Abstract: A novel process is disclosed for preparing a high melt viscosity block co-polyester of at least two different linear polyesters. The process comprises melt blending the polyesters and, thereafter, subjecting the melt blended polyesters to a temperature of 10.degree.-50.degree. C. below the melting point of the lowest melting ingredient in the blend until the melt viscosity has increased to at least 10,000 poises at a temperature 10.degree.-15.degree. C. above the melting point of the blend.

Abstract: Shaped articles comprising a branched, high molecular weight poly(alkylene terephthalate) polyester resin and obtained by providing a molten, self-supporting preform of the resin, shaping the molten preform into a final form and allowing the shaped preform to cool to structural rigidity.

Abstract: A foamable thermoplastic injection moldable composition comprising in admixture (a) a polyester resin, (b) a filler selected from the group consisting of fibrous glass or a mineral or mixtures thereof in an amount of from about 5 to about 50 weight percent and (c) a minor amount of a foaming agent. The compositions can also include flame retardant additives.

Abstract: Novel thermoplastic molding compositions are disclosed which are based on the combination of a linear thermoplastic polyester and a thermoplastic poly(ester-urethane).

Abstract: Normally rigid thermoplastic compositions comprising a poly(butylene terephthalate) and a second resinous component which contains from 1 to 40 wt.% of its repeating units comprised of a vinyl aromatic monomer are readily processable and form molded articles characterized by excellent surface appearance and outstanding physical properties. Illustrative embodiments having high resistance to distortion by heat comprise poly(butylene terephthalate) and from 5 to 35 wt.% of a second resinous component comprising 24 and 38 wt.% of styrene units and 76 and 62 wt.% of propylene units and butadiene units, respectively.

Abstract: A conductor or casing for shafts and cables, comprising a plastic tubular member having over a portion of its length a plurality of convolutions to permit bending and longitudinal compression and extension without substantial reduction in the internal diameter.