共查询到17条相似文献,搜索用时 140 毫秒
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以二烯丙基双酚A(DBA)和端乙烯基丁腈橡胶(VTBN)为增韧剂,两者与双马来酰亚胺(BMI)共聚后得到的预聚体作为酚醛型氰酸酯的改性剂,制备了一种改性酚醛型氰酸酯树脂。研究结果表明:DBA对酚醛型氰酸酯具有很好的催化作用,5%DBA[相对于氰酸酯(CE)质量而言]就可使CE在200℃以下固化;当m(DBA)∶m(VTBN)=5∶3时,体系的弯曲强度为132 MPa、冲击强度为12.6 J/m2、20℃和260℃剪切强度分别为16.88 MPa和9.77 MPa;改性体系的耐热性较好,其5%热失重分解温度和最大热分解速率温度分别为427.6℃和439.0℃。 相似文献
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研究了适用于RTM工艺的钡酚醛树脂的固化性能和工艺性能,以此为指导,采用RTM工艺制备了石英/钡酚醛复合材料,并对其力学性能和烧蚀性能进行了测试和分析.结果表明,石英/钡酚醛复合材料具有较好的整体力学性能,氧-乙炔线烧蚀率为0.092mm·s-1,质量烧蚀率为0.0707g·s-1. 相似文献
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改性氰酸酯的预聚工艺研究 总被引:3,自引:0,他引:3
本文研究酚醛环氧改性双酚A氰酸酯,用于制备热熔预浸料.双酚A氰酸酯和酚醛环氧树脂经过适当预聚后在室温下具有一定的粘附性,可制作出具有室温铺敷性的复合材料预浸料.将金属催化剂二月桂酸二丁基锡(DBTDL)加入改性体系,复合材料成型试验结果表明,DBTDL对树脂体系的预聚工艺有明显的改善作用,树脂体系可用于热熔工艺. 相似文献
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EPDM/酚醛树脂共混性能研究 总被引:3,自引:0,他引:3
邹德荣 《合成材料老化与应用》2003,32(4):3-5
在固体火箭发动机用烧蚀材料研究中,以三元乙丙橡胶(EPDM)为基体材料,以ZnO、TMTD、硫磺、白碳黑、酚醛等为配合剂,制备了EPDM橡胶基的烧蚀材料,采用酚醛作为增强剂,与EPDM进行共混,研究了酚醛的含量对材料性能的影响,测试了材料的物理机械性能和烧蚀性能。结果表明,当酚醛与EPDM的配比为75g时,可以使烧蚀材料形成稳定致密的炭化层,获得较低的烧蚀率,并且保持一定的机械性能。 相似文献
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研究了二烯丙基双酚A(DBA)催化改性酚醛型氰酸酯树脂(cy-5),通过差示扫描量热法(DSC)、热重分析(TG)、冲击性能和动态热机械分析(DMA)测试,分析了改性树脂的热性能和力学性能。研究表明:DBA对cy-5有催化和增韧的双重作用,当DBA的添加量为5%(质量分数)时,催化效果最为明显,含10% DBA的改性树脂固化物的冲击强度达到7.41 kJ/m2,改性树脂固化物的玻璃化转变温度(Tg)和储能模量(E')均有所降低,但幅度不大。 相似文献
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文中叙述了以烯丙基线性酚醛树脂(AF)改性BMI树脂基体制得的玻璃布复合材料的概况,对树脂基体、预浸料及复合材料的性能进行了研究。 相似文献
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特殊分子质量的邻甲酚酚醛树脂的合成及应用 总被引:1,自引:1,他引:0
采用碱酸分步催化的方法合成了一系列高分子质量、低分子质量分布的纯邻甲酚和以邻甲酚为主成分的邻甲酚系线形酚醛树脂。对产物的物理化学性能以及以该类树脂作为PS版成膜树脂时版材的成像性能进行了测试。研究了合成工艺对产物性能的影响。结果表明,酚醛比接近1∶1时,合成树脂的分子质量在9 000~12 000,Mw/Mn在2~4;酚类的加入顺序十分重要;在碱性阶段出水量需达到总出水量的1/3左右。可通过加入抗碱性的酚类化合物来调节树脂碱溶性或溶剂性能。该合成方法简单、成本低廉,污染小。合成的树脂可用于PS版、热敏CTP版以及LCD用抗蚀剂等方面。 相似文献
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Linear controlled molecular weight ortho-cresol novolac oligomers were crosslinked with epoxies to form tough, flame retardant networks with enhanced processability and reduced moisture uptake. At the networks' optimum stoichiometry, the fracture toughness, assessed by the critical stress intensity factor (KIC), was slightly higher for the cresol novolac–epoxy networks (1.1 MPa m1/2) than for similar phenolic novolac–epoxy networks (0.85 MPa m1/2). Cresol novolac–epoxy networks exhibited improved processability under melt conditions relative to phenolic novolac–epoxy materials, and this was attributed to the presence of a methyl group adjacent to the hydroxyl group on cresol repeat units, which reduced the rate of reaction between phenol and epoxy. The use of cresol novolac oligomers also reduced the network equilibrium water absorption, and this was likely due to the presence of the additional methyl on each repeat unit. The equilibrium water absorption for all cresol novolac containing compositions was between 1.7 and 2.1 wt%, comparable to epoxy networks. Cone calorimetry showed that the flame retardance of cresol novolac–epoxy networks was lower than that for the phenolic novolac–epoxy materials, but was far superior to the control epoxy networks. 相似文献
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Cyanate esters are a class of thermal resistant polymers widely used as thermal resistant and electrical insulating materials for electric devices and structural composite applications. In this article, the effect of 2,2′‐diallyl bisphenol A (DBA) on catalyzing the thermal curing of cyanate ester resins was studied. The curing behavior, thermal resistance, and thermal mechanical properties of these DBA catalyzed cyanate ester resins were characterized. The results show that DBA is especially suitable for catalyzing the polymerization of the novolac cyanate ester resin (HF‐5), as it acts as both the curing catalyst through depressing the exothermic peak temperature (Texo) by nearly 100°C and the toughening agent of the novolac cyanate ester resin by slightly reducing the elastic modulus at the glassy state. The thermogravimetric analysis and dynamic mechanical thermal analysis show that the 5 wt % DBA‐catalyzed novolac cyanate ester resin exhibits good thermal resistance with Td5 of 410°C and the char yield at 900°C of 58% and can retain its mechanical strength up to 250°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1775–1786, 2006 相似文献