Abstract: The invention relates to ZrO2-reinforced mullite fibers having a content of at least 0.1 wt. % of crystalline ZrO2, said mullite fibers being distinguished by significantly improved mechanical properties compared to unmodified mullite fibers. The invention further relates to processes for manufacturing such fibers, green fibers produced as an intermediate product in the process, and the use of the ZrO2-reinforced mullite fibers in fibre-matrix composite materials.

Abstract: A compound of formula (I) wherein: M is selected from Mo or W; X is selected from O or NR5; R1 and R2 are independently selected from H, C1-6 alkyl, and aryl; C1-6 alkyl and aryl optionally being substituted with one or more of C1-6 alkyl, C1-6 alkoxy, and O—C6H5; R3 is selected from a nitrogen-containing aromatic heterocycle being bound to M via said nitrogen; and from halogen; R4 is an aryl oxy group being bound to M via said oxygen of said aryl oxy group; wherein said aryl group Ar of said aryl oxy group is bound to a group Cat such to form a cationic ligand Cat+-Z—ArO—, wherein Z is either a covalent bond or a linker; R5 is alkyl or aryl, optionally substituted.

Abstract: The invention relates to a process for producing carbon fibers from cellulosic fibers, characterized in that cellulosic fibers, which contain a sulfonic acid salt of formula (I), wherein R1 represents a hydrocarbon group and K+ represents a cation, are converted into carbon fibers.

Abstract: A method for producing films, fibers, and moldings of a polybenzazole polymer (P) by reacting at temperatures of 0 to 120° C. a mixture including (a) aromatic dicarboxylic compound(s) (I): wherein Ar1 is optionally substituted phenylene, naphthalenediyl, anthracenediyl, biphenyldiyl, diphenylmethanediyl, diphenyl ether diyl, diphenyl thio ether diyl, diphenyl sulfone diyl, benzophenonediyl, pyridinediyl, pyrimidinediyl, furandiyl, or thiophenediyl, substituents being —F, —Cl, —Br, —OR1, and —C1-C10-alkyl, R1 being —H or —C1-C10-alkyl; X1 and X2 are independently-OR2, —F, —Cl, or —Br, R2 being —H, —C1-C10-alkyl, —C1-C10-alkenyl or a repeating unit (a): wherein m is a natural number from 1 to 50, and R3 is —H, C1-C10-alkyl, or C1-C10-alkenyl; (b) aromatic diamino compound(s) of formula (IIa), (IIb), (IIc) and/or (IId); (c) at least one ionic liquid (IL), to obtain a product, processing the product at temperatures 0 to 100° C. and heating of the articles obtained at temperatures of 250 to 500° C.

Abstract: The invention relates to a process for producing carbon fibers from cellulosic fibers, characterized in that cellulosic fibers, which contain a sulfonic acid salt of formula (I), wherein R1 represents a hydrocarbon group and K+ represents a cation, are converted into carbon fibers.

Abstract: The invention relates to an N-heterocyclic carbene complex of general formulas I to IV (I) (II) (III) (IV), according to which A1 stands for NR2 or PR2, A2 stands for CR2 R2?, NR2, PR2, 0 or S, A3 stands for N or P, and C stands for a carbene carbon atom, ring B is an unsubstituted or a mono or poly-substituted 5 to 7-membered ring, substituents R2 and R2? stand, inter alia, for a linear or branched C1-Cw-alkyl group and, if N and N each stand for NR2 or PR2, are the same or different, M in formulas I, II, III or IV stands for Cr, Mo or W, X 1 or X2 in formulas I to IV are the same or different and represent, inter alia, C1-C1s carboxylates and C1-C1s-alkoxides, Y is inter alia oxygen or sulphur, Z is inter alia a linear or branched C1-Cw-alkylenoxy group, and R 1 and R1? in formulas I to IV are, inter alia, an aliphatic or aromatic group.

Abstract: A method of producing carbon fibers from cellulose fibers comprises bringing cellulose fibers having a water content of more than 20 parts by weight of water per 100 parts by weight of cellulose fiber into contact with a solution of additives and thereafter converting the additized cellulose fibers comprising not less than 1 part by weight of additives per 100 parts by weight of cellulose into carbon fibers.

Abstract: The invention relates to an N-heterocyclic carbene complex of general formulas I to IV (I) (II) (III) (IV), according to which A1 stands for NR2 or PR2, A2 stands for CR2 R2?, NR2, PR2, 0 or S, A3 stands for N or P, and C stands for a carbene carbon atom, ring B is an unsubstituted or a mono or poly-substituted 5 to 7-membered ring, substituents R2 and R2? stand, inter alia, for a linear or branched C1-Cw-alkyl group and, if N and N each stand for NR2 or PR2, are the same or different, M in formulas I, II, III or IV stands for Cr, Mo or W, X 1 or X2 in formulas I to IV are the same or different and represent, inter alia, C1-C1s carboxylates and C1-C1s-alkoxides, Y is inter alia oxygen or sulphur, Z is inter alia a linear or branched C1-Cw-alkylenoxy group, and R 1 and R1? in formulas I to IV are, inter alia, an aliphatic or aromatic group.

Abstract: Latent photoactivatable precatalysts are provided for metathesis polymerization and has the general formula (Ru(NHC)n(X1)m(L)0p+((X2)?)p. Wherein NHC is an N-heterocyclic carbene, n=1 or 2; X1 is a C1-C18 mono or polyhalogenized carbolic acid or trifluoromethane sulfate; X2 is a C1-C18 mono or polyhalogenized carbolic acid, trifluoromethane sulfate, tetrafluoroborate, hexafluorophosphate, or hexafluoroantimonate; m=0, 1, or 2 and L=a C4-C18 carbolic acid nitrile or a C4-C18 carbolic acid di or trinitrile; o=6?n?m or 5?n?m and p=2?m.