Melt-processable polyesteramides having para-linked, substituted-phenylene radicals

#This invention relates to certain aromatic polyesteramides which exhibit desirable melt processability and hhich are useful in the production of films and fibers. More particularly, it relates to aromatic polyesteramides containing para-linked, substituted-phenylene radicals interconnected by ester and amide linkages. The polyesteramides exhibit melt anisotropy at temperatures of approximately 260.degree. C. and lower, and preferably, below approximately 240.degree. C.

#The production of polyamides, polyesters and polyesteramides suitable for high strength service without the use of reinforcing agents has been well known. These polymers have been variously described as being "liquid crystalline", "thermotropic", "mesogenic", and "anisotropic". In general, these polymers are thought to be characterized by parallel ordering of their molecular chains and are prepared from monomers which are generally long, flat and fairly rigid along the long axis of the molecule. The monomers commonly have chain-extending linkages that are coaxial or parallel. Numerous patents and publications describing polyesters, polyamides and polyesteramides are cited, for example, in U.S. Pat. No. 4,351,918, issued Sept. 28, 1982 to L. F. Charbonneau, et al.

#In general, it is well recognized that the mechanical and physical properties of polymeric films and fibers will depend upon the chemical structure of the monomers from which they are prepared and that such properties can be materially influenced by such molecular factors as chain stiffness, intermolecular forces, orientation and crystallinity. Accordingly, there has been considerable interest in the development of polyesters, polyamides and polyesteramides, having particular structural or molecular configurations for the realization of one or more particular properties suited to a desired application. Notably, there has been particular interest in the development of melt processable polymers capable of forming an anisotropic melt phase and suited to processing into films and fibers.

#The following non-limiting examples are illustrative of the present invention. All percentages are by weight except as otherwise indicated.

#This example illustrates the polycondensation of 2-trifluoromethyl-4-aminophenol and 2-trifluoromethylterephthaloyl chloride.

#A solution was prepared from 2.656 gm of 2-trifluoromethyl-4-aminophenol (0.015 mole, sublimed) in ten ml of dry dimethylacetamide, ten ml of methylene chloride and 4.5 ml of triethylamine. The solution was cooled in an ice/salt bath, under nitrogen, to 0.degree. C. To the resultnng solution there was added dropwise via a syringe, while maintaining the reaction temperature between 0.degree. to 5.degree. C., a solution of 2-trifluoromethylterephthaloyl chloride (4.066 gm; 0.015 mole) in 15 ml methylene chloride. After stirring for three hours, the reaction mixture was allowed to elevate to room temperature. To the reaction mixture were added 25 ml of dimethylacetamide to provide a clear, viscous solution which was then precipitated in methanol. A white, fibrous polymer was collected by filtration and was washed with methanol and dried under vacuum. The polymer (5.91 gm; 95%) was a polymer having the structure represented by formula (VI). Inherent viscosity (measured in dimethylacetamide, at 30.degree. C. and a concentration of 0.5 gm per dl) was 0.76 dl per gram.