Synthesis and properties of 1,3,4-oxadiazole-containing bismaleimides with asymmetric structure and the copolymerized systems thereof with 4,4′-bismaleimidodiphenylmethane
作者:Lianlian Xia、Xuejiao Zhai、Xuhai Xiong、Ping Chen
DOI:10.1039/c3ra45313h
日期:——
Two novel bismaleimide monomers containing 1,3,4-oxadiazole and asymmetric structure, i.e., 2-[4-(4-maleimidophenoxy)phenyl]-5-(4-maleimidophenyl)-1,3,4-oxadiazole (p-Mioxd) and 2-[3-(4-maleimidophenoxy)phenyl]-5-(4-maleimidophenyl)-1,3,4-oxadiazole (m-Mioxd), were designed and synthesized. The chemical structures of the monomers were confirmed using Fourier transform infrared spectroscopy (FTIR), 1H NMR and 13C NMR spectroscopy and elemental analysis. The thermal properties of the monomers were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results indicate that the incorporation of the 1,3,4-oxadiazole and asymmetric structure could improve the solubility and processability of the BMI monomers and the thermal stability of the resins. Composites composed of glass cloth and 4,4â²-bismaleimidodiphenylmethane (BMDM), which were modified with 2.5, 5 and 10 wt% p-Mioxd and m-Mioxd, respectively, were also prepared. The TGA and DMA results demonstrate that the resulting composites have excellent thermal stability with high residual weight percentage at 700 °C (>45%) and Tg (>450 °C).
两种新型的双马来酰亚胺单体含有 1,3,4-噁二唑和不对称结构,即 2-[4-(4-马来酰亚胺苯氧)苯基]-5-(4-马来酰亚胺苯基)-1,3,4-噁二唑 (p-Mioxd) 和 2-[3-(4-马来酰亚胺苯氧)苯基]-5-(4-马来酰亚胺苯基)-1,3,4-噁二唑 (m-Mioxd),被设计和合成。通过傅里叶变换红外光谱(FTIR)、1H NMR、13C NMR 光谱和元素分析确认了这些单体的化学结构。使用差示扫描量热法(DSC)和热重分析(TGA)研究了单体的热性质。结果表明,1,3,4-噁二唑和不对称结构的引入可以改善双马来酰亚胺单体的溶解性和加工性,以及树脂的热稳定性。还制备了由玻璃布和经过 2.5%、5% 和 10% p-Mioxd 及 m-Mioxd 修改的 4,4'-双马来酰亚胺二苯基甲烷 (BMDM) 组成的复合材料。热重分析(TGA)和动态机械分析(DMA)的结果表明,所得到的复合材料在 700°C 时具有优良的热稳定性,残留重量百分比超过 45%,并且玻璃化转变温度(Tg)超过 450°C。