Osirys - Newsletter - February 2015

netcomposites

Osirys - Newsletter - February 2015

Biocomposites With Good Outdoor DurabilityBiocomposite with good outdoor durability - coatings for outdoor use.Durability is one of the key issues in thedevelopment of fibre reinforced polymercomposites for construction.Since the application of FRP in theconstruction industry is quite recent,there is little knowledge of the short andlong term behaviour of these materials.The durability of FRP structures dependsboth on specific environmental conditions(alkalinity, moisture, temperature) and longterm effects (creep and relaxation, fatigueloading) among others.One of the objectives of the OSIRYSproject is to minimise the influence ofenvironmental factors and improve biocompositesoutdoor durability. To thatend, several protection strategies are nowcommercially available and will be testedduring this project.All these efforts are moving towards theobjective of increasing the use of biocompositesin the construction marketand to obtain more market penetration bymanufacturing components that fulfil allthe technical requirements from this verydemanding market.Applying a protection layer (coating) onthe exposed surfaceThere are two main ways to improveoutdoor performance of compositematerials. Either applying an externalprotection layer (coating) on the exposedsurface or modifying the resin formulation,adding additives to bring intrinsic propertiesto the matrix. In OSIRYS it was decided toapply external coatings to protect the biocompositeagainst deterioration causedby external factors such as UV rays,wind, rain and thermal changes, reducingmaintenance and increasing the life of thebuilding.On the basis of a deep analysis of most ofthe state of the art products commerciallyavailable, six coatings were selectedtaking into account several factors such asdesign requirements, process requirements(processability, price) and service conditions(service temperature, humidity degree).These coatings were applied by a roller onbio-composite laminates, see figure below.Compatibility and performance of thecoatings with the raw materials selectedto fabricate the bio-composite laminateswas evaluated by means of several tests,following either ASTM or EU standards(adhesion test, abrasion test, impact test). Asummary of the results obtained from all thetests carried out on the selected coatingscan be found in the table (right).From these results it is clear that mostof the coatings showed good impact andabrasion resistance and adhesion to thesubstrate. However, selection of the mostappropriate coating depends also on thefinal application and additional testing isneeded, such as:10 Osirys Project

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