Study of carbon fibers surface modification by plasma treatments for enhancing adhesion of the carbon fiber/pps composites interface

Author(s)

Alberto Lima Santos

• Document type: Doctoral Thesis
• Press: Guaratinguetá. 2015-05-14.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Guaratinguetá
• Defense date: 2015-02-06
• Advisor: Leide Lili Gongalves da Silva Kostov; Edson Cocchieri Botelho; Mario Ueda

Abstract

In this it has been carried out the processing of thermoplastic composites obtained from carbon fibers (CF) treated by plasma assisted techniques. The employed treatments were Dielectric Barrier Discharge (DBD) that is performed in atmospheric pressure, involving low energy and Plasma Immersion Ion Implantation (PIII), which is held in low pressure regime, consisting of higher energies. After these treatments, both treated and untreated samples, were characterized. A comparison of the results was carried out to determine which treatment is most effective to achieve better physico-chemical properties on the fibers to obtain thermoplastic composites, which were produced by hot compression molding. Several characterization techniques were employed, such as scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction, and some mechanical tests of the composites, such as interlaminar shear strength (ILSS) and dynamic mechanical analysis (DMA). After analyzing the results, it was verified that the DBD and PIII treatments are effective tools for improving the adhesion of the carbon fiber/polymeric matrix interface, due to the CF roughness increasing and the introduction of polar groups on the carbon fiber surface. Additionally, it was noticed an increase of composites shear strength that were produced with treated carbon fibers (DBD and PIII) (AU)

• FAPESP's process: 13/09842-4 - Study of carbon fibers surface modification by plasma treatments for enhancing adhesion on the carbon fiber/PPS composites interface
• Grantee: Alberto Lima Santos
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)