【摘要】 以邻烯丙基双酚A、多聚甲醛和烯丙基胺为原料,采用无溶剂的方法合成了一种不含β-氢的苯并嗪(2,2-二(3,8-二烯丙基-3,4-二氢-2H-1,3-苯并嗪)-丙烷(B-dbo).GPC和元素分析结果表明,此嗪中间体主要是单量体和二聚体.用FTIR和1HNMR对中间体结构进行了表征.结果表明,此苯并嗪的分子结构中存在三种反应官能团:嗪环、N-烯丙基、Ar-烯丙基.用DSC和FTIR研究三种反应基团在固化时的反应情况.将双酚A、邻烯丙基双酚A、TiCl4和PCl5作为催化剂按适量的比例加入B-dbo中,用DSC研究其固化行为,并对TiCl4催化试样在不同的固化温度下进行FTIR测试分析,提出在TiCl4催化下苯并嗪环副反应及开环固化机理.更多还原

【Abstract】 With substituted bisphenol A[2,2-bis(4-hydroxy-3-allylphenyl)propane], paraformaldehyde, and allylamine as the starting materials, a novel benzoxazine precursor without β-hydrogen is developed by a solventless procedure. The molecular structure is verified by FTIR, 1H NMR, GPC and EA. It is confirmed that there are three reactive groups on the benzoxazine structure: N-allyl, Ar-allyl, benzoxazine ring. As the ortho and para positions on the phenol are occupied by different groups, it is quite significant to investigate the reaction of the three groups. So we synthesize some other kinds of benzoxazine, isothermal differential scanning calorimetry(DSC) and Fourier transform infrared(FTIR) are used to determine the detailed reactions of the three groups. It indicates that N-allyl and benzoxazine ring react nearly at the same temperature(about 246 ℃), and Ar-allyl reacts at about 350 ℃. Further more, with two different kinds of catalysts, the as-synthesized benzoxazine precursor is also studied by DSC and FTIR to determine the influence of the catalysts on curing. {Among} the catalysts tested, Lewis acids show promising results, while phenolic catalysts can also decrease the onset curing temperature of the benzoxazine ring. Choosing one sample catalyzed by TiCl-4, the curing reactions are discussed at different temperatures by FTIR and a mechanism of the benzoxazine precursor catalyzed by TiCl-4 is suggested.更多还原