摘要:
A method for making a phosphonitrile halide of the formula (X(PX 2 =N) a PX 3 )) + A - wherein X represents a halogen, A represents X or (PX 6 ) - , and a is an integer of from 1 to 9, comprises a first step of reacting PX 5 and a disilazane under cooling in an inert non-chlorinated solvent and a second step of heating the reaction mixture to at least 50°C for a time sufficient to produce the phosphonitrile halide. The method may also include a third step of adding a cyclosiloxane of the formula ((CH 3 ) 2 SiO) b , wherein b is an integer of from 3 to 6, to the reaction mixture resulting from the second step to form a phosphonitrile halide containing species of the formula Z-((CH 3 ) 2 SiO) b -Z wherein Z is X or a group OPX 2 (NPX 2 ) a NPX 2 -, the phosphonitrile halide containing species having at least one group of the formula OPX 2 (NPX 2 ) a NPX 2 -. Also disclosed is the use of the phosphonitrile halide made by the method of the present invention as a catalyst for the polymerisation of organopolysiloxanes.
摘要:
L'invention a pour objet un procédé de préparation de compositions de polydichlorophosphazènes renfermant une teneur contrôlée d'oligomères cycliques. Le contrôle de cette teneur est obtenu par action sur la concentration du monomère (P₂ NO Cl₅ ou P₂ NS Cl₅) dans la solution dudit monomère soumis à polycondensation. L'invention concerne également des compositions renfermant ledit taux contrôlé d'oligomères cycliques.
摘要:
L'invention concerne la préparation de polychlorophosphazène. Le procédé est caractérisé en ce que le polymère est préparé par polycondensation de N(dichlorophosphoryl)trichlorophosphazène en présence d'une amine tertiaire. La présence d'amine tertiaire permet d'accroître notablement la vitesse de la réaction de polycondensation.
摘要:
Cyclic dichlorophosphazene trimer which is substantially pure except for catalytic impurities is purified by treating the trimer in the liquid phase with P 2 O 5 for 10-30 minutes at a temperature of 120-170°C. and atmospheric pressure, then subjecting the reaction mix to a single further purification step by sublimation, melt filtration, or distillation. The purified trimer will not polymerize in the absence of added catalyst at 300°C. or below.
摘要:
The oligomer content in crude polydichlorophosphazene polymer is reduced to less than about 7% by a continuous process wherein the crude polymer in solution is introduced into an extruder along with solvent selective for the oligomer whereby polymer coagulates and liquid phase rich in oligomer is formed and is prevented from exit at the polymer discharge end of the extruder by the concentration and coagulation of the polymer and is separated from the concentrated polymer upstream of the polymer discharge end by mechanical filtering.
摘要:
Linear phosphonitrilic chloride polymers are produced from linear phosphonitrilic chloride oligomers by means of a two-step process. In the first step a mixture of linear phosphonitrilic chloride oligomer having an average degree of polymerization of at least 4 is heated with an excess of ammonia or ammonium chloride. Cyclic phosphonitrilic chloride oligomer formed during the course of the first step is removed from the reaction mixture. After the removal of the cyclic oligomer the reaction mixture is subjected to the second step which involves heating the mixture in an inert liquid solvent (optionally in the presence of ammonia or amonium chloride) whereby the molecular weight of the linear phosphonitrilic chloride polymer is increased.
摘要:
Polychlorophosphazènes lineaires de formule générale: avec n égal ou supérieur à 4 et présentant le spectre infrarouge annexe (fig. 1). Ils sont préparés par polycondensation par chauffage du P trichloro-N dichlorophosphorylmonophosphazène avec libération contrôlée de POCl 3 suivant le schéma:
Utilisation pour la préparation de polyorganophosphazènes par substitution. Application notamment en tant que matériaux antiflamme, en tant que revêtements, en tant que fertilisants.
摘要:
L'invention a pour objet un procédé de régulation des masses moléculaires des polydichlorophosphazènes. Ce procédé, qui permet de réduire la masse moléculaire à une valeur déterminée, consiste à chauffer le polydichlorophosphazène en présence d'oxychlorure de phosphore. Les polydichlorophosphazènes peuvent conduire, après substitution, à une large gamme de polyorganophosphazènes.