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Byline: C. Scarponi, D. Maglione, G. Cosentino, F. Lenzi Aim of the present study is to evaluate the mechanical properties of hemp woven fabrics from Italian textile industry, to be utilised as reinforcement both for polypropylene and for epoxy matrix. Chemical treatments have been performed to improve interface adhesion: de-waxing, NaOH solution plus silane as a coupling agent (3-aminopropyl-trimethoxy silane), and an original methodology, consisting on a combination of two agents (3-trimethoxysilyl-propyl-methacrylate silane and peroxide of Methylethilketone). Good mechanical properties were found using untreated hemp woven, and chemical treatments led to small improvements: the obstacle to great benefits is the fibres pre-treatment, performed by textile producer.

Byline: C. Scarponi, C.S. Pizzinelli Aim of this work was to review information about natural long fibres reinforced composites focusing on interface, wettability, fibre-matrix adhesion, moisture absorption, correlating them with macroscopical mechanical properties. Weak fibre/matrix interface does not permit a complete performance exploitation in composite materials. Physical and/or chemical treatments can enhance adhesion and increase performances. Chemical treatments based on the employment of Sodium Hydroxide, Silanes and Maleic Anhydride are the most common in literature and have been reviewed with particular attention on mechanical performance improvements. In this work have also been described different used methodologies and critically analysed previous results and future applications.

Byline: C. Scarponi, M. Valente A new ultrasonic technique, in the form of reflection, was used to determine the internal damage status of very low-cost composite laminates, subjected to transversal impact loads at low-velocity. The natural base materials consist of jute fibres woven rovings embedded with a vinylester resin. The common moulding by vacuum bag polymerisation technique was applied to this very cheap material. 100U100U8mm square specimens were subjected to impact loads at different energies and the internal damage status, in form of delaminations, was determined by means of a new ultrasonic technique, pointed out by the authors themselves. Ultrasonic maps were obtained before and after the impact loads; the formers are necessary to evaluate the parameters of the ultrasonic system and to obtain the initial reference image. The experimental technique is described in the paper and some ultrasonic maps are presented and discussed. The damage is correlated to the impact loads.

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