Foaming technology of inorganic nanoparticle modified polypropylene

Abstract

The invention discloses a foaming technology of inorganic nanoparticle modified polypropylene. The technology comprises the steps of 1, conducting melt blending extrusion on uniformly mixed polypropylene PP and inorganic nanoparticles to obtain polypropylene/nanoparticle granules of which diameter is 2-4 mm and length is 2-5 mm; 2, putting the polypropylene/nanoparticle granules into a high pressure reactor, pumping carbon dioxide into the high pressure reactor, raising the temperature to an infiltration temperature of 170-180 DEG C, continuing to pump carbon dioxide into the high pressure reactor until a saturation pressure reaches 20-28 MPa, and maintaining the pressure for 20-50 min; 3, reducing the high temperature to a foaming temperature of 105-165 DEG C, maintaining pressure constant in a temperature raising process, and conducting heat preservation for 40-90 min; 4, decompressing to an ordinary pressure in 10 seconds, taking out a foaming material to put into an ice and water mixture to be subjected to quenching. According to the technology, by adding nanosilicon dioxide or nano mica granules into PP, the foaming capacity of polypropylene is strengthened, and the size of a foam hole is uniform.

Description

technical field [0001] The invention relates to the technical field of automobile materials, in particular to a foaming process of inorganic nanoparticle modified polypropylene. Background technique [0002] Polymer foamed material refers to a polymer-based material with numerous cells inside, and can also be regarded as a composite material filled with gas. It has the characteristics of low density, good heat and sound insulation performance, and high specific strength. It is widely used in household daily necessities, vehicles, insulation materials, packaging materials, flame retardant materials, electrical appliances, sports facilities, electronic products and other industries. High-performance foam materials play an important role in military, aerospace and other cutting-edge fields. [0003] There are many kinds of polymer foam materials, among which the most widely used are polystyrene (PS) and polyethylene (PE) foam materials. However, there are many defects in PS ...

AI Technical Summary

Problems solved by technology

Therefore, in recent years, many countries have vigorously developed PP foaming materials. However, since PP is a semi-crystalline polymer, the temperature range that can be foamed (collectively referred to as the foaming temperature range) is narrow, only 4°C, and it is difficult to foam.