反应介质对合成双酚A-苯胺型苯并噁嗪的影响

以多聚甲醛、苯胺和双酚A为原料,固定加料方式和反应温度等反应条件,改变溶剂种类和NaOH的用量,合成了双酚A-苯胺型苯并噁嗪树脂。采用1H NMR、凝胶化时间测试、DSC等方法对苯并噁嗪的结构、环化率和热固化行为进行了表征,研究了反应介质对苯并噁嗪合成反应的影响。实验结果表明,溶剂的介电常数越低或溶剂对原料双酚A或产物苯并噁嗪的溶解性越好,越有利于提高苯并噁嗪树脂的环化率和纯度;另外,随溶解多聚甲醛时所用NaOH用量的增加,苯并噁嗪的环化率、凝胶化时间和固化峰值温度都呈现先升高后降低的趋势,当NaOH质量分数(基于双酚A)为0.26%时,产物的环化率最高、凝胶化时间最长、固化峰值温度最高。     

高性能无卤／无铅覆铜板的制备

以苯并嗯嗪树脂（BOZ）、邻甲酚酚醛环氧树脂（CNE）、线性苯酚酚醛树脂（PN）、含磷阻燃剂以及一定量的无机填料作为树脂基体,选用适宜的溶剂,获得了加工性良好的树脂胶液,并利用差示扫描量热分析（DSC）研究了该多元体系的固化机理。通过调整树脂组分用量及优化工艺条件,制得了高耐热／湿热、低吸水率、综合性能良好的玻纤布基覆铜板,有望在“无卤无铅”化领域中得到应用。     

N-苯并[b][1，4]噁嗪-6-基-2，4-二甲基-5-噻唑酰胺类化合物的合成及杀菌活性

以2,4-二甲基噻唑-5-甲酸为原料,经酰化与取代苯并嗪酮胺反应,合成了16个未见文献报道的N-(7-氟-2,4-三取代-3-氧-3,4-二氢-2H-苯并[b][1,4]噁嗪-6-基)-2,4-二甲基-5-噻唑酰胺类化合物(3),所有目标化合物结构均通过1HNMR、IR和LC/MS确证。初步生物活性测试表明该类化合物具有不同程度的杀菌活性。在质量浓度500mg/L下,化合物3f、3e、3g对小麦白粉病菌抑制率分别达85.0%、95.0%、100.0%,表现出较好的抑制活性;化合物3i对油菜菌核病菌抑制率达82.2%。     

BMI改性苯并恶嗪树脂及其复合材料研究

采用双马来酰亚胺(BMI)对苯并恶嗪进行改性,通过溶液法制备了苯并恶嗪/BMI树脂基玻璃布复合材料,对其力学性能和吸水性能进行了研究,并研究了苯并恶嗪/BMI树脂体系的物理性能和反应特性.结果表明,随BMI用量的增加,苯并恶嗪/BMI树脂体系的凝胶时间缩短;体系的聚合过程只有一个放热峰,峰顶温度为232℃,且与BMI的用量无关;随BMI用量的增加,复合材料的弯曲强度和冲击强度升高,吸水率下降.     

Synthesis of linear polymers containing benzoxazine moieties in the main chain with high molecular design versatility via click reaction

Linear polymers with benzoxazine rings in the main chain have been synthesized applying click chemistry approach. These polymers possess molecular weights significantly higher than the benzoxazine polymers which have been chain extended via Mannich reaction. The number average molecular weight is estimated from size exclusion chromatography (SEC) to be between 20,000 and 40,000 Da. The structure of the polymers is confirmed by ¹H and ¹³C nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). Differential scanning calorimetry (DSC) is used to study crosslinking behavior of the polymers. The nature of the low temperature exotherm DSC peak observed in this work and the previous work of other authors is studied by model reactions. It is due to thermal coupling of the residual propargyl and azide end groups in the absence of active catalyst. In addition, a novel diazide-functional benzoxazine monomer has been prepared, showing a tremendous flexibility for applying click reaction to obtain various polymer architectures. Three types of polymers have been prepared from dipropargyl- and diazide-functional benzoxazine monomers. These polymers have been characterized by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA).     

苯并噁嗪及其在制备C/C复合材料领域的研究进展

综述了国内外新型热固性树脂苯并噁嗪聚合物的固化机理、固化体积变化、热分解机理及其复合材料的研究进展,并通过分析树脂体系的黏度、浸润性及其固化物的残炭率和炭的形貌,初步判断了苯并噁嗪树脂在制备C/C复合材料领域的应用前景。     

Investigation of polymerization of benzoxazines and thermal degradation characteristics of polybenzoxazines via direct pyrolysis mass spectrometry

Polymerization of benzoxazines and thermal degradation mechanisms of polybenzoxazines were investigated using the direct pyrolysis mass spectrometry (DP‐MS) technique. The benzoxazine structures were based on phenol and aniline and on bisphenol‐A and methylamine or aniline. Polymerizations of the benzoxazines were carried out by curing them at elevated temperatures without addition of initiator or catalyst. DP‐MS data showed the presence of chains generated by opposing polymerization reaction pathways indicating quite complex structures for the polybenzoxazines under investigation. Thermal decomposition of polybenzoxazines was started by the cleavage of methylamine or aniline linkages. It was determined that polybenzoxazines based on phenol were more stable than the corresponding bisphenol‐A‐based polybenzoxazines, while those based on methylamine were more stable than the corresponding polybenzoxazines incorporating aniline. Thus, it can be concluded that the presence of bulky groups decreased the extent of crosslinking which in return decreased the thermal stability. Copyright © 2012 Society of Chemical Industry     

高韧性聚醚脲型苯并嗪树脂的合成及力学性能

首先用端氨基聚醚、二苯甲烷二异氰酸酯（MDI）制备出两端含有氨基的聚醚型聚脲,然后用合成的聚醚型聚脲、双酚A和多聚甲醛为原料进行曼尼希反应合成出聚醚脲型苯并（口恶）嗪（PUBZ）,经高温固化后形成韧性优良的树脂。用FTIR、¹H NMR分析了PUBZ的化学结构,证实了所得的目标产物;用DSC对PUBZ的固化特性进行研究;用拉伸测试分析了含不同长度聚醚链PUBZ树脂的力学性能;用DMA和TGA测试分析了含不同长度聚醚链PUBZ树脂的热性能。结果表明：聚醚链段越长,PUBZ的固化温度越高,PUBZ树脂的玻璃化转变温度越低,相反其热稳定性越好;在力学性能中端氨基聚醚D-400/PUBZ树脂的韧性最好。     

二胺型苯并噁嗪化合物的合成、结构表征与热性能分析

以三种酚类化合物、4,4’－二氨基二苯砜和甲醛为原料,以二氧六环为溶剂制备了化学结构不同的噁嗪化合物,分别为3,3’－二苯砜-双（3,4＋二氢-2H-1,3-萘并噁嗪）、3,3,-二苯砜-双（3,4-二氢-2H-1,3-苯并噁嗪）、3,3’-二苯砜-双（6-苯基-3,4-二氢-2H-1,3-苯并噁嗪）。并用^1HNMR、FTIR方法确定了其化学结构。采用示差扫描量热分析（DSC）对噁嗪化合物的热行为和性能进行了分析。结果表明,不同化学结构的噁嗪化合物固化产物的热性能不同,3,3’-二苯砜-双（3,4-二氢-2H-1,3-苯并噁嗪）的固化产物具有相对较高的Tg,为212．10℃。     

Non-isothermal curing kinetics and thermal properties of benzoxazine-phenolic copolymers

Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular structure of the novolac-type phenolic resin and the benzoxazine-phenolic copolymer BP31. In order to understand the curing process of the copolymers, the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry (DSC), and the catalytical effect of phenolic hydroxyl on the curing behavior of copolymers was investigated. To investigate the thermal properties of this resin, the thermal degradation behaviors of the cured samples were studied by thermal gravimetric (TG) method, and glass-transition temperatures (T _g) of the cured copolymers were also evaluated by DSC. The dynamic Ozawa method was adopted to determine the kinetic parameters of the curing process as well. The activation energy is 78.8 kJ/mol and the reaction rate constant is in the range from 40.0 to 5.2 (K/min) ⁿ according to reaction temperatures. The Ozawa exponent decreases from 2.4 to 0.7 with the increase of reaction temperature, and curing mechanism is expounded briefly according to the results. TG result shows that the highest char yield of copolymers is 50.3%. The highest T _g of copolymers is 489 K, which is much higher than that of pure benzoxazine resin. Foundation item: Project (20050106) supported by the Key Science and Technology Item of Guangdong Province, China