Improving the utility,performance, and durability of wood- and bio-based composites

Key message

This paper briefly reviews the state of the art in various types of wood- and bio-based composites, summarizes recent advances, and then discusses future possibilities for improving the durability of wood- and bio-based composites.

Context

Wood can be processed and reformed into a number of different biocomposites.

Aims

We aimed at reviewing the state of the art in various types of wood- and bio-based composites.

Methods

Review of utility, performance and durability of wood- and bio-based composites.

Results

The advanced biocomposites will:Combine wood, natural biofibers, and non-biomaterials to create synergistic hybrid materials that far exceed performance capabilities of current biocompositesBe renewable, recyclable, and totally sustainableProvide superior performance and serviceability exceeding performance of current biocompositesBe more durable, dimensionally stable, moisture proof, and fire resistantBe less expensive to produce and use (over the life cycle of use) than the materials they replace

Conclusion

The next generation of advanced wood- and bio-based composites must provide high-performance construction and specialty products that simultaneously promote resource and environmental sustainability and provide advanced performance, long-term performance, enhanced durability, and value.

     

自然气候条件下木塑复合材料性质的变化

主要研究木塑复合材料在自然气候条件下性质的变化情况,并采用电子显微镜对材料表面的变化进行了检测分析,为木塑复合材料的生产和利用提供了依据.     

无机胶合人造板的发展历史及最新技术进展

本文介绍了以水泥、石膏和炉渣等无机材料为胶粘剂的人造板的发展历史，论述了无机胶合人造板制造的最新技术，展望了无机胶合人造板的发展前景。     

Ground vegetation has a major role in element dynamics in an ash-fertilized cut-away peatland

In Finland, recycling of wood-ash as a fertilizer has been widely studied in recent decades in peatlands drained for forestry. Wood-ash is reported to promote tree growth without any significant negative impacts on the environment and could, therefore, be a suitable option on cut-away peatlands, which are estimated to increase by 30,000 ha over the next ten years. However, the environmental effects of ash-fertilization on cut-away peatlands or on ground vegetation are not well known. We studied the effects of wood- and peat-ash application on the nutrient content in soil and plants and on the heavy metal content in the vegetation of a cut-away peatland. Six treatments of different quantities and mixtures of wood-ash, peat-ash, biotite, or Forest PK-fertilizer were replicated in three plots. Both wood- and peat-ash fertilization ensured an adequate level of nutrients for the early establishment and growth of ground vegetation and birch seedlings in a cut-away peatland. Dense pioneer moss cover was important in trapping the heavy metals, such as cadmium, which are present in the ash. Ground vegetation of mosses and herbaceous plants also had a major role in the retention of the nutrients that could otherwise have leached from the open cut-away peatland area during the early stages of afforestation. Both wood- and peat-ash proved to be suitable for the initial fertilization of afforested cut-away peatlands, but in order to guarantee a sufficient long-term potassium supply for tree growth, an application of biotite with the peat-ash is recommended.     

木质纤维/塑料复合材料的发展现状及应用

木质纤维/塑料复合材料是以木质纤维材料为基本体,与塑料通过不同的复合途径制成的一种新型复合材料,综合了木质纤维与塑料的性能特点,因而用途广泛.作者介绍了木质纤维/塑料复合材料的复合工艺、界面特性和改性处理以及产品的应用前景.     

沙柳材重组木的研制

以沙柳材为原料研制沙柳材重组木,并采用正交试验方法探讨了沙柳材重组木的热压压力、热压时间、热压温度以及施胶量等条件对产品性能的影响,得出实验室较佳的工艺参数。     

改善木塑复合材料界面相容性的途径

本文介绍了国内外在改善木塑复合材料的界面复合性能方面所采用的最新研究方法和取得的研究成果。几乎所有的研究都表明:在木塑复合过程中木材与热塑性高分子聚合物之间界面的粘合性能和作为填充物的木材在热塑性高分子聚合物基材中的分散性是影响木塑复合材料的物理、力学性能的主要因素。同时对如何改进木塑复合材料界面相容性的研究方法进行了系统的介绍。     

日本水泥刨花板的生产及对我国的借鉴

文章详细介绍了日本水泥刨花板的生产发展现状以及其产品的性能和用途，并以此为借鉴，结合我国的实际情况，对我国发展水泥刨花板生产提出具有建设性的参考意见。     

No-formaldehyde Wood-plastic Composite Plywood in China

As a new product invented by the Research Institute of Wood Industry, no-formaldehyde wood- plastic composite plywood is the harvest of the cross-study on wood-plastic composite and plywood industry. It has no formaldehyde emission, with an excellent environment-friendly performance and a good bonding quality. This paper analyses the strongpoints and market of this wood-plastic composite plywood.     

木塑复合材料的研究现状与应用前景

木塑复合材料是一种新型环境友好材料，是现代材料工业发展的主要方向之一。掌握国内外的发展势态．深入研究其结构和界面特性，对改善木塑复合材料的物理力学性能，推进产品的发展历程是十分必要的，文章就木塑复合材料的研究现状及应用前景进行了阐述。     

竹塑复合材料界面改性研究

竹塑复合材料作为复合材料研究热点领域,具有较高的商业附加值与更为突出的环保意义。竹塑复合材料的界面改性一直是困扰竹塑复合材料发展的一大难题,也是这一领域的研究热点。基于构成竹塑复合材料的界面构成体系,界面改性可以通过竹纤维的表面进行预处理、加入界面相容剂与改进加工工艺这3个方面进行。文中综合国内外研究现状,从这3个方面概述了竹塑复合材料界面改性技术的发展。     

尾叶桉材性指标在株内、株间和无性系间的变异性研究

以8年生尾叶桉(Eucalyptus urophylla S.T.Blake)无性系林为试材,就材性指标在株内、株间和无性系之间变异进行了研究分析。结果表明:纤维长度、纤维宽度、纤维长宽比、管孔弦向直径、纤维双壁厚度和纤维壁腔比在树干水平方向上的不同部位具有极显著性差异,呈由内向外逐渐增大的规律;微纤丝角度、单位面积管孔数和纤维腔径比在树于水平方向上的不同部位亦具有极显著性差异,但呈由内向外逐渐减小的规律;而木材胞壁率、木纤维比量、导管比量、射线比量、轴向薄壁组织比量和木纤维胞腔直径在树干水平方向上没有显著性变异;主要材性指标在同一无性系内的植株之间无显著性差异,但在无性系之间的差异均达到显著或极显著性水平。     

农林副产物／塑料复合材料的开发

本文重点讨论了农林副产物/塑料复合材料的加工与性能，存在的主要问题。并就控制这类复合材料的界面性能及其改性进行了详细分析。     

竹纤维增强聚合物基复合材料性能及应用

植物纤维来源丰富，能耗低，被认为是最具前景的绿色可再生资源。竹纤维具有成本低、密度小、比强度高等特点，与其他材料组成的复合材料是一种资源节约型和环境友好型材料。文章概述了竹纤维的结构组成与力学性能，综述了竹纤维增强聚合物基复合材料(BFRP)的研究与应用现状，在此基础上提出了BFRP今后的研究重点，包括竹纤维化学组成、界面性能及生产工艺等，以期为发挥其优良特性、扩大其应用领域提供参考。     

两种改性方法对桉木单板/聚乙烯膜复合材料力学性能影响

为提高塑料疏水表面与单板亲水表面之间的界面相容性,以聚乙烯薄膜为无甲醛胶黏剂制备复合材料。分析了热处理、碱处理对界面性能影响,确定了制备此类材料的优化工艺:热处理温度140 ℃,处理时间1 h,碱浓度3%时,复合材料力学性能较佳;热处理、碱处理可以增强复合材料的界面性能。     

Mechanical properties of natural fiber composites produced using dynamic sheet former

ABSTRACT

Composites formed from wood fibers and man-made cellulosic fibers in PLA (polylactic acid) matrix, manufactured using sheet forming technique and hot pressing, are studied. The composites have very low density (due to high porosity) and rather good elastic modulus and tensile strength. As expected, these properties for the four types of wood fiber composites studied here improve with increasing weight fraction of fibers, even if porosity is also increasing. On the contrary, for man-made cellulosic fiber composites with circular fiber cross-section, the increasing fiber weight fraction (accompanied by increasing void content) has detrimental effect on stiffness and strength. The differences in behavior are discussed attributing them to fiber/ fiber interaction in wood fiber composites which does not happen in man-made fiber composites, and by rather weak fiber/matrix interface for man-made fibers leading to macro-crack formation in large porosity regions.     

炭含量对竹炭/高密度聚乙烯复合材料电磁屏蔽和力学性能的影响

为了探究竹炭含量对竹炭基复合材料性能的影响,以竹炭(BC)和高密度聚乙烯(HDPE)为原料,采用"熔融挤出-模压"成型工艺制备竹炭/高密度聚乙烯(BC/HDPE)复合材料,通过对不同竹炭含量的BC/HDPE复合材料进行测试,研究炭含量对复合材料力学性能、热性能、电磁屏蔽性能以及微观结构的影响.结果表明,竹炭对BC/HD...     

术质复合材料作为建筑结构用材的应用

简要介绍了复合材料的种类、特点和木质复合材料的基本概念，并说明了木质复合材料作为建筑结构构件的优点。     

生物矿化原理与木材纳米结构复合材料

为促进传统木材改性技术产生新的发展 ,将生物矿化概念导入到木材科学与技术的研究领域中。本文综述了生物体系中生物矿化作用的基本内涵 ,探讨了基于这些原理之上的木质基纳米材料控制合成的构想 ,即通过立木形成层细胞分生的有机分子和无机离子在界面处的相互作用来设置矿化位 ,调节微环境 ,建立饱和溶液、提供有机质、搬运离子、加入添加剂等来控制生物矿化作用的方向和过程 ,实现用活立木制备木材纳米结构复合材。     

中国古代木结构建筑发展概况——原始社会时期中国木结构建筑的发展概况

从科学发展观的角度回顾了中国古代木结构建筑在原始社会时期的发展概况，指出了中国古代人类采用木结构建筑已有六七千年的历史，中国的古代建筑是以木结构为主发展起来的。建筑的发展是由天然岩洞到穴居、半穴居，然后上升到地面，由简单的原始木结构建筑逐渐发展为抬梁式（又称梁柱式或叠梁木式）结构建筑。这一历史时期，中国古代木结构建筑处于萌芽时期。