碳纤维增强苯并噁嗪树脂基复合材料的研究进展

苯并噁嗪是近年来发展起来的一种新型的高性能复合材料基体树脂。本文较系统地综述了国内外碳纤维增强苯并噁嗪复合材料的研究进展,介绍了苯并噁嗪树脂及其复合材料的性能特点,指出了进一步的发展趋势。     

苯并噁嗪树脂及其玻璃纤维增强复合材料的阻燃改性

应用聚磷酸铵(APP)对苯并噁嗪(BOZ)树脂及玻璃纤维(GF)/BOZ复合材料进行了阻燃改性,结合热分析和微观形貌分析等研究了材料的阻燃机制。结果表明:APP可以明显提高BOZ树脂的阻燃性能,随APP含量的提高,树脂体系的极限氧指数逐渐提高,添加量为3wt%时可使BOZ树脂的极限氧指数从基体的31.5%提高到34.5%,并达到UL 94V-0级。APP的加入使改性树脂体系的分解温度前移,玻璃化转变温度略有下降,改性树脂体系固化反应提前,反应过程变得缓和。APP的加入使GF/BOZ复合材料的阻燃性能进一步提高,10wt%GF/APP-BOZ复合材料的极限氧指数从GF/BOZ的51.0%提高到57.7%。微观形貌分析表明:APP的加入使APP-BOZ改性树脂及GF/APP-BOZ复合材料燃烧后生成更为致密的炭层,从而使材料的阻燃性能得到提高。     

一种含马来酰亚胺苯并噁嗪的合成及性能

以4-氨基苯基马来酰亚胺、甲醛、苯酚为原料,采用两步法经中间产物三嗪(TMIPT)合成苯并噁嗪(MIPB),并借助红外光谱(FT-IR)、核磁共振(1H-NMR)和元素分析(EA)等手段对产物MIPB进行了表征。通过差示扫描量热(DSC)、FT-IR和热重分析(TGA)对MIPB的热行为进行了研究,结果发现,MIPB化合物的熔点为113.3℃,相比于Ishida报道的MIB化合物147℃的熔点降低了33.7℃,MIPB在150℃的固化率大大增加,固化后的MIPB树脂5%热失重温度T5为348℃,10%热失重温度T10为368℃,800℃残炭率达到55.6%。     

含DOPO的双酚A-单苯并(口恶)嗪合成、表征及其固化特性

以双酚A、苯胺、多聚甲醛为原料,合成了双酚A-双苯并(口恶)嗪（DBOZ）,再用其与DOPO（9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物）反应,合成了含DOPO的双酚A-单苯并(口恶)嗪（DBDO）。采用红外、核磁共振（氢谱核磁共振和碳谱核磁共振）等分析手段对DBOZ和DBDO的化学结构进行了表征;采用差示扫描量热仪对DBOZ和DBDO的固化特性进行研究,使用热重分析分析了所得聚苯并(口恶)嗪的热稳定性。结果表明：在N₂气氛中,DBOZ在205℃左右开环聚合,热分解温度为312℃,在373℃分解速度达到最快,在800℃时的残碳率为37.19%;在N₂气氛中,DBDO的热分解温度为353℃,在443℃分解速度达到最快,在800℃时的残碳率为39.60%。     

开环聚合酚醛树脂研究进展

介绍了苯并恶嗪中间体的国内外研究概况。着重介绍了国内近年来在苯并恶嗪中间体合成、树脂固化反应研究和产品应用开发等方面取得的进展。     

Synthesis,curing behavior and thermal properties of fluorene-containing benzoxazines based on linear and branched butylamines

A series of fluorene-containing benzoxazine monomers based on linear and branched butylamines were successfully synthesized in high purity and good yield through a facile one-pot procedure by the reaction of 9,9-bis-(4-hydroxyphenyl)-fluorene with paraformaldehyde and isomeric butylamines. The chemical structures of the target monomers were characterized by Fourier transform infrared (FT-IR), Elemental analysis, ¹H and ¹³C nuclear magnetic resonance (NMR). The curing behavior of benzoxazine monomers was studied by differential scanning calorimetry (DSC) and FT-IR. The thermal properties of cured polybenzoxazines were measured by DSC and thermogravimetric analysis (TGA). The results reveal that the polarity of solvent and the basicity of butylamines produce clear effects on the synthesis of the butylamine-based benzoxazine monomers. Also, the basicity and steric effect of butylamines exhibit significant effects on the curing behavior of benzoxazine monomers and the thermal properties of their polymers. The glass transition temperature and thermal stability of branched butylamine-based polybenzoxazines are higher than those of the corresponding linear butylamine-based polybenzoxazine and traditional bisphenol A-based polybenzoxazines.     

Silane‐functional benzoxazine: synthesis,polymerization kinetics and thermal stability

A benzoxazine with siloxane and phenyl sulfone units (BS ‐b) was synthesized by using aminopropyltriethoxysilane, 4,4'‐dihydroxydiphenylsulfone and paraformaldehyde as precursors via Mannich condensation. Then the hydrolysis and polycondensation reactions of siloxane units were performed and benzoxazine bearing polysiloxanes (BS‐PSO ) were obtained. The ring‐opening polymerization reactions of both BS ‐b and BS‐PSO were studied by Fourier transform IR spectroscopy and DSC in non‐isothermal conditions. The kinetics of the polymerization of BS ‐b were found to be well described by using an n th‐order kinetic model for n = 0.7 (activation energy 141 kJ mol^?1). The BS‐PSO was also used to modify bisphenol‐A‐based benzoxazines (BA ‐a), and the morphological structure and thermal properties of the copolymer were investigated. The TGA results indicate that the silane‐functional polybenzoxazines display enhanced initial decomposition temperature and char yields in comparison with poly(BA ‐a). These results are believed to be important for the development of new flame‐retardant laminates. © 2017 Society of Chemical Industry     

氢氧化铝改性苯并噁嗪及阻燃性的研究

以加入氢氧化铝(ATH)提高苯并噁嗪树脂(BOZ)的阻燃性,并对阻燃聚苯并噁嗪树脂的性能进行研究.结果表明,当氢氧化铝质量分数大于20%时,聚苯并噁嗪树脂的阻燃性可以达到UL-94V0级.差示扫描量热(DSC)和动态机械分析(DMA)测试显示氢氧化铝的加入,使苯并噁嗪树脂开环固化反应放热热焓和峰值温度均有降低,使聚苯并...     

Thermal and dielectric properties of epoxy/DDS/CTBN adhesive modified by cardanol-based benzoxazine

Cardanol-based benzoxazine (Bz-C) was introduced to a ternary resin system to substitute carboxyl-terminated butadiene–acrylonitrile (CTBN) partially and improve the thermal and dielectric properties of the diglycidyl ether of bisphenol-A (epoxy)/4,4′-diaminodiphenylsulfone (DDS)/CTBN adhesive resin system. The effect of Bz-C on the curing behavior of blends was studied, and factors that affect the thermal, mechanical, and dielectric properties were discussed systematically. Results show that reactions between Ep, DDS, and Bz-C decrease the curing temperature of the quaternary blends and increase the cross-linking densities of the network, leading to higher glass-transition temperature and enhanced mechanical properties. The flexibility of the copolymer films was maintained by the introduction of the aliphatic side chain of Bz-C. Substitution of Bz-C for some group of CTBN in the cross-linked network resulted in decreased dielectric constant and dielectric loss in the copolymer films.     

Preparation and characterization of covalently functionalized graphene using vinyl‐terminated benzoxazine monomer and associated nanocomposites with low coefficient of thermal expansion

We describe the preparation of vinyl‐terminated benzoxazine‐functionalized graphene using free radical grafting. The resulting functionalized graphene (f‐graphene) was incorporated into bis(3‐allyl‐3,4‐dihydro‐2H‐1,3‐benzoxazinyl)methane (V‐BF‐a) monomer in order that nanocomposites could be prepared. Results of scanning electron microscopy and transmission electron microscopy revealed that the sheets of f‐graphene were well dispersed throughout the matrix, and there was a strong interfacial interaction between the f‐graphene and polyV‐BF‐a. The inclusion of f‐graphene into the nanocomposites resulted in a material with a high thermal stability and a low coefficient of thermal expansion (CTE); increasing the content of f‐graphene reduced the CTE significantly more. A reduction in the CTE of up to 48% was produced by adding just 1 wt% of f‐graphene; this corresponded to an increase of 12 °C in the glass transition temperature. These results suggest that f‐graphene nanocomposites can be ‘tuned’ to give materials with both a low CTE and a high thermal stability, and that graphene composites of this type can thus be manufactured to withstand a wider range of temperatures.