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.     

Synthesis and characterization of a novel siloxane‐imide‐containing polybenzoxazine

A novel siloxane‐imide‐containing polybenzoxazine based on N,N′‐bis(N‐phenyl‐3,4‐dihydro‐2H‐benzo[1,3]oxazine)‐5, 5′‐bis(1,1′,3,3′‐tetramethyldisiloxane‐1,3‐diyl)‐bis(norborane‐2,3‐dicarboximide) (BZ‐A1) was successfully synthesized. The thermal properties of BZ‐A1 are superior to those of conventional polybenzoxazines lacking siloxane groups. Polymerized BZ‐A1 possesses extremely low surface free energy (γ_s = 15.1 mJ m^?2) after curing at 230 °C for 1 h. Moreover, the surface free energy of polymerized BZ‐A1 is more stable than conventional bisphenol A‐type polybenzoxazine during thermal curing and annealing processes, indicating that polymerized BZ‐A1 is more suitable for applications requiring low surface free energy materials for high temperatures over long periods of time. Copyright © 2010 Society of Chemical Industry     

含磷烯丙基胺型苯并噁嗪的合成与表征

以含磷中间体(BPPP),烯丙基胺,甲醛溶液为原料合成了—种含磷烯丙基胺型苯并噁嗪,并采用核磁共振氢谱(1H-NMR)、傅里叶红外光谱(FTIR)、差示量热扫描仪(DSC)和热失重分析仪(TGA)对其化学结构、固化行为及热稳定性进行了表征.结果表明,含磷烯丙基胺型苯并噁嗪的固化温度为216℃.固化产物的5％和10％热失重温度分别为269和315℃.800℃时的残炭高达51％,表明聚苯并噁嗪具有良好的热稳定性.     

一种高耐湿无卤无铅覆铜板

当前无卤无铅CCL面临的问题很多,主要是从双面板材向多层板材转型过程中出现的吸湿耐热性和加工制造性,而这些是无铅PCB制程的可兼容,及产品长期稳定可靠的关键性能。文章分析了两类可行路线,并锁定最佳方向加以实施,结果非常理想。     

苯并口恶嗪/聚醚砜共混体系的相结构与性能

首次用20%聚醚砜(PES)改性二苯甲烷二胺型苯并口恶嗪(BOZ-M)。通过涂膜的方法得到外观均匀的韧性薄膜,并借助于扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)及动态机械分析仪(DMA)研究了固化物薄膜的微相结构、微相组成、耐热性能及力学性能。结果表明,共混体系在BOZ-M树脂固化过程中发生了明显相分离,形成以PES富集相为连续相、聚苯并口恶嗪(PBOZ-M)富集相为球形分散相的相反转结构的相形态,其中柔性的PES薄膜紧密包裹着PBOZ-M微球(1μm～3μm)。共混薄膜的玻璃化转变温度(Tg)为216℃,断裂伸长率为3.5%,具有优异的耐热性及力学性能。     

苎麻/苯并噁嗪层压板的制备及其阻燃改性

采用聚磷酸铵(APP)和磷氮类阻燃剂(NEWRAY911)对苎麻/苯并噁嗪树脂层压板进行阻燃改性,并通过万能材料试验机、极限氧指数(LOI)、垂直燃烧实验、热失重仪(TG)和微型燃烧量热仪(MCC)对层压板性能进行分析。实验结果表明:经过APP改性后的层压板LOI有明显的增加,但只有当APP添加量达到7%时层压板的垂直燃烧才能通过V0级,且APP过多的添加也使层压板的力学性能有较大的损伤。采用NEWRAY911阻燃改性苎麻织物不仅可以使层压板的阻燃性能得到改善,同时也减少APP的添加量,使苎麻/苯并噁嗪树脂层压板在阻燃改性的同时保持了良好的力学性能。经APP和NEWRAY911改性后的层压板明显减缓了分解速率、燃烧热释放量及释放速率,提高了热分解的残炭量。     

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...     

苯并噁嗪树脂改性研究进展

综述了近年来国内外在BOZ(苯并噁嗪)树脂基础研究与耐热改性等方面取得的研究性进展;介绍了BOZ树脂的改性方法,并对BOZ树脂的未来发展方向进行了展望。     

Synthesis and characterization of a novel acetylene‐ and maleimide‐terminated benzoxazine and its high‐performance thermosets

A novel acetylene‐ and maleimide‐terminated benzoxazine, 3‐(3‐ethynylphenyl)‐3,4‐dihydro‐2H‐6‐(N‐maleimido)‐1,3‐benzoxazine (MBZ‐apa), was successfully synthesized with N‐(4‐hydroxyphenyl)maleimide, paraformaldehyde, and 3‐aminophenylacetylene. The structure of the benzoxazine is confirmed by FTIR and ¹H‐NMR spectroscopies. MBZ‐apa is easily dissolved in common organic solvents. Differential scanning calorimetry (DSC) was used to study thermal cross‐linking behavior of MBZ‐apa. The DSC curve shows only a single exothermic peak due to the oxazine ring‐opening polymerization and the polymerization of the acetylene and maleimide groups occurring simultaneously in the same temperature range. Dynamic mechanical analyses (DMA) reveals that the novel polybenzoxazine exhibits high glass‐transition temperature (T_g) (ca. 348°C). The storage modulus arrives at 4.5 GPa in the range of room temperature to 330°C. The polybenzoxazine exhibits good thermal stability as evidenced by thermogravimetric analysis (TGA). Pyrolysis‐gas chromatography/mass spectrometry (Pyrolysis‐GC/MS) was employed to characterize the polybenzoxazine. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

丁胺-芴基苯并噁嗪/环氧共混树脂的性能研究

以双酚芴、正丁胺和多聚甲醛为原料,二氧六环为溶剂,通过Mannich缩合反应,合成了高纯度丁胺-芴基苯并噁嗪单体（BF-n-b）。以差式扫描量热仪（DSC）研究了苯并噁嗪单体/E-51环氧共混树脂的固化行为,通过动态热机械分析（DMA）和热重分析（TGA）研究了共混树脂的热机械和热稳定性能。结果表明,采用改进的制备方法简化了苯并噁嗪单体的合成过程,单体收率和纯度显著提高;苯并噁嗪/环氧共聚物的玻璃化转变温度（Tg）达到165~178℃,初始热分解温度（热失重5%）达312~342℃,800℃时残碳率最高达22.4%。