Polymers arylether

A large variety of newer poly(ether imide)s has been described. Included among these are perfluorinated polymers (96), poly(ester ether imide)s (97), poly(ether imide)s derived from A/,Ar-diamino-l,4,5,8-naphthalenetetracarboxyHcbisimide (98), and poly(arylene ether imide ketone)s (99). In addition, many other heterocyHc groups have been introduced into polyether systems, eg, poly(pyrazole ether)s (100) and poly(aryl ether phenylquinoxaLine)s (101) poly(aryl ether oxazole)s with trifluoromethyl groups (102) and polyethers with other heterolinkages, eg, poly(arylether azine)s (103). 

Miller, Neenan, et al.129,301 reported a general single-pot method (Scheme 6.5) for the preparation of poly(arylether) hyperbranched macromolecules (14 a-d), that are functionally analogous to linear poly(arylether) engineering plastics.129-3 1 The hyperbranched polymers were generated from phenolic A2B-type monomers (15 a-d), that were converted to the corresponding sodium phenoxides (16 a-d NaH, THF) and subjected to polymerization. 

Libanati, C., C. LaMarca, M.T. Klein, S.M. Andrews, and R.J. Cotter, Thermal Degradation ofPoly (arylether)Sulfones 2. Monte Carlo Simulation of Polymer Structure, Reaction and Diffusion., ACS Div. of Fuel Chem. Prep., 36, (2), 655-663, 1991. 

Ballard Advanced Materials (BAM) ionomers are sulfonated copolymers of trifluorostyrene and substimted trifluorostyrene monomers. BAM, a subsidiary of Ballard Power Systems, investigated the conducting polymers based on polyphenylquinoxaline (PPQ). These can be sulfonated in a wide range and were referred to as BAMIG (Ballard first generation) membranes, but these membranes were found to have short durability. To overcome this problem, BAM developed a second generation of advanced membranes based on two distinct material types. The first material type consisted of a series of sulfonated poly(2,6-diphenyl 1,4-phenylene oxide). The second material type consisted of a series of sulfonated poly(arylether sulfone). But the durability of these membranes was also insufficient. Since the durability of previous membranes was limited, Ballard produced a novel family of sulfonated membranes based on a,p,p-ttifluorostyrene monomers and a series of substituted ttifluoro-comonomers... 

Furthermore, in 2001, Ballard entered an alliance with Victrex to produce two new membrane alternatives. One membrane is based on sulfonated poly(arylether) ketone (a variant of PEEK) supplied by Victrex, which may be better suited to PEMFC fabrication applications. In March 2002, U.S. Patent 6,359,019 was issued to Ballard Power for a graft-polymeric membrane in which one or more trifluorovinylaromatic monomers are radiation graft polymerized to a preformed polymeric base. The strucmres of BAM membranes have been studied by way of small-angle neutron scattering (SANS) [97]. The study of the ionomer peak position suggests the existence of relatively small ionic domains compared to Nalion, despite large water content. Phase separation in the polymer matrix is possibly crucial for the membrane s mechanical and transport properties. 

Within the realm of BAM2G membranes, a series of partially fluorinated bisphenol A-type poly(arylether) sulfones were synthesized. As mentioned above, these materials initially exhibited acceptable, useful service-life performance, but were unable to provide more than 500 h of continuous running time. This led to the decision that a perfluorinated backbone would be most beneficial in achieving fuel cell longevity in performance and efficiency. Therefore, the a, 3,p-trifluorostyrene monomer was chosen as the most suitable platform on which to build BAM3G polymers [98]. The BAM3G has demonstrated over 100,000 h of cumulative performance in a wide variety of Ballard fuel cell hardware. The BAM3G membranes have... 

Jurs, J.L. Tour, J.M. Novel flame retardant poly-arylethers synthesis and testing. Polymer 2003, 44. 

In applying PALS to characterize free volume in semicrystalUne polymers, early studies suggested that positronium annihilation occurs exclusively in the amorphous phase. Thus, Nakanishi and co-workers [Nakanishi et al., 1989 Nakanishi and Jean, 1991] found in PALS studies of poly(arylether ether ketone) (PEEK) a linear relationship between I3 and percent crystallinity (Xc) ... 

In the case of an azobenzene-modified poly(arylether ketone amide) (see Chart 5.2), a pronounced volume contraction due to photo-induced trans-cis isomerization of the azobenzene groups was evidenced by means of size-exclusion chromatography (SEC) [25]. When irradiated in dilute N,JV-diethylacetamide solution, this polymer underwent a reduction in its hydrodynamic radius by a factor of 2.7, corresponding to a contraction of the hydrodynamic volume by a factor of about 20. This pronounced shrinkage effect is believed to be due to a large number of conformationally restricted backbone segments, because other more flexible polyamides and polyurea polymers exhibit much weaker contraction effects. 

Many kinds of AEMs based on quatemized polymers containing a quaternary ammonium group have been developed and tested in ADAFC, such as polyethersulfone cardo (QPES-C) [205], polyetherketone cardo (QPEK-C) [206], poly (phthalazinone ethersulfone ketone) (QPPESK) [207], poly(arylene ethersulfone) (QPAES) [208-210], QPAES cross-linked with tetraphenylolethane glycidyl ether (QPAES/4EP) [210], poly (arylether oxadiazole) (QPAEO) [211], poly styrene-block-poly (e thy lene-ran-butylene)-block-poly styrene (QSEBS) [212], poly(vinyl alcohol) (QPVA) [213], poly(vinyl chloride) (QPVC) [214], and poly (vinylbenzyl chloride) (QPVBC) [215]. The chemical structures of some of these polymers are shown in Fig. 6.13. 

Recently, Abd-El-Aziz and colleagues reported different hyperbranched poly(arylethers) (4,5) and poly(arylthioethers) (6) containing cyclopentadienyliron moieties, which were successfully furnished by nucleophilic substitution of A + Bj type monomers (Scheme 2.3) [54], The polymers were thoroughly characterized by standard spectroscopic analysis techniques, they exhibited generally low viscosities, and the organometallic complexes were stable up to 230 °C, as evaluated by thermal gravimetric analysis (TGA). 

However, the benzonitrile arylether polymers had no outstanding properties which would render them commercially... 

Polyketones are sulfonated by reaction with chlorosulfonic acid (see Chapter 5, p 162) and sulfonated aromatic polyether-polyketones have been obtained by treatment with mixtures of sulfur trioxide and chlorosulfonic acid. The sulfonated polymers are compression mouldable at high temperatures. Poly(arylether ketone) fibres of good dyeability were produced by treating the fibres with chlorosulfonic acid, sulfuric acid or sulfur trioxide. ... 

The Tg s for the poly(arylether oxadiazole)s 5a, 5b, and 5c were 205 C, 277 and 216 C, respectively, and for 6a and 6b were 234 C and 288 Cl, respectively. Thermal gravimetric analysis of 5b reveals that the polymer exhibits initial weight loss in air at 475 C (scan rate = 20 C/min.) whereas 6b exhibits initial weight loss in air at 405 C. Therefore, PAEO s prepared from 1 are predicted to show improved thermal stability compared to the PAEO s prepared from 3. 

Polymers containing arylamide units have been prepared by forming the amide bonds directly during polymerization or by using monomers that contain amide units and linking them, e.g. by nucleophilic substitution, to form poly(arylether amide)s. for example, Baek and Harris [119] prepared two self-polymerizable AB2 amide monomers, namely W,W -bis(4-fluorobenzoyl)-3,4-diamino-4 -hydroxydi-phenylether (Table 2, entry 1) and W,W -bis(4-fluorobenzoyl)-3,5-diamino-4 -hydroxybenzophenone (Table 2, entry 2), and polymerized them to afford a hb poly(aryl ether amide) and a hb poly (aryl ether ketone amide). The aryl fluoride-... 

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