scholarly journals Comparison of the mechanical characteristics of fibers and cell walls from moso bamboo and wood

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8230-8239
Author(s):  
Yanhui Huang ◽  
Benhua Fei
Keyword(s):  
Mechanical Properties ◽  
Cell Walls ◽  
Raw Materials ◽  
High Strength ◽  
Pinus Massoniana ◽  
Chinese Fir ◽  
Moso Bamboo ◽  
Wood Fibers ◽  
Masson Pine ◽  
Single Fibers

Bamboo and wood fibers are important raw materials for pulp and papermaking, as well as fiber-reinforced composites. The mechanical properties of single fibers and the cell walls of moso bamboo (Phyllostachys heterocycla), Masson pine (Pinus massoniana), and Chinese fir (Cunninghamia lanceolata) were tested via single fiber tensile test and nanoindentation; their fracture characteristics were also compared. The single fibers and cell walls of moso bamboo had superior mechanical properties compared with those of Masson pine and Chinese fir. The bamboo fibers exhibited high strength, high elasticity, and superior ductility. The results indicated that the differences between the mechanical properties of the fiber cells and cell walls of moso bamboo and those of wood were largely dependent upon cell shape and structure.

scholarly journals Multi-Scale Evaluation of the Effect of Phenol Formaldehyde Resin Impregnation on the Dimensional Stability and Mechanical Properties of Pinus Massoniana Lamb.

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 646 ◽  
Author(s):  
Wang ◽  
Chen ◽  
Xie ◽  
Cai ◽  
Yuan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Dimensional Stability ◽  
Cell Walls ◽  
Phenol Formaldehyde ◽  
Pinus Massoniana ◽  
Swelling Properties ◽  
Masson Pine ◽  
Pine Wood ◽  
Pinus Massoniana Lamb

The local chemistry and mechanics of the control and phenol formaldehyde (PF) resin modified wood cell walls were analyzed to illustrate the modification mechanism of wood. Masson pine (Pinus massoniana Lamb.) is most widely distributed in the subtropical regions of China. However, the dimensional instability and low strength of the wood limits its use. Thus, the wood was modified by PF resin at concentrations of 15%, 20%, 25%, and 30%, respectively. The density, surface morphology, chemical structure, cell wall mechanics, shrinking and swelling properties, and macro-mechanical properties of Masson pine wood were analyzed to evaluate the modification effectiveness. The morphology and Raman spectra changes indicated that PF resin not only filled in the cell lumens, but also penetrated into cell walls and interacted with cell wall polymers. The filling and diffusing of resin in wood resulted in improved dimensional stability, such as lower swelling and shrinking coefficients, an increase in the elastic modulus (Er) and hardness (H) of wood cell walls, the hardness of the transverse section and compressive strength of the wood. Both the dimensional stability and mechanical properties improved as the PF concentration increased to 20%; that is, a PF concentration of 20% may be preferred to modify Masson pine wood.

Effects of thermal modification on the physical, chemical and micromechanical properties of Masson pine wood (Pinus massoniana Lamb.)

Holzforschung ◽  
2018 ◽  
Vol 72 (12) ◽  
pp. 1063-1070 ◽  
Author(s):  
Xinzhou Wang ◽  
Xuanzong Chen ◽  
Xuqin Xie ◽  
Yan Wu ◽  
Linguo Zhao ◽  
...  
Keyword(s):  
Cell Walls ◽  
Lignin Content ◽  
Chemical Properties ◽  
Pinus Massoniana ◽  
X Ray Diffraction ◽  
Masson Pine ◽  
X Ray ◽  
Pinus Massoniana Lamb ◽  
Wet Chemical ◽  
Thermally Modified Wood

AbstractIn an attempt to evaluate the effects of thermal treatment on wood cell walls (CWs), Masson pine (Pinus massonianaLamb.) wood was thermally modified (TM) at 150, 170 and 190°C for 2, 4 and 6 h, respectively. The chemical properties, cellulose crystallinity (CrI) and micromechanics of the control and thermally modified wood (TMW) were analyzed by wet chemical analysis, X-ray diffraction and nanoindentation. The relative lignin content andCrI increased after the TM partly degraded the amorphous wood polymers. The relative lignin content was higher in TMW and the equilibrium moisture content decreased. Moreover, the elastic modulus (Er) and hardness (H) of TMW were lowered along with the creep ratio decrement (CIT) of CWs. However, a severe treatment (e.g. 190°C/6 h) may negatively affect the mechanical properties of CWs caused by the partial degradation of hemicelluloses and also cellulose.

scholarly journals Species-Specific Responses of Root Morphology of Three Co-existing Tree Species to Nutrient Patches Reflect Their Root Foraging Strategies

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhenya Yang ◽  
Benzhi Zhou ◽  
Xiaogai Ge ◽  
Yonghui Cao ◽  
Ivano Brunner ◽  
...  
Keyword(s):  
Tree Species ◽  
Root Length ◽  
Chinese Fir ◽  
Moso Bamboo ◽  
Foraging Strategies ◽  
Root Proliferation ◽  
Masson Pine ◽  
Root Foraging ◽  
Heterogeneous Soils ◽  
P Supply

Root foraging strategies of plants may be critical to the competition for nutrient resources in the nutrient patches, but little is known about these of co-existing tree species in subtropical regions. This study aimed to elucidate root foraging strategies of three co-existing tree species in nutrient heterogeneous soils by exploring their root distribution, root morphology, photosynthates allocation and nutrient accumulation. Seedlings of the three tree species [moso bamboo (Phyllostachys edulis), Chinese fir (Cunninghamia lanceolata), and masson pine (Pinus massoniana)] were grown for 8months under one homogeneous soil [uniform nitrogen (N) plus phosphorus (P)] and three heterogeneous soils (localized N supply, localized P supply, or localized N plus P supply). The biomass, root morphological parameters (i.e., root length and root surface area), specific root length (SRL), non-structural carbohydrates (NSCs, i.e., mobile sugar and starch) in roots, total N and total P of plants were measured. The plasticity and distribution of root system were analyzed by calculating the root response ratio (RRR) and root foraging precision (FP), respectively. The results are as follows (i) Chinese fir tended to forage more N by promoting root proliferation in the N-rich patch, while root proliferation of bamboo and pine did not change. For P, bamboo absorbed more P by promoting root proliferation in the P-rich patch. The total P content of Pine and Chinese fir under localized P supply treatment remain the same despite the fact that the root length in the P-rich patch and the FP increased. (ii) Chinese fir foraged more N by increasing root length and decreasing SRL in the NP-rich patch; bamboo foraged more N and P by increasing root length and SRL in the NP-rich patch. The FP and foraging scale (FS) of both bamboo and Chinese fir were significantly improved under localized N plus P treatment. (iii) The concentrations of NSC were positively correlated with root morphological plasticity for moso bamboo and Chinese fir. Our results indicated that higher morphological plasticity is exhibited in moso bamboo and Chinese fir than masson pine in nutrient heterogeneous soils, allowing them to successfully forage for more nutrients.

Evaluation of soil and water conservation capacities for plantations on the Simian Mountains of China

2013 ◽  
Vol 89 (02) ◽  
pp. 178-183
Author(s):  
Jing Li ◽  
Dandong Chang ◽  
Jinhua Cheng ◽  
Hongjiang Zhang ◽  
Haofeng Huang
Keyword(s):  
Water Conservation ◽  
Ideal Point ◽  
Pinus Massoniana ◽  
Chinese Fir ◽  
Soil And Water Conservation ◽  
Masson Pine ◽  
Conifer Plantation ◽  
Coniferous Plantation ◽  
Soil And Water ◽  
The Ideal

Eighteen indices were selected to evaluate soil and water conservation capacities of four different mixtures of plantations using the Ideal Point Method. Results indicate that a broadleaf plantation of robur (Lithocarpus glabra) and Chinese guger tree (Schima superba) had the best conservation capacity, a mixed broadleaf plantation of sweetgum (Liquidambar formosana), Chinese gugertree and camphor tree (Cinnamomum camphora) was ranked second. A mixed broadleaf–conifer plantation of Chinese fir (Cunninghamia lanceolata), Masson pine (Pinus massoniana) and Chinese gugertree ranked third with a mixed coniferous plantation (Chinese fir and Masson pine) fourth. Under similar climates and topographical conditions, broadleaf plantations have better soil and water conservation capacities than conifer plantations. Sensitivity analysis showed that litter amounts and soil properties are the most important indicators of soil and water conservation capacities of plantations. Suitable measures such as deep tillage should be used to improve soil aggregation in different plantations.

Variation of surface and bonding properties among four wood species induced by a high voltage electrostatic field (HVEF)

Holzforschung ◽  
2019 ◽  
Vol 73 (10) ◽  
pp. 957-965 ◽  
Author(s):  
Qian He ◽  
Tianyi Zhan ◽  
Haiyang Zhang ◽  
Zehui Ju ◽  
Lu Hong ◽  
...  
Keyword(s):  
High Voltage ◽  
Electrostatic Field ◽  
Wood Species ◽  
Phenol Formaldehyde ◽  
Lignin Content ◽  
Chemical Properties ◽  
Pinus Massoniana ◽  
Populus Tomentosa ◽  
Chinese Fir ◽  
Masson Pine

Abstract A high voltage electrostatic field (HVEF) was applied to enhance the bonding performance of wood composites prepared with phenol-formaldehyde (PF) adhesive and different wood species and radial cut combinations. Four wood species including Masson pine (Pinus massoniana), Chinese fir (Cunninghamia lanceolata), poplar (Populus tomentosa) and ayous (Triplochiton scleroxylon) were studied. The results of HVEF-treatment turn out to be species-dependent, and are related to the anatomical and chemical properties of wood. It was demonstrated by a statistical approach that the lignin content is the most significant parameter with a good correlation coefficient (R2 > 0.8). High lignin content leads to high free radical concentration at the wood surface and the HVEF enhanced the adhesive penetration depth, the maximal density and the bonding strength (Bst) at the interphase. On the contrary, high extract contents and large lumina diameters negatively impacted the surface modification by HVEF. The magnitude of the effects was in the following order: ayous < poplar < Masson pine < Chinese fir.

scholarly journals Improvement of Mechanical, Hydrophobicity and Thermal Properties of Chinese Fir Wood by Impregnation of Nano Silica Sol

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1632 ◽  
Author(s):  
Enguang Xu ◽  
Yanjuan Zhang ◽  
Lanying Lin
Keyword(s):  
Mechanical Properties ◽  
Cell Walls ◽  
In Situ Polymerization ◽  
Silica Sol ◽  
Chinese Fir ◽  
Nano Silica ◽  
Amorphous Sio2 ◽  
Covalent Bonds ◽  
Oh Groups

In this paper, a wood-SiO2 composite material was prepared via in-situ polymerization using vacuum/pressure impregnation technology using commercial scale nano silica sol and Chinese Fir (Cunninghamia lanceolate (Lamb.) Hook.). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG), and water contact angle were used to study the changes in the microstructure and physical and mechanical properties of this composite. The results showed that silica sol can penetrate and distribute into the wood cell cavities and surface of cell walls and hence combine with the substances of wood materials. FTIR results indicated that the –OH groups of wood can polycondense in-situ with silica sol to form Si–O–C covalent bonds, and amorphous SiO2 formed from Si–O–Si bonds between the –OH groups of silica sol did not change the crystalline structure of wood cell walls. This in-situ formulating composite significantly improved the compact microstructure, thermal and mechanical properties, and hydrophobicity of the composites.

scholarly journals Incorporation of In Situ Synthesized Nano-Copper Modified Phenol-Formaldehyde Resin to Improve the Mechanical Properties of Chinese Fir: A Preliminary Study

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 876
Author(s):  
Fan Li ◽  
Cuiyin Ye ◽  
Yanhui Huang ◽  
Xianmiao Liu ◽  
Benhua Fei
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Cell Walls ◽  
Phenol Formaldehyde ◽  
Environmental Scanning Electron Microscopy ◽  
Phenol Formaldehyde Resin ◽  
Chinese Fir ◽  
Formaldehyde Resin ◽  
The Impact

Phenol-formaldehyde (PF) resin, modified using nano-copper with varying contents (0 wt%, 1 wt%, 3 wt%), was manufactured to improve the mechanical properties of Chinese fir. The morphology, chemical, micromechanical and micromechanical properties of the samples were determined by transmission electron microscopy (TEM), atomic force microscopy (AFM), environmental scanning electron microscopy (ESEM), Fourier transform infrared spectroscopy (FTIR), nanoindentation (NI) and traditional mechanical testing. The TEM and AFM results indicated that the in situ synthesized nano-copper particles were well-dispersed, and spherical, with a diameter of about 70 nm in PF resin. From the FTIR chemical changes detected by FTIR inferred that the nano-copper modified PF resin penetrated into the Chinese fir cell walls and interacted with the acetyl groups of hemicellulose by forming a crosslinked structure. Accordingly, the micro-mechanical properties of the Chinese fir cell walls were enhanced after treatment with nano-copper modified PF resin. The filling of the PF-1-Cu resin (1 wt% nano-copper) in the wood resulted in 13.7% and 22.2% increases in the elastic modulus (MOE) and hardness, respectively, of the cell walls. Besides, the impact toughness and compressive strength of the Chinese fir impregnated with PF-1-Cu resin were 21.8% and 8.2% higher than that of the PF-0-Cu resin. Therefore, in situ synthesized nano-copper-modified PF resin is a powerful treatment method for Chinese fir due to improved diffusive properties and reinforcement of the mechanical properties.

Longitudinal mechanical properties of cell wall of Masson pine (Pinus massoniana Lamb) as related to moisture content: A nanoindentation study

Holzforschung ◽  
2011 ◽  
Vol 65 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Yan Yu ◽  
Benhua Fei ◽  
Hankun Wang ◽  
Genlin Tian
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Moisture Content ◽  
Pinus Massoniana ◽  
Regression Equations ◽  
Saturation Point ◽  
Masson Pine ◽  
Pinus Massoniana Lamb ◽  
Experimental Values

Abstract The in situ imaging nanoindentation technique was used to investigate how the moisture content (MC) affects the longitudinal mechanical properties of Masson pine cell wall. Furthermore, nanoindentation tests in liquid water were performed. The results indicate that elastic modulus, hardness, and compression yield stress of wood wall are all linearly correlated to the selected MC region in the range from 4.5% to 13.1%. Remarkable differences were found between the experimental values measured in water and the extrapolated values based on regression equations below fiber saturation point.

Improvement of Mechanical Properties of Lightweight Ceramics with the Addition of Alumina Fiber

2014 ◽  
Vol 608 ◽  
pp. 31-36
Author(s):  
Geun Hee Kim ◽  
Jae Hwan Pee ◽  
Yoo Jin Kim ◽  
Woo Seok Cho ◽  
Dae Wung Kim
Keyword(s):  
Mechanical Properties ◽  
Raw Materials ◽  
High Strength ◽  
Low Density ◽  
High Melting ◽  
Alumina Fiber ◽  
Mullite Phase ◽  
High Melting Temperature ◽  
The Matrix ◽  
Strength And Toughness

Lightweight ceramics have a low density, which leads to a decrease in strength and toughness. In the development of lightweight ceramics, high-strengthening technology is necessary. Alumina fiber was mixed with raw materials for the purpose of producing high-strength lightweight ceramics. After adding alumina fiber at 1, 3, and 5wt% and sintering at 1300°C, we found that strength and toughness increased in proportion to the amount. Instead of the high melting temperature of alumina fiber, it is reacted with matrix and generated mullite phase. And lots of alumina fiber remains in the matrix, thereby allowing improvements in strength and toughness. When alumina fiber was not added, we found a low density of 1.35~1.80 g/m3, along with low values for strength and toughness at 30~60MPa and 0.7~1.2 MPa m1/2 respectively. With 1wt% addition of alumina fiber, we obtained a higher strength of 92MPa at 1300°C, which is close to the strength of general white porcelains at 112MPa.

scholarly journals Chemical Structure and Mechanical Properties of Wood Cell Walls Treated with Acid and Alkali Solution

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 87 ◽  
Author(s):  
Enguang Xu ◽  
Dong Wang ◽  
Lanying Lin
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Cell Walls ◽  
Chemical Structure ◽  
Alkali Treatment ◽  
Middle Lamella ◽  
Crystallinity Index ◽  
Wood Fibers ◽  
Fiber Properties ◽  
And Performance

The mechanical properties of individual fibers are related to the production and performance of papers and fiberboards. This paper examines the behavior of the microstructure constituents of wood subjected to acid and alkali treatments. The chemical structure and mechanical properties of wood cell walls with different acid or alkali treatments was analyzed. The results show that, compared with acid treatment, the crystal size and crystallinity index of cellulose increased after alkali treatment, resulting in an increase in the cell wall elastic modulus. The mechanical properties of the wood cell wall S2 region were higher than those of the compound middle lamella (CML) region. There was a topochemical effect between the CML and the S2 region in acid and alkali-treated samples, which provided a major threshold that facilitates the production/separation of wood fibers for better strength fiber properties.

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