Higher poly ethers

With Phenols. The 2-hydroxylethyl aryl ethers are prepared from the reaction of ethylene oxide with phenols at elevated temperatures and pressures (78,79). 2-Phenoxyethyl alcohol is a perfume fixative. The water-soluble alkylphenol ethers of the higher poly(ethylene glycol)s are important surface-active agents. They are made by adding ethylene oxide to the alkylphenol at ca 200°C and 200—250 kPa (>2 atm), using sodium acetate or... 

A number of higher poly(vinyl ether)s, in particular the ethyl and butyl polymers, have found use as adhesives. When antioxidants are incorporated, pressure-sensitive adhesive tapes from poly(vinyl ethyl ether) are said to have twice the shelf life of similar tapes from natural rubber. Copolymers of vinyl isobutyl ether with methyl acrylate and ethyl acrylate (Acronal series) and with vinyl chloride have been commercially marketed. The first two products have been used as adhesives and impregnating agents for textile, paper and leather whilst the latter (Vinoflex MP 400) has found use in surface coatings. 

Poly ethers were next synthesized from isosorbide by means of a MW-assisted PTC method (Eq. 10). In addition to increasing the rate of the reaction, the MW affected the structure of the polymer (determined by MALDI/TOF mass spectrometry Tab. 5.7). Polymers of higher molecular weights, with ethylenic groups as chain terminations, were obtained conventional heating led to shorter hydroxylated compounds [21]. 

Thermooxidative stability of the fluorine-containing poly(ether ketone) (11) and poly(sulfide ketone) (13) from 15 is very high. The 5% weight-loss temperatures (DT5) are 391 and 436°C for poly(ether ketone) and poly(sulfide ketone) analogues having no fluorine atoms, whereas those of poly(ether ketone) (11) and poly(sulfide ketone) (13) are higher than 500°C. 

Of all the hydrocarbon-based PEMs, this group most likely has the largest variety of different systems. This is probably due to the wealth of prior knowledge of the nonsulfonated analogues that have been developed over the last several decades as well as the general expectation of higher thermal stability, better mechanical properties, and increased oxidative stability over polystyrene-based systems. Within the context of this section, polyarylenes are systems in which an aryl or heteroaryl ring is part of the main chain of the polymer. This section will, therefore, include polymers such as sulfonated poly (ether ether ketone) and sulfonated poly(imides) but will not include systems such as sulfonated polystyrene, which will be covered in Section 3.3.I.3. 

Sulfonated poly(arylene ether)s (SPAEKs) have also been developed for application in PEMs, with sulfonated poly(ether ether ketone) (SPEEK) (9a) as the archetypical example of this group. The base polymer of SPEEK is commercially available and relatively cheap, and sulfonation is a straightforward procedure using concentrated sulfuric acid. At sufficient levels of sulfonation, proton conductivity values for SPEEK are comparable to or higher than those of Nafion. However, this does lead to random copolymers where there... 

Is)max as shown in the diagrams of Figures 17-19 for the three prepolymer types discussed before (polyester, polyether, and polybutadiene). In the examples shown (Is)m ax is about equal for a poly ether (all polypropylene oxide) and a polyester (ca. 49 parts poly (neopentyl glycol) azelate, 35 parts poly (tripropylene glycol) azelate, 10 parts bis (2-ethyl-hexyl) azelate, 6 parts glycerolmonoricinoleate), and about 2 points higher for a polybutadiene binder (ca. 75 parts polybutadiene and 25 parts of a saturated hydrocarbon as plasticizer). 

CD are very rigid molecules and polyrotaxanes derived from them are expected to be more rigid than the starting backbone. Poly(methyl methacrylate side chain rotaxane) 56 had a Tg 20°C higher than the backbone itself. The same observation was also seen in side chain poly(ether ketone) and poly(ether sulfone) systems [96-102]. 

Whereas UL 94 delivers only a classification based on a pass-and-fail system, LOI can be used to rank and compare the flammability behavior of different materials. In Figure 15.2 the increasing LOI values are presented for different polymers as an example POM = poly(oxymethylene), PEO = poly(ethyl oxide), PMMA = poly(methyl methacrylate), PE = polyethylene), PP, ABS, PS, PET = polyethylene terephthalate), PVA = poly(vinyl alcohol), PBT, PA = poly(amide), PC, PPO = poly(phenylene oxide), PSU, PEEK = poly(ether ether ketone), PAEK = poly(aryl ether ketone), PES, PBI = poly(benzimidazole), PEI = poly(ether imide), PVC = poly(vinyl chloride), PBO = poly(aryl ether benzoxazole), PTFE. The higher the LOI, the better is the intrinsic flame retardancy. Apart from rigid PVC, nearly all commodity and technical polymers are flammable. Only a few high-performance polymers are self-extinguishing. Table 15.1 shows an example of how the LOI is used in the development of flame-retarded materials. The flame retardant red phosphorus (Pred) increases... 

Blends of poly(ether sulfone) 300 with the poly(hydroxyether) of bisphenol A proved to be quite homogenous and had better thermal stability, though phase separations occurred at higher temperatures <2003PLM867>. As a... 

The polymerization takes place with coupling at the C4 position of the 1-naphthoxy group. The restricted rotation about the C4—C4 binaphthyl bond of the poly(ether sulfone)s and poly(ether ketone)s resulted in higher glass transition temperatures than the analogous biphenyl poly-... 

An increase in M is also reported to increase the temperature at which a shear to craze transition occurs in both PC and poly(ether sulfone) (PES) and, above the transition temperature, the craze strain, or stress, is greater for the higher molecular weight samples These changes are a result of a greater resistance to disentanglement in the higher M polymers. 

Organic matrices are divided into thermosets and thermoplastics. The main thermoset matrices are polyesters, epoxies, phenolics, and polyimides, polyesters being the most widely used in commercial applications (3,4). Epoxy and polyimide resins are applied in advanced composites for structural aerospace applications (1,5). Thermoplastics Uke polyolefins, nylons, and polyesters are reinforced with short fibers (3). They are known as traditional polymeric matrices. Advanced thermoplastic polymeric matrices like poly(ether ketones) and polysulfones have a higher service temperature than the traditional ones (1,6). They have service properties similar to those of thermoset matrices and are reinforced with continuous fibers. Of course, composites reinforced with discontinuous fibers have weaker mechanical properties than those with continuous fibers. Elastomers are generally reinforced by the addition of carbon black or silica. Although they are reinforced polymers, traditionally they are studied separately due to their singular properties (see Chap. 3). 

Figure 12 shows the influence of the nominal draw ratio on the tensile properties for the poly(ether ester) C. The initial tensile modulus was nearly independent of the draw ratio. A higher strains the modulus increased proportionally to the draw ratio. As can be seen from Fig. 13, the effect of the extrusion velodty on the tensile properties was rather small. 

Not surprisingly a number of other poly(aryl ethers) have been prepared from aromatic dihalides not containing sulphone links. For example, a number have been prepared from difluorobenzophenone and, in general, it is found that such materials have TgS about 30-40°C lower than the corresponding sulphone polyether. In fact it is generally found that the higher Tg values are obtained with the sulphone poly ethers. 

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