共查询到19条相似文献,搜索用时 140 毫秒
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《胶体与聚合物》2021,(3)
通过对拉挤成型用树脂配方体系的研究,为拉挤用树脂配方的设计与改进提供思路与方向,从而满足拉挤生产中的不同需求。通过FTIR和GC-MS研究了树脂配方的成分,该配方主要由环氧/酸酐体系加上叔胺类促进剂以及添加剂组成;通过树脂凝胶试验仪和DSC研究了该树脂配方体系的固化反应行为,发现其在140℃时具有最短的凝胶时间(121.0 s)和固化时间(184.5 s),同时在升温速率为5℃/min时的最佳固化反应温度为136℃;对该树脂配方体系和环氧/酸酐体系固化物的力学性能、热变形温度进行了对比研究,发现该树脂配方体系在韧性较好的同时其热变形温度没有受到影响,进一步通过SEM研究发现拉挤用树脂配方体系为韧性断裂而环氧/酸酐树脂体系为脆性断裂。 相似文献
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耐高温拉挤环氧树脂及其复合材料性能研究 总被引:2,自引:1,他引:2
本文研究了改性多元缩水甘油胺型耐高温环氧树脂的固化动力学,分析了该树脂体系的浇注体性能,制备了碳纤维拉挤复合材料,并通过热机械分析(DMTA)考察了树脂浇注体及其复合材料的动态热机械性能.结果表明,树脂体系的凝胶化温度与固化温度相差较小,固化反应放热集中,适合于快速拉挤成型;其复合材料具有优良的耐高温性能,玻璃化温度(Tg)达到210℃以上. 相似文献
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本文阐述了玻璃钢挤拉工艺对树脂基体的主要工艺性能要求。对比了不饱和聚脂和环氧树脂的固化特点。指出,低粘度、快速固化是挤拉工艺对环氧树脂的重要工艺要求。为满足挤拉工艺发展的需要,建议开发挤拉专用环氧树脂。 相似文献
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碳纤维复合芯导线的卷绕性能主要取决于所用树脂体系的韧性,本文对高温碳纤维复合芯导线所用树脂体系进行了研究。试验结果表明:4,4’-二氨基二苯甲烷环氧树脂可以满足碳纤维复合芯的耐高温要求;为了进一步提高碳纤维复合芯导线的安全可靠性,采用核壳结构聚合物对树脂体系进行增韧,使碳纤维复合芯的卷绕性能进一步提高。选用4,4’-二氨基二苯甲烷环氧树脂和甲基纳迪克酸酐为主体树脂,加入其他辅料和10份增韧剂所得到的配方,经过拉挤试验及综合性能测试结果表明,本实验采取的树脂配方可以满足拉挤工艺及碳纤维复合芯导线40D卷绕性能要求。 相似文献
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拉挤成型复合材料由于其质量轻、强度高、生产成本低等优点被广泛应用。拉挤成型用树脂基体是影响复合材料工艺和性能的关键因素,掌握其在成型固化过程中的凝胶化和玻璃化行为对工艺制定和提高复合材料性能具有重要意义。文中制备了快速拉挤成型环氧树脂基体,采用动态差示扫描量热仪(DSC)和半经验的唯象模型研究了树脂固化度和固化时间、温度之间的关系,绘制了等固化度曲线;采用恒温DSC得到了基于DiBenedetto经验方程的玻璃化转变曲线;通过测试树脂的凝胶点,研究了凝胶时间和温度的关系。综合上述工作绘制了拉挤树脂体系的TTT(Time-Temperature-Transition)图,由TTT图确定了拉挤速度及模具温度设置。依据确定的工艺参数制备了拉挤板材,经超声扫描和DSC测试,复合材料内部无空隙,玻璃化转变温度达到了树脂完全固化水平。 相似文献
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环氧树脂耐高温基体在航空航天、特种涂料、电气及半导体电子等高新技术领域得到了广泛的应用。环氧树脂的性能在很大程度上受环氧树脂固化剂的影响,对比了三种不同胺固化剂对环氧树脂固化的影响,结果显示实验室自制的NH-POSS固化剂优于脂肪族和芳香族类胺固化剂,NH-POSS固化剂可以提高整个固化体系的耐高温性能,使其玻璃化转变温度高达234℃,是一种耐高温树脂。采用n级反应理论的动力学模型,并对热力学数据进行分析,拟合出了NH-POSS环氧树脂体系的固化工艺条件,为NH-POSS固化环氧树脂的加工工艺提供了理论依据。 相似文献
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A mathematical model has been developed to simulate the pultrusion process, namely the profiles of temperature and the degree of cure in both the axial and radial directions in a pultrusion die of cylindrical shape. For the study, the equations of continuity and energy transport, coupled with a kinetic expression for the curing reaction, were solved numerically, using a finite difference method. For the kinetic expression, we used an empirical expression of the form dα/dt = (k1 + k2αm)(1 ? α)n to describe the curing behavior of both unsaturated polyester and epoxy resins. Differential scanning calorimetry (DSC) was used to investigate the curing behavior of the following systems: unsaturated polyester resin/glass fiber, epoxy resin/glass fiber, and epoxy resin/carbon fiber. The results of DSC runs were used to determine the kinetic parameters, which enabled us to predict the effects on the pultrusion characteristics of the following variables: (1) the type of initiator; (2) the type of fiber reinforcement; (3) the type of resin; and (4) the pulling speed and hence the residence time. 相似文献
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高低温老化对碳纤维复合材料芯棒结构性能的影响 总被引:1,自引:0,他引:1
采用拉挤工艺制备了碳纤维增强环氧树脂基复合材料芯棒,并对其进行高低温人工加速老化试验,以及对老化前后碳纤维复合材料芯棒的横截面、外观颜色和密度进行了测试和分析。结果表明,高低温老化使芯棒颜色加深,主要对芯棒的外层产生一定的影响,内部结构没有明显变化;老化后芯棒的密度比老化前减小约2.5%,并且不同老化周期对芯棒的密度基本不变。 相似文献
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通过DSC分析及粘度和力学性能测试研究了海因环氧树脂/甲基六氢苯二酸酐/2-乙基-4-甲基咪唑体系的粘度特性,固化反应动力学,浇铸体及碳纤维增强拉挤成型复合材料的力学性能。结果表明,该体系在50℃下,15 h内粘度<500 mPa.s,可以满足拉挤工艺要求。其碳纤维复合材料的玻璃化温度达到206℃以上,剪切强度达到80 MPa,耐热性和力学性能良好。 相似文献
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The Combination of reaction injection molding and pultrusion has resulted in a new processing technique, RIM-Pultrusion, Which has been used to produce a thermoplastic epoxy prepreg. This prepreg has been used to produce a long-fiber injection molded phenoxy/carbon fiber composite with near-Zero void content. A heat-activated curing system has been developed, which allows injecton molding of the prepreg to form a thermostet long-finer epoxy/carbon finber composite. The RIM- pultrusion conditions for producing an injection moldable prepreg are described. Capillary rheomety is used to study the epoxy resin to determine the proper molar ratio for RIM-Pultrusion. The long-fiber epoxy compostie is analyzed with dynamic mechanical analysis (DMA) and Fourier transform infrared spectroscopy (FTIR). Also., the impact strength and solvent resistance of the long-fiber composite are examined. The properties of the thermoset long-fiber epoxy xomposite are compared to those of a thermoplastic injection molded long-fiber phenoxy composite. 相似文献
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采用超声波透射法成功实现了实时在线监测环氧树脂在不同条件下的固化反应过程,研究了超声波振幅衰减随固化反应时间的变化关系,探讨了中温条件下模具厚度和玻璃纤维对环氧树脂固化反应过程的影响。结果表明:振幅衰减呈现出先增加后减小并趋于稳定的规律;随着固化反应的进行,振幅衰减能够准确地反映出环氧树脂体系出现凝胶点的时间和黏稠态—凝胶态—玻璃态各相态的变化过程。提高温度能缩短固化时间,增加厚度和玻璃纤维能在一定程度上延缓凝胶点出现的时间,并对其机理进行了讨论。超声波在线监测为环氧树脂基复合材料的加工成型和制作工艺提供了理论依据和重要的技术手段。 相似文献
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The efficiency of an optical sensor embedded in a composite structure strongly depends on the interfacial adhesion between the optical fiber coating and the surrounding solid material. The present paper reports on the study of the interfacial adhesion of an optical fiber embedded in a composite material. A simple system composed of optical fibers embedded in an epoxy vinylester resin was first studied to evaluate the influence of embedded length, curing temperature and curing time. Pull-out tests on optical fibers bonded in epoxy vinylester/glass fiber composite material were carried out to measure the effect of glass concentration on the fiber bonding. The pull-out results showed no effect of both embedded length and curing temperature. However, an increase of the interfacial debonding stress is reported with increased curing time. For the optical fiber/composite system, a linear evolution of interfacial debonding stress with increasing glass fiber concentration is reported. 相似文献
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We conducted a feasibility study on the pultrusion of a glass‐fiber‐reinforced urea–formaldehyde (UF) composite using a proprietary method. The UF prepolymer synthesized in this study was prepared from blends of UF monomer and a curing agent (NH4Cl).The process feasibility, kinetic analysis, and dynamic mechanical properties of the glass‐fiber‐reinforced UF composites by pultrusion were investigated. From investigations of the long pot life of the UF prepolymer, the high reactivity of the UF prepolymer, and excellent fiber wet‐out, we found that the UF resin showed excellent process feasibility for pultrusion. A kinetic model, dα/dt = A exp(?E/RT)αm(1 ? α)n, is proposed to describe the curing behavior of a UF resin. Kinetic parameters for the model were obtained from dynamic differential scanning calorimetry scans with a multiple‐regression technique. The dynamic storage modulus of the pultruded‐glass‐fiber‐reinforced UF composites increased with increasing die temperature, filler content and glass‐fiber content and with decreasing pulling rate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1242–1251, 2002 相似文献