Abstract: An aromatic polyether contains within its chain the repeat units--Ph--CO--Ph-- I--?Ph--SO.sub.2 --Ph!n-- IIat a molar ratio I/II in the range 98:2 to 80:20 where Ph represents paraphenylene; the repeat units are linked through ether oxygen; and n is at least 1.1.It can be made by reacting together hydroxy and halogeno aromatic compounds corresponding to units I and II and to any minor units that are to be present. The reactants can be provided at least partly by a polymer containing an ether-linked succession of the units.

Abstract: An aromatic polyether contains within its chain the repeat units--Ph--CO--Ph-- I--[Ph--SO.sub.2 --Ph]n-- IIat a molar ratio I/II in the range 98:2 to 80:20 where Ph represents paraphenylene; the repeat units are linked through ether oxygen; and n is at least 1.1. pa It can be made by reacting together hydroxy and halogeno aromatic compounds corresponding to units I and II and to any minor units that are to be present. The reactants can be provided at least partly by a polymer containing an ether-linked succession of the units.

Abstract: according to the present invention (1) a titanium trihalide is ground in the presence of from 5 up to 75% molar, relative to the titanium trihalide, of (2) a Lewis Base compound which is an organo-phosphorus compound of the formulaR.sub.1 R.sub.2 R.sub.3 P(O).sub.aand either (a) from 1 up to 50% molar, relative to the titanium trihalide, of a titanium tetrahalide and/or (b) from 0.2 up to 50% molar, relative to the titanium trihalide, of an oxidizing agent, wherein when a titanium tetrahalide is present, the molar quantity of the organo-phosphorus compound is at least equal to the molar quantity of the titanium tetrahalide.The titanium halides (1) and (a) are preferably the chlorides. Suitable forms of titanium trichloride are obtained by the reduction of titanium tetrachloride with hydrogen, titanium metal, aluminum metal or an organo-aluminium compound.

Abstract: a process is provided in which a solid compound of a transition metal of Groups IVA to VIA is ground with at least one polymeric material containing sulphone groups and containing at least two repeat units of the formula:--Ar--SO.sub.2 --in which Ar is a bivalent aromatic radical and may vary from unit to unit in the polymer chain. The Ar radical preferably contains two aromatic rings linked together, as in: ##STR1## where X is an O or S atom, a direct link or the residue obtained by removing H from each --OH group present in an aromatic diol. If Ar varies the material is a copolymer. The polymeric material can be a polyethersulphone.The transition metal can be zirconium, vanadium or titanium. Preferably the transition metal compound is a halide such as titanium trichloride.