Abstract: The invention described herein provides a process for recycling a mixed polymer recycle stream containing polyester polymers, particularly polyethylene terephthalate (PET) typically in the form of carbonated soft drink or other containers. This novel process includes the steps of: (1) contacting the mixed polymer recycle stream with a solvent which selectively dissolves the PET. (2) separating the selective solvent containing PET from the residual mixed polymer, (3) cooling the selective solvent to precipitate the PET, and (4) removing the selective solvent from the precipitated PET. It is preferable that the mixed polymer recycle stream be prepared for recycling by conventional steps, such as water washing. In a preferred embodiment, the mixed polymer recycle stream is chemically washed subsequent to water washing and prior to contact with the selective solvent. The PET recovered is preferably combined with "virgin" PET and further processed to increase its molecular weight.

Abstract: A method for fabricating a monolithic polybenzbisazole article including the steps of:(a) dissolving at least one benzbisazole polymer in a strong acid at an elevated temperature;(b) transferring the resulting solution to a mold;(c) cooling the solution in the mold to a temperature below the gelation temperature of the acid-polymer mixture, thus providing a polymer-acid gel;(d) ageing the gel for about 0.25 to 10 days;(e) replacing the acid in the gel with water;(f) replacing the water in the gel with a lower aliphatic alcohol; and(g) densifying the gel.

Abstract: A stabilized polymer composition comprising a linear alternating polymer of carbon monoxide and at least one ethylenically unsaturated hydrocarbon, at least one melt stabilizing agent selected from the group consisting of titanium alkoxides. A process of preparing the composition and articles of manufacture produced from the composition are also disclosed.

Abstract: There are provided novel rod-like heterocyclic aromatic copolymers having peating groups of the formula: ##STR1## wherein n has a value of 0.01 to 0.50, wherein Ar is a para-oriented aromatic group and Q is an aromatic heterocyclic group of the formula: ##STR2## wherein Y is --S--, --O-- or --NR--, wherein R is selected from the group consisting of --H, alkyl having 1 to 4 carbon atoms, and aromatic having 1 or 2 aromatic rings.

Abstract: There are provided novel rod-like heterocyclic aromatic polymers having repeating groups of the formula: ##STR1## wherein Y is --S--, --O-- or --NR--, R is -H, an alkyl group having 1 to 4 carbon atoms or an aromatic group having 1 or 2 aromatic rings, and the bullet symbol (.cndot.) indicates hydrogen bonding.

Abstract: There are provided novel rod-like heterocyclic aromatic polymers having repeating groups of the formula: ##STR1## wherein Y is --S--, --O-- or --NR--, R is --H, an alkyl group having 1 to 4 carbon atoms or an aromatic group having 1 or 2 aromatic rings, and the bullet symbol (.cndot.) indicates hydrogen bonding.

Abstract: There are provided novel rod-like heterocyclic aromatic copolymers having repeating groups of the formula: ##STR1## wherein n has a value of 0.01 to 0.50, wherein Ar is a para-oriented aromatic group and Q is an aromatic heterocyclic group of the formula: ##STR2## wherein Y is --S--, --O-- or --NR--, wherein R is selected from the group consisting of --H, alkyl having 1 to 4 carbon atoms, and aromatic having 1 or 2 aromatic rings.