通过酚酞的硝化和还原,得到了一种新型的含酞结构和酚羟基的二胺单体,通过二胺和4,4'-六氟亚异丙基二(邻苯二甲酸酐)(6FDA)缩聚并高温亚胺化,得到了相应的含酚羟基聚酰亚胺PI-HP.利用1H-NMR、FTIR、GPC及热分析表征了PI-HP的结构和热性能,利用紫外-可见光谱表征了其透明性.结果表明,PI-HP在部分极性有机溶剂中如DMF、THF、丙酮中具有良好的溶解性,具有较高的热稳定性并在可见光区域具有较好的透明性,其含羟基可进一步修饰用于制备各种功能材料.
A polyimide containing phthalein groups and hydroxyl side-groups was synthesized.In the synthesis,a new diamine monomer containing phenolphthalein group was prepared by nitrification of phenolphthalein and followed with further reduction.The polyimide was obtained by polycondensation of the diamine monomer with 4,4′-hexafluoroisopropylidinedi(phtalic anhydride)(6FDA) and subsequent high temperature imidization step.The chemical structure of the monomer and polyimide was characterized by 1H-NMR and FTIR.GPC test gives the molecular weight(Mn) and polydispersity of the polyimide of 15500 and 2.47,respectively.The polyimide shows no obvious Tg in the range of 100~350℃ and a Td of 388℃ with 2.5% mass loss by thermal analysis(DSC and TGA).The polymer has good solubility in some aprotic polar organic solvents such as DMF,DMAc,etc.but is insoluble in weak polar organic solvents such as toluene.The UV-Vis transmittance and absorbance spectra show that the polyimide possesses good optically transparency in the visible region.For its aromatic hydroxyl side-groups containing structure,the polyimide can be further used as a precursor of high performance functional materials.