Plasma Polymerization on Unsized Basalt Fibres for Improving the Interfacial Strength With Polymer Matrices

Abstract

Basalt fibres are becoming a promising alternative to synthetic fibres as a green reinforcement phase in polymeric matrix composites, showing excellent mechanical, chemical and thermal properties. In this work we synthetized tetravinylsilane (TVS) or a mixture formed by tetravinylsilane and different percentages of oxygen on the surface of unsized basalt fibres through the Plasma-Enhanced Chemical Vapor Deposition (PECVD) technique for improving the fibre/matrix adhesion. Single fibre tensile test proved the effectiveness of the process, without any degradation of the mechanical properties of modified basalt fibres. Finally, through pull out tests, the interfacial properties of basalt fibres were studied, measuring increases up to 80% of the IFSS for modified fibres compared to neat fibres. This result is the consequence of a greater chemical compatibility between the fibres and the matrix, thanks to the presence of a higher number of Si-O-C groups, and of a mechanical interlocking effect promoted by the increased surface roughness of the plasma-modified fibres.