Halophosphazene polymers

US4522798A · kind A · utility

Assignee

• Ethyl Corporation · US

Inventors

• Genevieve S. Lum · Baton Rouge, US
• Hsueh M. Li · Baton Rouge, US
• F. Alexander Pettigrew · Baton Rouge, US

Key dates

• Filing date: Sep 8, 1983
• Grant date: Jun 11, 1985
• Expiry date: Sep 8, 2003

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B21/098
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A mixture of compounds of the formulas: EQU [X--(PX.sub.2 .dbd.N).sub.n --PX.sub.3 ].sup.+ [R].sup.- and EQU X--(PX.sub.2 .dbd.N).sub.n --POX.sub.2 wherein X is a halogen atom, R is X or PX.sub.6 or both of them, and n is an integer, usually below about 15, is heated either with no other reactant or with a suitable phosphorus reactant such as PX.sub.5 ; PX.sub.3 +X.sub.2 ; P+X.sub.2 ; or a mixture of two or more such phosphorus reactants so that a halophosphazene having a --PX.sub.3.sup.+ end group is formed as one of the co-products of the reaction. This co-product is a substance having the general formula EQU [X--(PX.sub.2 .dbd.N).sub.n --PX.sub.3 ].sup.+ [R].sup.- wherein X, R and n are as defined above. The other co-product is phosphoryl trihalide, POX.sub.3. In a second stage the resultant reaction product is heated with at least a stoichiometric amount (preferably, an excess) of a nitrogen source (e.g., NH.sub.3 ; NH.sub.4 Cl; etc.) so that hydrogen halide is evolved and halophosphazene polymer of a suitably high molecular weight is formed. By freeing the initial mixture of the --POX.sub.2 end group, the polymer formed in the second stage has greater linearity (less cross-lin…