碳纤维缠绕成型用环氧树脂体系研究

以甲基四氢苯酐、聚己内酯三醇和DMP-30制备了改性甲基四氢苯酐G920。将双酚A环氧树脂CYD-128、聚氨酯改性环氧树脂CYD-133、1,4-丁二醇二缩水甘油醚CYD-622和G920混合制得浇注体及碳纤维复合材料NOL环。采用粘度和力学性能测试、示差扫描量热分析、热重分析及扫描电镜分析对材料的性能进行了研究。结果表明,该树脂体系的粘度和适用期满足湿法缠绕成型工艺要求,浇铸体具有优异的耐热性能与力学性能,其制备的T-700碳纤维复合材料NOL环拉伸强度达到2 500 MPa,层间剪切强度达到69.9 MPa,具有优异的界面性能和强度保持率,适合T-700碳纤维的湿法缠绕成型。     

湿法缠绕成型T700碳纤维/氰酸酯树脂复合材料力学性能研究

研究了湿法缠绕成型的T700碳纤维/氰酸酯树脂复合材料NOL环及单向板力学性能。测试了树脂配方的粘度-温度特性,T700碳纤维/氰酸酯树脂复合材料NOL环的拉伸及剪切性能,采用SEM对NOL环拉伸试样破坏形貌进行了观察。测试了T700碳纤维/氰酸酯树脂单向板复合材料的常温拉伸性能、弯曲性能、层间剪切性能和高温弯曲性能。结果表明,树脂配方在25℃下的粘度为800 cps,可以直接在室温条件下用于复合材料湿法缠绕成型,并具有充分的使用期。NOL环的拉伸强度为2220 MPa,剪切强度为56. 8 MPa,树脂基体对碳纤维具有良好的浸润性,能够较好地发挥出碳纤维的高强度特性。T700碳纤维氰酸酯树脂单向板复合材料的高温力学性能优异,200℃下弯曲强度保留率高达60. 4%,250℃下弯曲强度保留率高达45. 0%。     

碳纤维的表面改性对导热顺丁橡胶性能的影响

研究了碳纤维的表面改性方法对碳纤维/顺丁橡胶(BR)复合材料的硫化特性、门尼粘度、导热性能和力学性能的影响.实验结果表明,碳纤维/顺丁橡胶复合材料与顺丁橡胶空白样相比,其硫化速度、导热系数与力学性能都有明显的提高.而碳纤维的表面改性对碳纤维/顺丁橡胶复合材料的硫化特性数据、门尼粘度和导热系数影响并不明显,加入碳纤维后的未改性的碳纤维/顺丁橡胶复合材料的导热性能最佳,其导热系数为0.527 W/(m·K),为顺丁橡胶空白样的1.7倍;经过高温氧化后碳纤维填充复合材料力学性能有所提高,其拉伸强度为2.39 MPa.     

一种RTM用耐烧蚀改性酚醛树脂性能研究

对一种新型改性酚醛树脂的粘度特性、耐热性和耐烧蚀性能及其复合材料的性能进行了研究,得出该树脂体系的粘度在60~120℃的范围内均小于800m Pa·s,且在70℃、80℃时工艺适用期大于150min;其玻璃化温度Tg为253℃,氮气气氛800℃残炭率可达到67.1%,质量烧蚀率和线烧蚀率分别为0.0766g/s、0.119mm/s;RTM成型碳纤维增强改性酚醛树脂复合材料的层间剪切强度和轴向压缩强度分别可达39.3MPa和177MPa,氧-乙炔烧蚀的线烧蚀率和质量烧蚀率分别为0.044mm/s、0.0762g/s。结果表明,该种树脂体系具有粘度低、工艺适用期长以及良好的耐热性和耐烧蚀性能,能很好地满足RTM工艺的要求,且其碳纤维针刺复合材料具有作为耐烧蚀材料的潜质。     

多官能环氧/DDS体系性能研究

以氯代四官能环氧树脂（EP）为基体树脂，二氨基二苯砜（DDS）为固化剂，碳纤维为增强材料，制备了多官能EP／DDS体系及其复合材料。通过对体系的凝胶时间，粘度－温度曲线，DSC曲线的分析，确定了体系的固化工艺为120℃/1h＋150℃/2h＋175℃/3h；其浇注体和复合材料层压板的力学性能较好，与美国Narmco公司的同类材料相当。     

一种可用于拉挤成型的改性苯并恶嗪树脂体系

将PM型苯并恶嗪与环氧树脂F-51按照质量比7∶3共混,加入适量的2-乙基-4-甲基咪唑作为固化剂,首次制备了能够适用于拉挤成型的树脂基体。采用凝胶时间测试,示差扫描量热分析,动态热机械分析(DMA)和力学性能测试研究了该树脂体系的粘度特性、固化行为和使用性能。结果表明,该体系150℃下的凝胶时间5 min,60℃粘度471 mPa.s,树脂浇注体的弯曲强度156.7 MPa,弯曲模量4.9 GPa,玻璃化转变温度180℃。该树脂体系具有凝胶快、粘度低以及较好的力学性能和耐热性等特点,能够满足拉挤成型工艺的要求。     

复合材料卡瓦专用胶粘剂的应用研究

通过粘度、力学性能测试及红外光谱分析对复合材料卡瓦专用胶粘剂的性能进行了研究。结果表明,复合材料卡瓦上镶嵌陶瓷牙齿前需预热处理,预热温度设定在50~60℃为宜,其胶粘剂体系粘度约为50 s。该胶的韧性和粘接性能优良,胶层可以有效传递载荷,固化物的冲击强度达到9.6 kJ/m2,满足复合材料桥塞坐封时的力学性能要求。     

碳纤维增强环氧树脂复合材料的液体成型及其性能研究

本文研究了不同温度下RIM145树脂的粘度和适用期,分析了不同温度下RIM145树脂和碳纤维单丝之间的浸润性;并以碳纤维单向布为增强材料,采用真空辅助灌注成型工艺制备了碳纤维增强环氧树脂(CF/EP)复合材料,研究了复合材料的力学性能,对层间剪切试样剖断面形貌进行了SEM分析,并研究了使用VAP单向透气膜辅助真空灌注成型工艺对CF/EP复合材料厚制件灌注质量的影响。研究结果表明,RIM145树脂基体在50~70℃粘度低、适用期长且树脂与碳纤维单丝之间的浸润性良好,适用于CF/EP复合材料的真空辅助灌注成型工艺;灌注的CF/EP具有良好的力学性能,树脂和纤维具有中等粘结强度界面,采用VAP单向透气膜辅助真空辅助灌注成型工艺可降低CF/EP复合材料的孔隙率。     

自行车架用碳纤维与环氧树脂浸润性研究

采用三种RTM工艺成型的环氧树脂体系分别对碳纤维进行浸润,并制备了自行车架用碳纤维复合材料。采用自制浸润度观察仪,粘度、表面张力和力学性能测试以及红外光谱和扫描电镜分析研究了不同环氧体系对碳纤维的浸润性。结果表明:粘度低的AF-802环氧树脂体系对碳纤维的浸润性最佳,最大浸润高度为28.41 mm;环氧树脂体系对含上浆剂碳纤维的浸润性能优于无上浆剂的碳纤维。浸润性改进有益于碳纤维复合材料弯曲强度提高,发挥碳纤维车架的整体效能,提高整车安全性。     

碳纤维/乙烯基酯树脂单向复合材料拉挤工艺研究

本文系统研究了引发体系的组成及含量，三段模具温度，内脱模剂的含量和碳纤维体积含量对碳纤维/乙烯基酯树脂复合材料拉挤工艺和拉挤复合材料性能的影响。确定了以上各参数的最佳范围，连续生产出性能优异的碳纤维拉挤复合材料。     

The development of glass fiber reinforced polystyrene for pultrusion. I: Process feasibility,dynamic mechanical properties,and postformability

A feasibility study on the pultrusion of a glass fiber reinforced polystyrene (PS) has been conducted using a proprietary method. The styrene prepolymer synthesized in this study was prepared from blends of styrene monomer and benzoyl peroxide (BPO). The process feasibility, dynamic mechanical properties, and postformability of the glass fiber reinforced PS by pultrusion have been investigated. By means of gel permeation chromatography, ¹H nuclear magnetic resonance (¹H-NMR), and a Brookfield viscometer, the molecular weight, conversion, and viscosity of the styrene prepolymer were obtained. From the investigations of the long pot life of styrene prepolymer, the high reactivity of styrene prepolymer, and excellent fiber wet-out, it was found that the PS resin showed excellent process feasibility for pultrusion. The dynamic storage modulus (E') of pultruded glass fiber reinforced PS composites increased with increasing die temperature, filler content, postcuring and glass fiber content, and with decreasing pulling rate. The composite can be postformed by thermoforming under pressure, and mechanical properties of postformed composites can be improved.     

高低温老化对碳纤维复合材料芯棒结构性能的影响

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。     

高温老化对碳纤维增强双马来酰亚胺树脂基复合材料力学性能的影响研究

本文对国产碳纤维增强双马来酰亚胺树脂复合材料进行了高温老化力学性能测试和分析,通过扫描电子显微镜分析了高温老化对碳纤维／双马复合材料力学性能的影响。结果表明,老化1000h的力学性能未出现明显下降趋势,纤维与树脂基体粘接牢固,界面完好,该复合材料的高温老化性能优异。     

一种低粘度双马树脂及其复合材料的性能研究

对一种适用于RTM工艺的低粘度双马树脂QY8911-Ⅳ进行了研究,考察了树脂体系的粘度特性和固化特性,并对不同后固化温度下的树脂固化物的耐热性、力学性能及吸水性等进行了全面考察。结果表明,该树脂体系具有粘度低(80℃为200mPa·s)、固化收缩小(1%)、耐热性好(T_g为260℃)、力学性能好(弯曲强度为170 MPa、冲击强度为20 kJ/m~2)和吸水率低(0.39%)等特点。选择合适的注射工艺和固化工艺,以此树脂为基体,采用RTM工艺,制备出了碳布增强的复合材料,并对其力学性能进行了测试,其弯曲强度和冲击强度分别为754 MPa和110.9 kJ/m~2。     

Pultruded fiber reinforced blocked polyurethane (PU) composites. II. Processing variables and dynamic mechanical properties

Unidirectional fiber reinforced blocked polyurethane (PU) composites have been prepared by the pultrusion process. The effects of processing variables on the mechanical properties and dynamic mechanical properties of fiber reinforced PU composites by pultrusion have been studied. The processing variables investigated included pulling rate (in-line speed), die temperature, postcure time and temperature, and filler type and content. The dynamic mechanical properties of the composites produced by the process were studied utilizing dynamic mechanical spectrometer. Results show that the composites possessed various optimum pulling rates at different die temperatures. From the DSC data analysis, swelling ratio, and mechanical properties, the optimum die temperature was determined. It was found that the mechanical properties increase with filler content for various types of filler. The increasing of mechanical properties depends on the optimum postcure temperature and time. However, the properties decreased for longer postcure times since the composite materials were degraded. The glass-transition temperature (T_g) increased slightly and the damping peak (tan δ) was broadened due to fiber reinforcement. The dynamic mechanical moduli (G′, G″) of pultruded PU composites are apparently higher than those of the matrices. The moduli (G′, G″) increase with increasing fiber and filler content, and the damping peak becomes broad. Effect of postcuring on the degree of crosslinking, T_g, and dynamic modulus will be discussed.     

一种高性能环氧树脂固化体系的研究

通过凝胶化测试和示差扫描量热分析（DSC）,研究了CYD128／DMP-30体系固化反应性,20℃凝胶化时间为70min;测试了浇铸体力学性能和耐热性,其中拉伸强度为50．2MPa,拉伸模量为3．5GPa,弯曲强度为156．7MPa,冲击强度为15．0（kJ·m^-2,玻璃化温度（Tg）为96℃。研究了连续纤维增强CYD128／DMP-30体系复合材料的性能,其中连续玻璃纤维增强复合材料弯曲强度为954．8MPa,连续碳纤维增强复合材料弯曲强度为1057．4MPa。     

Pultruded fiber reinforced thermoplastic poly(methyl methacrylate) composites. Part II: Mechanical and thermal properties

A novel process has been developed to manufacture poly(methyl methacrylate) (PMMA) pultruded parts. The mechanical and dynamic mechanical properties, environmental effects, postformability of pultruded composites and properties of various fiber (glass, carbon and Kevlar 49 aramid fiber) reinforced PMMA composites have been studied. Results show that the mechanical and thermal properties (i.e. tensile strength, flexural strength and modulus, impact strength and HDT) increase with fiber content. Kevlar fiber/PMMA composites possess the highest impact strength and HDT, while carbon fiber/PMMA composites show the highest tensile strength, tensile and flexural modulus, and glass fiber/PMMA composites show the highest flexural strength. Experimental tensile strengths of all composites except carbon fiber/PMMA composites follow the rule of mixtures. The deviation of carbon fiber/PMMA composite is due to the fiber breakage during processing. Pultruded glass fiber reinforced PMMA composites exhibit good weather resistance. They can be postformed by thermoforming, and mechanical properties can be improved by postforming. The dynamic shear storage modulus (G′) of pultruded glass fiber reinforced PMMA composites increased with decreasing pulling rate, and G′ was higher than that of pultruded Nylon 6 and polyester composites.     

基于DSC法的混杂纤维增强树脂基复合材料拉挤工艺研究

为提高碳纤维/玻璃纤维混杂增强树脂基复合材料(以下简称混杂纤维复合材料)拉挤型材的固化质量和力学性能,通过差示扫描量热分析(DSC)法,得出了相同配方条件下复合材料的4种不同升温速率下的固化DSC曲线,运用T–β外推法初步确定了三段式加热拉挤成型方法的温度工艺参数范围。在此基础上,选择直径为10 mm的混杂纤维棒材作为研究对象,变化不同的拉挤温度和速度制备型材,并对其分别进行力学性能试验,研究拉挤工艺参数对复合材料力学性能的影响,从而根据力学性能表征进一步明确适合于本配方的生产工艺参数。结果表明,通过以上方法所得到的混杂纤维复合材料拉挤工艺参数能够满足制备混杂纤维复合材料型材的要求;与传统的经验方法相比,采用该方法更为高效和准确。     

The unidirectional glass fiber reinforced furfuryl alcohol for pultrusion. II. Correlation of processing parameters for optimizing the process

Unidirectional glass fiber reinforced furfuryl alcohol (FA) composites have been prepared by the pultrusion processes. The optimum processing parameters of the glass fiber reinforced FA composites by pultrusion has been studied. The effects of the optimum processing parameters on the properties (flexural strength, flexural modulus, notched Izod impact strength, glass transition temperature (T_g), dynamic shear storage modulus (E'), shrinkage ratio, and roughness) investigated including die temperature, pulling rate, postcure temperature and time, and filler type and content. Results show that the pultruded composites possessed various optimum pulling rates at different die temperatures. On the basis of the DSC diagram, the swelling ratio and the mechanical properties of pultruded composites, the optimum die temperature can be determined. The mechanical properties and T_g increase at a suitable postcure temperature and time. Furthermore, the properties which decrease due to the degradation of pultruded composites for a long postcure time will be discussed. The mechanical properties of pultruded composites reach a maximum value at various filler content corresponding to the talc and calcium carbonate, respectively, and then decreased. When the fillers are added to the pultruded glass fiber reinforced FA composites, the shrinkage ratio of composites become smaller, and the surface of composites became smooth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

In‐situ pultrusion of urea‐formaldehyde matrix composites. II: Effect of processing variables on mechanical properties

Unidirectional fiber reinforced urea‐formaldehyde (UF) composites have been prepared by the pultrusion processes. The effects of the processing parameters on the mechanical properties (flexural strength and flexural modulus, etc.) of the glass fiber reinforced UF composites by pultrusion has been studied. The processing variables investigated included die temperature, pulling speed, postcure temperature and time, filler type and content, and glass fiber content. The die temperature was determined from differential scanning calorimetry (DSC) diagram, swelling ratio, and mechanical properties tests. It was found that the mechanical properties increased with increasing die temperature and glass fiber content, and with decreasing pulling rate. The die temperature, pulling speed, and glass fiber content were determined to be 220°C, 20–80 cm/min, and 60–75 vol%, respectively. The mechanical properties reached a maximum value at 10, 5, 5, and 3 phr filler content corresponding to the kaolin, talc, mica, and calcium carbonate, respectively, and then decreased. The mechanical properties increase at a suitable postcure temperature and time. Furthermore, the properties that decreased due to the degradation of composite materials for a long postcure time are discussed. POLYM. COMPOS., 27:8–14, 2006. © 2005 Society of Plastics Engineers