Polysulfide phenolic

Phenolic Resins. At elevated temperatures, phenoHc resins are cured with polysulfide resins through a condensation reaction. The product may be considered a block copolymer of the rigid phenoHc resin and the flexible polysulfide. Thus, the polysulfide acts to flexibiHze the resulting polymer. 

Sulfur Dyes. These dyes are synthesized by heating aromatic amines, phenols, or nitro compounds with sulfur or, more usually, alkah polysulfides. Unlike most other dye types, it is not easy to define a chromogen for the sulfur dyes (qv). It is likely that they consist of macromolecular stmctures of the phenothiazone-thianthrone type (72), in which the sulfur is present as (sulfide) bridging links and thiazine groups (1). 

The manufacture of sulfur dyes involves sulfurisation processes, the chemistry of which remains rather mysterious and may arguably be considered still to be in the realms of alchemy The processes involve heating elemental sulfur or sodium polysulfide, or both, with aromatic amines, phenols or aminophenols. These reactions may be carried out either as a dry bake process at temperatures between 180 and 350 °C or in solvents such as water or aliphatic alcohols at reflux or at even higher temperatures under pressure. C. I. Sulphur Black 1, for example, is prepared by heating 2,4-dinitrophenol with sodium polysulfide. 

A family of elastomeric foams has been developed by Rand 129) for use as stress relief coatings on electronic components in encapsulated electronic assemblies. Polysulfide, silicone and polyurethane elastomers blended with glass and phenolic microspheres have been used to formulate syntactic foams (Fig. 10) These foams are used to minimize the stress caused by differential thermal expansion between the component and the encapsulant. 

Fig. 10. Compression stress-strain properties of various elastomeric syntactic foams129> (l)urethane elastomer binder and glass microspheres y = 640 kg/m3, void fraction 0.321 (2) polysulfide elastomer binder and phenolic microspheres y = 1500 kg/m3, void fraction 0.133 (3) silicone elastomer binder and glass microspheres y = 610 kg/m3, void fraction 0.407...

Sulfur dyes are water-insoluble, macromolecular, colored compounds which are produced by bridging aromatic amines, phenols, and amino phenols with sulfur and/or sodium polysulfide [16], These dyes are of little interest for dyeing paper. Only C.I. Sulphur Black 1 (36), the most important dye of all in terms of volume, is used for special paper dyeings. 

Alloyed blends consisting of epoxy-phenolic, epoxy-nylon, and epoxy-polysulfide adhesives... 

Environment Epoxy + polyamine Epoxy + anhydride Epoxy + polyamide Epoxy- phenolic Epoxy- polysulfide Epoxy-nylon Phenoxy (thermoplastic)... 

PB PBI PBMA PBO PBT(H) PBTP PC PCHMA PCTFE PDAP PDMS PE PEHD PELD PEMD PEC PEEK PEG PEI PEK PEN PEO PES PET PF PI PIB PMA PMMA PMI PMP POB POM PP PPE PPP PPPE PPQ PPS PPSU PS PSU PTFE PTMT PU PUR Poly(n.butylene) Poly(benzimidazole) Poly(n.butyl methacrylate) Poly(benzoxazole) Poly(benzthiazole) Poly(butylene glycol terephthalate) Polycarbonate Poly(cyclohexyl methacrylate) Poly(chloro-trifluoro ethylene) Poly(diallyl phthalate) Poly(dimethyl siloxane) Polyethylene High density polyethylene Low density polyethylene Medium density polyethylene Chlorinated polyethylene Poly-ether-ether ketone poly(ethylene glycol) Poly-ether-imide Poly-ether ketone Poly(ethylene-2,6-naphthalene dicarboxylate) Poly(ethylene oxide) Poly-ether sulfone Poly(ethylene terephthalate) Phenol formaldehyde resin Polyimide Polyisobutylene Poly(methyl acrylate) Poly(methyl methacrylate) Poly(methacryl imide) Poly(methylpentene) Poly(hydroxy-benzoate) Polyoxymethylene = polyacetal = polyformaldehyde Polypropylene Poly (2,6-dimethyl-l,4-phenylene ether) = Poly(phenylene oxide) Polyp araphenylene Poly(2,6-diphenyl-l,4-phenylene ether) Poly(phenyl quinoxaline) Polyphenylene sulfide, polysulfide Polyphenylene sulfone Polystyrene Polysulfone Poly(tetrafluoroethylene) Poly(tetramethylene terephthalate) Polyurethane Polyurethane rubber... 

To overcome the difficulties of ESI-MS, Simonsick and Prokai added sodium cations to the mobile phase to facilitate ionization [165,166]. To simplify the resulting ESI spectra, the number of components entering the ion source was reduced. Combining SEC with electrospray detection, the elution curves of polyethylene oxides) were calibrated. The chemical composition distribution of acrylic macromonomers was profiled across the molar mass distribution. The analysis of poly(ethylene oxides) by SEC-ESI-MS with respect to chemical composition and oligomer distribution was discussed by Simonsick [167]. In a similar approach aliphatic polyesters [168], phenolic resins [169], methyl methacrylate macromonomers [169] and polysulfides have been analyzed [170]. The detectable mass range for different species, however, was well below 5000 g/mol, indicating that the technique is not really suited for polymer analysis. 

In contrast to the sulfide/polysulfide mechanism for cleavage of the P-O-4 linkage in phenolic structures, anthrahydroquinone (AHQ) is able to promote the... 

This chapter will deal with the chemistry and applications of epoxies, phenolics, urethanes, and a variety of current vogue high-temperature polymers. Applications in fiber-reinforced plastics will be discussed in the individual sections on resin chemistry where appropriate. Separate sections will deal with adhesives and sealants. Adhesives are most important because, as early history demonstrates, they led the way to the application of resins in aerospace. A section is also included on silicone and polysulfide sealants. Although these materials are elastomers rather than resins, no discussion of aerospace polymers would be complete without some mention. Some major thermosetting polymers have been omitted from this review. Among these are the unsaturated polyesters, melamines, ureas, and the vinyl esters. Although these products do find their way into aerospace applications, the uses are so small that a detailed discussion is not warranted. 

The polysulfide resin called for in these specifications is a dichloroethylformal polysulfide in the 1000 molecular v eight range. The accelerators are tertiairy amines consisting of a blend of 2, 4, 6-tridimethyl-aiainomethyl phenol (DKP-30), and dime thy laminoe thy 1 phenol (EMP-IO). 

A variety of two component adhesives and sealants are currently available for applications requiring the ultimate in bonding and sealing efficiency and performance. Included among these conventional systems are epoxies, urethanes, polyesters, silicones, polysulfides and some modified phenolics and acrylics. Although their performance can be and usually is quite satisfactory, most are limited by pot life and fixturing requirements - and the need for thorough substrate treatment and cleanliness. 

Toluene diisocyanate polysulfide reaction products [153]. Phenol-formaldehyde polysulfide condensation polymers [154]. 

A great many of outstanding adhesive formulations are based on epoxy resins. A broad spectrum of adhesive formulations with a wide range of available properties have resulted from the use of polymeric hardeners such as polyamides and polyamines, phenolics, isocyanates, alkyds, and combinations of amines with polysulfide elastomers, and the alloying of the epoxy with compatible polymeric film-formers, such as poly(vinyl acetate) and certain elastomers. 

Adhesive abbreviations are as follows EP, amine-cured epoxy P, polysulfide rubber flexibilizers EP/20P, EP/ 40P, and EP/60P, amine-cured epoxy with 20, 40, and 60 parts polysulfide flexibilizer EPI, emulsion polymer isocyanate ISO, isocyanate MF, melamine-formaldehyde PF, phenol-formaldehyde PF/PVA, phenol-formaldehyde flexibilized with poly(vinyl acetate) PVA, poly(vinyl acetate) PRF, phenol/resordnol-formaldehyde RF, resorcinol-formaldehyde UF, urea-formaldehyde UF/filler, UF with wheat flour UF/MF/fiUer, UF/MF copolymer with wheat flour. 

Sealant adhesion is improved by the incorporation of additives. Typical phenolic resin additives are Methylon AP-108, Durez 16674, Bakelite BRL 2741, and Resinox 468. Epoxies are also good adhesion promoters. Silanes (e.g., A-187 and A-189) are known to increase adhesion. Table 1 lists five types of sealant formulations suggested by Panek that are useful in several end applications [10]. Generally, the integral fuel tank polysulfide sealant consists of two parts 9 parts by weight of sealant base components mixed with 1 part by weight of accelerator. A typical composition is shown in Table 2. 

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