Yin, Lu-meng;Yang, Ming-wei;Liu, Quan;Li, Xiang;Zhang, Yan;Zhi, Xin-Xin;Qi, Hao-ran;Liu, Jin-gang;Lv, Feng-zhu published 《Electrospun Polyimide Ultrafine Non-woven Fibrous Membranes Containing Phenyl-substituted Quinoxaline Units with Improved Hydrolysis Resistance for Potential Applications in High-temperature Water Environments》 in 2022. The article was appeared in 《Fibers and Polymers》. They have made some progress in their research.COA of Formula: C31H20O8 The article mentions the following:
Two organo-soluble polyimide resins containing phenyl-substituted quinoxaline units (PIPQ) were successfully prepared via the two-step chem. imidization procedure from an aromatic diamine, 6(7)-amino-2-(4-aminophenyl)-3-phenylquinoxaline (PQDA) and aromatic dianhydrides with flexible mol. structures. The derived PIPQ-1 resin from PQDA and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and the PIPQ-2 resin from PQDA and 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) were all soluble in polar aprotic solvents, such as N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAc). The PIPQ/DMAc solutions with the solid contents of 25-35 wt% were used as the starting mediums and the PIPQ ultrafine non-woven fibrous membranes (UFMs) were successfully prepared by the one-step electrospinning (ES) procedure. The fabricated PIPQ UFMs exhibited good thermal stability with the 5% weight loss temperatures (T5%) of 537°C for PIPQ-1 (6FDA-PQDA) and 517°C for PIPQ-2 (BPADA-PQDA) in nitrogen, resp. In addition, the PIPQ UFMs exhibited glass transition temperatures (Tg) higher than 252°C. The PIPQ UFMs survived even during the aging in boiling aqueous sodium hydroxide solution (concentration: 20 wt%) for 3 h while the PI-ref UFM totally hydrolyzed during the test. And 5,5′-((Propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(isobenzofuran-1,3-dione) (cas: 38103-06-9) was used in the research process.
5,5′-((Propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(isobenzofuran-1,3-dione)(cas: 38103-06-9) is a diallyl based epoxy modification agent that blends with the resin to improve the mechanical property of the epoxy material.COA of Formula: C31H20O8 It is majorly used in novalac based resins, which can be further cured with bismaleimides (BMI) for aerospace, electronics and wireless communication based applications.