玻璃纤维布/苎麻纤维布混杂增强不饱和聚酯树脂的研究

采用玻璃纤维布与苎麻纤维布混杂增强不饱和聚酯(UP)树脂制备复合材料,研究玻纤布与苎麻布的相对比例及偶联剂处理对复合材料力学性能的影响,研究了不同复合材料的吸水性并与玻璃纤维复合材料和苎麻纤维复合材料二者进行了比较。结果表明,混杂纤维增强复合材料的拉伸强度、拉伸模量随混杂纤维中苎麻布含量的增加而下降,弯曲强度及弯曲模量在混杂纤维中苎麻布与玻纤布的比例为10∶20和15∶15时分别达到最大值188.09 MPa和1.56 GPa;所有偶联剂处理均可明显改善复合材料的拉伸模量及弯曲模量,硅烷类偶联剂的效果更佳,NDZ401可使复合材料的拉伸强度得到最大幅度(37.66%)的提高,而KH570及NDZ401对改善弯曲强度效果最佳;复合材料吸水后,厚度变化率大于宽度变化率,温度升高,复合材料吸水后尺寸变化率及吸水率均增大,混杂纤维复合材料的吸水率与玻纤布复合材料的吸水率相近,远低于苎麻布复合材料的吸水率。     

表面改性对竹纤维与聚丙烯纤维混杂毡平铺复合材料湿热老化影响

采用碱处理以及碱-偶联剂处理竹纤维,利用非织造和热压工艺制备了竹纤维(BF)与聚丙烯纤维(PP)混杂毡平铺复合材料。研究了改性前后竹纤维与聚丙烯纤维混杂毡平铺复合材料的湿热老化行为的变化,并用SEM研究了复合材料界面结合状况。结果表明:竹纤维与聚丙烯纤维混杂毡平铺复合材料的吸湿规律符合Fick吸湿定律,和竹纤维含量无关,复合材料的吸湿行为不仅与竹纤维含量有关,还与材料内部孔洞密切相关。湿热老化对复合材料拉伸性能影响不显著,经过碱处理或者碱-偶联剂处理后,竹纤维与聚丙烯纤维混杂毡平铺复合材料耐湿热老化性能有较明显的提升效果,综合考虑湿热老化后复合材料的性能,碱-偶联剂处理后复合材料耐湿热老化性能最优,当湿热老化60 d后,复合材料的弯曲和拉伸强度分别为60.55、33.10 MPa,较未处理分别提高了49.51%、18.06%,弯曲和拉伸模量分别为3.91、3.58 GPa,较未处理分别提高了64.7%、7.28%。SEM结果显示:经过碱-偶联剂处理后,竹纤维与聚丙烯树脂之间的黏结得到了提升,复合材料内部孔隙减少,阻碍了水分在材料内的扩散,从而提升了复合材料的耐湿热老化性能。     

不饱和聚酯树脂／大麻纤维复合材料紫外老化性能的研究

采用模压工艺制备不饱和聚酯树脂/大麻纤维复合材料,研究紫外线光老化试验对此种复合材料及氨水处理复合材料力学性能的影响,利用红外光谱(FTIR)技术研究老化前后复合材料结构的变化.研究结果表明,氨水处理大麻纤维可以改善复合材料的拉伸性能以及拉伸模量.未处理及氨水处理的复合材料,在试验一个周期后,两种复合材料的拉伸强度较老化前分别提高了10.8%和19.1%,未处理的复合材料的弯曲强度在两个试验周期时达到最大值.氨水处理的复合材料,在试验的第一周期时,拉伸模量下降最快,进一步老化之后,下降幅度明显减缓.氨水处理的复合材料的拉伸模量在第三个试验周期结束时,弯曲模量和冲击强度比未老化前分别上升6.3%和25.3%.FTIR显示,老化后,两种复合材料的吸收峰强度减弱,但氨水处理的复合材料吸收峰强度比未处理的强.     

基于阀体制造的先进树脂基复合材料性能研究

研究了不同改性方法对酚醛团状膜塑料（BMC）、酚醛片状膜塑料（SMC）、乙烯基SMC材料力学性能的影响,分析了树脂基与纤维相的改性作用机制,得到了三者中具有最佳力学性能的复合材料,并通过仿真分析验证了不同复合材料用于制造阀体的可行性。结果表明,3种材料的拉伸性能为乙烯基SMC>酚醛BMC>酚醛SMC,弯曲性能为酚醛BMC>乙烯基SMC>酚醛SMC,乙烯基SMC的综合力学性能最佳;成型温度为160 ℃、模压压力为9 MPa、保温时间为30 min时,乙烯基SMC的拉伸强度、拉伸模量、弯曲强度、弯曲模量分别达到148.26 MPa、4.50 GPa、92.33 MPa、2.39 GPa;阀体静力学分析结果表明,乙烯基SMC与酚醛BMC均满足阀体制造要求。     

椰壳纤维/PBS可降解复合材料的研究

采用碱溶液和偶联剂对椰壳纤维进行表面处理,用转矩流变仪的密炼装置,制备未进行表面处理的不同纤维含量的椰壳纤维/PBS(聚丁二酸丁二醇酯)复合材料和经表面处理的不同纤维含量的椰壳纤维/PBS复合材料。重点研究了椰壳纤维和偶联剂含量对复合材料力学性能的影响。结果表明,椰壳纤维含量和偶联剂含量对复合材料的力学性能影响最大。当椰壳纤维含量为45%时,复合材料的力学性能最好,其拉伸强度、弯曲强度和冲击强度分别为38.59 MPa、52.43 MPa、10.45 k J/m2;偶联剂含量对冲击强度影响不大,但氢氧化钠浓度对冲击强度有一定影响。随着椰壳纤维含量的增加,材料的力学性能相应提高;偶联剂含量增加,纤维-树脂的界面黏结性能提高,材料的力学性能随之提高。扫描电子显微镜(SEM)图片显示,碱处理和偶联剂很好地改善了纤维-树脂的界面黏结性能。     

用于树脂传递模塑(RTM)的高性能树脂基体研究

通过选用低黏度液体酸酐为环氧树脂的固化剂,制得了一种用于RTM的高性能树脂体系。该树脂体系在室温25℃时的黏度仅为0.11 Pa.s左右,25℃时的适用期在24 h以上,Tg为160℃;其碳纤维复合材料层压板拉伸强度860 MPa,拉伸模量70.0 GPa,弯曲强度820 MPa,弯曲模量61.5 GPa。结果表明该树脂体系具有黏度低、适用期长、较高的Tg的特点,且固化树脂和复合材料力学性能良好,能满足RTM对高性能树脂基体的要求。     

碱处理对不饱和聚酯树脂/苎麻布复合材料力学性能及界面形貌的影响

本文以氢氧化钠(NaOH)溶液处理苎麻布,采用模压工艺制备不饱和聚酯(UP)树脂/苎麻布复合材料,研究碱液处理对苎麻布、复合材料力学性能及表面、界面形貌的影响.实验结果表明,经适当碱液处理后,苎麻布的拉伸断裂强力及拉伸断裂伸长率均增加,苎麻布的表面形貌更加光滑蓬松,复合材料的拉伸强度及弯曲强度均下降,但冲击强度及弯曲模量得到提高.30wt%NaOH溶液处理可使复合材料的弯曲模量达到最大值,166.38MPa,比未经碱液处理所制得复合材料的弯曲弹性模量提高了110%.碱处理后,复合材料的冲击断面上纤维被树脂紧紧包裹,纤维裸露拔出现象远不如未处理复合材料那样明显.     

辐射改性三维编织增强聚合物复合材料的研究

采用Co—60γ射线辐照的方法对碳纤维表面进行活化处理和对丙烯酸环氧酯树脂进行辐射固化，进而制备出高性能的纤维增强聚合物复合材料。经检测，得到的复合材料的力学性能为：弯曲强度382MPa，弯曲模量24．3GPa，剪切强度276MPa，冲击强度165kJ．m^-2。     

一种增强PC树脂用高折射率玻璃纤维性能研究

详细对比研究了一种高折射率玻璃纤维的光学性能、力学性能以及对PC树脂的增强效果.结果表明,这种玻璃纤维的折射率达到了1.585左右,拉伸强度超过2700 MPa,拉伸模量超过92 GPa,增强PC树脂时,复合材料透光率提高了6倍以上,拉伸强度、弯曲强度、弯曲模量均提高5％以上,综合性能明显优于普通玻璃纤维.     

碳纤维湿法缠绕用环氧树脂基体研究

以TDE-85树脂和AFG-90树脂为主体树脂,混合芳香胺为固化剂,研究了一种适合于碳纤维复合材料湿法缠绕成型的树脂配方。结果表明,该树脂的黏度低(＜550 mPa·s)、适用期长,其浇铸体具有优异的力学性能,其拉伸强度为107 MPa,拉伸模量为4．09 GPa,弯曲强度为161 MPa,弯曲模量为3．88 GPa,断裂伸长率超过6%。用其制备的T-700碳纤维缠绕复合材料界面粘接好,NOL环层间剪切强度达到66．8 MPa,拉伸强度达到2．44 GPa。     

不饱和聚酯树脂/大麻纤维复合材料性能的研究

采用模压工艺制备了不饱和聚酯(UP)树脂/大麻纤维复合材料,研究了大麻纤维加入量及纤维的碱处理、乙酰化处理及偶联剂处理对复合材料力学性能的影响;采用傅立叶变换红外光谱仪对复合材料的结构进行了表征和分析。结果表明,随着大麻纤维含量的增加,UP树脂/大麻纤维复合材料的拉伸弹性模量逐渐增加,拉伸强度、弯曲强度、弯曲弹性模量及冲击强度等均先降低而后逐渐增大;偶联剂处理对复合材料力学性能的改善效果最好;偶联剂与纤维之间发生了酯化反应。     

偶联剂处理对碱式硫酸镁晶须填充UP树脂浇铸体力学性能的影响

利用钛酸酯类偶联剂NDZ101、NDZ401和硅烷类偶联剂KH550、KH570对碱式硫酸镁晶须进行处理,研究了几种偶联剂及其加入比例对晶须填充不饱和聚酯树脂(UP)浇铸体力学性能的影响,并结合应力-应变曲线和SEM的图片,对试验结果进行了讨论。实验结果表明,采用偶联剂处理晶须可改善其填充UP树脂浇注体的拉伸强度、拉伸模量、弯曲模量和冲击强度。其中,采用2%KH570进行处理,拉伸强度改善幅度最高,可提高47.54%;采用3%NDZ101进行处理,拉伸模量和弯曲模量均获得最大幅度的提高,分别为65.99%和69.33%;而采用4%KH550进行处理,却可最大幅度地提高冲击强度,为29.21%。对弯曲强度而言,偶联剂处理总体上对其影响效果不如其它的力学性能那样明显。相对而言,硅烷类偶联剂的效果优于钛酸酯类的偶联剂。加入4%KH570和5%KH550时获得的弯曲强度最大,分别为54.43MPa和53.19MPa,较未处理的浇铸体弯曲强度分别提高了25.10%和22.25%,而采用NDZ101或NDZ401,弯曲强度值却基本上都下降。碱式硫酸镁晶须填充UP树脂浇铸体的断裂属于脆性断裂。     

Influence of alkali fiber treatment and fiber processing on the mechanical properties of hemp/epoxy composites

Industrial hemp fibers were treated with a 5 wt % NaOH, 2 wt % Na₂SO₃ solution at 120°C for 60 min to remove noncellulosic fiber components. Analysis of fibers by lignin analysis, scanning electron microscopy (SEM), zeta potential, Fourier transform infrared (FTIR) spectroscopy, wide angle X‐ray diffraction (WAXRD) and differential thermal/thermogravimetric analysis (DTA/TGA), supported that alkali treatment had (i) removed lignin, (ii) separated fibers from their fiber bundles, (iii) exposed cellulose hydroxyl groups, (iv) made the fiber surface cleaner, and (v) enhanced thermal stability of the fibers by increasing cellulose crystallinity through better packing of cellulose chains. Untreated and alkali treated short (random and aligned) and long (aligned) hemp fiber/epoxy composites were produced with fiber contents between 40 and 65 wt %. Although alkali treatment generally improved composite strength, better strength at high fiber contents for long fiber composites was achieved with untreated fiber, which appeared to be due to less fiber/fiber contact between alkali treated fibers. Composites with 65 wt % untreated, long aligned fiber were the strongest with a tensile strength (TS) of 165 MPa, Young's modulus (YM) of 17 GPa, flexural strength of 180 MPa, flexural modulus of 9 GPa, impact energy (IE) of 14.5 kJ/m², and fracture toughness (K_Ic) of 5 MPa m^1/2. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Development and application of triglyceride-based polymers and composites

Triglyceride oils derived from plants have been used to synthesize several different monomers for use in structural applications. These monomers have been found to form polymers with a wide range of physical properties. They exhibit tensile moduli in the 1–2 GPa range and glass transition temperatures in the range 70–120 °C, depending on the particular monomer and the resin composition. Composite materials were manufactured utilizing these resins and produced a variety of durable and strong materials. At low glass fiber content (35 wt %), composites produced from acrylated epoxidized soybean oil by resin transfer molding displayed a tensile modulus of 5.2 GPa, a flexural modulus of 9 GPa, a tensile strength of 129 MPa, and flexural strength of 206 MPa. At higher fiber contents (50 wt %) composites produced from acrylated epoxidized soybean oil displayed tensile and compression moduli of 24.8 GPa each, and tensile and compressive strengths of 463.2 and 302.6 MPa, respectively. In addition to glass fibers, natural fibers such as flax and hemp were used. Hemp composites of 20% fiber content displayed a tensile strength of 35 MPa and a tensile modulus of 4.4 GPa. The flexural modulus was ∼2.6 GPa and the flexural strength was in the range 35.7–51.3 MPa, depending on the test conditions. The flax composite materials had tensile and flexural strengths in the ranges 20–30 and 45–65 MPa, respectively. The properties exhibited by both the natural- and synthetic fiber-reinforced composites can be combined through the production of “hybrid” composites. These materials combine the low cost of natural fibers with the high performance of synthetic fibers. Their properties lie between those displayed by the all-glass and all-natural composites. Characterization of the polymer properties also presents opportunities for improvement through genetic engineering technology. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 703–723, 2001     

玄武岩纤维增强高密度聚乙烯的力学性能

玄武岩纤维(BF)未经改性处理和经硅烷偶联剂(KH–550和KH–570)进行处理后,添加到高密度聚乙烯(PE–HD)基体树脂中,增强PE–HD的力学性能,用傅立叶变换红外光谱和扫描电子显微镜对硅烷偶联剂处理的BF进行表征,同时,用SEM观察BF增强PE–HD复合材料的拉伸断面。结果表明,随着未经改性处理BF添加量增加,PE–HD复合材料的拉伸强度、弯曲强度逐渐提高,当添加量达到30%时,拉伸强度达到45.5 MPa,提升79.1%;弯曲强度达到41.3 MPa,提升118.9%。经KH–550和KH–570处理的BF添加量达到20%时,PE–HD复合材料的拉伸强度均达到45 MPa以上,其后随着BF添加量继续增加,拉伸强度变化不大,而弯曲强度随BF添加量的增加逐渐增大。当BF添加量达到30%时,BF改性与否对PE–HD复合材料的力学性能的影响不大。当改性BF添加量为5%~15%时,KH–550改性的PE–HD复合材料的力学性能较KH–570改性的高;当改性BF添加量为20%,25%时,KH–570改性的PE–HD复合材料的力学性能较KH–550改性的高。     

UPR/苎麻布/碱式硫酸镁晶须复合材料Ⅰ——偶联剂处理晶须对复合材料力学性能的影响

选用钛酸酯偶联剂NDZ101、NDZ401和硅烷偶联剂KH550、KH570分别对碱式硫酸镁晶须进行预处理,采用模压工艺制备不饱和聚酯树脂/苎麻布/碱式硫酸镁晶须复合材料,研究了偶联剂加入比例对复合材料力学性能的影响。结果表明:除了KH570外,其他几种偶联剂均可保持或提高复合材料的拉伸强度和冲击强度;除了NDZ101之外,其他几种偶联剂均可提高复合材料的弯曲强度,当选用2%的KH550进行处理时,复合材料的弯曲强度最高,达到104.78 MPa,较未经偶联剂处理的复合材料的弯曲强度(95.18 MPa)提高了10.09%;利用硅烷类偶联剂处理晶须,对复合材料的拉伸模量、弯曲模量的改善效果优于钛酸酯类偶联剂;偶联剂处理不能改变复合材料脆性断裂的性质。     

Mechanical and viscoelastic properties of soybean oil thermoset reinforced with jute fabrics and carded lyocell fiber

Composites and hybrid composites were manufactured from renewable materials based on jute fibers, regenerated cellulose fibers (Lyocell), and thermosetting polymer from soybean oil. Three different types of jute fabrics with biaxial weave architecture but different surface weights, and carded Lyocell fiber were used as reinforcements. Hybrid composites were also manufactured by combining the jute reinforcements with the Lyocell. The Lyocell composite was found to have better mechanical properties than other composites. It has tensile strength and modulus of about 144 MPa and 18 GPa, respectively. The jute composites also have relatively good mechanical properties, as their tensile strengths and moduli were found to be between 65 and 84 MPa, and between 14 and 19 GPa, respectively. The Lyocell‐reinforced composite showed the highest flexural strength and modulus, of about 217 MPa and 13 GPa, respectively. In all cases, the hybrid composites in this study showed improved mechanical properties but lower storage modulus. The Lyocell fiber gave the highest impact strength of about 35 kJ/m², which could be a result of its morphology. Dynamic mechanical analysis showed that the Lyocell reinforced composite has the best viscoelastic properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011