Novel conductive type expanded polypropylene beads and preparation method thereof

Abstract

The invention discloses a preparation method of novel conductive type expanded polypropylene (EPP) beads. The preparation method comprises: S1, carrying out ultrasonic dispersion, commixing and stirring, and heating and reflowing on polyethylene powder, graphene nanoplatelets, a silane coupling agent and a diluent to obtain a waxy graphene parent material; S2, mixing, drawing and dicing polypropylene resin, a nucleating agent, a lubricant and an antioxidant and the graphene parent material prepared by the step S1 through an extruder to prepare an expanded polypropylene master batch; S3, adding the expanded polypropylene master batch prepared by the step S2 into a reaction kettle, and heating and pressurizing; when reaching pre-set temperature and pressure, instantaneously releasing pressure through a pressure releasing valve to an ambient atmosphere, so as to obtain the novel conductive type expanded polypropylene beads. By combining a super-critical CO2 kettle type foaming process, the EPP with light weight, excellent mechanical properties and stable and controllable conductive performance can be prepared, and the requirements on products with different conducting capabilities by all application fields in the market are met, so that an application field of the conductive EPP is further widened.

Description

technical field [0001] The invention relates to a novel conductive expanded polypropylene bead, a preparation method thereof and a graphene masterbatch used for preparing the bead. Background technique [0002] Expanded polypropylene (EPP) is a crystalline polypropylene / carbon dioxide composite material with excellent performance. Due to its high closed cell rate, it has unique and superior mechanical properties, chemical resistance, heat insulation, and light weight. Fast and environmentally friendly new materials. Graphene has high hardness and is a two-dimensional structure formed by stacking a single layer of carbon atoms. It has the characteristics of large specific surface area, excellent electrical and mechanical properties, etc. Conductive EPP has a special role in electronics, military, frequency measurement, etc. due to its controllable and stable surface resistance and excellent mechanical properties. At present, the production process of conductive polypropylen...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved in the present invention is to overcome the defects of the prior art, and provide a preparation method of a novel conductive expanded polypropylene bead, which adopts a still-type foaming process, combined with a special graphene masterbatch, effectively solves the problem of Problems such as heavy product quality, uneven dispersion of conductive carbon black, unstable conductivity, incompatibility of conductivity and excellent mechanical properties, etc.

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