Poly alkyl and aromatic ethers

5 Poly(alkyl and aromatic ethers) - Organic acids accelerate the photodegradation of poly(isobutylene oxide) while epoxy glass fiber composites can be 

The major product is the ketodiester with methanol as a major volatile. The photoyellowing is associated with polyconjugation formed via the dehydration of hemiacetals. 

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Poly(alkyl and aromatic ethers) - Using laser flash photolysis poly(2,6-dimethyl-l,4-phenylene oxide) undergoes scission at the phenolic link to give phenoxy radicals . Poly(vinyl methyl ether) has been shown to undergo a complex series of photoprocesses as shown in Scheme 2. ... 

Other macromolecules are formed by condensing their monomers to form a repeat functional group (e.g., esters, amides, ethers) interspersed by alkyl chains, aromatic rings, or combinations of both. These condensations are characterized frequently, although not always by the loss of some by product (e.g., water, alcohol). The methods of formation of these polymers are far more varied than those of addition polymers. Examples of condensation polymers are (a) poly(esters), (b) poly(urethanes), (c) poly (carbonate), and (d) polyphenylene oxide). 

The lower members of the homologous series of 1. Alcohols 2. Aldehydes 3. Ketones 4. Acids 5. Esters 6. Phenols 7. Anhydrides 8. Amines 9. Nitriles 10. Polyhydroxy phenols 1. Polybasic acids and hydro-oxy acids. 2. Glycols, poly-hydric alcohols, polyhydroxy aldehydes and ketones (sugars) 3. Some amides, ammo acids, di-and polyamino compounds, amino alcohols 4. Sulphonic acids 5. Sulphinic acids 6. Salts 1. Acids 2. Phenols 3. Imides 4. Some primary and secondary nitro compounds oximes 5. Mercaptans and thiophenols 6. Sulphonic acids, sulphinic acids, sulphuric acids, and sul-phonamides 7. Some diketones and (3-keto esters 1. Primary amines 2. Secondary aliphatic and aryl-alkyl amines 3. Aliphatic and some aryl-alkyl tertiary amines 4. Hydrazines 1. Unsaturated hydrocarbons 2. Some poly-alkylated aromatic hydrocarbons 3. Alcohols 4. Aldehydes 5. Ketones 6. Esters 7. Anhydrides 8. Ethers and acetals 9. Lactones 10. Acyl halides 1. Saturated aliphatic hydrocarbons Cyclic paraffin hydrocarbons 3. Aromatic hydrocarbons 4. Halogen derivatives of 1, 2 and 3 5. Diaryl ethers 1. Nitro compounds (tertiary) 2. Amides and derivatives of aldehydes and ketones 3. Nitriles 4. Negatively substituted amines 5. Nitroso, azo, hy-drazo, and other intermediate reduction products of nitro com-pounds 6. Sulphones, sul-phonamides of secondary amines, sulphides, sulphates and other Sulphur compounds... 

Alkylated aromatic lubricants, phosphate esters, polyglycols, chlorotrifluoroethylene, siUcones, and siUcates are among other synthetics that came into production during much that same period (28,29). Polyphenyl ethers and perfluoroalkyl polyethers have followed as fluids with distinctive high temperature stabiUty. Although a range of these synthetic fluids find appHcations which employ their unique individual characteristics, total production of synthetics represent only on the order of 2% of the lubricant market. Poly(a-olefin)s, esters, polyglycols, and polybutenes represent the types of primary commercial interest. 

Dimethyl sulfate alkylates almost quantitatively sterically hindered aromatic poly(pyridine ether)s and poly(pyridine ether sulfone)s in nitrobenzene. The reaction can be illustrated as follows ... 

Scheme 13.2 Selected phosphonated aromatic backbone polymers (a) phospho-nated pol5 aiylene ether),(b) phosphonated poly(phenyl sul-fone), (c) poly(m-phenylene-5-phosphonic acid), (d) PAES with a phosphonic acid group directly attached to the aromatic backbone, (e) methylenephosphonic acid functionalized PAES, (f) PAES with a phosphonated aUgrl chain, (g) PAES bearing a bis(phosphonic acid) on short alkyl chains, and (h) PAES with a pendant phenyl-CF2P03H2 group. ...

The poly(phenylene oxide)s are also referred to as polyoxyphenylenes and poly(phenylene ether)s. Variations in the configuration of the ether group, ie, ortho, meta, or para, and in the extent and type of substitution, eg, alkyl, halo, etc, on the aromatic backbone give rise to a large number of possible homo- and copolymers. The polymers with para-oriented ethers have been studied most extensively and several have significant utility. Poly(2,6-dimethyl-l,4-phenylene oxide) [25134-01-4] (DMPPO), prepared by General Electric by the oxidative coupling polymerization of 2,6-dimethylphenol, is marketed as PPO resin. Blends of... 

Because of good thermal and hydrolytic stability, excellent mechanical and chemical stability, low cost, and commercial availability of sulfonated aromatic hydrocarbon polymers, recent research has focused on the synthesis and development of sulfonated aromatic hydrocarbon polymers specifically for high-temperature PEMFCs. Typical examples include sulfonated poly(ether ether ketone) (SPEEK) or poly(ether ketone ketone) (SPEKK) [1,2], sulfonated poly(ether sulfone) (SPSE) [3], alkyl sulfonated polybenzimidazole (PBI), sulfonated naphthalenic polyinrides (sNPl) [4-6], sulfonated polyCphenylene sulfide) [7,8]. Both post- and pre-sulfona-tion methods have been used in the past. Other than the post-sulfonation modification of aromatic polymers, recently, efforts have been dedicated to direct polycondensation from sulfonic acid containing monomers to synthesize sulfonated polymers [9]. The latter approach, namely pre-sulfonation, is widely applied because of the ease of controlling sulfonation degree and deactivated sites in the arylene backbones, which further avoid side reactions such as decomposition and hydrolysis of polymers resulted from the post-sulfonation method. 

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