins exhibit reduced swell and maintenance of flexibility and adhesion when immersed in these fluids. In view of this, LP-modified epoxies are used on oilrigs, fuel-storage installations and chemical plants (Figure 10.4). 

Plasticizers phthalates, phosphates, adipates, azelates, sebacates, epoxi-dized plasticizers. Plasticizers are used mainly in PVC compounding, the most important being the phthalates. Esters of aliphatic acids are used in footwear and household refrigerator parts where low-temperature flexibility is required. 

Unsubstituted and Heat Reactive. The first class, the unsubstituted, heat-reactive resins, are made by using phenol, cresols, and xylenols. They are multifunctional and thus can be cross-linked to form films. They are soluble in alcohols, ketones, esters, and glycol ethers and insoluble in aromatic and aliphatic hydrocarbons. They will tolerate some water in their solvents and, in some cases, are completely water soluble. They are compatible with polar resins such as amino resins, epoxies, polyamides, and poly(vinyl butyral), though compatibility on curing is dependent on reaction between the two resins. Less polar resins such as alkyds and drying oils are incompatible. 

Allyl alcohol undergoes reactions typical of saturated, aliphatic alcohols. Allyl compounds derived from allyl alcohol and used industrially, are widely manufactured by these reactions. For example, reactions of aUji alcohol with acid anhydrides, esters, and acid chlorides yield aUyl esters, such as diaUji phthalates and allyl methacrylate reaction with chloroformate yields carbonates, such as diethylene glycol bis(allyl carbonate) addition of allyl alcohol to epoxy groups yields products used to produce allyl glycidyl ether (33,34). 

Synthesis of Aliphatic-Cycloaliphatic Epoxy Compounds with Glycidyl Ester Groups... 

Side and cross members are pretreated by blasting and phosphating. An electrode-posited primer coating follows and is sometimes immediately overcoated with a topcoat based on an air-drying alkyd or epoxy ester, or on an oven-drying alkyd-melamine resin combination. After assembly of the truck, a third layer (i.e., a second topcoat) is applied that serves as a supply finish. These finishes are mostly two-pack acrylic aliphatic isocyanate topcoats. Water-based two-pack systems and powder coatings are the most recent developments. 

Benzyl alcohol [100-51-6] is miscible with organic solvents apart from aliphatic hydrocarbons. It dissolves cellulose esters and ethers, fats, oils, alkyd resins, natural and synthetic resins, and colorants. Polymers—with the exception of lower poly(vinyl ethers) and poly(vinyl acetates)—are not dissolved. Small amounts of benzyl alcohol improve the flow and gloss paints, delay the evaporation of other solvent components, and have a plasticizing effect in physically drying paints. It is used in ballpoint pen inks. Benzyl alcohol reduces the viscosity in two-pack epoxy resin systems. 

Plasticizers include esters of aromatic and aliphatic acids and anhydrides, epoxidized oil, phosphate esters, hydrocarbon oils and polymeric materials. PVC is the polymer most in need of plasticizers, but polyvinyl acetate, epoxies, cellulose nitrate and acetates also require these additives. 

---