摘要:
The present invention relates to a method of creating a carbon-heteroatom bond, and preferably a carbon-nitrogen bond, by reacting a leaving group-bearing unsaturated compound and a nucleophilic compound. In particular, the invention relates to the creation of a carbon-nitrogen bond, using a method involving the arylation of nitrogenous organic derivatives; the inventive method consists in creating a carbon-heteroatom bond by reacting a leaving group-bearing unsaturated compound and a nucleophilic compound introducing a heteroatom which can be substituted for the leaving group, thereby creating a carbon-heteroatom bond, in the presence of a palladium-based catalyst, optionally a ligand. The invention is characterized in that the reaction takes place in the presence of an effective quantity of a metal hydroxide or ammonium hydroxide which is associated with an alcohol-type solvent.
摘要:
The present invention relates to a process for preparing functionalized polyorganosiloxane (POS) resins comprising units M: (R3SiO1/2), Q: (SiO4/2) and M′: (YaR3-aSiO1/2) and optionally D: (R2SiO2/2) and/or D′: (RYSiO2/2) and T: (RSiO3/2) and/or T′: (YSiO3/2), with, in these units: R=C1-C10 alkyl or a C8-C12 aryl and Y a functional group (e.g.: Si—H), by redistribution of POS resins using POSf bearing functional units M′ and/or D′ and/or in the presence of an acid catalyst of the trifluoromethane-sulfonimide (TFSI) type. The present invention also relates to the aforementioned catalyst system.
摘要翻译:本发明涉及一种制备官能化聚有机硅氧烷(POS)树脂的方法,其包括单元M:(R 3 SiO 1/2),Q:(SiO 4) / 2)和M':(Y a a R 3-a SiO 1/2)和任选的D:(R 和/或D':(RYSiO 2/2/2)和T:(RSiO 3/2/2) 和/或T':(YSiO 3/2/2),在这些单元中:R = C 1 -C 10 - 通过使用POSf承载官能单元M'将POS树脂重新分配,通过重新分配POS树脂,以及Y为官能团(例如:Si-H) 和/或D'和/或在三氟甲烷 - 磺酰亚胺(TFSI)型的酸催化剂存在下进行。 本发明还涉及上述催化剂体系。
摘要:
A method has been developed for making regenerated cellulose yarn. The method includes the steps of spinning a solution derived from cellulose or a cellulose derivative in a molten state through at least one extrusion die, then regenerating the cellulose by treating the resulting yarn, wherein a silylated cellulose derivative is prepared by reaction with a silylating agent; the silylated cellulose is extracted from the synthesis reaction medium; then spun through at least an extrusion die; and the resultant yarn treated with a desilylation agent to regenerate the cellulose and a siloxane. The resulting cellulose yarns or fibers may be used for making woven or knitted textile surfaces or non-woven surfaces. Said yarns or fibers are also useful as reinforcing fibers in elastomeric materials and more particularly, in tires.
摘要:
The present invention relates to a process for preparing multifunctionalized polyorganosiloxanes (POSs) comprising alkoxyl functional siloxyl units and siloxyl units each having an SH functional group, which consists in introducing the SH functional group by the reaction of H2S on a precursor POS of formula: A—(RXSiO)a—(RYSiO)b—B where R is especially a C1-C6 alkyl radical, X is a C1-C15 alkoxyl radical, Y is a C2-C30 hydrocarbon group which includes an ethylenically unsaturated group from which the SH functionality derives, a is a number ranging from 1 to 150, b is a number ranging from 1 to 150, the number a+b ranging from 2 to 300 and A and B are terminal groups which are selected respectively, from, in particular, on the one hand (R)3SiO— radicals taken alone or as mixtures with (R)2XSiO— and/or R(X)2SiO— and/or (X)3SiO— radicals and on the other hand —Si(R)3 radicals taken alone or as mixtures with —SiX(R)2 and/or —Si(X)2R and/or —Si(X)3 radicals.
摘要:
The hydroxylated inorganic oxide support is functionalized by grafting at least one type of polyhydrosiloxane oil having from 10 to 200 siloxane units, the grafting being provided, on the one hand, by covalent bonds formed from a dehydrogenation/condensation reaction between Si-H groups of the polyhydrosiloxane oil and free hydroxyls of the hydroxylated support and, on the other hand, by hydrogen bonds between hydroxyls of the hydroxylated support and oxygen atoms of the polyhydrosiloxane oil, which exhibits free SiH groups.
摘要:
Novel boron/nitrogen compounds having the formula (1): ##STR1## and the products of the at least partial reduction thereof, are converted into BN ceramic materials by thermally polymerizing same, whether or not in the presence of suitable polymerization catalyst, and then pyrolyzing the boron/nitrogen polymers thus obtained.
摘要:
Acetylenic derivatives of general formula ##STR1## in which R.sub.1 denotes a hydrogen atom or a phenyl radical or a radical of general formula ##STR2## in which R.sub.2 and R.sub.3, which may be identical or different, denote a hydrogen atom or a saturated or unsaturated aliphatic radical, substituted if appropriate, or form together a cycloaliphatic radical, R.sub.4 denotes a hydrogen atom or a saturated or unsaturated aliphatic radical, a hydroxy, alkyloxy, methanesulphonyloxy, benzenesulpnonyloxy or p-toluenesulphonyloxy radical, R.sub.5 denotes a hydrogen atom or a saturated aliphatic radical, R.sub.6 denotes a hydrogen atom or a saturated or unsaturated aliphatic radical are made by reaction of an acetylenic derivative of general formulaR.sub.1 --C.tbd.C--H (III)with an allyl derivative of general formula ##STR3## in the presence of a cuprous salt and an anhydrous organic base. The compounds of formula (I) are useful in organic synthesis, in particular in the preparation of the vitamins A and E.
摘要:
Crosslinked boron/nitrogen preceramic polymers are prepared by reacting (a) admixture of a trihalogenoborane A and a compound B containing at least one dihalogenated boron atom, with (b) an amino compound C containing at least one --NH.sub.2 group; the resulting polymers are facilely pyrolyzed into boron nitride ceramic materials.
摘要:
Novel ceramic materials include a boron nitride matrix and an amount of silicon values, such ceramic materials comprising a core volume having an external sheath layer on an outer face surface thereof, with the majority of said silicon values being distributed throughout the external layer.
摘要:
Crosslinked boron/nitrogen preceramic polymers are prepared by reacting (a) admixture of a trihalogenoborane A and a compound B containing at least one dihalogenated boron atom, with (b) an amino compound C containing at least one --NH.sub.2 group; the resulting polymers are facilely pyrolyzed into boron nitride ceramic materials.