改性剂对木塑复合材料力学性能影响的研究

采用木材纤维,分别与PE、PS、ABS、SAN等热塑性高分子聚合物,经热压复合工艺制成木塑复合板材,通过加入不同的改性剂以及改变改性剂的加入量,研究它们对木塑复合材料力学性能的影响。结果表明:改性剂的加入能使木材纤维与各种热塑性高分子聚合物很好地胶接;改性剂不同对木塑复合材料的性能产生不同的影响;改性剂的加入量为木材纤维用量的5%时,该法制作的木塑复合板材力学性能最佳。     

木塑复合材料的研究

木塑复合材料,是以高分子材料中的热塑性树脂为母体,加入木材纤维素和木质素,以及多种化学助剂,经高温混炼而成的一种新型复合材料。它可代替木材和部分金属,广泛用于各个领域。1 国内外对木塑复合材料的研究与进展60年代初,世界各国就开始了木塑复合材料的研究,产品刚一问世,即受欢迎,取     

改善木塑复合材料性能的方法讨论

木塑复合材料是一种新型结构用材,目前已经大量应用于建筑装饰以及汽车、飞机制造等行业,是一种性能较为稳定的建设材料,但是在木塑复合材料的生产过程中由于其粘合性能的好坏直接影响着木塑复合材的强度,本文通过对木材或塑料等高分子基材进行相应处理方法的讨论,提出了提高木塑复合材性能的方法与途径。     

共挤出成型木塑复合材料研究进展与应用

木塑复合材料(WPCs)是一类以热塑性聚合物为基体,以木质纤维为填充增强材料,通过熔融复合,采用挤出、注塑或模压等成型工艺而制备的复合材料,兼具木材的生态特性和热塑性聚合物的可重复加工性能,是一类生态和经济效益显著的环境友好材料,近几十年来获得飞速发展。然而,传统WPCs由于其耐UV老化性能差,受到长期力载荷和热负荷时易发生蠕变和热变形,由此导致的耐久性和安全性隐患制约了其市场发展,迫切需要加以解决并向高附加值和多功能化等方向拓展。共挤出成型木塑复合材料(Co-WPCs)是采用共挤出成型技术将不同组分的核/壳材料复合而成的多层木塑复合材料,可以较低的成本和较高的效率,赋予WPCs高附加值和多功能化。笔者主要介绍了Co-WPCs的研究现状,并结合核/壳结构的特征,概述了Co-WPCs的研究进展,包括力学性能、尺寸稳定性、耐候性能、阻燃性能等;重点阐述了2种新型Co-WPCs的发展状况,为共挤出木塑的创新和发展提供新思路;最后提出共挤出木塑复合材料发展所面临的挑战和问题,阐明了未来研究的重点。     

偶联剂对木塑复合材料性能的影响

研究了两种偶联剂——马来酸酐(偶联剂1)和异氰酸酯(偶联剂2)对木塑复合材料性能的影响。确定木材纤维与热塑性聚合物的比例7:3、复合材料的设计密度为0．7g／cm3,在热压温度175℃、热压时间8min、偶联剂1或偶联剂2 加入比例均为2％的试验条件下,对比分析偶联剂产生的作用。结果表明:偶联剂2对复合材料的力学性能影响显著;对于同一种偶联剂,所用的热塑性聚合物材料不同,对复合材料性能的影响也存在较大的差异。     

Effect of chemical modification on the properties of wood/polypropylene composites

对以铝酸酯为偶联剂对木粉进行表面改性处理后制备的木粉/聚丙烯复合材料的力学性能和形态学特征进行了研究。结果表明:铝酸酯偶联剂可以增加木塑复合材料的抗冲击强度,但会对复合材料的抗拉强度和抗弯强度造成负面的影响。对木塑复合材料的动态力学性能和微分扫描热量分析研究表明,以铝酸酯作为偶联剂,对木塑复合材料的储存模量和损失模量有少许增加,同时可降低材料的熔点和熔解热。利用扫描电镜观察木塑复合材料的木材与塑料界面发现,经铝酸酯处理过的木材与聚丙烯复合界面之间具有更好的相容性。这些研究结果表明,在木塑复合材料制造过程中利用廉价的铝酸酯作为木材化学改性剂,对改善复合材料的性质同样起作良好的作用。图6 表2 参16。     

木塑复合工艺因子对复合材料性能的影响

选用2种人工林木材(马尾松与杨木)和3种废弃塑料(聚乙烯、聚丙烯及聚苯乙烯)为原料,采用木材与塑料冷混-热压工艺,通过正交试验研究不同树种、木材组元形态、补强剂、塑料种类、板材密度及不同木塑混合比等复合工艺因子对木塑复合材料性能的影响.结果表明树种、木材组元形态、塑料种类、木塑复合比例、板材密度与补强剂等复合工艺因子对木塑复合材料性能有不同程度的影响;提高塑料在木塑复合材料中的比例也可以达到与添加酚醛补强剂同样或更好的结果;以杨木原料、细长刨花形态、聚丙烯塑料、板材密度为1g*cm-3等为最佳复合工艺因子,制成的复合材料性能达到或超过相关普通刨花板,包括室外结构用刨花板性能指标.     

木塑复合材料的连接方式

<正>聚合物基木塑复合材料(wood-plastic composites,简称WPC)是指以经过预处理的植物纤维或粉末(如木、竹、花生壳、椰子壳、亚麻、秸秆等)为主要组分(含量通常达到60%以上),与高分子树脂基体复合而成的一种新型材料,它兼有木材和塑料两者的性能优点,     

木塑复合材的研究,生产及发展概述

木塑复合材的研究、生产及发展概述任玉坤（广州市木材工业公司研究所广州５１０１６０）木材塑料（或聚合物）复合材料简称塑合木或木塑复合材。它是由英语Ｗｏｏｄ－ｐｌａｓｔｉｃ（或Ｗｏｏｄ－ｐｏｌｙ－ｍｅｒ），Ｃｏｍｐｏｓｉｔｅｓ（或Ｃｏｍｂｉｎａｔｉｏｎ）...     

木塑复合材料的表面润湿性研究

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.     

不同改性剂对木塑复合材料性能的影响研究

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。     

Wood-polymer combinations: The chemical modification of wood by alkoxysilane coupling agents

Summary Vinyl polymers in wood-polymer combinations fill cell cavities but do not bond to nor enter cell walls to any noticeable extent. The wood dimensional stability thus remains virtually unchanged. Nonleachable-bulking treatments which react with the cell wall material tend to diminish wood strength properties and do not appear to show promise for providing a link between the cell wall and the polymer. Alkoxysilane coupling agents are widely used to modify the interface between dissimilar materials, such as glass fibers and thermoplastic or thermosetting resins. The coupling agent -methacryloxypropyltrimethoxysilane was used in this study with trembling aspen, white birch and eastern white pine woods. Antishrink efficiencies comparable to those reported for reactive chemical wood modifiers were obtained. This treatment did not require acidic or basic reaction conditions which could cause wood strength reductions. Its effects upon wood strength and the extent of bonding to the cell wall are presently under investigation.The authors are grateful for financial support by the Natural Sciences and Engineering Research Council of Canada     

木塑复合板主要工艺对材料性能的影响

研究了木粉与聚丙烯为主要原料的复合材料的主要力学性能和尺寸稳定性.实验结果表明:热压时间对复合材料的力学性能有一定的影响,加压时间为9min,复合板的力学强度较优,吸水厚度膨胀率小;木塑配比对复合材料的力学性能有较大的影响,随着配比的增加,板性能呈现逐渐下降的趋势;配比对吸水厚度膨胀率影响明显,木粉的比例越高,吸水厚度膨胀率越高.     

Properties of PEG/thermally modified wood flour/polypropylene (PP) composites

In order to improve the dimensional stability of wood-polymer composites, wood flour pre-treated by polyethylene glyco1 (PEG) at two different concentrations and then thermally treated at 140°C, was used as raw material to produce wood flour/polypropylene (PP) composites at a wood content of 40%. The structure of modified wood flour was analyzed with a scanning electron microscope (SEM) and its effect on the physical and mechanical properties of wood flour/PP composites was evaluated. The SEM results indicated the "bulking" effect of PEG on wood flour, which resulted in reduced water uptake. The combination of PEG and heat treatment further improved the moisture resistance of the composites. However, PEG modification had a negative effect on the flexural modulus of rupture (MOR) and the modulus of elasticity (MOE); whereas heat treatment partly compensated for this reduction. For dynamic mechanical properties, PEG treatment decreased the storage modulus (E′). However, the heat treatment resulted in an increase of E′ of the wood flour/PP composites, with the temperature of loss factor peaks shifting to a higher temperature.     

木材/蒙脱土(MMT)纳米插层复合材料的制备构想

基于聚合物 蒙脱土纳米插层复合材料的研究成果 ,综述了插层复合方法的原理、工艺过程和产品性能 ,分析比较了单体插层原位聚合和聚合物直接插层等方法。从木材与蒙脱土的结构和组成特性出发 ,分析比较了木材与聚合物溶解、熔融性的不同 ,讨论了利用插层复合原理制备木材 蒙脱土纳米复合材料的基本构想 ,并进一步提出了相应的技术路线和工艺流程概念图。     

Design of wood/montmorillonite (MMT) intercalation nanocomposite

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.     

Design of Wood/Montmorillonite (MMT) Intercalation NanocompositeCollege of Material Science and Technology, Beijing Forestry University, Beijing 100083, P.R.China

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.     

木塑复合材料的应用及其发展前景

介绍了木塑复合材料的成分、加工工艺，该材料的适用范围及其力学性能，以及国内外木塑复合材料制品的发展现状和市场前景，为加快我国木塑复合材料产业的发展，提出了三点意见。