Impact of mineralization in Hevea brasiliensis fibers on the production of extruded fiber-cements with cellulosic micro/ nanofibrils (MFC/NFC) and quartzite residues
Abstract
New processes and applications for waste generated in forestry and mineral activities favor the circular economy and reduce pressure on conventional raw materials, thus promoting the sustainability of activities. This research aimed to apply quartzite powder to replace limestone and fibers and cellulosic micro/nanofibrils (MFC/NFC) from Hevea brasiliensis as reinforcement in extruded fiber-cement. To improve fiber/matrix compatibility, some fiber treatments with NaOH and A & ell;(2)(SO4)(3) + C6H8O7 were also evaluated. The fiber cements were produced by an extrusion process using a formulation of 66.5 % of CPV-ARI Portland cement, 28.5 % of quartzite powder and 5 % of fiber reinforcement. The physical (apparent density, water absorption, and porosity), mechanical properties (modulus of rupture, modulus of elasticity, limit of proportionality, and toughness), thermal conductivity, and microstructural properties of the fiber-cements were evaluated after 28 days of curing. Treatments with 5 % fibers exhibited better mechanical performances. It was possible to improve the microstructure and physical-mechanical performance of the composites using small amounts of MFC/NFC (0.5 %). Quartzite positively affected the properties and provided thermal comfort (similar to 0.11 W/mK). Therefore, the materials showed promise for producing extruded fiber-cement composites.
