Sea Gras

Seagrass leaves and fibers can be easily collected in the seashores in the Mediterranean Sea (seagrass Posidonia oceanica) and the North Sea (seagrass Zostera marina). The aim of our project is to produce seagrass based composites and investigate their properties.

Project 1. Inorganic bonded composites
The objective of this project is to prepare inorganic-bonded composites using gypsum, ordinary Portland cement and metakaolin-geopolymers as binders. For the production of gypsum boards, amounts of seagrass and wood fibers (1 – 6 wt%) have been incorporated and the mixtures have been casted and set to cure. The mechanical properties of boards have been carried out. Gypsum boards can be used as interior dividing walls. The inclusion of lignocellulosic fibers can increase both bending strength and toughness of the boards. For the production of ordinary Portland cement boards, high amounts of seagrass fibers (22-52 wt%) have been added. Panels containing low amounts of cement can be used for both interior and exterior applications (exterior facades and boards containing high amount of fibers are recommended to be used for roofing, flooring as well as diving walls). As a substitute of Portland cement a more environmentally friendly binder (geopolymer) has been utilized to prepare panels intended for exterior applications. The possible applications are the same as those mentioned for cement boards. Panels have high fire, water and termite resistance

Project 2. Insulation boards
The North Sea seagrass Zostera marina has been used to produce flexible insulation boards using BiCo as a binding system. The low thermal conductivity and the resistance to fire has made them ideal candidates to replace synthetic and other non-abundant in the coastal areas lignocellulosic materials. BiCo seagrass boards could be used for roofing insulation. Another type of seagrass leaves (Posidonia oceanica) which have a similar structure with Zostera marina are foreseen to be used for the preparation of insulation boards using pMDI as a binder. Posidonia leaves are a waste material which is usually removed from the shores especially in the touristic season and get damped and left decomposing. Their availability and fire resistance (contain salts which hinders the ignition and flame forming) makes them interesting candidates for producing lignocellulosic based materials.