Study On Preparation And Conductivity Of Expanded Nylon-6/graphite Composite

Nylon-6 is one kind of pioneer engineering plastic, which has been widely applied to machine tool,auto car,mechanism,weave,traffic and chemical industry, because of it is able to bear oil,friction,shake and chemical medicine and has high strength,heat stability, etc. However, some deficiencies, such as poor capacity of anti-acid and anti-base, low impact intensity, highly moisture absorption and flammability, limit its broader application. So its properties usually improved by the way of altogether-polymerization,blending,filling,molecules-complex and so on.Expanded graphite (EG) not only keeps the fine electrical conductivity of graphite, but also has the excellent ability of lubricating,anti-high temperature,anti-erosion and so on. So it has been widely applied to prepare conductive,wearable,antifriction and fireproofing composites. It could mechanically blend with nylon-6 as fine filler, and could get along with monomers as raw material to synthesis composites by in situ polymerization, then the material properties of the resulting composites are improved relative to the virgin polymer.In this paper we use the 50 mesh flake graphite as raw material to prepare the graphite intercalation compound (expendable graphite), which could expand at low temperature. The sulfur-free expandable graphite was used as expanding agent to synthesize the expanded PA-6/graphite composites for the first time. The expanding agent and nylon-6 were mixed to process by in-situ polymerization, using the heat energy effect to expand and improve the properties of nylon-6, finally get a new kind of low-density,porous,conductive composite. The main work of this thesis:1. Using 50 mesh (320um) flake graphite as raw materials to prepare sulfur-free highly expandable graphite, and the expandable graphite could expand at low temperature.2. The structure of expandable graphite had been measured by UV, SEM, HPLC, IR and XRD, etc.3. The different expanded nylon-6/graphite conductive composites have been synthesized using expandable graphite as expanded agent, in high temperature and common pressure.4. The structure of expanded nylon-6/graphite composites had been measured by IR, SEM, XRD and TEM, the electrical resistance was determined and the experimental mechanisms had been researched roughly.5. The antistatic nylon film was prepared under ultrasonic irradiation with different raw materials, and the influence of different factors was researched roughly.