Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/10550
Title: Desempenho de fibrocimentos extrudados produzidos com poupas celulósicas modificadas com silanos
Authors: Tonoli, Gustavo Henrique Denzin
Rabelo, Giovanni Francisco
Savastano Junior, Holmer
Fiorelli, Juliano
Abreu, Luciana Barbosa de
Keywords: Compósitos
Durabilidade
Extrusão
Modificação química
Reologia
Composites
Durability
Extrusion
Chemical modification
Rheology
Issue Date: 29-Oct-2015
Publisher: Universidade Federal de Lavras
Citation: MENDES, R. F. Desempenho de fibrocimentos extrudados produzidos com poupas celulósicas modificadas com silanos. 2014. 158 p. Tese (Doutorado em Ciência e Tecnologia da Madeira)-Universidade Federal de Lavras, Lavras, 2014.
Abstract: The objective of this study is to evaluate the physical-mechanical performance and the of fibercement composites produced with eucalyptus pulp surface-modified with different types of silanes at different concentrations and application methods. For the production of fibercement composites are used cellulose pulps bleached eucalyptus, obtained by the kraft process. The silanes used for surface funcionalization of the cellulose fibers pulp were isobutyltrimethoxysilane (IBTMS), methyltrimethoxysilane (MTMS) and noctyltriethoxysilane (OTES). The surface treatment of cellulose pulps is done in two ways, one by hydrolysis of the solution, with 10, 25 and 50% concentrations of application and another by direct application of the product in cellulose pulp with 25% concentration of application. After the composites production, these had their physical and mechanical properties evaluated after 28 days of curing and after 200 and 400 cycles aging. The results it can be concluded that: 1) The three types of silanes (MTMS, IBTMS And OTES) were efficient in the chemical modification of the cellulose pulps, providing lower mean values of moisture absorption, 2) The 25 and 50% concentrations of silanes showed the best results modification; 3) The treatment with cellulose pulps modified by direct application of the IBTMS and MTMS silanes prevented extruding the mixture; 4) The composites produced with the modified pulps by OTES and IBTMS silanes, applied via hydrolysis, showed the best results for water absorption, apparent porosity and shrinkage properties when tested after 28 days of curing and after 200 and 400 cycles accelerated aging; 5) After accelerated aging, chemical modifications of the pulps, regardless of the type of silane and application form, caused significant increase in MOR, MOE and LOP properties; 6) The three types of silanes used allowed the improvement and maintenance of the mechanical performance of the fibercement after 200 and 400 cycles accelerated aging; and 7) The combination of hydrophilic pulp with the extrusion process, using low water-cement ratio and shows high densification and consequently better fiber-matrix relation, allows to obtain a product with good mechanical properties for a longer period of time.
URI: http://repositorio.ufla.br/jspui/handle/1/10550
Appears in Collections:Ciência e Tecnologia da Madeira - Doutorado (Teses)

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