纤维缠绕CEm基复合材料力学性能研究

为使氰酸酯(Cyanate ester,CE)树脂适合纤维缠绕工艺,对氰酸酯树脂进行了改性.改性的目的是在不降低纯氰酸酯基复合材料耐热性能的前提下,使氰酸酯树脂适合纤维缠绕.用TG/DTA研究了氰酸酯树脂改性前(略为CE)及其改性后(略为CEm)的复合材料热分解温度;用复合材料单向板研究了CErm基复合材料的力学性能,并与目前应用量大面广的环氧基复合材料的力学性能进行了比较.研究结果表明:改性后的氰酸酯基复合材料不仅可以充分发挥CE基复合材料具有的耐高温优势,而且能充分发挥复合材料0°方向的力学性能.     

纤维缠绕用改性氰酸酯树脂体系研究

本文采用环氧树脂对氰酸酯树脂进行改性,研究出适合纤维湿法缠绕的改性氰酸酯体系.通过凝胶实验和DSC等方法研究了改性树脂体系的固化性能,以及改性树脂体系粘度随温度和时间的变化趋势,从而确定其纤维缠绕工艺温度、速度等参数及树脂体系的使用期.对改性树脂基体的热性能、介电性能、力学性能以及改性树脂基体与玻璃纤维、碳纤维的界面性能进行了研究.     

纤维热熔法缠绕用氰酸酯树脂基体研究

用DSC和VHR方法研究催化剂二月桂酸二丁基锡（DBTDL）对双酚A氰酸酯及环氧改性氰酸酯体系反应的影响。根据纤维热熔缠绕要求，研制出工艺适用的改性氰酸酯树脂基体。热熔工作温度100℃。碳纤维增强复合材料层剪强度测试结果表明，基体适用于纤维热熔法缠绕复合材料。     

低成本中温固化湿法缠绕用树脂基体及其国产碳纤维复合材料

针对国产T700碳纤维、中温固化及湿法缠绕的特点,制备了一种适合国产T700碳纤维湿法缠绕用的低成本树脂基体,研究了树脂基体热性能、力学性能、使用期和成本,测试了该树脂基体与国产T700碳纤维制备的复合材料的力学性能。结果表明:该树脂体系耐热性良好且力学性能优异,适宜中温固化,粘度和使用期满足湿法缠绕工艺要求,成本降低超过65%;该树脂基体与国产T700碳纤维制备的复合材料力学性能优异,0°拉伸强度为1988.15 MPa,0°压缩强度为821.02 MPa,弯曲强度为1839.94 MPa,剪切强度为89.51 MPa。     

改性氰酸酯纤维缠绕工艺研究

本文采用环氧树脂改性氰酸酯树脂,研究出适用于纤维湿法缠绕的低粘度并具有较高耐热性能的改性树脂体系。通过试验研究确定了树脂体系的纤维湿法缠绕工艺,对改性树脂与碳纤维复合材料的力学性能进行了研究,并进行了标准容器爆破试验。研究结果表明：改性氰酸酯树脂体系的粘度小（420mPa·S,25℃）,并具有较长使用期（30小时以上）,完全适用于湿法缠绕工艺。使用改性氰酸酯体系缠绕的标准容器,其纤维方向复合材料性能相当于环氧树脂体系缠绕的容器,并且具有较高的玻璃化转变温度（Tg=232℃）,与现有的环氧树脂体系相比,玻璃化转变温度提高了30％～40％。     

氰酸酯复合材料缠绕成型工艺的研究

以液态双酚A型氰酸酯(CE)为树脂基体,碳纤维T-700为增强纤维,缠绕制备了氰酸酯基复合材料(CF/CE)。结果表明:抽真空处理可以有效控制CF/CE的含胶量并降低孔隙率,CF/CE的Tg为241.9℃,孔隙率为1.22%时剪切强度可达101.98MPa。     

二氧化硅粉体改性E—Si／CE固化动力学的研究

采用非等温差示扫描量热法（DSC）研究了纳米二氧化硅（SiO2）和微米SiO2的混合粉体改性环氧基硅烷（E—Si）／氰酸酯（CE）树脂体系固化动力学;用Kissinger、Crane和Ozawa法确定固化动力学参数。结果表明,Kissinger式求得的表观活化能为66．09kJ／mol;Ozawa法求得的表观活化能为7001kJ／mol;根据Crane理论计算该体系的固化反应级数为0.89。计算了不同升温速率所对应的不同温度的频率因子和反应速率常数;求得了改性体系的固化工艺参数：凝胶温度130．74℃、固化温度160．96℃和后处理温度199.16℃,确定了体系的最佳固化工艺。与E—Si／CE体系对比表明,SiO2的加入可以降低E—Si／CE体系的活化能,使其固化能在较低温度下进行。     

环氧改性氰酸酯树脂的研究

综述采用环氧树脂增韧改性氰酸酯树脂的共聚反应机理、固化催化体系，以及环氧树脂／氰酸酯树脂固化体系的性能和复合材料的性能。环氧树脂与氰酸酯树脂反应生成恶唑啉酮五元环，降低了氰酸酯树脂的交联密度，使韧性提高；催化剂可以明显提高共聚反应速度，改变产物含量；改性后的氰酸酯树脂具有优良的综合力学性能和成型工艺性，且介电性能及耐热／湿热性能无较大损失。     

纳米SiO_2改性EP/BMI/CE树脂体系固化动力学研究

采用非等温差示扫描量热(DSC)法对纳米二氧化硅/环氧树脂/双马来酰亚胺/氰酸酯(nano-SiO2/EP/BMI/CE)树脂进行了固化反应动力学和固化工艺研究。通过Kissinger法和Ozawa法求得了nano-SiO2/EP/BMI/CE树脂体系固化反应动力学的表观活化能。结果表明:改性CE树脂体系的固化工艺参数为凝胶温度112℃、固化温度195℃及后处理温度213℃,进而确定了改性CE树脂体系的最佳固化工艺条件为"150℃/3 h→180℃/3 h→200℃/2 h";改性CE树脂体系的平均表观活化能为59.90 kJ/mol。     

动态力学分析法用于评价环氧树脂基体与复合材料耐热性的研究

用动态力学方法（DMA）研究了4种酸酐固化环氧树脂基体及一种拉挤环氧／玻璃纤维复合材料,力学损耗曲线上的损耗峰对应温度为材料的玻璃化温度Tg,弹性模量曲线上的切线玻璃化温度为材料的短时使用耐热温度Tu,弹性模量开始明显下降处为材料的长期使用耐热温度Tr。结果表明,DMA测量环氧树脂基体及其复合材料的玻璃化温度Tg具有很高的灵敏度,△Tg〈1℃;通过Tg可以比较不同环氧树脂基体及改性树脂配方的耐热性,确定最佳树脂配比,评价复合材料的耐热性;根据复合材料试样两次动态力学试验扫描得到的△t可以评价复合材料的制造工艺;根据Tu、Tr可以进一步评价环氧树脂基体及其复合材料的耐热性,为具体用途初选合适的耐热配方。     

纤维缠绕成型聚酰亚胺基复合材料性能研究

以第2代聚酰亚胺(Polyim ide-Ⅱ,PI-Ⅱ)为基体,采用纤维缠绕成型工艺制作了T700/PI-Ⅱ(碳纤维/Polyim ide-Ⅱ)、S2/PI-Ⅱ(高强玻璃纤维/Polyim ide-Ⅱ)复合材料。研究了纤维缠绕成型PI-Ⅱ复合材料的界面性能和耐热性能。采用扫描电镜(SEM)研究了T700/PI-Ⅱ以及S2/PI-Ⅱ复合材料的剪切断口形貌,用于分析PI-Ⅱ复合材料的界面性能;采用TG/DTA 6300热分析仪测定T700/PI-Ⅱ以及S2/PI-Ⅱ复合材料的热分解温度,用于研究T700/PI-Ⅱ以及S2/PI-Ⅱ复合材料的耐热性能。本文研究也包括S2/PI-Ⅱ复合材料在300℃高温的层间剪切强度保留率。研究结果表明:T700/PI-Ⅱ复合材料在空气氛围中的起始热分解温度(TID)为549℃,S2/PI-Ⅱ复合材料为542℃。S2/PI-Ⅱ复合材料在300℃高温的层间剪切强度保留率为72%。     

Toughened epoxy resin matrix for a membrane shell by wet filament winding

A toughened epoxy resin matrix was obtained with a reactive toughening agent and methyl hexahydrophthalic anhydride as a curing agent. The mechanical properties of the modified epoxy resin and its glass‐fiber‐reinforced composites were investigated systematically. The modified epoxy resin matrix possessed many good properties, including a high flexural strength (138 MPa), high elongation at break (5.2%), low viscosity, long pot life at room temperature, and good water resistance. In addition, the glass‐fiber‐reinforced composites showed a high strength conversion ratio of the glass fiber (86.7%) and good fatigue resistance. The results demonstrated that the modified epoxy resin matrix is very suitable for applications in reverse osmosis membrane shell products fabricated with wet filament winding for water treatment. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Novel high‐performance wave‐transparent aluminum phosphate/cyanate ester composites

Advanced wave‐transparent composites are the key materials for many cutting‐edge industries including aviation and aerospace, which should have outstanding heat resistance, low dielectric constant and loss as well as good mechanical properties. A novel kind of high‐performance wave‐transparent composites based on surface‐modified aluminum phosphate AlPO₄(KH‐550) and cyanate ester (CE) was first developed. The dielectric and dynamic mechanical properties of AlPO₄(KH‐550)/CE composites were investigated intensively. Results show that AlPO₄(KH‐550)/CE composites have decreased dielectric loss and higher storage moduli than pure CE resin; in addition, the composites with suitable AlPO₄(KH‐550) concentration remain the outstanding thermal property and low dielectric constant of pure CE resin. The reasons attributing to these results are discussed from the effects of AlPO₄(KH‐550) on the key aspects such as morphology, curing mechanism, and interfacial adhesion of composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Resin transfer molding of natural fiber reinforced polybenzoxazine composities

Kenaf fiber is incorporated in a polybenzoxazine (PBZX) resin matrix to form a unidirectionally reinforced composite containing 20 wt% fiber by a resin transfer molding technique. Two types of benzoxazine monomer are synthesized and used as resin mixtures: Benzozazines based on bisphenol‐A/aniline (BA‐a) and phenol/aniline (Ph‐a). The effects of varying BA‐a:Ph‐a ratio in the resin mixture and curing conditions on mechanical properties of pure PBZX resin and kenaf/PBZX composites are studies. The Flexural strength of the pure PBZX resin increases with increasing ratio of BA‐a:Ph‐a, curing temperature and curing time, but the impact strength increases only slightly. PBZX resin has lower water absorption and higher flexural modulus, when compared with unsaturated polyester (UPE) resin. PBZX composites with 20 wt% fiber content have lower flexural and impact strengths, but higher moduli compared with UPE composites with the same fiber content.     

绝缘制品用低成本树脂体系研究

本文研究开发出一种适用于纤维湿法缠绕并具有较好耐热性能的绝缘制品用低成本树脂体系。通过玻璃化转变温度、DSC分析方法研究了树脂体系的固化性能、热性能。通过试验摸索出了树脂体系的纤维湿法缠绕工艺,对树脂体系的介电性能、力学性能进行了研究,并对树脂体系与玻璃纤维复合的界面性能、力学性能进行了研究。本文研究的树脂体系具有良好的工艺性能、耐热性能、绝缘性能和机械性能,可以满足绝缘材料应用的需要。     

耐酸性玻璃钢拉挤电绝缘芯棒的研制

本文采用丙烯酸改性酚醛环氧树脂，并地以此树脂为基体，以DDSA为增韧剂所制成的玻璃钢芯棒进行了研究。通过DSC及凝胶化时间的测试对该树脂基体的固化反应进行了分析，并对其浇铸体以及玻璃纤维复合材料的性能进行了测试。结果表明：用此树脂基体制得的玻璃钢芯棒具有优异的耐酸性、耐热性以及良好的机电性能。     

一种回转体类构件用中低温固化环氧树脂体系研究

采用等温黏度实验和浇铸体力学性能测试来优选自制改性固化剂CUR–1的配比,通过不同升温速率下的固化过程差示扫描量热并对固化物进行傅立叶变换红外光谱分析,确定了体系的固化制度,研制出一种适用于发动机壳体或结构复杂的回转体类结构件的碳纤维湿法缠绕树脂基复合材料的中低温固化环氧树脂体系,用湿法缠绕工艺制作单向纤维缠绕成型复合材料环(NOL环)并进行了性能测试。结果表明:当CUR–1的含量为15份时,树脂体系具有适于湿法缠绕工艺的黏度和使用期,树脂可在80℃完全固化,同时浇铸体拉伸强度为84 MPa,拉伸弹性模量为3.8 GPa,断裂伸长率为5.4%,热变形温度为131℃。该树脂体系与纤维粘结性好,NOL环力学性能高,NOL环拉伸强度为2 451 MPa,拉伸弹性模量为146 GPa,层剪切强度为55 MPa。     

Comparative study of interphase evolution in polysiloxane resin-derived matrix containing carbon micro and nanofibers during thermal treatment

The work presents the results of research on composite materials made of silicon-containing polymer-derived ceramic matrix composites (PDC-Cs) and nanocomposites (PDC-NCs). Carbon micro and nanofibers (CFs and CNFs) were used as reinforcements. The interactions between carbon micro and nanofibers and polysiloxane matrix, as well as interphase evolution mechanism in composite samples during their heating to 1000 °C were studied. CF/resin and CNF/resin composites were prepared via liquid precursor infiltration process of unidirectionally aligned fibers. After heating to 700 °C–800 °C, decomposition of the resin in the presence of CNFs led to the formation of fiber/organic-inorganic composites with pseudo-plastic properties and improved oxidation resistance compared to as-prepared fiber/resin composites. The most favourable mechanical properties and oxidation resistance were obtained for composites and nanocomposites containing the maximum amount of carbon nanoparticles precipitated in the SiOC matrix during the heat treatment at 800 °C. The precipitated carbon phase improves fiber/matrix adhesion of composites.     

氰酸酯树脂/纳米氧化铜复合材料制备及性能

将无机纳米氧化铜(CuO)粒子加入氰酸酯树脂(CE),以有机锡(DBTDL)实现自由基引发,定量加入环氧树脂(E–54)制得CE/CuO系列复合材料.测试了复合材料的力学性能、导热性能和耐酸碱腐蚀性能,讨论了复合材料性能得以改变的原因.结果表明,无机纳米CuO粒子的引入,有利于CE基体树脂的聚合,无机纳米CuO粒子含量...     

Processing of boron filament wound composites

Boron fiber reinforced composites have been extensively evaluated in epoxy resin matrix materials, which are satisfactory for applications in comparatively moderate environments, and are usually inapplicable at temperatures in excess of 400°F. For use in high temperature environments in excess of this figure, it is necessary to use more thermally stable resins. A modified phenolic resin was selected for this application because of the versatility of the material and the successful performance of phenolics in glass fiber reinforced structures. The modifications increased the viscosity and tack of the formulation so that consolidation could not be readily accomplished by a combination of tension and heat during the winding process, so that a multi-stage winding process with intermediate consolidation steps became necessary. Winding a complex path to make a uniformly thick wall on a frustrum required further modifications to the basic winding process. The successful solution of these problems and the development of structurally sound composites was the primary object of this work.