Effects of Methane Cold Plasma in Sisal Fibers

Abstract

One of the main problems in using vegetable fibers as reinforcement in aggressive cement matrix is the penetration of alkaline products in the porous structure of the filaments, making them very fragile with the time. In this sense a series of physical and chemical methods of surface modification has been used in order to improve its characteristics. The plasma surface modification technique is a physical method surface modification that utilizes ionized gas at low pressure to change the chemical nature and the substrate surface morphology of both organic and inorganic materials without changing their intrinsic properties. This is considered an environmentally friendly process without generation of contamination and has a low operating cost compared to some chemical (such as silane based) treatments. In the present study, the sisal fibers were treated with methane plasma generated by direct electric current during 10, 20 and 30 min with gas flow of 5 cm3/s and current of 0.10 A. The study presents some mechanical, physics and chemical characteristics of sisal fiber after being subjected to treatment with methane cold plasma. The results presented indicate that treatment with methane cold plasma induced changes in sisal fibers at all times of exposure to treatment (10, 20 and 30 min). However, the major changes in structural and mechanical components may be seen in fibers treated with 10 min of exposure to plasma.