Study of Vinyltrimethoxysilane Modified Wood Flour/HDPE Composites

2011 ◽  
Vol 183-185 ◽  
pp. 2148-2153
Author(s):  
Chun Tao Li ◽  
Wei Hong Wang ◽  
Qing Wen Wang ◽  
Yan Jun Xie ◽  
Yong Ming Song ◽  
...  

Wood plastic composites (WPC) are a new type of green environmental composites with high performance and added value. In this paper, poplar wood flour was modified with vinyltrimethoxysilane(A-171) to improve the interfacial compatibility and enhance the interfacial bonding between the polar wood flour and nonpolar plastics. Then the modified wood flour was blended with high density polyethylene (HDPE) and prepared composites by extrusion. The effects of amount and solution concentration of A-171 on the properties of WPC were investigated. FTIR analysis indicated that polycondensation grafting reaction occurred between A-171 and wood flour. Compared to untreated wood flour/HDPE composites, both mechanical properties and water resistance of the composites were improved and presented optimal performance when the dosage of A-171 was 4%. The storage modulus G' and viscosity η*of the composites decreased but the loss tangent tanδ increased compared to the untreated composites. G' and η* raised with the increase of A-171, however, tanδ decreased. Solution concentration of A-171 did not show significant effect on the mechanical properties of composites, but water resistance of composites decreased with the increase of solution concentrateon of A-171.

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Jinguang Wei ◽  
Fei Rao ◽  
Yuxiang Huang ◽  
Yahui Zhang ◽  
Yue Qi ◽  
...  

Natural wood has certain advantages such as good processability and high specific strength and thus has been used for millennium as a structural material. But the mechanical performance and water resistance, particularly for fast-growing species, are unsatisfactory for high-end applications. In this study, the “new-type” scrimber technology was introduced to radiata pine (Pinus radiata D. Don) scrimbers. The structure, mechanical properties, and dimensional stability of the scrimber panels were investigated. Results showed that OWFMs as basic units of scrimber had been very even in size and superior permeability. The scrimbers exhibited a three-dimensional porous structure, and the porosity had a decrease with increasing density. Both OWFMs and densification contributed to the high performance in terms of mechanical properties and water resistance. The flexural, compressive, and short-beam shearing strength were significantly enhanced with increasing density. As the density was 0.80 g cm−3, the flexural strength (MOR) was approximately 120 MPa, much larger than many selected wood-based panels. Moreover, the water resistance and dimensional stability also were closely related to the density. At the density of 1.39 g cm−3, the water absorption rate and thinness swelling rate of the panels in boiled water were only 19% and 5.7%, respectively.


Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 439-447 ◽  
Author(s):  
Ru Liu ◽  
Shupin Luo ◽  
Jinzhen Cao ◽  
Yu Chen

Abstract Wood flour/polylactic acid (WF/PLA) composites were produced with a WF content of 50% based on three types of waterborne polyacrylate (PA) emulsions including a PA homopolymer emulsion and two types of silane-PA copolymer emulsions as coupling agents. Two silanes were in focus, namely, γ-methacryloxypropyl- trimethoxysilane (silane-1) and vinyltrimethoxysilane (silane-2). The emulsions and the modified WFs were characterized, and the effects were investigated in terms of emulsion type and their loading levels on the mechanical properties of WF/PLA composites. (1) Both types of silanes could be successfully copolymerized with PA to form stable emulsions. (2) With increasing PA loading, the mechanical properties (except for flexural modulus) of the composites increased at first before reaching the maximum values at 4% PA loading and then the properties worsened. However, these values were larger than those of pure composites, especially in cases when PA-silane emulsions were applied. (3) PA modified with silane-1 showed the best coupling effect among all the three PA emulsions. The results can be interpreted that PA emulsions are effective coupling agents for the preparation of high-performance WPCs.


2019 ◽  
Vol 6 (11) ◽  
pp. 191154 ◽  
Author(s):  
Chen Chen ◽  
Fusheng Chen ◽  
Boye Liu ◽  
Yan Du ◽  
Chen Liu ◽  
...  

Peanut meal (PM) has recently emerged as a potential protein source for wood adhesives, owing to superior features such as high availability, renewability and eco-friendliness. However, the poor properties of unmodified PM-based wood adhesives, compared with their petroleum-derived counterparts, limit their use in high-performance applications. In order to promote the application of PM-based wood adhesives in plywood industry, urea (U) and epichlorohydrin (ECH) were used to enhance the properties of the adhesives and the modification mechanism was investigated. PM-based wood adhesives made with U and ECH were shown to possess sufficient water resistance and exhibited higher apparent viscosity and solid content than without. Fourier-transform infrared spectroscopy results suggested that U denatured PM protein and expose more reactive groups, allowing ECH to react better with U-treated PM protein to form a dense, cross-linked network which was the main reason for the improvement of the properties. The crystallinity increased from 2.7% to 11% compared with the control, indicating that the molecular structure of the resultant adhesive modified by U and ECH became more regular and compact owing to the cross-linked network structure. Thermogravimetry tests showed that decomposition temperature of the protein skeleton structure increased from 307°C to 314°C after U and ECH modification. Scanning electron microscopy images revealed that using U and ECH for adhesives resulted in a smooth protein surface which prevented moisture penetration and improved water resistance. PM-based adhesives thus represent potential candidates to replace petroleum-derived adhesives in the plywood industry, which will effectively promote the rapid development of eco-friendly adhesives and increase the added value of PM.


2009 ◽  
Vol 24 (11) ◽  
pp. 3397-3406 ◽  
Author(s):  
Dongdong Gu ◽  
Yifu Shen

The poor wettability between ceramics and metals is a main obstacle in obtaining high-performance metal-matrix composites (MMCs) parts using direct metal laser sintering (DMLS). Rare earth (RE) elements, due to their unique physical and chemical properties, have high potential for improving laser processability of MMCs. In this work, a comparative study was performed to investigate the influence of RE–Si–Fe addition on microstructural features and mechanical properties of DMLS processed tungsten carbide (WC) particle reinforced Cu MMCs parts. It showed that by adding 3 wt% RE–Si–Fe, the WC reinforcing particles were refined, the particle dispersion state was homogenized, and the particle/matrix interfacial compatibility was enhanced. The RE–Si–Fe-containing WC/Cu MMCs parts possessed significantly elevated mechanical properties, i.e., densification level of 95.7%, microhardness of 417.6 HV, fracture strength of 201.8 MPa, and friction coefficient of 0.8. The metallurgical functions of the RE–Si–Fe additive for the improvement of DMLS quality of MMCs parts were discussed.


Author(s):  
Qiangqiang Liu ◽  
Haojia Du ◽  
Wenhua Lyu

In order to improve the performance of soft plantation wood, an environmentally friendly inorganic-organic hybrid wood modifier was developed. First, using urea and melamine as crosslinking agents, the waterborne glucose silicone resin (MUG) was prepared with glucose under the catalysis of inorganic acid and metal ions. Then MUG resin was diluted to 10% and 20% mass fraction, and compounded with sodium silicate (S) of 20% and 10% mass fraction, so the inorganic-organic hybrid G10S20 and G20S10 wood modifier were obtained respectively. Then plantation poplar wood (Populus tomentosa) were impregnated and modified with them. Their physical and mechanical properties were tested and compared with those of the wood treated with S of 20% mass fraction (S20). Infrared analysis showed that amino resin characteristic structure (CO-NH-) existed in MUG resin. The resin has good permeability. Compared with S20 modified wood, the degree of shrinkage of G10S20 or G20S10 modified wood is reduced, their moisture absorption is reduced, and their dimensional stability is improved. Waterborne glucose silicone modifier can effectively improve the wood density, modulus of elasticity, modulus of rapture and compression strength. SEM analysis showed that the cell wall of G20S10 modified wood was significantly thicker than the untreated wood, and there were columnar and granular solid substances attached in some cell cavities, ducts and corners, etc. EDX showed that the number of Si elements on the cell wall was significantly increased compared with the control, indicating that the modifier effectively entered the wood cell wall. The waterborne glucose silicone resin can greatly improve the physical and mechanical properties of wood through organic-inorganic hybridization. It is a green, non-formaldehyde, eco-friendly, low cost, compound wood modifier with broad application prospects.


2019 ◽  
Vol 36 (1) ◽  
pp. 31-46 ◽  
Author(s):  
Haoqun Hong ◽  
Quannan Guo ◽  
Haiyan Zhang ◽  
Hui He

The article presents the preparation of a high-performance wood–plastic composites with improved interfacial interactions by adding ternary-monomer graft copolymers as the interfacial modifiers and by braising wood flour (WF) and investigates their effects on the rheological properties of recycled polyethylene (rPE)/WF composites. The processing properties, capillary rheological properties, dynamical rheological properties, and mechanical properties were investigated. Results show that graft copolymer of polyethylene is effective in improving the interfacial interactions of rPE/WF composites, dramatically changing the rheological and mechanical properties. The braising of WF enlarges the gaps of cells and promotes the infiltration of rPE into the gaps, as promoting the increasing in mechanical properties of rPE/WF composites and significantly changing the rheological properties of the composites.


2021 ◽  
Author(s):  
Nataliya Khodosova ◽  
A. Dmitrenkov ◽  
V. Zayats

The study of the surface tension of wood of various tree species impregnated with used sunflower oil was carried out. Samples of birch, pine and linden wood were used for oil treatment. Impregnation of wood materials was carried out by the method of “hot-cold baths”. As an impregnating material, used refined fryer oil was used. In more detail, the paper examines the effect of an impregnating composition based on used fryer oil, with a filler and a desiccant on birch wood. Wood flour of coniferous wood species and a metal salt-based drier were used as a filler. The surface tension for all images was determined by the edge angle of wetting. For this purpose, the method of a liquid drop on the surface of a solid body was used. It was found that the impregnation of untreated wood with deep-frying oil leads to an increase in the surface tension on all samples, to a greater extent this is typical for pine wood. The introduction of a 1% siccative in the impregnating composition together with wood flour reduces the drying time and improves the water-repellent properties of birch wood.


BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2227-2236
Author(s):  
Vedat Çavuş

The aim of this study was to produce mahogany (Swietenia macrophylla) wood flour filled polypropylene (both recycled and virgin) composites and to determine the effects of maleic anhydride-grafted polypropylene (MAPP) on the interfacial compatibility, density, and other mechanical properties of the resulting composites. Approximately 40 wt% of mahogany wood flour, and 60 wt% of polypropylene, 3 wt% of MAPP, 1.5 wt% of zinc stearate, and 1.5 wt% of wax were used during composite manufacturing. Test specimens were manufactured using extrusion and injection molding processes. The flexural, tensile, impact, and hardness properties of all specimens were determined. Scanning electron microscopy was used to study the morphology and interfacial compatibility of the filler in prepared composites. The test results showed that MAPP use and the filler rates affected the density and mechanical properties of test specimens.


2009 ◽  
Vol 79-82 ◽  
pp. 1527-1530
Author(s):  
Yong Feng Li ◽  
Yi Xing Liu ◽  
Hai Peng Yu ◽  
Wen Shuai Chen

Wood as a porous structure has weak durability and unsatisfactory mechanical properties which limits its utilization. For this reason, the study presents a two-step method to prepare a new modified wood material—Wood Polymer Composite. Maleic anhydride(Man) firstly penetrates into the porous structure of wood, followed by a reaction with wood cell walls. Then, Styrene(St) with some Man and a few amount of initiator, AIBN, permeate through the whole wood and react with the above modified wood. The structural characterization of wood polymer composite with SEM and FTIR indicates that Man reacts successfully with the hydroxyl group of wood cell wall by its anhydride group, and further reacts fully with styrene as a free radical copolymerization form by its double bond; and thus the polymer fills in wood cell lumina as a solid form, which combines the wood cell walls without any evident crack. The testing results of properties show that the mechanical properties of wood polymer composite increase by about 50%-250% over those of unmodified wood, and its durability improve 1.9-4.89 times than untreated wood.


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