期刊：
Progress in Organic Coatings,2022年167:106846 ISSN：0300-9440
通讯作者：
Ping Li<&wdkj&>Yingfeng Zuo
作者机构：
[Zhang, Mengying; Li, Ping; Li, Xianjun; Yuan, Guangming; Zuo, Yingfeng] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China;Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, PR China;[Lu, Jianxiong] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China<&wdkj&>Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, PR China
通讯机构：
[Ping Li; Yingfeng Zuo] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China
摘要：
To improve the wettability, the surface free energy, and film adhesion performance of silicate-modified poplar wood (SMPW) surfaces, different silane coupling agents (KH550, KH560, KH570, and KH580) were applied to SMPW surfaces. The properties including film adhesion, functional groups, wettability, penetration depth, and surface free energy were analyzed and characterized by film adhesion tests, FT-IR, XPS, SEM, contact angle measurements, optical magnifying microscope test, and surface free energy calculations. The results showed that the film adhesion of poplar wood, SMPW, and the silane coupling agents KH550, KH560, KH570 and KH580 treated SMPW surfaces were grade 1, grade 3, grade 1, grade 0, grade 1, and grade 0, respectively. The SEM test results were consistent with results of the paint film adhesion. According to the XPS results, there were two binding energies peaks at 99–104 eV and 151–155 eV, corresponding to Si 2p and Si 2s, respectively, indicating that the form of Si had changed. In the FITR spectra, the SiOSi stretching and bending vibrations on the surface of the modified material treated with silane coupling agents were significantly stronger than that of the SMPW, indicating that silane coupling agents chemically bonded to the surface of the SMPW. The contact angles of the WBSV on the surface of poplar material, SMPW and silane coupling agent KH550, KH560, KH570, and KH580 were 50.60°, 77.17°, 52°, 45.92°, 52.83°, and 47.20°, respectively. The wettability of the surface after silicate modification was lower than that of the poplar material. After silane coupling agent treatment, the wettability of the surface to the WBSV was improved to varying degrees. The surface free energy of poplar and SMPW were 46.88 and 37.72 (10−3 J·m−2), respectively, illustrating that SMPW reduced the surface free energy. The surface free energy of SMPW treated with silane coupling agents KH550, KH560, KH570, and KH580 was 45.10, 50.93, 44.06, and 49.49 (10−3 J·m−2), respectively, which showed that the surface free energy of SMPW treated with different silane coupling agents was higher than that of SMPW.
摘要：
Sodium silicate (Na2SiO3) was used as a modifier to improve the properties of bamboo scrap/magnesium oxychloride (BS/MOC) composites. The results showed that the strength phase 5 was increased, and gel-like 5MgO-MgCl2-8H2O crystals were formed in these BS/MOC composites with added Na2SiO3 and thus, the mechanical strength enhanced. In addition, Na2SiO3 formed chemical bonds with BS/MOC composites to prevent 5-phase crystal hydrolysis and enhance composites water resistance. The mechanical strength and water resistance were shown to reach a maximum after curing for 28 d with 0.5% Na2SiO3.
期刊：
International Journal of Biological Macromolecules,2021年182:2108-2116 ISSN：0141-8130
通讯作者：
Yingfeng Zuo
作者机构：
[Liao, Chenggang; Li, Xingong; Chen, Kang; Li, Ping; Zuo, Yingfeng; Li, Xianjun] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Yingfeng Zuo] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China
摘要：
To improve the performance of wheat straw/polylactic acid (WS/PLA) composites, four different silane coupling agents were used for constructing compatible interfaces and then examined by scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray diffractometry and thermogravimetric analysis. The blending and tensile strengths of silane-modified composites were effectively enhanced, with KH-570-modified composite exhibiting the best blending and tensile strengths. Water resistance analysis of silane-modified composites was reduced and contact angles larger, indicating that water resistance performance of this composite had been effectively improved. The KH-570-modified composite exhibited the best water resistance performance. Strain scanning showed that, in the linear viscoelastic region, the storage modulus (G') of modified composite was larger than that of unmodified composites. Frequency scanning showed that the G' and complex viscosity (eta*) of modified composites were greater than those of unmodified composites. From strain analysis and frequency scanning, the modified performance of the silane agent was observed to effectively improve composite interfacial compatibility, with KH-570-modified composite exhibiting the best effect. XRD analysis showed that silane coupling agent modification improved the crystallinity of composites with the improvement of KH-570 the best. And the thermal stability of silane-modified composites was improved and the thermal stability of KH-570modified composite the best.
通讯机构：
[Yingfeng Zuo] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, People’s Republic of China
摘要：
The difference between wood supply and demand was sought to be alleviated by considering fast-growing Chinese fir wood, based on its characteristics of large yield but poor performance. Modification of fast-growing Chinese fir wood is an effective method for improving the wood's characteristics. Sodium silicate/magnesium chloride-modified fir (SS-MCMF) was prepared by adding magnesium chloride (MC) in the process of silicate (SiO32−) impregnation, with sodium silicate (SS)-modified fir (SSMF) and natural wood (NW) as references. The products were then tested for physical and mechanical properties and bonding mechanisms. The results showed that the bending strengths of SSMF and SS-MCMF specimens were increased by 36.16 and 62.97%, respectively, compared with NW specimens, and the compressive strength of SSMF and SS-MCMF specimens increased by 39.90 and 90.67%, respectively. The hardness of SSMF and SS-MCMF specimens increased from 3685 (of NW) to 5534 and 5843 N, respectively. The water absorption rate of samples after 96 h water exposure decreased from 159.25 to 97.39 and 83.06%, respectively, and the leaching rate at 14 days decreased from 16.01 to 8.92%. In addition to improvements in physical, mechanical, and fixing properties, FTIR and XRD analyses confirmed that SS damaged lignin and hemicellulose in this wood and that Si–O–Si and Si–O–C structures were indeed formed in these modified samples. The addition of MC effectively protected the wood from possible SS damage while also greatly improving its performance. Therefore, the combination of SS and MC for modifying Chinese fir was an efficient, green, and environment-friendly impregnation modification method.
期刊：
Construction and Building Materials,2021年281:122600 ISSN：0950-0618
通讯作者：
Zuo, Yingfeng(zuoyf1986@163.com)
作者机构：
[Xiao, Junhua; Wang, Jian; Wu, Yiqiang; Zuo, Yingfeng; Wang, Shu] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Xiao, Junhua] Guangdong Testing Inst Prod Qual Supervis, Foshan 528300, Guangdong, Peoples R China.
通讯机构：
[Yingfeng Zuo; Yiqiang Wu] C;College of Material Science & Engineering, Central South University of Forestry & Technology, Changsha 410004, Hunan, PR China
摘要：
To solve the problem of agricultural waste, modified straw/magnesium oxychloride lightweight composites (M-SMOCL) with light-weight and high strength were prepared using magnesium oxychloride cementitious material (MOC) as the matrix, modified straw as reinforcing material and other reagents as additives. The effects of coupling agents, including KH-550, KH-560, KBM-603, HY-201, on straw groups and water absorption, as well as the mechanical strength and water resistance of the composites, were examined and discussed. The results showed that coupling agents reduced straw hydrophilicity and water absorption, improved composite performance. KBM-603 in particular possessed the best modification effects, with water absorption of straw treated with IBM-603 decreased to 27%, and the composite compressive and bending strengths of reached the maximum values of 12.93 MPa and 4.78 MPa, respectively. FT-IR and SEM showed that straw treated with KBM-603 bonded more closely to the matrix, creating the best interface results. (C) 2021 Elsevier Ltd. All rights reserved.
期刊：
Journal of Materials Research and Technology,2021年12:2257-2266 ISSN：2238-7854
通讯作者：
Yingfeng Zuo<&wdkj&>Yiqiang Wu
作者机构：
[Wu, Yiqiang; Zuo, Yingfeng; Li, Ping; Wang, Shu; Sheng, Guoan; Zheng, Long] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
通讯机构：
[Yingfeng Zuo; Yiqiang Wu] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
摘要：
This study was aimed to solve the problem of large waste from bamboo processing residues, improve the quality of building composites, give composites biological properties, and expand the use of composites. Highly efficient and excellent bamboo scrap/ magnesium oxychloride composites were prepared, with homogeneous structure and chemical bonding constructed with magnesium oxychloride cementitious material as the raw material, bamboo scraps as reinforcement material, and polycarboxylate superplasticizer (PCE) as modifier. The influence of PCE addition on molding performance, mechanical performance, and water resistance of the resulting composites were examined and discussed. Scanning electron microscopy, X-ray diffractometry, and thermogravimetric analyses were used to characterize the microscopic morphology, crystal structure, and heat resistance of composites, respectively. The results showed that, when PCE addition was 0.3% (by vol), the fluidity of magnesium oxychloride slurries was conducive to composite molding, provided the best compressive strength, bending strength, and water resistance, and the composite performance observed to improve with extended storage time. In addition, with 0.3% PCE, the interface between bamboo scraps and the magnesium oxychloride matrix in the composite material was the best, showing more 5-phase crystals and the best heat resistance. This strategy not only improved the functionality of this kind of composite but also provided a good solution for the use of bamboo processing residues. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC
摘要：
Large-scale parallel bamboo strand lumber (PBSL) structural elements are often subjected to local compression especially in beam-to-column connections as well as in beam-to-beam connections. The current paper presents an experimental investigation on the local compression behaviour of PBSL. 20 specimens were collected from different parts of a PBSL block under radial and tangential compression loading. Load-displacement curves of all specimens were recorded and observed failure patterns were carefully investigated to understand underlying mechanics. Tangentially loaded specimens predominantly failed due to debonding of fibres triggered by deformations perpendicular to the grain. On the other hand, radially loaded specimens showed a combined failure caused by debonding in perpendicular to the grain direction as well as tensile failure of bamboo fibres in the longitudinal direction. Key design parameters such as elastic modulus, stiffness, ultimate strength and Poisson's ratio for all specimens were computed and compared against end vs middle specimens as well as radial vs tangential specimens. Radially loaded specimens showed higher load carrying capacity due to better bonding, whilst the specimens collected from the middle part of the PBSL block were relatively more ductile than the others. Analytical models for load-displacement repose as well as for stress-strain behaviour were proposed for the considered specimens. Ramberg-Osgood based stress-strain model showed good agreement with test results. (C) 2020 Elsevier Ltd. All rights reserved.
作者机构：
[李萍] College Furniture and Art Design, Central South University of Forestry and Technology, Changsha;410004, China;[张源; 吴义强; 袁光明; 李贤军; 左迎峰] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha;[李萍; 张源; 吴义强; 袁光明; 李贤军; 左迎峰] 410004, China
期刊：
Construction and Building Materials,2021年285:122902 ISSN：0950-0618
通讯作者：
Zuo, Yingfeng(zuoyf1986@163.com)
作者机构：
[Wang, Jian; Wu, Yiqiang; Zuo, Yingfeng; Huang, Xianglan; Wang, Shu] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Yingfeng Zuo] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China
摘要：
To expand the application of magnesium oxychloride cement (MOC) as a kind of engineering materials in the construction field, organic-inorganic hybrid modifications were performed. Waterborne epoxy resin/magnesium oxychloride composites (WER/MOC) with high-strength and water-resistance were prepared using a simple and green method with MOC as matrix and WER as reinforcement. The effects of WER on the resulting composite's viscosity, mechanical strength, water resistance, phase composition, thermal stability, and micromorphology were discussed. The results demonstrated that WER reduced the viscosity of the WER/MOC complex system, and the composite water resistance and compressive strength were improved, which were mainly attributed to chemical reactions between WER and MOC to form a crosslinked network structure. Meanwhile, XRD analysis results showed that the intensity of the diffraction peak of the 3-phase decreased and 5-phase increased with WER addition to the composite and no new crystal phase appeared. The compressive strength, water resistance, thermal stability, and porosity of these WER/MOC composites reached the best values when the WER mass proportion was 4.8%. Here, the composite water absorption rate decreased to 8.7%, softening coefficient increased to 17.8%, middle compressive strength (sealed for 7 d) at 48.0 MPa, and dry bulk density increased to 1.34 g/cm3. Thus, these WER/MOC composites were suitable for use as engineering materials in the construction and road industries. (C) 2021 Elsevier Ltd. All rights reserved.
期刊：
Wood Science and Technology,2021年55(3):837-855 ISSN：0043-7719
通讯作者：
Yingfeng Zuo
作者机构：
[Wu, Yiqiang; Yuan, Guangming; Sun, Zhenyu; Zuo, Yingfeng; Lv, Jianxiong; Wang, Zhangheng] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Lv, Jianxiong] Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China.
通讯机构：
[Yingfeng Zuo] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, People’s Republic of China
摘要：
The use of fast-growing wood can reduce the environmental impact of the wood industry, but the low strength and flammability of these woods prevent their widespread application. Chinese fir not only has the general defect of fast-growing wood, but also has weak permeability due to aspirated pits. To improve its performance, environment-friendly modifier sodium silicate (SS) and WEP (waterborne epoxide resin) as the dipping solution, microwave pretreatment and multi-step emptying-pressure (MSEP) impregnation method were employed to prepare hybrid-modified wood. Microwave pretreatment was found to destroy pit membranes of Chinese fir and increase permeability. WEP addition reduced the wood's -OH content and promoted formation of more Si-O-Si structures, while also forming a fusiform hybrid structure with SS through Si-O-C bonds. The mechanical properties and water resistance of SS/WEPW (hybrid-modified wood) were higher than those modified by SS alone. The bending strength, elastic modulus, compressive strength, and transverse, tangential, and radial hardness of SS/WEPW5% (5% WEP) reached 97.20, 8504.87, 57.73, 5113.50, 2536.37, and 2192.35 MPa, respectively. The water resistance performance was also significantly improved. Compared with SSW, the 7-day weight leaching ratio (WLR) and water absorption rate (WAR) were reduced by 49.26 and 11.09, respectively, and the 14-day anti-shrink efficiency (ASE) of SS/WEPW5% can reach 86.87%. Furthermore, the flame retardant and smoke suppression performances of hybrid-modified wood were also improved, with the heat release rate (HRR), smoke produce rate (SPR), mean carbon monoxide yield (mean COY), and mean carbon dioxide yield (mean CO2Y) of SS/WEPW5% significantly lower and the peak of CO and CO2 release almost 1/10th that of unmodified wood. SS/WEP hybrid-modified wood was improved in terms of mechanical properties, water resistance performance, and flame retardancy, which laid the foundation of its use as a high-performance wooden material.
摘要：
The problem of utilizing substantial bamboo residual waste while also improving the quality of building composites was addressed by preparing bamboo scrap/magnesium oxychloride composites using bamboo scraps as a reinforcing material and magnesium oxychloride as a matrix. However, problems remain, such as poor interface compatibility and poor water resistance, which limit its application range. Herein, nano-silica (nSiO(2)) was found to build a crystal nucleus and a network structure in the composites, such that the bamboo scrap/magnesium oxychloride composites had higher mechanical properties and water resistance. In addition, the nSiO(2) crystal nucleus structure promoted the composites hydration process, promoted the growth of the 5-phase crystals and the close arrangement of the cross, thereby improved composites strength. The nSiO(2) build a network structure at composites interface, which improved the compatibility of composites interfaces, thus improving water resistance. At the same time, nSiO(2) and the crystal nuclei adsorbed a portion of CO2 and CO, which had a certain hindering effect on the release of toxic gases in fire, and provided new ideas for fire safety protection. These results expanded the scope of application of building composites, which can be used in the fields of fireproof materials and building decoration materials, and provided a good solution for bamboo processing waste, thus making a certain contribution to green environmental protection. (C) 2021 The Author(s). Published by Elsevier B.V.
作者机构：
[Zuo, YF; Lu, JX; Wu, Yiqiang; Yuan, Guangming; Li, Ping; Zuo, Yingfeng; Zhang, Yuan; Lu, Jianxiong] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Lu, Jianxiong] Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China.;[Li, Ping] Xiangnan Univ, Coll Art & Design, Chenzhou 423000, Hunan, Peoples R China.
通讯机构：
[Zuo, YF; Lu, JX; Lu, Jianxiong] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China.
关键词：
Chinese fir wood;dimensional stability;flame retardant;imitating human respiration;silicate;smoke suppression
摘要：
Inorganic impregnation strengthening of Chinese fir wood was carried out to improve the strength, dimensional stability, flame retardancy, and smoke suppression of Chinese fir wood. Sodium silicate was used as reinforcement, a sulfate and phosphate mixtures were used as a curing agent, and Chinese fir wood was reinforced by the respiratory impregnation method (RIM) that imitating human respiration and vacuum progressive impregnation method (VPIM). The weight percentage gain (WPG), density increase rate, distribution of modifier, bending strength (BS), compressive strength (CS), hardness, and water resistance of unreinforced Chinese fir wood from the VPIM and RIM were compared. It was found that RIM could effectively open the aspirated pits in Chinese fir wood, so its impregnation effect, strengthen effect and dimension stabilization effects were the best. RIM-reinforced Chinese fir wood was filled with silicate both horizontally and vertically. At the same time, the transverse permeability of silicate through aspirated pits was significantly improved. The chemical structure, crystalline structure, flame retardancy, smoke suppression, and thermal stability of VPIM- and RIM-reinforced Chinese fir wood were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), cone calorimeter (CONE), and thermogravimetric analysis (TGA). The results indicated that although the crystallinity of RIM-reinforced Chinese fir wood decreased the most, more chemical crosslinking and hydrogen bonding were formed in the wood, and the strengthen effect was still the best. Compared with VPIM-reinforced Chinese fir wood, RIM-reinforced Chinese fir wood had lower heat release rate (HRR), peak-HRR, mean-HRR, total heat release (THR), smoke production rate (SPR), and total smoke production (TSP), higher thermal decomposition temperature and residual rate. It was indicated that RIM-reinforced Chinese fir wood was a better flame retardant, and has a smoke suppression effect, thermal stability, and safety performance in the case of fire.
