Epoxy resin Aromatic amine

The most common way to convert LP polymers to solid elastomers is to couple the terminal -SH groups. This is done either by oxidation to disulfides using organic or inorganic oxidizing agents or by reaction with epoxy resins, aromatic amines, diisocyanates, aldehydes, etc [16,35] ... 

Aromatic and Heterocyclic Glycidyl Amine Resins. Among the specialty epoxy resins containing an aromatic amine backbone, the following are commercially significant. 

In addition to electrical uses, epoxy casting resins are utilized in the manufacture of tools, ie, contact and match molds, stretch blocks, vacuum-forrning tools, and foundry patterns, as weU as bench tops and kitchen sinks. Systems consist of a gel-coat formulation designed to form a thin coating over the pattern which provides a perfect reproduction of the pattern detail. This is backed by a heavily filled epoxy system which also incorporates fiber reinforcements to give the tool its strength. For moderate temperature service, a Hquid bisphenol A epoxy resin with an aHphatic amine is used. For higher temperature service, a modified system based on an epoxy phenol novolak and an aromatic diamine hardener may be used. 

Aromatic amines formed from the reduction of azo colorants in toy products were analysed by means of HPLC-PDA [703], Drews et al. [704] have applied HPLC/ELSD and UV/VIS detection for quantifying SFE and ASE extracts of butyl stearate finish on various commercial yarns. From the calibrated ELSD response the total extract (finish and polyester trimer) is obtained and from the UV/VIS response the trimer only. Representative SFE-ELSD/UV finish analysis data compare satisfactorily to their corresponding SFE gravimetric weight recovery results. GC, HPLC and SEC are also used for characterisation of low-MW compounds (e.g. curing agents, plasticisers, by-products of curing reactions) in epoxy resin adhesives. 

Resinous adducts, 10 394 Resinous odor, 3 229t Resins. See also Epoxy resins Lacquer resins Novolac resins Phenolic resins Resole resins Thermoplastic resins acidic cation-exchange, 12 191 advanced materials, 1 693 antilipemic agents, 5 141 aromatic glycidyl amine, 10 372—373 chromatographic, 14 383-384 for coatings, 7 95-107 derived from furfuryl alcohol, 12 271— 272... 

Curing agents account for much of the potential hazard associated with use of epoxy resins. There are several major types of curing agents aliphatic amines, aromatic amines, cycloaliphatic amines, acid anhydrides, polyamides, and catalytic curing agents. The latter two types are true catalysts, in that they do not participate in the curing process. 

With the diglycidyl derivative of bisphenol A, aromatic amines such as 4,4 -methylene dianiline or diaminodiphenyl sulfone provide good thermal stability for the final cured resin. Although aliphatic primary amines react more rapidly (triethylenetetramine cures the above epoxy resin based on bisphenol A in 30 min at room temperature and causes it to exotherm up to 200°C), they are more difficult to handle and offer poor thermal stability. 

The liquid polymer is converted to the rubbery state by reagents that react with mercaptan (-SH) and side groups of the polymer segments by oxidation, addition or condensation to effect sulfide (-S-S-) bond formation. The oxidation reactions are exothermic and accelerated by an alkaline environment. The most commonly employed oxidizing agents which are suitable for curing liquid polymers are cobalt or manganese or lead octoate, p-quinonedioxime and di- or tri-nitrobenzene. Epoxy resin also reacts with liquid polysulfide polymers by addition in the presence of an aliphatic or aromatic amine and polyamide activator as shown in Equation 5.8 ... 

Epoxy adduct of aromatic amine (25) Araldite (Series) Epoxy resins... 

A great variety of aromatic diamines and aliphatic di- and poly-amines are used as epoxy resin curing agents, and tert-amines can act as catalysts for anionic epoxide homopolymerisation. 

A formulation used in USA is 54.7 parts epoxy resin, 10.3 parts aromatic amine, and 30.0 parts BJO phenolic microsphere. It has an apparent density of 336 kg/m3 and is viable for two hours. The mixture is hardened at 71 °C for 2 hours or at 82 °C for 1 hour 88). Recently, Prigozhin and Krasnikova 89) successfully applied simplex planning to the formulation of EDS materials with good properties. In addition to glass and phenolic microspheres, polystrene18), carbon38 40>, and mineral microspheres 18,59) have also been used. 

The mechanisms of radiation damage and effects of hardeners were studied recently by pulse radiolysis [89], The epoxy resins require a relatively large amount of curing agents (hardeners), most of them are aromatic and aliphatic amines such as diamino diphenyl methane or triethylene tetramine. On the basis of the emission spectra and kinetic behavior of excited states observed, the radiation resistance of aromatic and aliphatic amine curing epoxy resin was explained by internal radiation protection effects due to energy transfer. 

The radiation effects on dielectric properties of an epoxy resin (Epilox EG 34 with aromatic amine hardener Nr 105) were studied by Jahn et al. with electron,... 

Tetraglycidyl ether of tetraphenolethane is an epoxy resin that is noted for high-temperature and high-humidity resistance. It has a functionality of 3.5 and thus exhibits a very dense crosslink structure. It is useful in the preparation of high-temperature adhesives. The resin is commercially available as a solid (e.g., EPON Resin 1031, Resolution Performance Polymers). It can be crosslinked with an aromatic amine or a catalytic curing agent to induce epoxy-to-epoxy homopolymerization. High temperatures are required for these reactions to occur. 

Glycidyl amine epoxy resins are reaction products of aromatic amines and epichlorohy-drin. They have high modulus and high glass transition temperature. These resins find use in aerospace composites and high-temperature adhesive formulations. 

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