剑麻/FRP废渣/UP复合材料制备及性能研究

采用硅烷偶联剂KH-550和KH-570分别对纤维增强复合材料(FRP)废渣进行表面处理。制备了剑麻纤维/FRP废渣增强不饱和聚酯树脂复合材料。研究了FRP废渣的表面处理方式、FRP废渣含量和剑麻纤维含量对复合材料力学性能、吸水性和热性能等影响。结果表明,经过偶联剂处理的复合材料的力学性能和热稳定性均增强。当FRP废渣质量分数为30.0%,剑麻纤维质量分数为10.0%时,经KH-570处理复合材料的拉伸强度、弯曲强度和冲击强度分别提高22.8%,21.4%和19.2%。FRP废渣经过偶联剂处理后,复合材料的吸水性降低。     

碱处理对剑麻纤维增强聚乳酸可降解复合材料性能的影响

以剑麻纤维(SF)和聚乳酸(PLA)为原料,通过注塑成型工艺制备了剑麻纤维增强聚乳酸可降解复合材料。研究了连续碱处理剑麻纤维(CASF)和未改性处理剑麻纤维(USF)在不同含量时对复合材料力学性能、吸水性及可降解性能的影响。结果表明:剑麻纤维的质量分数会显著影响复合材料的力学性能、吸水性和降解性能。相较于未改性处理剑麻纤维(USF),碱处理剑麻纤维(CASF)可以进一步提高复合材料的力学性能,降低复合材料的吸水率,延缓剑麻纤维增强可降解树脂基复合材料的降解速率,且酶降解法相较于土埋法降解能够显著加快复合材料的降解速率。当剑麻纤维含量为20%时,CASF/PLA复合材料的拉伸强度、弯曲强度和弯曲模量相较于纯PLA和USF/PLA分别提高了32.71%、10.08%;19.63%、12.11%;97.33%、12.40%;其冲击强度相较于纯PLA提高了71.19%。     

浓强碱溶液处理对不饱和聚酯树脂/苎麻布复合材料界面性能的影响

利用不同质量分数的NaOH溶液处理苎麻布,并与不饱和聚酯树脂形成复合材料。研究了碱的质量分数及碱处理时间对树脂与苎麻布之间的接触角的影响;观察了碱处理前后苎麻布的表面形貌及复合材料的冲击断面形貌;探讨了碱处理可提高麻塑复合材料力学性能的机理。结果表明：NaOH溶液处理可降低树脂在苎麻布上的接触角,苎麻布表面因碱处理而变得更加光滑蓬松,复合材料的冲击断面上,纤维被树脂紧紧包裹着,说明碱处理可改善纤维与树脂之间的界面结合。     

短切苎麻/剑麻纤维增强聚酯及酚醛复合材料的性能研究

本文采用偶联剂A-151、KH-550对苎麻、剑麻纤维进行了偶联处理，比较分析了纤维表面处理前后苎麻、剑麻纤维增强不饱和聚酯及酚醛树脂复合材料的力学性能。结果表明，纤维偶联处理后，复合材料的力学性能有明显提高，吸水率有所降低。     

不饱和聚酯/剑麻纤维复合材料性能的研究

采用乙酰化、氰乙基化、KMnO4、甲苯二异氰酸酯(TDI)以及硅烷偶联剂等不同化学方法对剑麻纤维(SF)进行表面处理，然后将SF细化，与不饱和聚酯共混，通过模压成型制成不饱和聚酯／剑麻纤维复合材料，对复合材料的冲击强度、弯曲强度、热失重温度(Td)、电性能、吸水性能与SF处理方法的关系进行了研究，同时，考察了SF用量对复合材料各性能的影响。结果表明：SF处理方法对复合材料的电性能、热性能和吸水性影响不大；SF用量对复合材料的力学性能、吸水性影响较大，对电性能影响较小；当SF用量为10％，采用硅烷偶联剂和TDI处理SF时，复合材料强度较高、耐磨性好、综合性能较好。     

剑麻预处理对热塑性淀粉复合材料力学性能及降解性能的影响

采用碱、蒸汽爆破等对剑麻纤维进行预处理,考察了不同预处理方法对剑麻纤维增强热塑性淀粉力学性能及降解性能的影响。结果表明:碱处理能够提高复合材料的力学性能,延长材料降解周期,是制备剑麻纤维增强热塑性淀粉复合材料有效的预处理方法;剑麻纤维增强热塑性淀粉的机理是甘油在淀粉及剑麻纤维之间起到桥梁作用,提高了热塑性淀粉与剑麻纤维的界面结合力,从而提高了复合材料的力学性能。     

剑麻柄处理方法对剑麻纤维／脲醛树脂复合材料的性能影响

采用碱处理、偶联剂处理、醋酸处理等方法，对剑麻柄进行处理，再与自行合成的脲醛树脂(UF)进行捏合、模压，制成剑麻纤维／脲醛树脂共混复合材料。研究了碱处理最佳工艺以及不同处理方法对复合材料的力学性能、耐磨性、耐水性、电性能和热性能的影响，并与木粉／UF复合材料的性能进行了对比。结果表明：剑麻柄的处理方法对复合材料的电性能、热性能和吸水性影响不大；采用乙酰化处理剑麻柄时，复合材料强度较高。耐磨性好，此时剑麻纤维／UF复合材料的各项性能接近木粉／UF复合材料的性能     

玄武岩纤维改性不饱和聚酯树脂的性能研究

本研究用未经处理的和酸化改性的玄武岩纤维分别对不饱和聚酯树脂进行填充改性,探究玄武岩纤维不同用量以及不同酸化时间对不饱和聚酯树脂的力学性能以及摩擦性能的影响。结果表明:未经改性的玄武岩纤维用量为2%时,不饱和聚酯基复合材料拉伸强度提高41%,冲击强度提高13%而摩擦系数降低58%,玻璃化转变温度提高50%,综合性能最优;而后将玄武岩纤维进行酸化,制备2%玄武岩纤维/不饱和聚酯复合材料,通过拉伸与冲击性能测试。结果表明酸化时间为1.5h时,复合材料性能最佳。     

改性剑麻纤维增强聚乳酸复合材料热性能研究

依据丙交酯配位开环反应原理,在剑麻纤维表面接枝上聚乳酸分子支链进行表面改性,并与未处理、碱处理表面改性对比,研究了表面改性方法对剑麻纤维热性能的影响。使用熔体共混模压成型工艺制备了改性剑麻纤维增强聚乳酸复合材料,并研究了不同表面改性方法对复合材料热性能的影响。结果表明,剑麻纤维的加入使得复合材料的热稳定性略有降低,其中碱处理略高于未处理,而接枝处理降幅最大。同时,纤维的加入有利于复合材料异相成核,提高结晶度,其中以接枝剑麻纤维的促进作用最为突出。     

剑麻纤维树脂基复合材料研究和展望

介绍剑麻纤维树脂基复合材料国内外研究现状和展望,重点介绍了剑麻纤维／不饱和聚酯树脂,剑麻纤维／环氧树脂,剑麻纤维／ＬＤＰＥ,剑麻纤维／玻纤／ＰＶＣ等复合材料的物理力学性能。     

Mechanical properties of sisal natural fiber composites according to strain rate and absorption ratio

The effects of strain rate and water absorption properties can be used to evaluate the environmental degradation of sisal fiber reinforced polymer–matrix composites. Composites of vinylester and epoxy resin, reinforced by sisal fiber, were manufactured using the RTM method. To examine how the mechanical properties change with different surface treatments of a fiber, three fibrous composites with nontreated, permanganate, and silane treatments were compared in this experiment. Material fracture occurred as the brittleness hardened due to an increase in strain rate. The tensile strength was the largest in the permanganate‐treated epoxy composites, while the untreated vinylester had high elongation and fracture energy. The highest tensile strength value occurred at a 30% absorption ratio. POLYM. COMPOS., © 2011 Society of Plastics Engineers.     

The influence of chemical surface modification on the performance of sisal‐polyester biocomposites

This article concerns the effectiveness of various types and degrees of surface modification of sisal fibers involving dewaxing, alkali treatment, bleaching cyanoethylation and viny1 grafting in enhancing the mechanical properties, such as tensile, flexural and impact strength, of sisal‐polyester biocomposites. The mechanical properties are optimum at a fiber loading of 30 wt%. Among all modifications, cyanoethylation and alkali treatment result in improved properties of the biocomposites. Cyanoethylated sisal‐polyester composite exhibited maximum tensile strength (84.29 MPa). The alkali treated sisal‐polyester composite exhibited best flexural (153.94 MPa) and impac strength (197.88 J/m), which are, respectively, 21.8% and 20.9% higher than the corresponding mechanical properties of the untreated sisal‐polyester composites. In the case of vinyl grafting, acrylonitrile (AN)‐grafted sisal‐polyester composites show better mechanical properties than methyl‐methacrylate (MMA)‐grafted sisal composites. Scanning electron microscopic studies were carried out to analyze the fiber‐matrix interaction in various surface‐modified sisal‐polyester composites.     

A Comparative Study on the Mechanical Properties of Jute and Sisal Fiber Reinforced Polymer Composites

The aim of the present study is to investigate and compare the mechanical properties of raw jute and sisal fiber reinforced epoxy composites with sodium hydroxide treated jute and sisal fiber reinforced epoxy composites. This is followed by comparisons of the sodium hydroxide treated jute and sisal fiber reinforced composites. The jute and sisal fibers were treated with 20% sodium hydroxide for 2 h and then incorporated into the epoxy matrix by a molding technique to form the composites. Similar techniques have been adopted for the fabrication of raw jute and sisal fiber reinforced epoxy composites. The raw jute and sisal fiber reinforced epoxy composites and the sodium hydroxide treated jute and sisal fiber reinforced epoxy composites were characterized by FTIR. The mechanical properties (tensile and flexural strength), water absorption and morphological changes were investigated for the composite samples. It was found that the sodium hydroxide treated jute and sisal fiber reinforced epoxy composites exhibited better mechanical properties than the raw jute and raw sisal fiber reinforced composites. When comparing the sodium hydroxide treated jute and sisal fiber reinforced epoxy composites, the sodium hydroxide treated jute fiber reinforced composites exhibited better mechanical properties than the latter.     

Unsaturated polyester‐toughened epoxy composites: Effect of sisal fiber on thermal and dynamic mechanical properties

In the present study, the mechanical and thermal properties of sisal fiber‐reinforced unsaturated polyester (UP)‐toughened epoxy composites were investigated. The sisal fibers were chemically treated with alkali (NaOH) and silane solutions in order to improve the interfacial interaction between fibers and matrix. The chemical composition of resins and fibers was identified by using Fourier‐transform infrared spectroscopy. The UP‐toughened epoxy blends were obtained by mixing UP (5, 10, and 15 wt%) into the epoxy resin. The fiber‐reinforced composites were prepared by incorporating sisal fibers (10, 20, and 30 wt%) within the optimized UP‐toughened epoxy blend. Scanning electron microscopy was used to analyze the morphological changes of the fibers and the adhesion between the fibers and the UP‐toughened epoxy system. The results showed that the tensile and flexural strength of (alkali‐silane)‐treated fiber (30 wt%) ‐reinforced composites increased by 83% and 55%, respectively, as compared with that of UP‐toughened epoxy blend. Moreover, thermogravimetric analysis revealed that the (alkali‐silane)‐treated fiber and its composite exhibited higher thermal stability than the untreated and alkali‐treated fiber systems. An increase in storage modulus and glass transition temperature was observed for the UP‐toughened epoxy matrix on reinforcement with treated fibers. The water uptake behavior of both alkali and alkali‐silane‐treated fiber‐reinforced composites is found to be less as compared with the untreated fiber‐reinforced composite. J. VINYL ADDIT. TECHNOL., 23:188–199, 2017. © 2015 Society of Plastics Engineers     

碱处理对酚醛树脂/剑麻纤维复合材料性能的影响

用碱处理方法对剑麻纤维(SF)进行表面改性,再与酚醛树脂(PF)混合、塑炼、模压成型,制备了PF／SF复合材料,对其冲击强度、弯曲强度、耐磨性、吸水性及热性能进行测试,借助偏光显微镜和扫描电子显微镜观察、分析了复合材料的形态结构。结果表明,经碱处理的SF提高了PF／SF复合材料的综合性能,其原因与界面作用得到加强有关。     

Studies on mechanical properties of sisal fiber/phenol formaldehyde resin in‐situ composites

Phenol formaldehyde resin (PF) reinforced with short sisal fibers (SF) were obtained by two methods, direct‐mixing and polymerization filling. Impact and bending properties of resulting composites were compared. Under the same compression molding conditions, polymerization filled composites showed better mechanical properties than those of direct‐mixed composites. The influences of fiber modifications on the mechanical properties of SF/PF in‐situ (polymerization filled) composites have been investigated. Treated‐SF‐reinforced composites have better mechanical properties than those of untreated‐SF‐reinforced composites. The effects of SF on water absorption tendencies of SF/PF composites have also been studied. In addition, sisal/glass (SF/GF) hybrid PF composites of alkali‐treated SF were prepared. Scanning electron microscopic studies were carried out to study the fiber‐matrix adhesion. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

剑麻/钢纤维增强改性酚醛树脂力学和摩擦性能

采用改性酚醛树脂为基体,剑麻/钢纤维混杂为增强纤维,通过辊炼、模压成型工艺制备了剑麻/钢纤维增强酚醛树脂复合材料.研究了剑麻纤维的加入及含量对聚砜改性酚醛树脂复合材料力学性能、摩擦磨损性能及热稳定性能的影响.结果表明:剑麻纤维质量分数为15%、钢纤维为10%时,复合材料的冲击和弯曲强度分别为3.82 kJ/m2和59.6 Mpa,达到最大;随着剑麻纤维含量的增加,复合材料的摩擦系数降低,热稳定性能下降,当剑麻纤维质量分数为10%时,复合材料的摩擦性能优异;复合材料的磨损面呈现黏着磨损和疲劳磨损特征.     

Preparation and characterization of poly(vinyl chloride)/virgin and treated sisal fiber composites

Mechanical property changes, thermal stability, and water absorption capacity of poly(vinyl chloride) (PVC)/sisal fiber composites were assessed with respect to the effect of maleic anhydride chemical treatments of the sisal fiber, for five different sisal fiber contents, varying from 0 to 30% by weight in the composite. The composites prepared with the untreated sisal exhibited higher tensile modulus and hardness than the unloaded resin, while elongation and tensile strength were reduced. The deterioration in the mechanical properties of PVC blended with sisal fiber is attributed to the presence of moisture, interfacial defects at the fiber and polymer interface, and fiber dispersion in the PVC matrix. The amount of absorbed water is a function of the amount of fiber in the composite (F0 = 0 phr, F5 = 0.77 phr, and F20 = 4.83 phr). The comparison of the results of characterization of F5, F20, and F30 formulations prepared with the untreated fibers and the treated ones showed a reduction in absorbed water after the chemical treatment of fiber with maleic anhydride (F0 = 0 phr, F5 = 0.28 phr, and F20 = 2.99 phr), thus improving the mechanical properties of composites prepared with the treated sisal. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3630–3636, 2007     

剑麻纤维增强聚丙烯复合材料的力学性能研究

本文介绍了剑麻纤维(SF)增强聚丙烯(PP)复合材料的制备方法，测定了不同纤维长度下．采用不同PP含量复合材料的无缺口冲击强度、弯曲强度和弯曲模量．并借助扫描电子显微镜对SF/PP复合材料的无缺口冲击破坏断口进行观察。结果表明，在一定范围内增加纤维长度和降低基体含量有利于复合材料力学性能的提高。