Conduction Mechanism and Conductivity Behaviour of Pure Polypropylene (PP) and Polypropylene-Banana Fiber (PP-B) Composites

摘要

Fibers reinforced composite materials offer a combination of strength and modulus that are either comparable to or better than many traditional metallic materials.The research on natural fiber based composite materials fit well into this ecological image.This paper reports the conduction mechanism and ac conductivity,activation energy behavior of Polypropylene and banana fiber reinforced thermoplastic composites.Polypropylene[-CH_(2)-CH_(2)-CH_(2)-]n and different fiber content(wt.%)of polypropylene-banana fibers(natural fiber)composites were fabricated using a hot-press molding system.The optimum fabrication parameters were established(initial pressure,temp.etc.).These composite test samples were fabricated so the short fibers were randomly oriented in the matrix.The detail investigation of the a.c.conductivity and conduction mechanism of polymer composites would provide information about the relaxation processes,activation energy etc.which are dependent on frequency,temperature and time.The activation energy involved in the above processes can also be estimated from this study.The measurements were performed over a wide range of frequency of 60 Hz to 3 MHz and temperature range from 30℃(303°K)to 110℃(383°K).Experimental results of the ac properties of pure polypropylene and polypropylene-natural banana fiber composites were compared.It has been established that the fabricated composition changes its insulating property after adding the natural fibers and gives the better conductivity properties.