1. Assessment of chemical and mechanical behavior of bamboo pulp and nanofibrillated cellulose exposed to alkaline environments
- Author
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Viviane da Costa Correia, Mònica Ardanuy, Holmer Savastano, Josep Claramunt, Universitat Politècnica de Catalunya. Departament de Ciència dels Materials i Enginyeria Metal·lúrgica, Universitat Politècnica de Catalunya. Departament d'Enginyeria Agroalimentària i Biotecnologia, and Universitat Politècnica de Catalunya. TECTEX - Grup de Recerca en Tecnologia Tèxtil more...
- Subjects
Materials science ,Polymers and Plastics ,Cel·lulosa ,02 engineering and technology ,engineering.material ,Bamboo-pulp industry ,010402 general chemistry ,01 natural sciences ,law.invention ,Degradation ,Polpa de fusta ,chemistry.chemical_compound ,law ,Nanofibrillated cellulose ,Ultimate tensile strength ,High alkalinity ,Hemicellulose ,Cellulose ,Bamboo ,Bambú ,Cement ,Calcium hydroxide ,Pulp (paper) ,Bamboo pulp ,Pulpwood ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Geopolymer ,Portland cement ,chemistry ,Chemical engineering ,engineering ,0210 nano-technology - Abstract
This study was performed to study the effects of the cement paste composition (calcium aluminate cement—CAC and a geopolymer in comparison to Portland cement—OPC) on bamboo pulp and nanofibrillated cellulose (NFC). The changes in the composition and chemical structure of the fibers were analyzed by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). The changes in the mechanical strength were evaluated through tensile tests on the fibers after immersion on the cement pastes, in the form of sheets. The XPS results showed that the immersion of the pulp and NFC in the different pastes (CAC, geopolymer and OPC) modified the chemical surface of these fibers: it was found removal of lignin and extractives and some degradation of hemicellulose and cellulose. The FTIR analysis indicated modifications in the hydrogen bonds energy. The tensile strength of pulp sheets decreased in 70% and 34% after immersion in OPC and geopolymer, respectively. The tensile strength of the NFC sheets decreased 36%, 68% and 54% after immersion in OPC, CAC and geopolymer, respectively. Thus, the response of the bamboo pulp and NFC immersed in different cement pastes was different due the inherent characteristics of such fibers, and not only the Portland cement should be considered as harmful to lignocellulosic fibers. Although CAC and geopolymer are free of calcium hydroxide, the high alkalinity of these pastes also accelerated the degradation process of lignocellulosic fibers. more...
- Published
- 2019
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