【摘要】：預(yù)浸料是由樹(shù)脂浸潤(rùn)連續(xù)纖維或織物得到的組合物,通常樹(shù)脂體系呈B階段,是復(fù)合材料的中間體。環(huán)氧樹(shù)脂作為最常用的中溫固化預(yù)浸料樹(shù)脂基體,必須具有良好的斷裂韌性從而使預(yù)浸料中的纖維能有效傳遞應(yīng)力,同時(shí)需要通過(guò)控制基體樹(shù)脂的粘度來(lái)調(diào)整預(yù)浸料的粘接性能,并降低預(yù)浸料的樹(shù)脂流動(dòng)度以滿足復(fù)合材料成型工藝要求。本論文采用聚氨酯預(yù)聚體接枝改性制備本征柔性環(huán)氧樹(shù)脂(Intrinsic Flexible Epoxy Resin,簡(jiǎn)稱IFEP),應(yīng)用于預(yù)浸料樹(shù)脂體系和中溫固化碳纖維預(yù)浸料中,以實(shí)現(xiàn)增韌效果和復(fù)合材料成型工藝適應(yīng)性的統(tǒng)一。1.以二苯基甲烷二異氰酸酯(MDI)與聚氧化丙烯二醇(PPG, Mn=1000,2000,3000)通過(guò)預(yù)聚反應(yīng)制備端異氰酸酯基聚氨酯預(yù)聚體(PPU1000, PPU2000, PPU3000),進(jìn)而與雙酚A型環(huán)氧樹(shù)脂的羥基發(fā)生接枝反應(yīng)得到不同分子量的本征柔性環(huán)氧樹(shù)脂IFEP (IFEP1000, IFEP2000,IFEP3000)。異氰酸根基團(tuán)含量測(cè)試表明預(yù)聚反應(yīng)4h可達(dá)理論值,紅外光譜和核磁共振波譜可確認(rèn)PPU和IFEP的結(jié)構(gòu),凝膠滲透色譜(GPC)測(cè)試表明PPU及IFEP分子量與理論值一致。2.利用三種本征柔性環(huán)氧樹(shù)脂(IFEP1000, IFEP2000, IFEP3000)制備了三種增韌樹(shù)脂體系,考察了三種樹(shù)脂體系的粘彈性、固化動(dòng)力學(xué)、沖擊韌性、熱性能和增韌機(jī)理。流變測(cè)試表明隨著PPG分子量的增加,IFEP增韌環(huán)氧樹(shù)脂體系的特征松弛時(shí)間延長(zhǎng),凝膠時(shí)間縮短。相對(duì)于純環(huán)氧樹(shù)脂體系,IFEP增韌環(huán)氧樹(shù)脂體系韌性大幅提升,其中,IFEP2000增韌環(huán)氧樹(shù)脂體系KIC和沖擊強(qiáng)度達(dá)到最佳。由于聚氨酯組分和環(huán)氧樹(shù)脂溶解度參數(shù)的不同導(dǎo)致聚氨酯在環(huán)氧樹(shù)脂基體中發(fā)生微相分離,IFEP2000增韌體系具有適中的相疇尺寸及分布,綜上,以IFEP2000增韌環(huán)氧樹(shù)脂體系綜合性能最佳。3.應(yīng)用IFEP2000本征柔性環(huán)氧樹(shù)脂制備了不同IFEP含量的增韌樹(shù)脂體系,考察了不同樹(shù)脂體系的力學(xué)性能、固化特性、熱性能和微觀形貌等。力學(xué)測(cè)試表明隨著IFEP含量增加,IFEP增韌體系沖擊強(qiáng)度提高,60 wt%IFEP增韌環(huán)氧樹(shù)脂體系效果最佳。DSC測(cè)試表明IFEP增韌樹(shù)脂體系固化反應(yīng)放熱減少,DMA結(jié)果顯示隨著IFEP含量增加,IFEP增韌樹(shù)脂體系Tg先下降后上升,60 wt%IFEP增韌環(huán)氧樹(shù)脂體系Tg可達(dá)166℃。SEM測(cè)試表明隨著IFEP含量增加,聚氨酯微相分離程度增大,60wt%IFEP增韌環(huán)氧樹(shù)脂體系微相分離相疇為0.148～0.497μ m。4.應(yīng)用60wt%IFEP2000制備環(huán)氧樹(shù)脂體系,以熱熔兩步法工藝制備了T300碳纖維預(yù)浸料,考察了預(yù)浸料的粘溫曲線、樹(shù)脂流動(dòng)度,并評(píng)價(jià)了復(fù)合材料板材的力學(xué)性能和微觀形貌。結(jié)果表明相對(duì)于末增韌環(huán)氧樹(shù)脂基預(yù)浸料,IFEP增韌預(yù)浸料具有更寬的加工窗口,樹(shù)脂流動(dòng)度降低,層間斷裂韌性、層間剪切強(qiáng)度、沖擊后壓縮強(qiáng)度(CAI)提高,SEM結(jié)果顯示IFEP增韌樹(shù)脂基體與碳纖維結(jié)合緊密,聚氨酯在樹(shù)脂基體中發(fā)生微相分離。
[Abstract]:Prepreg is a composition made of resin infiltrated continuous fiber or fabric. Usually, the resin system is in stage B and is the intermediate of composite material. Epoxy resin, as the most commonly used medium temperature curing prepreg resin matrix, must have good fracture toughness so that the fibers in the prepreg can effectively transfer stress. At the same time, it is necessary to adjust the adhesive properties of the prepreg by controlling the viscosity of the matrix resin, and reduce the resin mobility of the prepreg to meet the requirements of the composite molding process. In this paper, the intrinsic flexible epoxy resin (Intrinsic Flexible Epoxy Resin, was prepared by polyurethane prepolymer grafting modification. IFEP), was used in prepreg resin system and medium temperature curing carbon fiber prepreg. In order to realize the unity of toughness effect and the adaptability of composite molding process. Isocyanate terminated polyurethane prepolymer (PPU1000, PPU2000, PPU3000) was prepared by prepolymerization of diphenylmethane diisocyanate (MDI) with polypropylene oxide diol (PPG, Mn=1000,2000,3000). Then the intrinsic flexible epoxy resin IFEP (IFEP1000, IFEP2000,IFEP3000) with different molecular weight was obtained by grafting with hydroxyl groups of bisphenol A epoxy resin. The content test of isocyanate group showed that the theoretical value could be reached by prepolymerization for 4 h, the structure of PPU and IFEP could be confirmed by IR and NMR spectra, and the molecular weight of PPU and IFEP was consistent with the theoretical value. 2. Three kinds of toughened resin systems were prepared by using three kinds of intrinsic flexible epoxy resin (IFEP1000, IFEP2000, IFEP3000). The viscosity, curing kinetics, impact toughness, thermal properties and toughness mechanism of the three resin systems were investigated. The results showed that the characteristic relaxation time and gel time of IFEP toughened epoxy resin system were prolonged and the gel time was shortened with the increase of molecular weight of PPG. Compared with pure epoxy resin system, the toughness of IFEP toughened epoxy resin system is greatly improved, among which IFEP2000 toughened epoxy resin system KIC and impact strength are the best. Due to the different solubility parameters of polyurethane and epoxy resin, polyurethane is separated in epoxy resin matrix. IFEP2000 toughened system has moderate phase domain size and distribution. The comprehensive properties of epoxy resin system toughened by IFEP2000 are the best. Toughened resin systems with different IFEP content were prepared by IFEP2000 intrinsic flexible epoxy resin. The mechanical properties, curing properties, thermal properties and micromorphology of different resin systems were investigated. The mechanical test showed that the impact strength of IFEP toughened system increased with the increase of IFEP content, and the effect of 60 wt%IFEP toughened epoxy resin system was the best. DSC test showed that the curing reaction heat release of IFEP toughened resin system decreased, and DMA results showed that with the increase of IFEP content, The Tg of IFEP toughened resin system decreased at first and then increased, and the Tg of 60 wt%IFEP toughened epoxy resin system reached 166 鈩，

本文編號(hào)：2485043