Effect of Si–Al molar ratio on microstructure and mechanical properties of ultra-low density fiberboard

• Published in: European journal of wood and wood products 2016-03, Vol.74 (2), p.151-160
• Main Authors: Chen, Tingjie, Wu, Zhenzeng, Niu, Min, Xie, Yongqun, Wang, Xiaodong
• Format: Article
• Language: English
• Subjects: Aluminum; Aluminum compounds; Aluminum silicates; Aqueous solutions; Biomedical and Life Sciences; Bond strength; Bonding strength; Bulk density; Ceramics; chemical structure; Composites; Fiberboard; fiberboards; Glass; Infrared spectrometers; Life Sciences; Machines; Manufacturing; Manufacturing industry; Mechanical properties; Microstructure; Modulus of elasticity; Modulus of rupture; Natural Materials; Original; Photoelectrons; Processes; Scanning electron microscopy; silicon; Silicon compounds; sodium silicate; Sodium silicates; spectrometers; spectroscopy; Träteknik; Wood Science & Technology; Wood Science and Engineering; X ray spectrometers; X-radiation; X-ray diffraction
• ISSN: 0018-3768; 1436-736X; 1436-736X
• DOI: 10.1007/s00107-015-0986-x

Si–Al compounds represent the substances having silicium (Si) and aluminum (Al) in the mixed aqueous solution of sodium silicate and aluminum silicate. Their chemical structure depends on Si–Al molar ratio. In this study, several Si–Al molar ratios were used to prepare different Si–Al compounds. These Si–Al compounds were added in the manufacturing process of ultra-low density fiberboards (ULDFs) to examine the effects of Si–Al molar ratio on the microstructure and the mechanical properties of ULDFs. Scanning electron microscope-energy dispersive spectroscopy, X-ray photoelectron spectrometer, infrared spectrometer, X-ray diffractometer and electronic universal testing machine were used to analyze the microstructure and mechanical properties of ULDFs. The results showed that the microstructure and bulk density of ULDFs were affected by Si–Al molar ratios. The mechanical properties of ULDFs were also significantly affected because of Si and Al components being uniformly distributed on the fibers’ surface and formation of Si–O–C bond. When Si–Al molar ratio was 2:1, the modulus of elasticity, modulus of rupture and internal bond strength of the ULDF was up to 20.78, 0.17, and 0.025 MPa, respectively.