Abstract: An easily recyclable cross-linked isotactic polypropylene that is additionally miscible with polyethylene is formed from a chemical reaction of combining a polymer, sulfur, peroxide, an accelerator, and at least one additive. The polymer can be mixtures of isotactic polypropylene homopolymer with an elastomer; mixtures of isotactic polypropylene homopolymer with thermoplastic-based mixes; mixtures of isotactic polypropylene copolymer with an elastomer; mixtures of isotactic polypropylene copolymer with thermoplastic-based mixes; or combinations thereof. The accelerator can be a sulfur accelerator.

Abstract: A method for preparing reversibly cross-linked isotactic polypropylene having a degree of crystallinity substantially identical to a degree of crystallinity of a starting polypropylene by mixing in the presence of heat, a polymer of isotactic polypropylene homopolymer; isotactic polypropylene copolymer; mixtures of isotactic polypropylene homopolymer and copolymer with an elastomer, an organic peroxide, and an accelerator, forming macro-radicals; the simultaneously coupling the macro-radicals with a sulfur obtaining an optimum cross-linking degree and a product made by the method.

Abstract: An elastomer containing chemically bonded metal atoms is prepared by reacting a diene elastomer such as a nitrile rubber with the reaction product of an epoxy resin and a metal containing polymer. The metal containing polymer is prepared by reacting a polycarboxylic acid and a metal complex which is a reaction product of tungsten carbonyl and/or molybdenum carbonyl with pyrrolidine.