共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
3.
木材苯酚碳素纤维材料的研究 总被引:1,自引:0,他引:1
介绍了以木材液化和现代纳米纺丝技术为基础的木材苯酚液化产物制备碳素纤维材料的构思、技术路线和存在的问题,为解决木材纳米、微米材料的制备开拓了新思路。 相似文献
4.
木材的液化及其液化生成物的利用 总被引:1,自引:0,他引:1
本主要归纳了木材的液体方法包括木材的苯酚液化和多羟基醇液化技术,对木材在不同液化条件下的反应生成物性质也进行了简要介绍,对木材液化研究的现状和发展趋势进行了讨论,目的在于使液化技术这一木材应用的新领域得到更好的开发. 相似文献
5.
木材液化技术研究现状及产业化发展 总被引:7,自引:2,他引:5
扼要介绍了国内外木材液化技术研究的现状,分析了开发木材液化研究领域的重要性,并对木材液化技术的研究方向、发展趋势以及该技术在我国实现产业化应用的前景提出了建议. 相似文献
6.
木材的苯酚及多元醇液化反应机理研究进展 总被引:1,自引:0,他引:1
综述了国内外在木材苯酚液化及多元醇液化反应机理研究方面的进展,指出了研究木材液化反应机理的重要性,归纳了今后木材液化反应机理研究的发展趋势。深化木材液化反应机理研究可以揭示木材液化的本质,补充和完善木材液化理论研究体系,也有利于实现液化过程的绿色化、降低液化成本、建立液化工艺与产物性质之间的调控机制、加快木材液化技术应用的产业化进程。 相似文献
7.
木材苯酚液化产物制备碳纤维的初步探讨 总被引:2,自引:0,他引:2
为拓宽木材液化产物的应用领域,提高木材产品的附加值,实现木材的高效利用,在研究木材苯酚液化产物特性的基础上,提出了木材苯酚液化产物碳纤维材料的制备构思和工艺路线。利用木材苯酚液化产物为前驱体,通过加入反应剂如六次甲基四胺等调制纺丝液,熔融纺丝后将纤丝在甲醛和盐酸混合溶液中加热固化形成网状交联结构,然后在惰性气体保护下高温炭化制备成碳纤维,同时对制备过程中可能存在的影响因素进行了分析。 相似文献
8.
9.
纳微米科学与技术在木材工业的应用前景展望 总被引:43,自引:6,他引:37
本文对纳米和微米技术在木材工业上的应用前景进行展望,预测未来纳微米技术可能对木材工业产生的影响,利用纳微米技术可能形成造纸的高得浆率方法,木材在变成纳微米尺寸后,木材的材料特异性质、尺寸效应及其变化机理,以及木材改性的显微结构关系可能使木材改性出现突破性进展。当木粉变成纳微米的粒度后,原木材理化指标发生变化,在细粉状态下进行木材液化可以改变木材液化的方式和成本,使木材液化真正工业化。在复杂木雕制品加工中,采用RPM技术利用直接CAD将纳微米木酚形成复杂木雕制品,可能开创一种新的木材加工方法。利用木材细胞的自组装方式可形成新的木基复合材料,纳米木粉生产的无污染胶粘剂可能代替含甲醛的有毒胶、胶粘剂的绿色革命可能从木材的纳微米技术开始。 相似文献
10.
化学转化木材为热塑性材料 总被引:12,自引:1,他引:11
木材是不溶不熔的材料。近年来研究发现通过适当的化学改性反应特别是经典的纤维素酯化和醚化反应对木材进行化学改性,可使木材转化为可溶可熔的新型热塑性高分子材料。这些热塑性木材可单独或与合成高聚物共混热压加工成型为各种形状的类塑料产品,或利用其热熔性制造自粘合型纤维板、微粒板或木板材。这些新发现为扩大木材的加工方法、劣废木材资源更有效的综合利用及提高木材的应用价值开辟了全新的途径,故已成为近10多年来木材综合利用新技术研究开发的热点之一。本文综述了该领域的研究开发现状。 相似文献
11.
热塑性聚合物之间的熔融共混改性和木材纤维与热塑性聚合物之间的复合,加入偶联剂均可提高复合材料的润湿性,对材料的相容有利;在偶联剂加入量相同的情况下,增加木材纤维的用量可以加速材料的润湿速度,有利于提高材料的润湿性;在热塑性聚合物用量一定的前提下,改变加入的增强材料的形状,对材料润湿性有影响,木材纤维可以提高复合材料的润湿性. 相似文献
12.
CCB是一种性能优良的木材防腐剂,但它的抗流失性能不如CCA,由于它是水溶性防腐剂,故处理后木材的尺寸亦不稳定。本研究采用在防腐剂中添加聚合物或树脂的方法来提高CCB的抗流失性能,使CCB处理材的尺寸稳定性大大提高。研究结果表明,在CCB中添加少量聚乙烯醇缩醛树脂后,铜、铬、硼的流失与不加树脂相比分别减少57.63,78.53和96,46%;木材湿胀性在弦向减少91.97%、径向减少88.34%、体积减少84,20%;处理材的抗腐力也明显提高。 相似文献
13.
14.
不同改性剂对木塑复合材料性能的影响研究 总被引:3,自引:0,他引:3
采用木材纤维分别与PE、PS、ABS、SAN四种塑料制成木塑复合材料,根据物理力学性能的检测,研究了不同改性剂对木塑复合材料性能的影响。结果表明:加入改性剂能改善木材纤维与所用塑料交接性能,改性剂可以提高复合材料的力学强度;不同的改性剂对复合材料的性能产生不同的影响,异氰酸酯胶改性效果比较好。木塑复合材料既保持了木质材料原来的优良品质,又具有塑料的一些特性,其防水性、尺寸稳定性、力学强度等指标均有较大改善。图5参6。 相似文献
15.
Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other disciplines. The compounding of wood and inorganic MMT on nanoscale molecular level has high potential to greatly improve the mechanical properties, fire retardance, abrasion resistance, decay resistance, dimensional stability and other properties of wood. Based on the great achievements of polymer/montmorillonite (MMT) nanocomposites, this paper reviewed nano intercalation compounding methods (i.e. in-situ intercalative polymerization and direct polymer intercalation), and discussed the structure, properties and modification of montmorillonite (MMT). According to the main chemical components and particular structure of wood, the authors discussed the liquefaction and plasticization of wood, compared the dissolvability and meltability between wood and polymer, and then systematically put forward the basic idea, technological processes and schematic diagram to prepare wood/MMT nanocomposites (WMNC). The key technology to prepare WMNC is either to introduce delaminated MMT nanolayers into wood with the help of some intermediate polymers, or to obtain liquefied wood or plasticized wood from the complicated natural composite. It is applicable and effective to realize wood/MMT nanoscale compounding with the help of proper intercalation agent and medium polymer through the proposed "one-step" or "two-step" impregnating processes. 相似文献
16.
Design of wood/montmorillonite (MMT) intercalation nanocomposite 总被引:4,自引:0,他引:4
Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other disciplines. The compounding of wood and inorganic MMT on nanoscale molecular level has high potential to greatly improve the mechanical properties, fire retardance, abrasion resistance, decay resistance, dimensional stability and other properties of wood. Based on the great achievements of polymer/montmorillonite (MMT) nanocomposites, this paper reviewed nano intercalation compounding methods (i.e. in-situ intercalative polymerization and direct polymer intercalation), and discussed the structure, properties and modification of montmorillonite (MMT). According to the main chemical components and particular structure of wood, the authors discussed the liquefaction and plasticization of wood, compared the dissolvability and meltability between wood and polymer, and then systematically put forward the basic idea, technological processes and schematic diagram to prepare wood/MMT nanocomposites (WMNC). The key technology to prepare WMNC is either to introduce delaminated MMT nanolayers into wood with the help of some intermediate polymers, or to obtain liquefied wood or plasticized wood from the complicated natural composite. It is applicable and effective to realize wood/MMT nanoscale compounding with the help of proper intercalation agent and medium polymer through the proposed “one-step” or “two-step” impregnating processes. 相似文献
17.
小兴安岭低质林改造后小径木和采伐剩余物综合利用探讨 总被引:1,自引:0,他引:1
通过对小兴安岭低质林改造过程中产生的中小径木和采伐剩余物研究,分析中小径木和采伐剩余物的产生量,提出其利用途径和价值。结果表明:改造采伐时产生的大径木、中径木、小径木、短小材和薪材的出材量分别为1.13m^3/hm^2、32.15m^3/hm^2、38.30m^3/hm^2、4.79m^3/hm^2和12.68 m^3/hm^2,中小径木和薪材的出材量较高;改造地每公顷中小径木直接出售可获得6.5万元的收入。采伐剩余物总量为16.92 m^3/hm^2。小径木除了直接销售外,还可加工成拼版材、压缩木、重组木和单板层积材等。采伐剩余物可加工成木片,再根据不同的工艺加工成刨花板、纤维板、木丝板及纸张等用途。中小径木和采伐剩余物的综合利用可有效利用林区资源,提高林区经济效益。 相似文献
18.
Alireza Bastani Stergios Adamopoulos Holger Militz 《Wood material science & engineering》2017,12(4):236-241
The shear strength of furfurylated, N-methylol melamine (NMM) and thermally modified wood bonded with emulsion polymer isocyanate, polyvinyl acetate (PVAc), and polyurethane (PU) adhesives was examined. Furfurylation and NMM modification of Scots pine had a significant negative effect on the bonding strength with all adhesives irrespective of the treatment intensity. The obtained low-shear strength values were related to the brittle nature of the wood after modifications rather to the failure of the bondline. PVAc showed a better bonding performance with both furfurylated and NMM modified wood while the combination of furfurylated wood and PU gave the highest reduction in bonding strength (47–51%). Shear strength also decreased significantly after thermal modification in both Scots pine (36–56%) and beech (34–48%) with all adhesives. With the exception of thermally modified beech samples bonded with PU, bondline was found to be the weakest link in thermally modified wood as it was revealed by the wood failure surfaces. Bondline thickness and effective penetration of adhesives did not relate to the shear strength of all modified wood materials. The lower shear strength of modified wood could be attributed to other factors, such as the reduced chemical bonding or mechanical interlocking of adhesives, and the reduced strength of brittle modified wood substrate. 相似文献
19.
As water moves inside the wood, the gluelines might act as barriers that are potentially leading to local moistening. Even low amounts of water may influence the mechanical performance of glued wood products. Dynamic vapor sorption analysis was performed to assess the sorption processes of six commercial wood adhesives. Vapor sorption isotherms were compared with vapor uptake dynamics. Phenol–resorcinol–formaldehyde showed high moisture uptake of 18 %, while vapor diffusion speed was low. Fish glue showed a water uptake of 45 % at otherwise moderate vapor uptake speed. Melamine–formaldehyde resin gained 22 % water, and polyvinyl acetate absorbed 10 %. The latter was also the fastest vapor absorbing adhesive. Polyurethane only absorbed 3.5 % of moisture at medium uptake speed. Mechanisms of water diffusion seem to be driven by (1) the available free volume in the polymer and (2) the interacting ionic groups of the polymer chain. While the free volume could be linked to the accumulated moisture, the ionic group interaction might determine the measured vapor diffusion dynamics. 相似文献
20.