PVC木塑复合材料的耐热增强改性

采用模压成型制备了一系列聚氯乙烯(PVC)/氯化聚氯乙烯(CPVC)配比不同、无机刚性粒子含量不同的木塑复合材料。通过力学性能测试、热变形温度测试、扫描电子显微镜观察等手段对上述木塑复合材料的耐热性及力学性能进行了研究。结果表明,CPVC和无机刚性粒子均显著改善了PVC木塑复合材料的耐热性和力学性能。与PVC木塑复合材料相比,当PVC/CPVC配比为50/50,白云母或凹凸棒土的用量为3份时,改性木塑复合材料的热变形温度分别提高了14.3℃和19.7℃,且力学性能较好。凹凸棒土对木塑复合材料的耐热增强改性效果优于白云母。     

亚临界乙醇对木塑复合材料力学性能的影响

通过亚临界乙醇辅助反应挤出法,以纳米有机膨润土和超细重质碳酸钙作为填料制备木塑复合材料,考察了亚临界乙醇对木塑复合材料力学性能的影响,并用傅里叶红外光谱和扫描电子显微对木塑复合材料进行了分析。结果表明,亚临界乙醇能改善木粉与聚丙烯(PP)之间的界面结合,在亚临界乙醇作用下,超细重质碳酸钙能更好地发挥增强增韧效果,当添加1份超细重质碳酸钙时,有亚临界乙醇制备的木塑复合材料的冲击强度比无亚临界乙醇的提高了34%。     

剑麻/含红土聚乙烯基复合材料制备与性能

针对废旧地膜资源化利用过程中出现的高成本和低性能问题,本文提出了废旧地膜免清洗和剑麻纤维边角料增强的废旧地膜资源化利用技术。采用挤出造粒和注塑成型工艺,制备了剑麻边角料填充含红土废旧聚乙烯复合材料,分析了红土和剑麻纤维边角料对废旧地膜的填充作用。结果表明,红土颗粒使废旧地膜注塑试样的拉伸模量、硬度和耐热温度分别提高了34.4%、41.3%、和33.1%。红土颗粒难以和塑料基体形成良好的界面粘结,导致含红土废旧地膜注塑试样的拉伸强度、弯曲性能和冲击强度轻微降低,表明红土颗粒不能对废旧地膜进行增韧增强,但可以提高模量和耐热温度。剑麻纤维边角料对含红土废旧地膜具有明显的增强增韧作用,随着剑麻纤维添加量的增加,剑麻纤维填充的含红土废旧地膜复合材料的力学性能增加。剑麻纤维填充量超过一定值后,会在复合材料中引入气孔,同时会降低剑麻纤维的分散程度,出现剑麻聚集体,导致复合材料的力学性能降低。     

纳米木塑复合材料的制备与研究

以回收高密度聚乙烯(HDPE)塑料为基体,以木粉为填料,添加不同种类的纳米填料和自主合成的纳米填料处理剂,采用双螺杆挤出造粒后模压成型工艺制备纳米木塑复合材料。研究了不同种类的纳米填料、纳米填料处理剂含量等对纳米木塑复合材料力学性能的影响,并对材料断面结构进行了SEM分析。结果表明:纳米填料处理剂能够提高材料的界面相容性,当处理剂含量为2.5%和纳米蒙脱土含量为10%时,材料的力学性能达到最大值。     

聚氯乙烯/植物纤维木塑复合材料的性能研究

以植物纤维、聚氯乙烯(PVC)为原材料制备植物纤维/PVC木塑复合材料,研究了植物纤维种类与含量及偶联剂含量对复合材料洛氏硬度、冲击强度、弯曲强度以及拉伸强度等力学性能的影响。结果表明,20%含量稻壳粉填充PVC木塑复合材料的硬度最大,40%含量稻壳粉填充PVC木塑复合材料硬度最小,复合材料的硬度几乎不随花生壳粉含量的变化而变化,20%含量稻壳粉填充PVC木塑复合材料的拉伸强度和弯曲强度都最大。植物纤维/PVC木塑复合材料的吸水性能随着稻壳粉和花生壳粉等植物纤维含量的增加而增强,50%含量稻壳粉/PVC木塑复合材料的吸水率最大。添加偶联剂的稻壳粉填充PVC木塑复合材料的力学性能有所提高,吸水性降低,在一定程度上提高材料的耐磨性能,降低损耗。     

聚氯乙烯/植物纤维木塑复合材料的性能研究

以植物纤维、聚氯乙烯(PVC)为原材料制备植物纤维/PVC木塑复合材料,研究了植物纤维种类与含量及偶联剂含量对复合材料洛氏硬度、冲击强度、弯曲强度以及拉伸强度等力学性能的影响。结果表明,20%含量稻壳粉填充PVC木塑复合材料的硬度最大,40%含量稻壳粉填充PVC木塑复合材料硬度最小,复合材料的硬度几乎不随花生壳粉含量的变化而变化,20%含量稻壳粉填充PVC木塑复合材料的拉伸强度和弯曲强度都最大。植物纤维/PVC木塑复合材料的吸水性能随着稻壳粉和花生壳粉等植物纤维含量的增加而增强,50%含量稻壳粉/PVC木塑复合材料的吸水率最大。添加偶联剂的稻壳粉填充PVC木塑复合材料的力学性能有所提高,吸水性降低,在一定程度上提高材料的耐磨性能,降低损耗。     

PLA木塑复合材料性能研究及界面处理分析

以稻壳、竹粉、杨木粉作为聚乳酸(PLA)的增强材料,添加硅烷偶联剂进行界面处理,采用模压成型的方法制备PLA木塑复合材料,研究了纤维的种类与含量以及偶联剂对PLA木塑复合材料力学性能和吸水性能的影响,并采用体式显微镜对其形貌和结构进行了表征。结果表明,杨木粉对PLA复合材料的增强效果最好;杨木粉、稻壳、竹粉质量分数为30%时,PLA木塑复合材料的拉伸强度最大,分别为16.26,11.27,14.17 MPa,杨木粉质量分数为30%时PLA木塑复合材料的冲击强度最大,为4.44 kJ/m~2,随着复合材料中木粉含量的增加,其吸水率呈上升趋势;添加硅烷偶联剂改性使PLA/竹粉复合材料的拉伸强度最大提高了119.74%,冲击强度最大提高了86.52%,改性后的木塑复合材料各组分较为均匀、空洞和缺陷较少。     

AKD改性PETG/废纸粉木塑复合材料制备工艺

为了提高废纸的利用率,保护森林资源,开发绿色无污染的木塑复合材料,使用废弃纸箱和聚对苯二甲酸乙二酯–1,4–环己二甲酯(PETG)作为原料,利用烷基烯酮二聚体(AKD)对其进行改性制备木塑复合材料。选取碱处理浓度、时间、温度和AKD添加量四个方面进行实验,探究对PETG木塑复合材料力学性能、吸水性能和热稳定性的影响,并且结合红外和微观形貌表征,确定了对废纸纤维进行改性的木塑复合材料的最佳工艺为:NaOH溶液浓度15%,碱处理温度60℃,碱处理时间60 min,AKD最佳添加量为废纸粉质量的2%。     

不同树脂基木塑复合材料的性能对比

由于木塑复合材料中所用的木质纤维填料一般只能承受200℃加工温度,因此,木塑复合材料一般采用聚乙烯、聚丙烯、聚氯乙烯等加工温度较低的热塑性树脂。基体树脂类型不同时,木塑复合材料的性能差异较大。本文初步研究了基体树脂类型及木质纤维类型对木塑复合材料制品性能的影响规律,这对人们根据制品的应用领域舍理地选择基体树脂和木质纤维具有一定的参考价值。     

海泡石/空心微珠/环氧树脂复合涂层在镁合金表面的隔热性能研究

通过SEM、TGA、隔热性能测试等方法研究了加入不同量无机填料的环氧树脂复合涂层的结构和性能。无机纤维海泡石的加入提高了环氧树脂的耐热性能,同时在空心微珠之间起到填充和阻热的作用。当纤维状无机填料海泡石与球状无机填料空心玻璃微珠的加入量分别达到15%时,厚度约3.0mm的涂层在经受500℃高温2 min后,镁合金基体背面温度大约为300℃。随着无机填料加入量的进一步增加,隔热效果反而变差。在实验结果的基础上,建立了两种填料高分子复合材料的传热模型,分析了两种填料在涂层隔热过程中的作用机理。     

Preparation and characterization of LDPE and PP—Wood fiber composites

Natural fiber reinforced composites is an emerging area in polymer science. These natural fibers are low cost fibers with low density and high specific properties. These are biodegradable and nonabrasive. The natural fiber composites offer specific properties comparable to those of conventional fiber composites. However, in development of these composites, the incompatibility of the fibers and poor resistance to moisture often reduce the potential of natural fibers, and these draw backs become critical issue. Wood‐plastic composites (WPC) are a relatively new class of materials and one of the fastest growing sectors in the wood composites industry. Composites of wood in a thermoplastic matrix (wood–plastic composites) are considered a low maintenance solution to using wood in outdoor applications. WPCs are normally made from a mixture of wood fiber, thermoplastic, and small amounts of process and property modifiers through an extrusion process. In this study, Wood–plastic composites (WPC) are produce by adding a maleic anhydride modified low density polyethylene coupling agent to improve interfacial adhesion between the wood fiber and the plastic. Mixing is done with twin screw extruder. Subsequently, tensile strength, the modulus of elasticity, % elongation, hardness, Izod impact strength, melt flow index (MFI), and heat deflection temperature (HDT) are determined. Thermal transition temperatures and microstructure are determined with DSC and SEM, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Recycling of waste FRP and corn straw in wood plastic composite

Waste fiber reinforced polymer (FRP) combined with corn straw fiber was recycled and incorporated in wood plastic composite (WPC). The synergistic enhancement effect of glass fiber and corn straw fiber was investigated. The results show that there was a good physical interlocking structure among glass fiber of waste FRP, corn straw fiber and poly(vinyl chloride) (PVC) in WPC, which led to the enhancement of mechanical properties of WPC. With 30 phr (parts per hundreds of resin) waste FRP, the tensile strength and flexural strength of WPC were improved to 24 and 66 MPa, increased by 31% and 23% with respect to starting WPC. This study reveals that waste FRP and corn straw fiber can be good alternative for wood fiber in the production of WPC. POLYM. COMPOS., 38:2140–2145, 2017. © 2015 Society of Plastics Engineers     

Influence of wood fiber size on extrusion foaming of wood fiber/HDPE composites

Foaming of wood fiber/plastic composites (WPC) with a fine‐celled structure can offer benefits such as improved ductility and impact strength, lowered material cost, and lowered weight, which can enhance their utility in many applications. Although a great deal of attention is now being focused on these composites in the scientific literature, there are still numerous aspects of WPC processing that need elucidation. In this context, this article investigates the effects of wood fiber (WF) size on fine‐celled extrusion foaming of WPC in terms of cell size, cell size distribution, and foam density. The effects of WF size and coupling agent content on the viscosity of WPC are also investigated. The experimental results revealed that the small‐sized WF provides a better cell morphology, a smaller cell size, and a better cell uniformity in WPC foams. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Characterization of wood-filled thermoplastic polyurethanes for the injection molding process

Fiber fillings of wood plastic composites (WPC) are almost exclusively limited to standard plastics such as polyethylene and polypropylene. At the Kunststofftechnik Paderborn of the University of Paderborn the wood fiber filling of engineering plastics is being promoted. WPC with different fiber types and fiber contents based on two thermoplastic polyurethanes (TPU) were compounded and subsequently characterized. We found that the physicochemical properties of the materials differ from standard plastic-based WPC. Wood filling with increasing fiber content did not immediately correlate with an increase in density. A decrease in density and swelling of the compound was detected with reaching a critical fiber content. Our compounds showed an increased water absorption at high-fiber contents over time, which can be described logarithmically. The observed viscosity curves obey the Ostwald and de Waele power law, but an increased viscosity at increased fiber content was not apparent for both TPU matrices.     

纳米载银抗菌剂对木塑复合材料的抗菌效果分析

以高密度聚乙烯和木粉为主要原料,采用热压成型的方法制备木塑复合材料。测量复合材料腐蚀前后的质量变化、弯曲强度、色差、表面张力和表面形貌,研究了纳米载银抗菌剂对木塑复合材料抗菌性能的影响。结果表明:纳米载银抗菌剂对木塑复合材料具有一定的抗菌效果,且纳米载银抗菌剂用量为4.5份时,其抗菌效果最佳。     

几种木塑复合材料的性能对比

研究了木粉及界面增容剂含量对木塑复合材料(WPC)力学性能的影响,分析了增容剂对WPC熔融性能的变化。使用木粉填充可提高不同树脂基WPC的模量,但却降低了HDPE基WPC的拉伸强度及HDPE基、PP基WPC的弯曲强度。     

木塑复合材料热解特性

通过热重分析(TGA)和裂解/气质联用(Py-GC/MS)对杨木/高密度聚乙烯(HDPE)木塑复合材料(WPC)进行热解,考察了木粉和聚烯烃塑料热解过程中的相互作用。结果表明:生物质和塑料热解过程中存在明显的协同作用,杨木在较低的温度下即开始发生热解,其提供的自由基参与了聚烯烃热解反应,产生了更多的轻质烃类产物。而聚烯烃分解产生的碳氢化合物向生物质分解产生的自由基提供氢,促进挥发性物质生成,部分抑制了活性自由基进一步聚合结焦,得到了更多的挥发性产物和减少了固体残炭。     

Density reduction behaviors and cell morphology in extrusion of LLDPE/wood fiber composites with physical and chemical blowing agents

Foamed wood fiber/plastic composites (WPC) with a fine-cell structure offer many benefits compared with the unfoamed WPC, such as the reduced material cost and density, the improved toughness, and the enhanced processability. However, it is extremely challenging to achieve the desired density reduction and obtain a fine-cell structure simultaneously. One of the obstacles is that the volatiles released from the wood fiber (WF) during processing should be suppressed to ensure a fine-cell structure. Linear low-density polyethylene (LLDPE) has a relatively low melting temperature, and it can reduce the processing temperature and suppress volatiles when used as a polymer matrix for foamed WPC. This paper systematically investigates the foamability of LLDPE/WF composites in a continuous foam extrusion, with both a chemical blowing agent and a physical blowing agent (PBA). It turns out that the PBA-based foaming led to a smaller cell size and a narrower cell size distribution. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48829.     

增容剂对再生聚丙烯/木粉复合材料性能的影响

以再生聚丙烯(PP)、锯末木粉为原料,采用双螺杆挤出机挤出造粒制备了塑木复合材料。研究了增容剂马来酸酐接枝PP(PP-g-MAH)用量对再生PP/木粉复合材料吸水性、拉伸性能、弯曲性能、冲击性能、硬度和热变形温度等性能的影响,并采用扫描电子显微镜分析了材料的断面形态。结果表明,PP-g-MAH可以增加木粉与PP的界面结合力,提高复合材料的性能,其最佳用量为6～9份。     

木纤维增强热塑性复合材料的界面研究现状

综述了目前国内外关于木纤维增强热塑性复合材料界面的研究进展，介绍了常用的几种改善木塑复合材料界面相容性的方法，并分析了各自的优缺点。