Rigid-rod polymers

A process for preparing fibers of a rigid-rod polymer having monomer repeat units of the formula:

• ##STR14## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25, the process comprising wet spinning solutions wherein the dissolved solids comprise at least about 50% by weight of said polymer.

A process for preparing fibers of a rigid-rod polymer having monomer repeat units of the formula:

• ##STR15## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25, the process comprising dry jet wet spinning solutions of said polymer wherein the dissolved solids comprise at least about 50% by weight of said polymer.

A process for orienting film or fibers of a rigid-rod polymer having monomer repeat units of the formula:

• ##STR16## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25, the process comprising drawing or stretching film or fiber comprising said polymer which has been plasticized with between 0.1% and 10% solvent, wherein the solvent is removed either subsequent to or during the drawing process.

A process for coating solid articles with a rigid-rod polymer having monomer repeat units of the formula:

• ##STR17## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25, the process comprising application of a solution comprising said polymer, wherein the dissolved solids comprise at least about 50% by weight of said is polymer, followed by removal of solvent.

A process for coating solid articles with polymer compositions containing at least about 50% by weight of a rigid-rod polymer having monomer repeat units of the formula:

• ##STR18## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25, the process comprising spraying the article with molten droplets of said polymer composition.

A process for coating solid articles with polymer compositions containing at least about 50% by weight of a rigid-rod polymer having monomer repeat units of the formula:

• ##STR19## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25, the process comprising powder coating the article with said polymer composition.

A process for fabricating a composite article by pultrusion of fibers comprising a rigid-rod polymer having monomer repeat units of the formula:

• ##STR20## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25 with a lower melting thermoplastic.

A process for fabricating a composite article by pultrusion of a thermoplastic composition comprising a rigid-rod polymer having monomer repeat units of the formula:

• ##STR21## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25 with fibers which will not melt under the pultrusion conditions.

A process for orienting the polymer molecules of an article comprising a rigid-rod polymer having monomer repeat units of the formula:

• ##STR22## wherein each R.sub.1, R.sub.2, R.sub.3, and R.sub.4 on each monomer unit, independently, is H or a solubilizing side group, where at least one out of one hundred of the monomer units incorporates a solubilizing side group and wherein the polymer has a number average degree of polymerization of at least about 25 by heating and stretching the article.

A process for orienting the polymer molecules of an article comprising a segmented rigid-rod polymer having monomer repeat units of the formula:

• ##STR23## wherein ##STR24## is a repeat unit in a rigid-rod polyphenylene segment, wherein each R.sub.1, R.sub.2, R.sub.3 and R.sub.4 on each monomer repeat unit, independently, is H or a solubilizing side group, where n is the number of rigid-rod monomer units in each such rigid-rod segment, where at least one out of one hundred of the monomer units in the rigid-rod polyphenylene segments incorporate a solubilizing side group, and wherein --(A).sub.m -- are non-rigid segments, wherein the rigid-rod polyphenylene segments have a number average segment length (SL.sub.n) at least about 8, and m is 1 or greater, by heating and stretching the article.