影响木材纤维／聚丙烯复合材料力学性能的因子

以木材纤维和聚丙烯为原料,使用马来酸酐偶联剂,采用SJSH30/SJ45双阶单双螺杆挤出机组制作木材纤维/聚丙烯复合材料.探讨了一次、二次加工方式中木材纤维与聚丙烯比例以及MAPP偶联剂和二次加工对于复合材料力学性能的影响.结果表明:在没有添加偶联剂的前提下,木材纤维含量30%时检测的弯曲强度、抗拉强度和冲击强度均达最高值;纤维含量40%时弹性模量最高;原料经过回收后的二次加工,对于复合材料的力学性能没有影响;无论一次还是二次复合,加入偶联剂均可以提高复合材料的力学性能,并且随着偶联剂用量的增加复合材料力学性能提高.     

马来酸酐偶联剂对麦秸／废旧聚丙烯复合材料性能的影响

以麦秸和废旧聚丙烯为原料,以马来酸酐作为偶联剂,异氰酸酯(MDI)作为胶黏剂,采用热压工艺压制麦秸/废旧聚丙烯复合材料,通过正交实验研究了偶联剂对该复合材料力学性能的影响。结果表明:单独施用马来酸酐偶联剂,内结合强度极低,静曲强度较低,吸水厚度膨胀率较高,板材性能差;与施用马来酸酐偶联剂相比较,单独施用MDI胶黏剂,内结合强度提高,吸水厚度膨胀率值降低,材料的综合性能好于施用马来酸酐偶联剂的情况,但还不能完全达到刨花板国家标准(GB/T4897.1-4897.7-2003)要求;同时施用马来酸酐偶联剂和MDI胶黏剂时,除密度对内结合强度影响较大外,聚丙烯含量对内结合强度、马来酸酐用量对内结合强度、施胶量对静曲强度和吸水厚度膨胀率均有显著影响,其中马来酸酐用量对内结合强度的影响最为显著。但过多的马来酸酐不但起不到促进作用,反而影响了胶黏剂的胶结性能。     

木塑复合材料力学性能影响因素研究

采用木材刨花与LDPE、HDPE.和PP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,研究了塑料基质种类、刨花用量与偶联剂种类对木塑复合材料力学性能的影响。结果表明:相较于LDPE和PP,由HDPE制成的木塑复合材料力学性能更佳;所使用的三种偶联剂,以硅烷偶联剂的效果最好;随着刨花用量的增加,木塑复合材料的抗弯曲性能逐步提高,但内结合强度逐渐下降。     

机械参数对木塑复合材性能的影响

以桦木粉和HDPE为原料,采用双螺杆挤出机造粒,单螺杆挤出机成型的方法加工木塑复合材.在加工过程中,改变双螺杆挤出机三、四、五区的温度和螺杆转速,并加入一定比例的MAPE做为偶联剂.结果表明,转速在40RPM时,温度是130℃、135℃、145℃、152℃、157℃、170℃时的复合材料的综合性能较好.     

木塑复合纤维板生产工艺研究

介绍了以低密度聚乙烯和木纤维为主要原料制造木塑复合纤维板的生产工艺,研究了木塑比例、偶联剂加入量、热压温度及热压时间对木塑复合纤维板力学及防水性能的影响。     

旧报纸纤维增强回收聚丙烯复合材料性能研究

以旧报纸（ONP）和废塑料（回收聚丙烯塑料）为原料,马来酸酐接枝聚丙烯为相容剂,采用热压成型法制备了废纸纤维/回收聚丙烯复合材料,研究了ONP纤维含量对复合材料力学性能和吸水性能的影响,采用红外光谱仪、扫描电镜对复合材料组成和复合界面进行了分析。结果表明,ONP纤维对复合材料具有良好的增强效果,当ONP纤维含量为30%时,复合材料拉伸强度和弯曲强度分别达到32.36 MPa和43.37 MPa,与不加ONP的废塑料相比,分别提高了66.1%和69.6%;随ONP纤维含量的增加,复合材料中羟基的特征吸收峰逐渐增强,材料吸水率不断上升;扫描电镜分析显示,当ONP纤维含量较低时,纤维与聚丙烯之间具有良好的界面,ONP纤维含量超过30%后,复合材料界面相容性下降明显。     

HDPE基木塑复合材料力学性能的研究

为研究如何改善HDPE基木塑复合材料的力学性能,分别考察了不同木粉含量、不同偶联剂及增容剂对复合材料力学性能的影响,通过测试和观察复合材料的力学性能和微观形貌,得出以下结论:木粉的加入增加了复合材料的刚性,但降低了材料的韧性;添加了硅烷偶联剂制备的复合材料力学性能较好;MA-PP使材料综合性能最好.     

竹粉/高密度聚乙烯紫外光快速成型材料的界面相容性分析

采用马来酸酐作为增容剂,在混粉中通过竹粉与高密度聚乙烯(HDPE)的配比、马来酸酐相容剂添加量等因素,分析竹粉与HDPE的紫外光快速成型复合材料的相容性。试验结果为:竹粉与HDPE配比为1∶9时,复合材料的拉伸强度最高,是24.07MPa,吸水率最低为1.2%,马来酸酐添加量为竹粉/HDPE混粉的3%时,复合材料的相关性能较优,即复合材料的相容性最佳。     

基于ANSYS的木塑挤出3D成型研究

针对目前3D成型技术原材料单一以及木塑挤出成型的局限性,提出了一种木塑挤出3D成型方法。建立了三维成型平台与挤出部分的匹配关系;探究了在成型层厚度为0.5 mm,挤出速度匹配范围在12.74~63.69 mm/s的条件下,动模板移动速度范围为20~100 mm/s。通过分析聚丙烯基木塑复合材料成型温度场和应力场模拟得出:随着动模板移动速度提高,应力波动减小,成型过程中的最大应力值和最大变形量增大。研究表明,动模板移动速度是木塑挤出3D成型的一个重要因素。在实际生产中,为保证成型效率和质量,可以适当提高动模板移动速度,同时也要按照匹配关系提高挤出速度。     

挤出温度和螺杆转速对木塑制品外观性能的影响

介绍了木塑复合材料的主要生产工艺.实验采用两步法挤出成型工艺制作HDPE基木塑复合材料,研究挤出温度和螺杆转速对木塑复合材料外观性能的影响.结果表明:当木塑复合材料使用HDPE和杨木粉作为主要原料,木塑比为6∶4时,与之相适应的工艺条件为:挤出成型温度为130℃,150℃,155℃,155℃,135℃;螺杆转速为7.5r/min.     

银离子络合蚕丝纤维的工艺研究

采用单宁酸（TA）预处理再络合银离子的方法处理真丝纤维,确定了单宁酸处理真丝纤维的较优工艺以及各种因素对纤维络合银离子能力的影响情况。结果表明,真丝纤维经单宁酸处理后增重现象明显;经单宁酸预处理的真丝纤维吸附银离子的能力明显高于普通真丝纤维,且吸附能力随着纤维TA增重率的提高而提高。研究还发现,碱性条件更有利于TA预处理真丝纤维对银离子的吸附。     

Effects of wood fiber content and coupling agent content on tensile properties of wood fiber polyethylene composites

This study investigated the effects of coupling agent content, wood fiber content and wood fiber type on the mechanical properties of wood fiber-reinforced polymer composites (WPC). This study adopted a response surface strategy of a 20 run optimal design for these three factors. The WPC modulus of elasticity was mainly influenced by wood fiber type and wood fiber content, and tensile stress at break depended on wood fiber type, wood fiber content and coupling agent content, whereas strain at break was significantly affected by wood fiber content and coupling agent content, but not significantly influenced by wood fiber type.     

Preliminary study of the stiffness enhancement of wood–plastic composites using carbon nanofibers

Vapor-grown carbon nanofibers (CNFs) were compounded into polypropylene (PP) with southern pine wood flour (WF) by high shear melt blending to investigate the reinforcement effects of CNFs on the stiffness of conventional wood flour/plastic composites. CNF loadings of 1, 2 and 5 parts by weight per 100 parts of PP were employed with three WF levels (20, 40 and 60 parts). Maleated polypropylene (MAPP) was used as a coupling agent to improve WF to PP compatibility. The incorporation of CNFs significantly increased the modulus of elasticity of these nanocomposites with MAPP addition. The presence of 0.61 wt?% of CNF within a 36.6%WF/1.83%MAPP/61%PP composite exhibited a modulus (7590 MPa) that was 59% greater than its counterpart without CNF (36.8%WF/1.84%MAPP/61.4%PP) (4783 MPa) and 90% greater than pure PP. The origin of this enhancement is not yet understood.     

An experimental investigation on mechanical and tribological properties of Himalayan nettle fiber composite

The main focus of the present research work was to explore mechanical and tribological properties of Himalayan nettle fiber and unsaturated polyester resin (GP) using hand lay-up method. Four composite laminates were prepared by adding the Himalayan nettle fibers by weight percentage (5%–20%). The various properties (e.g., tensile strength, hardness, impact strength, and abrasion wear) were calculated for the composite laminates. It was found that the significant variation in properties was observed when fiber addition was in the range 15%. The change in the properties was negligible when fiber addition was increased from 15% by weight.     

Preparation and characterization of polypropylene/wood flour/nanoclay composites

In this study, the effects of coupling agent and nanoclay loading on the mechanical properties and water absorption of composites are investigated. Composites based on polypropylene (PP), wood flour, nanoclay, and maleated polypropylene (MAPP) were made by melt compounding and then injection molding. The mechanical analysis showed that the biggest improvement of the tensile and flexural strengths can be achieved for the nanoclay loading at 3%. However, further increasing of the loading of nanoclay resulted in a decrease of all the mechanical properties. The maximum tensile and flexural strengths (increase of ??46%, compared to the pure PP) were achieved in the composites when 7.5% MAPP was used as coupling agent in the manufacture of the composites. Finally, it was found that addition of nanoclay or MAPP reduced the water absorption property of the composites. However, the extent of improvement in the water absorption is more prominent with MAPP.     

Einfluß der Espenholzdichte und-entnahmezone auf ausgewählte Eigenschaften des Holz-Polystyrol-Systems

The quality of aspen wood polystyrene composites is decisively influenced by the stem position and the height of the tree trunk from which the wood was selected. Wood density is only of secondary imporance. To produce wood polymer composites, aspen wood taken from sapwood areas is particulary suitable. Aspen wood taken from the heartwood zone is not suitable for producing composites due to lack of styrene saturation. This fact is caused by the presence of thyloses in vessels of these areas. The number of annual rings comprising heartwood zone in the specimen ranged from 12 rings at breast height diameter to 5 rings at a stem height of 15 m. In the alburnous aspen wood polystyrene composite narrow cell lumina are completely filled. However, large diameter tracheids are covered only by a thick polystyrene layer. The presence of polystyrene was also observed within cell walls. During composite production using higher density sapwood layers a higher temperature peak occurs during the polymerization process. Dimensional stability of the aspen polystyrence composite depends mainly on the place in the trunk crossection from which the sample was taken. The highest dimensional stability was shown by a composite of sapwood layers containing the greatest amount of polystyrene. Bending strength of the aspen wood polystyrene composite depends not only on the polystyrene content in the wood but also on the original strength of the wood itself. Composite producted from wood of higher density are characterized by higher bending strength. Hardness of the aspen wood polystyrene composite is, in principle, dependent on the polystyrene contents. An increase in polystyrene content imporves composite hardness compresive in particular perpendicular to grain.     

Exploring the potential of milkweed stalk in wood plastic manufacture

The physical and mechanical properties of milkweed composites based on different loads of milkweed flour and maleic anhydride grafted polypropylene (MAPP) using polypropylene as matrix are investigated in this study. There levels of milkweed fibers (30, 40, and 50 wt.%), one level of mixed milkweed flour (20:20 wt.% fiber:bark), and two levels of MAPP (4 and 6 wt.%) were used to prepare natural fiber-reinforced composites. Physical and mechanical properties including flexural, tension, impact, and thickness swelling were evaluated according to ASTM standards. The result demonstrated that addition of milkweed flour fluctuates mechanical properties of reinforced composite. However, the optimum load of milkweed flour was different in each test. Generally, 40 wt.% mixed flour composite in comparison with 40 wt.% milkweed composite showed lower mechanical results and higher thickness swelling. MAPP as a coupling agent improved physical and mechanical properties of milkweed-filled composites in most properties. The results of this study depicted positive effects of lignocellulose fibers and coupling gent and also negative effect of bark flour as a function of lower cellulose and higher extractive contents on physical and mechanical properties of milkweed-reinforced composites.     

色木、桦木压缩木物理力学性质探讨

通过测试色木压缩木,桦木压缩木的物理力学性能指标,证明色木,桦 木压缩木的各项物理力学性能均相近,可以作为纺织器材用压缩木材料进行生产。