三维编织光固化3D打印复合材料的制备及力学性能

光敏树脂固化后的低强力一直是阻碍光固化3D打印技术发展的主要因素,利用三维编织织物的结构特点弥补光固化3D打印构件强力弱的缺点,文章重点研究了在光固化3D打印技术的基础上,结合三维编织技术制备3D打印复合材料的方式方法及对该种复合材料的力学性能进行测试分析。结果表明:三维编织光固化3D打印复合材料相对于纯光敏树脂材料,其弹性模量和拉伸断裂强度显著增加;高强聚乙烯纱线的增强效果最好,玻璃纤维纱线增强效果次之,碳纤维纱线增强效果最差。     

碱处理对涤纶/光敏树脂复合材料力学性能的影响

针对光敏树脂经3D打印成型后试样力学性能较差问题,采用涤纶长丝增强光敏树脂的方法,使用光固化3D打印设备将涤纶长丝和光敏树脂复合成型制备涤纶增强复合材料。为获得较好的增强效果,对涤纶进行碱处理,研究了碱处理各条件下涤纶的减量率与纤维形貌和力学性能的关系,以及其对复合材料力学性能的影响。结果表明:随着减量率的增加,涤纶的形貌及力学性能改变越明显;当涤纶减量率为16.2%时,纤维表面出现连续纵向沟壑,力学强度下降6%,纤维的增强效果最好;经过改性处理的涤纶增强复合材料的拉伸强度和弯曲强度分别达到78 MPa和471 MPa,相比于未处理的纤维增强复合材料分别提升了66%和336%。     

硅烷偶联剂改性处理对玻璃纤维织物增强聚苯硫醚复合材料性能的影响

针对聚苯硫醚存在韧性差的问题,通过热压成型工艺将玻璃纤维织物与聚苯硫醚树脂混合制备玻璃纤维增强聚苯硫醚复合材料.为获得较好的界面黏结性能,采用硅烷偶联剂KH560对玻璃纤维进行改性处理.借助扫描电子显微镜、摆锤冲击试验机、万能试验机等研究了不同质量分数硅烷偶联剂KH560处理对玻璃纤维表面形态及复合材料力学性能的影响....     

黄麻纤维毡的表面处理及其增强复合材料的力学性能

用3种不同的化学处理剂,碱、KMnO4和A-151硅烷偶联剂分别对黄麻纤维针刺毡表面进行处理,采用真空辅助树脂传递模塑法制备黄麻纤维毡增强乙烯基酯树脂复合材料。借助动态接触角分析了黄麻纤维的表面能变化,并通过SEM观察了纤维表面和复合材料的拉伸断裂面。研究结果表明:经表面处理后,黄麻纤维表面能有所降低,纤维表面的微观结构发生变化,纤维与树脂的界面相容性得到改善,综合力学性能提高。经A-151硅烷偶联剂处理后,复合材料的力学性能提高最为显著,拉伸强度和弯曲强度分别提高了51.38%和77.46%。     

玻璃纤维增强稻壳粉/非医疗废弃物秸塑复合材料的性能

将玻璃纤维掺入稻壳粉/非医疗回收塑料秸塑复合材料中,制备出具有增强效果的环保型秸塑复合材料,探讨玻璃纤维的长度和含量对秸塑复合材料力学性能的影响。研究表明,随着玻璃纤维加入量和长度的增加,秸塑复合材料的力学性能呈现先增加然后降低的趋势,当玻璃纤维的含量为23%,长度为6mm,同时采用3%的硅烷偶联剂处理后,稻壳粉/非医疗回收塑料秸塑复合材料的力学性能达到最优,拉伸强度、拉伸模量、弯曲强度、弯曲模量分别为16.27MPa、1241.14MPa、19.91MPa、1207.21MPa。通过观察复合材料断口的SEM图片,表明玻璃纤维的拔出为秸塑复合材料主要的破坏形式。     

3D打印成型的玻璃纤维增强聚乳酸基复合材料

为解决3D 打印树脂基材料强力低的问题,提出利用纤维增强树脂基材料的方法,采用3D 打印技术将玻璃纤维和聚乳酸复合并且快速成型,并研究了填充密度和切片层厚对于复合材料力学性能的影响。试验结果表明,当试样打印的填充密度达到90%时,试样的弯曲强度和拉伸强度分别可达到49.26和21.28MPa。试样切片层厚为0.1 mm时,所得到的拉伸强度和弯曲强度分别为20.4 和52.87 MPa。试样的拉伸强度随着切片层厚的增加而减少,随着填充密度的增加而增加。试样的弯曲强度与切片层厚是负相关,与填充密度是正相关。通过分析不同种类试样截面的扫描电镜图发现,纤维束浸润树脂基体的程度与试样的层厚和填充密度密切相关,填充密度的增加和层厚的减少有利于纤维束与树脂基体的结合。     

高性能玻璃纤维复合毡制备关键技术对复合材料性能的影响

开发具有更高强度和模量的玻璃纤维增强复合材料能更好地满足市场的新需求。文章利用不同的方法将不同规格的玻璃纤维纱线和涤纶丝制备了5种玻璃纤维织物,研究了织物的编织工艺和成型方式等关键制备技术对复合材料的树脂渗透率及复合材料力学性能的影响。研究表明:织物的针脚长度、0°细纱的材质和成型方式等因素影响织物孔隙率、树脂浸透率及复合材料的力学性能。采用二次成型方法和0°玻璃纤维细纱作为绞织纱有利于提高织物的孔隙率,保持规整的织物结构,并有助于提高复合材料的整体力学性能。经优化后的工艺制备得到的玻璃纤维复合材料具有较高的拉伸强度和拉伸模量,预计其将在风电叶片行业中具有广泛的工程应用价值。     

香蕉纤维与UPR复合材料的制备及性能研究

利用有机硅烷偶联剂KH-550、Na OH和CH3COOH 3种功能剂对香蕉纤维进行改性处理,并将3种不同改性香蕉纤维和未改性香蕉纤维分别与不饱和聚酯树脂(UPR)通过热压法制备香蕉纤维与UPR复合材料,进一步测试复合材料的形态结构、力学性能、密度和吸水性。结果表明,与未改性香蕉纤维与UPR复合材料相比,经有机硅烷偶联剂KH-550改性处理的香蕉纤维与UPR复合材料的形态结构和力学性能更好,其拉伸强度和弯曲强度分别为42.1 MPa和76.3 MPa,比未改性的复合材料分别提高了40.8%和65.5%,并且改性复合材料的密度为0.85 g/cm3,吸水率为1.46%,实用性提升,寿命增加。     

KH550改性对微纳纤维素/聚乳酸复合3D打印材料性能的影响

为提高微纳纤维素（MNC）与聚乳酸（PLA）复合材料的性能,将分散于二氯甲烷的MNC与溶解于二氯甲烷的PLA 通过溶液共混法进行复合,成功制备了适用于FDM型3D打印机的MNC/PLA复合3D打印线材。采用硅烷偶联剂KH550对MNC进行改性,考察了KH550用量对MNC的晶型结构及对MNC/PLA复合材料断面形态和机械性能的影响,进一步研究了KH550改性MNC对MNC/PLA复合材料3D打印性能的影响。结果表明,溶液共混法制备的MNC/PLA复合3D打印线材可在保持复合材料机械性能的基础上将高含量的MNC与PLA均匀复合;1%用量（相对于MNC绝干质量）的KH550可改善复合材料的界面相容性且复合材料的机械性能最佳;制备的MNC/PLA复合3D打印线材经FDM型3D打印机可成功打印出3D打印产品。     

表面改性羟基磷灰石晶须填料增强牙科复合树脂

用羟基磷灰石晶须填料制备可促进牙齿再矿化且力学性能优良的牙科复合树脂。用正硅酸乙酯对羟基磷灰石(HAP)晶须进行表面改性后,通过硅烷偶联剂对填料进行处理,提高其与树脂的界面相容性,并用改性后的HAP晶须与树脂复合制备了HAP/树脂复合材料。改性后的晶须分散性良好,与树脂界面相容性增强,复合材料强度有显著提升(One-wayANOVA,p<0.05)。羟基磷灰石晶须可显著提高树脂强度,有望成为龋齿修复的新材料。     

碳纤维/聚丙烯/聚乳酸增强复合材料的力学性能

为在不改变碳纤维/聚丙烯(PP)复合材料力学性能前提下,降低复合材料中PP含量以减轻环境降解压力,通过在碳纤维/PP复合材料树脂体系中掺杂可降解的聚乳酸(PLA)形成共混树脂体系,并经热压成型制备碳纤维增强共混树脂复合材料。探究了PLA、PP共混体系质量比对复合材料冲击、弯曲和拉伸性能的影响。结果表明:随着树脂体系中PLA质量分数的增加,复合材料的冲击强度和弯曲强度都呈先降低后升高、再降低的趋势,拉伸强度呈现先升高后降低的趋势;当PLA质量分数为60%时,复合材料的冲击强度和弯曲强度最高,分别为21.8 kJ/m²和112.5 MPa,拉伸强度为37.2 MPa,复合材料的综合物理力学性能最优,与未添加PLA的复合材料的力学性能相近。     

Lengthwise jute fibre properties variation and its effect on jute–polyester composite

In this study, the jute reeds were equally divided lengthwise from root to tip in three portions namely root, middle and tip. The fibre diameter, fineness, tensile strength and bundle strength of the three portion jute were evaluated and compared. Unidirectional composites containing about 35(wt/wt)% jute fibre by weight were produced in unsaturated polyester resin matrix. The effect of fibre property variation in composite’s mechanical properties was studied. Tensile and flexural properties of composites made from three portions of jute reed were studied. It was observed that tensile and flexural strength of root portion based composites are 44% and 35% higher than tip portion based composites. Tensile and flexural modulus of tip portion based composites is 18% and 17% higher than root portion based composites.     

玻璃纤维多轴向经编复合材料的制备及拉伸性能研究

以环氧树脂为基体,分别以玻璃纤维多轴向经编针织物和玻璃纤维机织物作为增强材料,通过手糊法制备复合材料,并通过试验对比研究两种复合材料的拉伸性能。结果表明,经编复合材料沿各个轴向的拉伸强度比复合前多轴向经编针织物及机织复合材料的强度均有明显提高,增幅均在50%以上,说明多轴向经编复合材料具有更优异的力学性能。这为进一步扩大玻璃纤维多轴向经编复合材料的应用领域提供了有力证据。     

Effect of Chemical Treatment on Thermal,Mechanical and Degradation Behavior of Banana Fiber Reinforced Polymer Composites

ABSTRACT

The current research endeavor, explores the thermal, mechanical, and degradation behavior of alkaline treated banana fibers reinforced polypropylene composites. Composites incorporating BF (20% w: w) treated with NaOH (5% w: v) aqueous solution were developed using extrusion-injection molding processes. After chemical treatment, the tensile, flexural and impact strength of the composite increases by 3.8%, 5.17%, and 11.50%, respectively. Scanning electron microscope (SEM) observations of tested specimens confirm the fiber pull out and fiber fracture as the main reasons for failure of developed composites under tensile and impact loading. The specimens were exposed to two different environments, water immersion and soil burial for 5 weeks for the degradation studies. The degradation behavior of composites was measured in terms of variation in weight and mechanical properties (tensile, flexural, and impact). The maximum degradation in mechanical properties was observed for the composites buried under soil. The composite lost 7.69%, 12.06%, and 3.27% of tensile, flexural, and impact strength, respectively.     

Effect of Filler Content of Chemically Treated Short Bagasse Fiber-Reinforced Cardanol Polymer Composites

In this work, the sugarcane bagasse fiber was used as a filler to make a new type of biodegradable composite, using the cardanol resin, as a fully biodegradable thermosetting polymer matrix. Biocomposite performance was improved by chemically modified bagasse fiber using alkaline treatment. Two sets of composites were prepared with a fiber length of 10 and 20 mm with various weight percentages viz., 0, 5, 10, 15, and 20 of cardanol resin using a compression molding machine. The mechanical properties were studied using some tests and the morphological study in flexural fractured specimens was carried out using SEM. The thermal properties of biodegradable polymer composites were evaluated using TGA. The chemical formation of the new biocomposites was also examined by the FT-IR spectroscopy technique. The result proved that the morphology of the composites has improved the bonding between the fiber and resin, thus leading to enhancement of the mechanical properties. The result had shown the tensile and flexural strength with an increase in the range of bagasse fiber up to 15 wt% in both the sets. The TGA results showed that biocomposites of 15 wt% in both sets had the highest thermal stability. This investigation recommended the possibility of introducing bio-fiber obtained from waste agricultural residues in polymer matrix composites.     

Effect of grafting generations of poly(amidoamine) dendrimer from the sisal fiber surface on the mechanical properties of composites

In order to improve the mechanical properties of sisal fiber-reinforced polypropylene composites, the sisal fibers were grafted with poly(amidoamine) dendrimer and the effects of grafting generations on the mechanical properties of composites were studied. The results reveal that the tensile, flexural, and impact strength of the composites are improved considerably with the poly(amidoamine) dendrimer grafting treatment. For the 2.0 generation treatment with the poly(amidoamine) dendrimer, the tensile, flexural, and impact strength of the composites at 30 wt% fiber loading increase by 29%, 13%, and 54%, respectively. However, the thermal and mechanical properties of the sisal fibers decrease after prolonged grafting treatment.     

Mechanical properties improvement of silane addition epoxy/3D orthogonal woven composite material

In this study, the influence of silane addition on mechanical properties of epoxy/3D orthogonal glass fiber woven composite was studied. The KH560 silane modification composite specimen reinforced with 3D orthogonal woven fabric/epoxy was manufactured by means of Resin Infusion under Flexible Tooling. The mechanical properties of the epoxy/3D glass fiber woven composites were characterized by tensile and bending tests. The tensile and bending properties of silane-modified 3D orthogonal woven glass composite in warp and weft directions were compared with the pristine or epoxy/glass composite material not coupled using silane. The results show that the tensile and bending properties in warp and weft directions have been improved due to the silane addition. The bonding strength between the fiber and matrix was improved and the delamination and debonding between fiber and matrix was retarded and shifted to cohesive failure of the matrix due to the silane modification. Electron microscopy of the fracture and failure modes of the test specimens were used to support the results and conclusions.