Dynamic Packing Molding Polypropylene (ipp) Strengthening And Toughening Of Specimen

Being the diameter of isotactic Polypropylene's spherocrystal grain bigger leads to its brittle temperature higher, resistance to impact and high temperature stiffness worse. The other reason that polypropylene's theoretical strength and actual strength has long odds, and actual strength is only 0.18% of the theoretical strength means that latent capacity of the mechanical property of the Polypropylene material will be empoldered largely in the future. Therefore reinforcement and toughening of Polypropylene material becomes the chief subject that the general-purpose plastics is reformed into engineering plastics.Our group acquired the reinforcement of Polypropylene material by the Oscillating Packing Injection moldings (OPIM), however, the brittleness of the reinforcement material is remarkable. Therefore by the theory of elastomer toughening, the Polypropylene material is added mPE so as to increasing the toughness of Polypropylene material. The other hand ,by the feature of 3 nucleating agent, Polypropylene material is added β nucleating agent to increase the toughness. Added β nucleating agent , the impact strength and the tensile strength of the dumbbell samples by the OPIM is respectively 16.81 times and 1.77 times of pure polypropylene samples' impact strength(2.01kJ/m2) and tensile strength(31.04MPa) by conventional injection moldings. For the square plate samples added β nucleating agent by the OPIM ,the impact strength and tensile strength in machine direction( MD) is respectively 11.37times and 1.47times of those of the samples by conventional injection moldings, and the impact strength and tensile strength in transverse direction(TD) is 5.75times and 1.19times of those of the samples by conventional injection moldings. Added mPE, the impact strength and tensile strength of the dumbbell samples by the OPIM is 22.29times and 1.59times of those the samples by conventional injection moldings. For the square plate samples by the OPIM, the impact and tensile strength in MD is 9.61 and 1.42times of those of the pure polypropylene samples by the conventional injection moldings, in the same time ,the impact strength in TD is 5.41times of the samples bythe conventional injection moldings and the tensile strength in TD decreases 3.96% than that of the sample of conventional injection moldings. Heat treating of the samples by the OPIM improves the toughness insignificantly.Comparing these test data, we can get a conclusion that the samples by the OPIM gains reinforeced and toughened by adding nucleating agent . Therefore adding the nucleating agent and processing by OPIM have the ynergistic effect.