Emeritus Prof. FRANK R. JONES
Department of Materials Science and Engineering
The University of Sheffield, UK
Professor Frank R Jones began his career at Scott-Bader & Co Ltd, a pioneer and major innovator in Glass fibre Reinforced Plastics, attending part-time courses and eventually achieving the Associateship of the Plastics Institute (now Institute of Materials Minerals and Mining). After a PhD in Cationic Polymerisation at Keele University and Post Doctoral research in Mainz and York, he joined Surrey University and established research programmes to understand the environmental performance of Composite Materials. He joined the Department of Ceramics, Glasses and Polymers (now Materials Science and Engineering), University of Sheffield, in 1985, to set up Composites and Surface Analysis Laboratories, which specialised in interdisciplinary research linking environmental and interfacial performance to the mechanics of composite materials. Becoming Professor in 1993. Most recent research has developed Smart Self Healing Composites. He has been Emeritus Professor since 2009. He has published over 350 papers in journals and books and edited several texts. He was Scala Lecturer at ICCM 17 in 2009 and is a World Fellow of the International Committee on Composite Materials (2007). A textbook entitled Composites Science Technology and Engineering is in the process of publication.
Controlling Interphases in Glass Fibre Composite Materials
The presentation will review interphase formation in composite materials from glass and carbon fibres, which are conventionally surface treated. The structure of silane coupling agents in the presence of other sizing polymers is considered. Depending on the nature of the matrix and sizing polymers the interphase can be either graded or distinct. The function of the interphase is to transfer stress between the fibres and matrix especially at a fibre-break so as to ensure the material exhibits ‘tough’ behaviour under load. We know from carbon fibre development that a perfect interfacial bond leads to brittle behaviour whereas with a poor fibre-matrix bond the composite cannot realise its optimum performance. Intermediate surface treatment ensures an optimum interlaminar shear strength and fracture strength. With glass fibres, interphase structure and properties determine the efficiency of the interfacial stress transfer and hence performance. With glass fibre composites the nature of the interface and interphase is controlled by technological choice of sizing and coupling agent. Thus to control the performance of fibre composites other surface engineering techniques need consideration. Plasma polymerisation can be used to deposit a conformal coating, which combines a coupling function with the protection afforded by a polymeric coating. Acrylic acid based plasma copolymers have been deposited onto glass and other fibres and the interfacial performance characterised. The disadvantage of conventional plasma techniques is the use of high vacuum. Atmospheric plasma technologies have been recently developed and are potentially more efficient at providing fibres with a functional coating.