木/塑复合材料及其增强机理的研究

本文概述了木/塑复合材料的主要配方、工艺和材料的主要力学性能、物理特性及其与其他材料性能比较;观察和分析木/塑复合材料的微观结构形态研究其增强机理;简要提出木/塑复合材料的应用范围。     

木／塑复合材料物理机械性能的评定

木/塑复合材料是一种造价低、用途广的新型复合材料。本文着重概述木/塑复合材料的机械强度和物理性能的评定。     

杂交狼尾草木塑复合材料的制备及性能研究

以杂交狼尾草为原料制备木塑复合材料,采用木粉改性剂对狼尾草秸杆粉进行部分降解实现狼尾草秸杆粉的改性,改善木塑复合材料制备中材料的流动特性.改变木粉改性剂的添加量和狼尾草秸杆粉与塑料的配比,测试成型复合材料的物理力学性能.研究表明,木粉改性剂的加入对材料的抗弯、抗拉、阻水性能影响显著.随着粉/塑比的提高,材料的密度、表面硬度、抗弯性能都随之增加,抗拉性能和阻水性能则随之下降.综合来看,在粉/塑比5:5、5%木粉改性剂处理的情况下,材料的综合性能最优.     

木陶瓷/金属复合材料的研究现状

总结了木陶瓷/金属复合材料及其预制体模板的制备机理和制备方法的研究现状;详细介绍了木陶瓷/金属复合材料的力学性能、热学性能、阻尼性能和摩擦学性能及其应用等方面的研究成果;探讨了木陶瓷/金属复合材料的发展前景及当前存在的问题;最后提出了一种以麻纤维织物为模板材料制备纤维织物遗态陶瓷/金属复合材料的新思路.     

增塑剂种类对淀粉/聚乳酸复合材料性能的影响

分别以乙二醇、甘油、聚乙二醇400和甲酰胺为增塑剂对淀粉/聚乳酸复合材料进行增塑处理,研究增塑剂种类对淀粉/聚乳酸复合材料性能的影响。采用XRD、SEM、TGA以及旋转流变仪对复合材料的相容性进行了表征,并测试了复合材料的熔融指数、力学性能和吸水率。结果表明,增塑剂对淀粉/聚乳酸复合材料的相容性改善效果依次为甘油甲酰胺乙二醇聚乙二醇400。淀粉/聚乳酸复合材料的力学性能和吸水率受相容性影响,呈现相容性越好,力学强度越大,断裂伸长率越大,吸水率越低的趋势。醇类增塑剂增塑复合材料的熔融流动性随着分子链增长逐渐变差,而甲酰胺增塑复合材料的熔融流动性过大。     

TiO2增强桉木/聚氯乙烯复合材料耐腐蚀性能

为改善桉木/聚氯乙烯（PVC）复合材料耐霉菌（黑曲霉）腐蚀性能,添加TiO₂制备TiO₂-桉木/PVC复合材料,并对复合材料进行霉菌加速腐蚀试验（加速腐蚀条件:温度为28℃,湿度为85%）。对比研究了腐蚀前后TiO₂-桉木/PVC复合材料的色差、力学和吸水性能及官能团、微观形貌和热稳定性变化。结果表明:TiO₂可提高桉木/PVC复合材料的耐霉菌腐蚀性能,TiO₂添加量为2wt%时,TiO₂-桉木/PVC复合材料腐蚀后表观霉菌相对较少,色差值和吸水率较未添加TiO₂的桉木/PVC复合材料分别降低了69.32%和13.33%;拉伸、冲击及弯曲强度、弯曲模量分别提高了31.17%、39.44%、40.75%、10.99%;2wt% TiO₂-桉木/PVC复合材料热分解各阶段失重温度较高,热稳定性较好;TiO₂添加量较高时会影响桉木纤维与PVC的界面结合,致使TiO₂-桉木/PVC复合材料更易受到霉菌的腐蚀。      

天然橡胶/改性碱木素复合材料的制备及性能研究

对碱木素进行羟甲基化改性,并以此为原料制备天然橡胶/改性碱木素复合材料。研究了复合材料的力学性能、热稳定性、加工性能以及碱木素的微观形貌。结果表明:当甲醛用量为1.0mol/kg碱木素,改性碱木素添加量为10%,丙三醇添加量为6g/100g改性碱木素时,复合材料的力学性能最优。热重分析显示:天然橡胶和复合材料的热稳定性十分接近,复合材料的成炭量有所增加。橡胶加工性能分析(RPA)表明:碱木素经改性后,在天然橡胶中的分散性得到了改善,与天然橡胶基体的相容性得到了提高;复合材料的储能模量、损耗模量和损耗因子增加。     

木粉原位接枝共聚共混制备复合材料

在乳酸和木粉的非均相体系中,乳酸脱水生成的丙交酯,和桑树木粉中含有羟基的高聚物进行原位接枝共聚生成木粉接枝聚乳酸(Wood-g-PLA),体系中同时生成的均聚乳酸(PLA)与Wood-g-PLA原位共混得到Wood-g-PLA/PLA复合材料.用红外光谱对改性木粉与原料木粉进行对比分析,表明木粉表面被成功接枝改性.利用SEM、TG、万能力学试验机等仪器分析了改性木粉/聚乳酸复合材料的界面相容性以及热、力学性能,发现材料中Wood-g-PLA与聚乳酸融为一体无相分离现象.Wood-g-PLA含量对复合材料的拉伸强度有一定影响,但对弯曲强度影响不大.材料力学性能有待提高.     

利用原子力显微镜研究预处理对木棉纤维/CdS纳米复合材料形貌结构的影响

对木棉纤维进行预处理,然后用预处理后木棉纤维与CdS进行原位复合制备木棉纤维/CdS纳米复合材料。利用扫描电镜(SEM)和原子力显微镜(AFM)对复合材料表面形貌结构进行了观察。用AFM定量地分析了预处理方法对木棉纤维/CdS纳米复合材料表面超微三维结构的影响。研究表明,相比未处理木棉纤维,预处理后木棉纤维/CdS纳米复合材料上CdS粒子的吸附量增大,且经过TEMPO氧化处理的木棉纤维所复合的CdS粒子的分布最均匀,粒径最均一。对于基于植物质纤维素资源为原料的纤维素/无机纳米复合材料的制备及其结构表征具有重要的参考价值。     

四种植物纤维/高密度聚乙烯木塑复合材料耐海水腐蚀性能比较

为比较桉木、杨木、竹粉和稻壳为改性相的高密度聚乙烯（HDPE）基四种木塑复合材料耐海水腐蚀性能,对其进行模拟海水加速腐蚀试验,测试四种HDPE基木塑复合材料腐蚀前后力学性能和色差值,分析其腐蚀前后微观形貌和官能团变化。结果表明:模拟海水腐蚀导致四种HDPE基木塑复合材料两相结合质量变差（裂隙和空洞增多）,力学性能下降,色差值变大（桉木/HDPE、杨木/HDPE和稻壳/HDPE复合材料趋于变白、变黄和变绿,竹粉/HDPE复合材料趋于变白、变蓝和变绿）,羟基含量增多。模拟海水腐蚀21天,四种HDPE基木塑复合材料弯曲强度和弯曲模量降幅为:桉木/HDPE复合材料分别为12.94%和23.18%;竹粉/HDPE复合材料分别为15.45%和23.20%;稻壳/HDPE复合材料分别为18.53%和25.15%,杨木/HDPE复合材料分别为18.52%和34.21%。模拟海水腐蚀后,力学性能下降和颜色变化及断面裂隙和孔洞缺陷最少的是桉木/HDPE复合材料,最多的是杨木/HDPE复合材料。      

刨花板／铝／环氧树脂复合板力学性能分析

刨花板／铝／环氧树脂复合板是一种新型的叠层材料,它以刨花板和铝为主要原料。着重研究刨花板和铝复合的工艺条件及其与复合板性能间的关系。     

DIY materials

The democratization of personal fabrication technologies in parallel to the rising desire of individuals for personalizing their products offers great opportunities to experiment with advanced, distributed and shared production processes as well as design new materials. In this article, we introduce the notion of Do-It-Yourself (DIY) Materials, which are created through individual or collective self-production practices, often by techniques and processes of the designer's own invention. They can be totally new materials, modified, or further developed versions of existing materials. In order to provide an operational vocabulary to discuss DIY materials, we have collected 27 DIY material cases developed in the last five years. We group the collected cases under two main categories: (1) DIY new materials: which focus on creative material ingredients (e.g. a material made of dried, blended waste citrus peel combined with natural binders); and (2) DIY new identities for conventional materials: which focus on new production techniques, giving new expressions to existing materials (i.e. they do not necessarily contain new ingredients, such as 3D printed metal). Grounded on the commonalities of collected cases, we discuss the design opportunities, including new aesthetic impressions offered through DIY material design practices.     

Comparing the mechanical performance of synthetic and natural cellular materials

This work compares the mechanical performance of agglomerated cork against synthetic materials typically used as impact energy absorbers. Particularly, the study will focus on the expanded polystyrene (EPS) and expanded polypropylene (EPP).Firstly, quasi-static compression tests are performed in order to assess the energy storage capacity and to characterize the stress–strain behavior cellular materials under study. Secondly, guided drop tests are performed to study the response of these materials when subjected to multiple dynamic loading (two impacts). Thirdly, finite element analysis (FEA) is carried out in order to simulate the compressive behavior of the studied materials under dynamic loading.Results show that agglomerated cork is an excellent alternative to the synthetic materials. Not only for being a natural and sustainable material but also for withstanding considerable impact energies. In addition, its capacity to keep some of its initial properties after loading (regarding mechanical properties and dimensions) makes this material highly desirable for multiple-impact applications.     

基于听觉感知的被击阻尼板冲击声合成方法

为了合成任意材料板的冲击声,提出了一种基于球-板撞击模型的冲击声合成方法,并进行了感知验证。通过在铝、玻璃和木材三种材料之间进行差值的方法,给出了二维材料感知空间中任意虚拟材料的冲击声合成方法。设计并完成了两组主观评价实验,实验1通过材料辨识实验研究了合成声和录音对材料辨识的影响,实验2产生材料渐变的冲击声连续统,并对材料控制策略进行感知评估。结果表明,与录音相比使用合成声可以获得更好的材料辨识结果,此外听者对材料的辨识结果与阻尼的变化趋势一致,从而验证了本文冲击声合成方法的有效性。     

纸/铝/塑复合软包装材料摩擦系数的分析

通过对纸铝塑复合薄膜正反两摩擦基材面相互摩擦及不同角度摩擦的动、静摩擦系数值的测定,比较并分析了不同摩擦基材面和不同摩擦方向对其大小的影响,从而对这种新材料的摩擦系数有了进一步的认识.结果表明:摩擦方向对摩擦系数的影响不大,实际生产中主要需考虑摩擦基材面对摩擦系数的影响.     

Automotive Friction Materials: from Experience to Science

An optimizing friction material formulation technique based on Golden Section and Relational Grade Analysis was developed. Approach 2 of this technique was tested by using 7 ingredients including 2 fibers, 4 fillers and 1 binder as raw materials. By doing 19 formulations, an optimizing one (BU18)was obtained with stableμ and averageμ = 0.451 and wear = 3.46 wt %.     

AgSnO2电触点材料制备方法进展

综合评价了AgSnO2电触点材料的制备方法,对比分析了粉末冶金法、合金内氧化法、预氧化合金粉末法和反应合成法等几种制备方法的优缺点,简要介绍了AgSnO2电触点材料的应用进展及国内外差距,并展望了AgSnO2电触点材料的发展趋势.     

Past,Present, and Future of Soft-Tissue Prosthetics: Advanced Polymers and Advanced Manufacturing

Millions of people worldwide experience disfigurement due to cancers, congenital defects, or trauma, leading to significant psychological, social, and economic disadvantage. Prosthetics aim to reduce their suffering by restoring aesthetics and function using synthetic materials that mimic the characteristics of native tissue. In the 1900s, natural materials used for thousands of years in prosthetics were replaced by synthetic polymers bringing about significant improvements in fabrication and greater realism and utility. These traditional methods have now been disrupted by the advanced manufacturing revolution, radically changing the materials, methods, and nature of prosthetics. In this report, traditional synthetic polymers and advanced prosthetic materials and manufacturing techniques are discussed, including a focus on prosthetic material degradation. New manufacturing approaches and future technological developments are also discussed in the context of specific tissues requiring aesthetic restoration, such as ear, nose, face, eye, breast, and hand. As advanced manufacturing moves from research into clinical practice, prosthetics can begin new age to significantly improve the quality of life for those suffering tissue loss or disfigurement.     

Biomorphic mineralization: From biology to materials

Since material properties are structure-dependent, new and interesting properties are expected from unusual or complex structures. Biomorphic mineralization is a technique that produces materials with morphologies and structures resembling those of nature living things, through employing bio-structures as templates for mineralization. The products, biomorphic materials, combine natural geometry with synthetic material chemistry. Fundamental information along with recent advances in biomorphic mineralization and biomorphic materials are provided in this review through discussions on the following aspects: biomorphic materials produced through synthesis or assembly using a range of templates including biomolecules, microorganisms, plants and animals; processing methods and mechanisms of biomorphic mineralization; properties and emerging applications of biomorphic materials in multiple areas including electronics, magnetics, photonics, biotech, sensing, and filtration. The potential of various natural structures for biomimicking to produce advanced materials will be also discussed. We conclude by making a prospect on biomorphic mineralization and biomorphic material, which is the product of close conversations between human and nature and the product of close co-operation between scientists from diverse fields.