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综述了近年来氨酚醛树脂、钡酚醛树脂等广泛使用的传统酚醛树脂(PF),硼改性酚醛树脂(BPF)、苯并恶嗪树脂(BZ)和酚三嗪树脂(PT)等部分改性PF,以及以聚芳基乙炔树脂(PAA)为代表的新型高残炭树脂的研究进展。分析了传统PF不能满足先进热防护材料发展需求的原因。着重介绍了BPF主要的合成方法和热分解机理、BZ的分子改性设计和共混共聚改性以及PAA的改性和固化过程中存在的主要问题。对比介绍了不同耐烧蚀基体在高温热环境下的残炭率,以及其在制备工艺、实际应用等方面所存在的问题,并且展望了树脂基耐烧蚀复合材料未来在纳米改性方面的发展趋势。 相似文献
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酚醛树脂烧蚀性能研究进展 总被引:10,自引:0,他引:10
简单介绍了在酚醛树脂烧蚀性能的改进研究中硼酚醛、铝酚醛、磷酚醛、聚酚醚和酚三嗪树脂的烧蚀性能,也介绍了使用芳基酚、烷基酚与DA改性剂改进的酚醛树脂的烧蚀性能,以及开环聚合酚醛树脂和新型酚醛树脂S-157与S-158的主要性能。同时介绍了氯化磷腈改性酚醛树脂和提高酚醛树脂成炭率的其它改性研究。指出了改性酚醛树脂仍然是今后常规武器系统使用的一种低成本热防护材料的树脂基体。 相似文献
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耐烧蚀复合材料用改性酚醛树脂研究进展 总被引:15,自引:5,他引:15
本文从结构改性、共混改性等方面介绍了近年来国内外对耐烧蚀复合材料用各种改性酚醛树脂的合成方法、分子结构、改性机理以及改性后酚醛树脂的性能和应用概况,并指出今后改性酚醛树脂仍是一种低成本耐烧蚀复合材料的树脂基体,在航天材料领域有着广泛的应用。 相似文献
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综述了无机元素改性和结构改性两种方法改性酚醛树脂以提高其耐烧蚀性能的研究进展。无机元素改性主要包括硼改性酚醛树脂和钼改性酚醛树脂,对无机元素改性酚醛树脂的耐烧蚀性能进行比较发现,钼改性酚醛树脂的耐烧蚀性能较好,并给出了不同的改性机理;结构改性包括芳基酚、苯并噁嗪、马来酰亚胺、氰基、炔基改性酚醛树脂,介绍了现已合成的不同改性酚醛树脂的合成方法及其耐烧蚀性能:结构改性酚醛树脂的耐烧蚀性能都有很大的提高,但是炔基改性存在固化温度太高的缺点,综合性能不是很好。 相似文献
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《现代塑料加工应用》2017,(5)
在碱性条件下,以腰果酚部分代替苯酚与甲醛反应制得腰果酚改性酚醛树脂,并以该树脂为原料制备腰果酚改性酚醛树脂泡沫。结果表明:当苯酚/腰果酚物质的量比为9/1、缩聚反应温度90℃、催化剂加入量为苯酚和腰果酚总质量4%时,所得树脂黏度为25 Pa·s,符合最佳发泡黏度范围。当苯酚/腰果酚物质的量比为9/1时,改性树脂在400℃时的残炭量(94.6%)要比未改性树脂的残炭量高7.1%,压缩强度由改性前的0.08 MPa提高到改性后的0.14 MPa。扫描电镜结果表明:在相同条件下,改性后的酚醛树脂泡沫泡孔更为均匀。 相似文献
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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。 相似文献
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将FB硼酚醛树脂和E-51环氧树脂按不同比例,配制成耐烧蚀胶粘剂,通过热重分析(TGA)优选出残炭率高的耐烧蚀刮涂胶粘剂。在优选的胶粘剂中掺入质量分数为3%~12%的MoSi2,以得到改性的胶粘剂。通过烧蚀试验、TGA、X-射线衍射(XRD)和扫描电镜分析(SEM),研究了MoSi2对胶粘剂烧蚀率、残炭率、残炭组成和残炭形貌的影响。研究表明,MoSi2可显著降低胶粘剂的线烧蚀率和质量烧蚀率,提高了胶粘剂的残炭率。反应生成的热稳定性高的SiO2、SiC和MoC3,可改善胶粘剂的残炭形貌。 相似文献
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以玻璃纤维(GF)为增强材料,制备了玻纤/醋酸锆改性酚醛树脂(GF/ZPF)复合材料,考察了树脂中锆含量对复合材料弯曲强度、线烧蚀率的影响以及复合材料线烧蚀率和烧蚀形貌随烧蚀时间的变化。结果表明,ZPF在1000℃的残炭率为68.7%,相比纯酚醛树脂(PF)提高了21.7%;当树脂中锆含量为14%时,GF/ZPF复合材料的弯曲强度达到最高值642MPa;当锆含量由10%增加到15%时,GF/ZPF复合材料的线烧蚀率由0.0305mm/s降低到0.0208mm/s;随着烧蚀时间的延长,GF/ZPF复合材料的线烧蚀率基本没有变化,表明GF/ZPF复合材料具有优异的耐烧蚀性能。 相似文献
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烧蚀复合材料用酚醛树脂的结构表征及性能 总被引:1,自引:0,他引:1
采用FTIR、GPC、DSC及TG等方法对4种烧蚀复合材料用酚醛树脂(钨酚醛树脂(WPR)、硼酚醛树脂(BPR)、高残炭酚醛树脂(HCYPR)、S-157酚醛树脂)固化前的结构、分子质量及其分布、固化历程、热失重特性进行了表征和对比,以便为烧蚀复合材料基体的筛选提供理论依据。研究结果发现,S-157PR的分子质量最小,分布最窄,浸润性最好;4种酚醛树脂的固化峰温依次为HCYPR>BPR>WPR>S-157PR;800℃残炭率依次为BPR>HCYPR>WPR>S-157PR。 相似文献
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酚醛树脂热降解过程中的结构变化 总被引:2,自引:1,他引:1
采用综合热分析对比研究了自制酚醛树脂和商业酚醛树脂的热降解过程,利用固体核磁共振和红外光谱技术研究了热降解过程中树脂结构的变化规律以期指导成炭率高、热稳定性高的新型酚醛树脂的合成。结果表明:酚醛树脂的热降解过程可分为3个阶段:首先是醚键以及未反应的羟甲基等端基的热降解;其次是亚甲基热解断裂为甲基;然后是酚羟基发生脱水环化成炭。其中亚甲基的热解对酚醛树脂的热稳定性及高温下的成炭性能有着至关重要的作用。固体核磁共振比红外光谱更直接,更清晰地反应出酚醛树脂在热降解过程中的结构变化。 相似文献
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An idealized mechanism for the carbonization of phenolic resins was adopted and an equation was derived for the char yield. In simplified cases this was shown to be a function giving a maximum of 67.9% at a 1:1 formaldehyde/phenol molar ratio, falling rapidly at lower and slowly at higher ratios. In experimental verification, the alkalicatalyzed reaction of phenol and formaldehyde at various molar ratios was studied and the resulting resins were characterized and carbonized. The char yields were found to correspond well with predictions, with a maximum of about 67.2% in the region of 1.1:1 formaldehyde/phenol molar ratio. 相似文献
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酚醛改性聚芳基乙炔基复合材料探索 总被引:12,自引:0,他引:12
闫联生 《玻璃钢/复合材料》2001,(4):22-24,31
聚芳基乙炔(PAA)树脂具有残碳率高、吸水率低、固化反应为加聚反应、无低分子物副产物逸出等特点,是专为新一代树脂基热防护复合材料而研制的。但其与碳布的浸润性及粘接性能差,碳布增强复合材料的剪切强度较低。本文采用酚醛树脂对PAA树脂进行改性处理,在不降低残碳率的情况下,明显改善了PAA树脂与碳布的粘接性能。改性后碳/聚芳基乙炔复合材料的剪切强度由5.5MPa提高到11MPa以上。 相似文献
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Junjun Feng Lixin Chen Junwei Gu Zeyu He Jin Yun Xiaobin Wang 《Journal of Polymer Research》2016,23(5):97
Phenol, zinc acetate dihydrate and paraformaldehyde are firstly performed to synthesize thermoplastic phenolic resin (PR), then phenylboronic acid (PBA) and other two boron compounds (4-hydroxymethyl phenylboronic acid & boronic acid) are introduced to fabricate the boron-containing thermoplastic phenolic resins (BPRs). The corresponding molecular structure, softening points, thermal decomposition temperature and char yield ratio of the BPRs are characterized and investigated by FTIR, NMR, XPS and TGA. Compared to pure thermoplastic PR, all the BPRs present relatively higher softening points, more excellent thermal decomposition temperature and higher char yield values. BPR-a exhibits the optimal thermal decomposition temperature (T 5 of 317.4 °C) and char yield ratio at 800 °C (69.6 %). 相似文献
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Novel phenolic resins bearing methylol and phenyl ethynyl functions and curing by both condensation and addition mechanisms were synthesized by the reaction of 3‐(phenyl ethynyl) phenol (PEP) with formaldehyde under alkaline conditions. Resins with varying relative concentration of the two functional groups were synthesized and characterized. The resins underwent a two‐stage cure, confirmed by both DSC and DMA analyses. The low‐temperature cure due to methylol condensation led to early gelation of the system. The ultimate curing through addition reaction of phenylethynyl group required heating at 275°C. The cured resins exhibited better thermal stability and anaerobic char yield in comparison to a conventional resole. The thermal stability and char‐yielding property showed a diminishing trend with enhanced methylol substitution. Resin with F/P ratio less than unity offered excellent thermal stability and anaerobic char yield. The thermal degradation of the cured resins occurred in two kinetic steps. Methylene groups favored the initial degradation, whereas the higher temperature carbonization process was independent of the network structure. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3371–3377, 2001 相似文献
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《Ceramics International》2017,43(17):14599-14607
The carbonized behavior of binders (carbores pitch, mesophase pitch, high temperature pitch and phenolic resins) was investigated. Meanwhile, the influence of binders, Ni-catalyst and heat treatment on structure and properties of low carbon Al2O3-C materials was researched. Mesophase pitch and high molecular weight resin provided higher carbon yield. The synergistic interaction of pitch and phenolic resin provided the higher carbon yield than that of single component. Ni-catalyst changed structure and morphology of bonded carbon promoting the transition of amorphous carbon to crystalline carbon increasing carbon yield and degree of graphitization. High molecular weight phenolic resins, mesophase or carbores pitch and Ni-catalyst worked together providing low carbon Al2O3-C samples of excellent strength performance in a wide temperature range and high resistance of thermal shock. Embedding coke in N2 could promote the generating of carbon fibers which obviously enhanced thermal shock resistance of low carbon (6% flake graphite) Al2O3-C materials after heat treatment. 相似文献
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With the ever increasing demand for fuel savings on vehicles, there is a strong push to replace metal with polymeric + fiber (carbon/glass) composites. However, the replacement of metal with polymeric composites can lead to additional fire risk. Our study focused on glass fiber reinforced polymer composites meant for vehicular structural applications, and flammability performance of these composites was studied by cone calorimetery. The effects of fiberglass loading, nanocomposite use (clay, carbon nanofiber) and polymer type (epoxy, phenolic) were studied under a heat flux of 50kW/m2 to better understand the potential effects that these variables would have on material flammability. It was found that as fiberglass loading increased, flammability decreased, but at a cost to structural integrity of the residual polymer + fiber char. The use of nanocomposites has little effect on reducing flammability in this set of samples, but the use of phenolic resins in comparison with epoxy resins was found to yield the greatest improvements in flammability performance. Further, the phenolic system yielded a higher level of structural integrity to the final polymer + fiberglass char when compared with the other polymer systems of low heat release. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献