John Brewster Rose

Synthesis and properties of polyaryletherketones

Crystalline polyarletherketones of high molecular weight have been prepared previously by polycondensation of aroyl fluorides such as 4-phenoxybenzoyl fluoride in liquid HF, but not by polyether synthesis because these polymers are not soluble in the recommended (see Farnham et al., J. Polym. Sci., Al, 1967, 5, 2375) dipolar aprotic solvents such as dimethyl sulphoxide or sulpholane. We find that tough, crystalline polyaryletherketones and copolyaryletherketone-sulphones can be obtained by polycondensation of bis-4-halogenophenyl ketones (plus bis-4-halogenophenyl sulphones for copolymers) with the potassium salts of bis-4-hydroxyphenyl ketones at 280°–340°C using certain diaryl sulphones as solvents for the reactions. There is no evidence for structural anomalies in the polyetherketone made by polycondensation of bis-4-fluorophenyl ketone with the bis-phenoxide from bis-4-hydroxyphenyl ketone, but synthesis of this polymer by polycondensation of the potassium salt of 4-fluorophenyl 4-hydroxyphenyl ketone gave products containing some gel and soluble polymer in which the chains appear to be branched. Several different polyaryletherketones give almost identical X-ray diffraction patterns, and in the unit cells of these polymers (fibre repeat distance 10.0A) ether and carbonyl linkages are interchangeable; Tg and Tm for these polymers are recorded.

Poly(arylene ether sulphones) by polyetherification: 2. Polycondensations☆

Abstract Several alkali metal halogenophenylsulphonyl phenoxides have been polymerized in the melt and in solution. Poly(arylene ether sulphones) have also been prepared by polycondensation of 4-halogenophenylsulphonyl compounds with phenols in the presence of potassium fluoride. The effects of structural factors on the ease with which polymers of high molecular weight could be obtained were examined and found to correlate with previous data concerning functional group reactivities. A procedure for the synthesis of polymer samples containing branched macromolecules has been devised and evaluated.

Poly(arylene ether sulphones) by polyetherification: 1. Synthesis of halogenophenols

Abstract Several 4-halogenophenylsulphonylphenols, useful as intermediates for the synthesis of poly(arylene ether sulphones), have been prepared by partial hydrolysis of the corresponding dihalides and/or by the reaction of 4-halogenoarylsulphonyl chlorides with diaryl carbonates under Friedel—Crafts conditions followed by hydrolysis of the sulphonylated carbonates. The novel reagent, diphenyl carbonate-4,4′-disulphonyl chloride, has been prepared by chlorosulphonylation of diphenyl carbonate and used to introduce the 4-hydroxyphenylsulphonyl group into aryl halides, thus providing a third general route to the halogeno phenols. 4-Fluoro-3′-hydroxydiphenyl sulphone and the 4-fluoro-2′-hydroxy derivative have been synthesised by classical procedures.

Relative reactivities of the functional groups involved in synthesis of poly(phenylene ether sulphones) from halogenated derivatives of diphenyl sulphone

Initial rate constants for the self condensation of halogenophenoxides (111) in anhydrous dimethyl sulphoxide were also determined. The order of halogen reactivities found was F>CI~Br with p-halogenophenyl sulphonyl groups showing greater reactivity than the o-isomers, while displacement from the m-halogeno sulphones was very slow and comparable with the rate of sulphone bond fission. Phenoxide reactivities were found to vary in the order:

Synthesis of poly(arylene sulphones) by polycondensation of arylsulphonyl chlorides under friedel-crafts conditions

Abstract This paper reports an extension of our previous work on the synthesis of poly(arylene sulphones), and describes the preparation of these polymers by the self-condensation of certain dinuclear arylsulphonyl chlorides, catalysed by ferric chloride. In contrast with polyalkylations performed under Friedel-Crafts conditions, it is found that polysulphonylation leads to essentially linear polymers. A detailed structural examination, using i.r. and n.m.r. spectroscopy, of isomeric poly(diphenylene ether sulphones), is also described. It is shown that the structure of this polymer, prepared by different Friedel-Crafts polysulphonylation reactions, is dependent upon the structure of the monomers.

Sulphonation of poly(phenylene ether sulphone)s containing hydroquinone residues

Abstract Analysis, mainly by n.m.r. spectroscopy, shows that when copolymers comprising phenylene-ether-phenylene-sulphone and phenylene-ether-phenylene-ether-phenylene-sulphone repeat units are dissolved in 98% sulphuric acid, the ether-phenylene-ether groups are monosulphonated completely, but the other phenylene groups remain unchanged. Thus, sulphonation of these copolymers in this way provides a simple technique for preparing poly(phenylene ether sulphone)s sulphonated to a predetermined extent. The solution viscosities, glass transition temperatures and water up-take of the sulphonated copolymers increase as the extent of sulphonation is increased.

Poly(arylene ether sulfone)s by polyetherification: 5. Effects of molecular structure on toughness

Abstract Densities, glass transition temperatures and notched impact strengths (NIS) (before and after storing the test samples at 150°C) have been measured for several series of poly(arylene ether sulfone)s. Consideration of these data together with those presented in Part 4 and by other workers suggests that for polymers with molecular weights (as indicated by solution viscosity) above the entanglement molecular weight, the symmetry of the polymer chains is the most important structural factor deciding NIS. Polymers with the more symmetrical chains provided test samples showing relatively high values for NIS, while the less symmetrical ones, especially those containing phenylene rings linked by ortho - or meta -oriented inter-ring bonds, gave samples for which lower NIS values were obtained. Following recent advances defining the importance of crazing in brittle failure, it is suggested that this effect of symmetry on NIS arises because increasing asymmetry leads to higher values for the chain contour length between entanglements.

Poly(arylene ether sulphones) by polyetherication: 3. Molecular weight, molecular weight distribution and the possibility of chain branching☆

Abstract Measurements of solution viscosity, melt viscosity, and molecular weight by osmometry and by light scattering, made on a series of isomeric poly(phenylene ether sulphones) show that the reduced solution viscosities of these polymers can be taken as a useful indication of their relative molecular weights independently of their isomeric composition. Gel permeation chromatography provides confirmation for this view and indicates that these polymers contain a structural irregularity which may involve chain branching.

Structures of the poly(diphenylene ether sulphones) obtained by polysulphonylation

Abstract A study of hydrogen chloride evolution versus time curves for polysulphonylations, conducted in the presence of excesses of sulphonyl chloride groups, shows that chain branching proceeds very much more slowly than chain extension, but that branching occurs to a greater extent in reaction (iii) than in reactions (i) and (ii). The proportion of linear repeat units, I and II, and branch point units, III, are estimated by analysis of the hydrogen chloride evolution curves, and/or by an n.m.r. technique involving spectrum accumulation. The results show that high polymers obtained from reaction (iii) contain the units I, II and III in the approximate percentage proportions 90 : 10 : 1·6 respectively, while the polymers from reactions (i) and (ii) consist essentially of unit I ( ca . 99 per cent) and contain less than 0·7 per cent of the branch point units, III.