Abstract: Polymer compositions having improved resistance to thermoforming sag are disclosed. The compositions comprise a first and second portion selected from the group comprising polypropylene, propylene-ethylene copolymers and mixtures thereof wherein a first portion of the composition is (1) mixed with from about 500 to about 3000 ppm of antioxidant; and (2) irradiated with a dosage of from about 10 to about 20 Mrads gamma or electron beam of ionizing radiation in air, and the second portion of said polymer composition is non-irradiated. The first portion is present in an amount effective, from about 1.0% to about 10.0%, to increase the elasticity of the polymer composition in the molten state by at least 10% as compared to the second portion of said polymer composition.

Abstract: Polymer compositions having a first and second portion selected from polypropylenes, polyethylenes, propylene-ethylene copolymers and mixtures thereof having enhanced crystallization properties and a method for producing the same are disclosed. Antioxidant is mixed with the first portion, 0.01 to 1.25 wt %, of the composition which is then irradiated to a dosage of 5-30 Mrads of ionizing radiation in air to induce cross linking. The irradiated first portion is then blended with the non-irradiated second portion. The cross-linked polymer is believed to provide nucleation sites for the initiation of crystallization, thereby enhancing crystallization of the polymer as evidenced by elevated DSC freeze points. Crystallization of the polyolefin is enhanced without any detrimental effects on hexane or xylene extractability of the polymer and without degrading the composition to any appreciable extent.

Abstract: Improved resin compositions for use in multiple cavity stretch blow molding processes comprising: (a) a propyleneethylene copolymer resin including from about 5% to about 15% of a second stage polymer characterized by a cycle time of T.sub.1, when used to produce containers in multiple cavity stretch blow molding processes; (b) from about 0.1% to about 1.0% of a nucleating agent prepared by irradiating in air a mixture of a propylene homo or copolymer and about 500 to about 3000 ppm of antioxidant with a sufficient amount of ionizing radiation to cause said nucleating agent to have a xylene insoluble content of at least 30%. The improved resin composition is characterized by a cycle time of T.sub.2 when used to produce containers in multiple cavity stretch blow molding processes such that the ratio of T.sub.2 /T.sub.1 is less than 0.95.

Abstract: A propylene polymer molding composition which is resistant to discoloration and losses in physical properties upon sterilization by high energy radiation is comprised of a blend of a propylene polymer with small amounts of a polymeric hindered amine, an alkyl phosphite and a specific hindered phenolic antioxidant as necessary additives.

Abstract: Blends of propylene polymer, ethylene-vinyl acetate copolymer and optionally a synthetic rubber, with small amounts of a polyterpene resin as a compatabilizer, possess excellent properties for the manufacture of heat-sealable and sterilizable films as well as for the manufacture of molded speciality sealed containers and bottles.

Abstract: Blends of propylene polymer, ethylene-vinyl acetate copolymer and optionally a synthetic rubber, with small amounts of a polyterpene resin as a compatabilizer, possess excellent properties for the manufacture of heat-sealable and sterilizable films as well as for the manufacture of molded speciality sealed containers and bottles.

Abstract: Polyolefin resin pellets of greater uniformity of shape and characterized by an almost complete absence of tails are obtained by the use in the pelletizing apparatus of dies which have been coated by a thin layer of finely divided solid lubricant such as molybdenum disulfide or, preferably, graphite applied to the interior surfaces of the die by cross bombardment with a stream or streams of finely divided solid lubricant under pressure.