李偉++黃虹云++吳永慶
摘要:通過對黃麻纖維熱處理、堿處理、硅烷偶聯(lián)劑處理和異氰酸酯處理進(jìn)行表面改性,并對改性黃麻纖維布進(jìn)行熱壓工藝處理,最后采用VARTM成型工藝制備黃麻纖維增強環(huán)氧樹脂復(fù)合材料,并對其性能進(jìn)行了系統(tǒng)研究.通過掃描電鏡(SEM)分析表明,熱處理和堿處理的黃麻纖維增強環(huán)氧樹脂復(fù)合材料的界面粘結(jié)未得到明顯改善,而通過硅烷偶聯(lián)劑和異氰酸酯處理的黃麻纖維增強環(huán)氧樹脂復(fù)合材料的界面粘結(jié)性能得到了顯著的提高.將硅烷偶聯(lián)劑和異氰酸酯處理的黃麻纖維布通過熱壓處理不僅可以增加復(fù)合材料中黃麻纖維體積含量,而且可以提高復(fù)合材料的綜合性能,復(fù)合材料力學(xué)性能研究表明,經(jīng)硅烷偶聯(lián)劑處理后的黃麻纖維增強復(fù)合材料拉伸強度、模量和彎曲強度分別提高了18.6%,71.4%和50.2%.經(jīng)異氰酸酯處理的黃麻纖維增強復(fù)合材料的拉伸強度、模量和彎曲強度分別提高了16.3%,34.0%和50.3%.
關(guān)鍵詞:黃麻纖維;復(fù)合材料;熱壓工藝;硅烷偶聯(lián)劑;異氰酸酯
中圖分類號:TQ327.8 文獻(xiàn)標(biāo)識碼:APreparation of Jute Fibers Reinforced Epoxy
Resin Composites by VARTM
LI Wei,HUANG Hongyun, WU Yongqing
(College of Materials Science and Engineering, Hunan Univ,Changsha,Hunan410082,China)Abstract: In this research, the jute fibers were first treated with heating, alkali, silane coupling agent and isocyanate respectively, then the jute fibers fabrics were treated with hot pressing process, and finally, the jute fiber reinforced epoxy resin composites were fabricated with VARTM molding process. Scanning Electron Microscopy (SEM) analysis shows that the interface bonding of jute fibers treated with heating and alkali reinforced epoxy resin composites has not been improved, but the interface bonding of composites has been significantly improved with the jute fibers treated with silane coupling agent and isocyanate. The hotpressing process can not only increase the jute fibers volume content in the composites but also improve the performance of composites by the jute fibers treated in advance with silane coupling agent and isocyanate. The mechanical properties of the composites show that tensile strength, modulus and flexural strength of the jute fiber treated with the silane coupling agent reinforced composite increase by 18.6%, 71.4% and 50.2%, respectively, and the tensile strength, modulus and flexural strength of the jute fiber treated with the isocyanate reinforced composite increase by 16.3%, 34.0% and 50.3%, respectively.
Key words:jute fiber;composites;hot pressing process;silane coupling agent;isocyanate
麻纖維是一種天然植物纖維,具有價格低廉、可生物降解、優(yōu)良的力學(xué)性能等優(yōu)點.相比于合成纖維,天然麻纖維具有更好的吸能效果,能制造出高性能的復(fù)合材料,可廣泛地應(yīng)用于汽車制造工業(yè)[1-2].
麻纖維種類較多,常見的麻纖維有苧麻[3]、黃麻、亞麻等.黃麻是最廉價的天然纖維之一,黃麻纖維纖維素質(zhì)量分?jǐn)?shù)約為57%~60%,單纖細(xì)度為15~18 μm,單纖長度為1.5~5 mm,因為單纖維短且長度參差不齊,故無法單纖維紡紗.黃麻纖維具有不規(guī)則的多邊形混合截面,吸濕性和透濕性較苧麻要高2%~4.5%.其生物分解性好,初始彈性模量高,不起球,抗菌能力優(yōu)異,生產(chǎn)成本低,因此具有很好的市場應(yīng)用前景.
湖南大學(xué)學(xué)報(自然科學(xué)版)2015年第12期李偉等:VARTM制備麻纖維增強環(huán)氧樹脂復(fù)合材料研究麻纖維由纖維素、半纖維素、木質(zhì)素、果膠和脂肪蠟質(zhì)組成,不同麻纖維組成有差別.麻纖維的主要成分為纖維素,纖維素分子結(jié)構(gòu)中含有大量的羥基,故麻纖維表面極性較大,表現(xiàn)出強的親水性,容易從空氣中吸收水份,導(dǎo)致麻纖維與基體材料的界面結(jié)合不佳.而且天然麻纖維的大分子結(jié)晶度和取向度高,纖維外表面粗硬、無卷曲且勾結(jié)強度低.所以將麻纖維作為樹脂基復(fù)合材料的增強材料時,一般需要對麻纖維進(jìn)行表面改性處理[1,3-5].