Meng, Xiangsheng;Yan, Jingling;Fan, Weifeng;Liu, Jingfeng;Wang, Zhen;Li, Guodong published 《Thermosetting polyimides and composites based on highly soluble phenylethynyl-terminated isoimide oligomers》 in 2014. The article was appeared in 《RSC Advances》. They have made some progress in their research.Application of 2657-87-6 The article mentions the following:
Highly soluble phenylethynyl-endcapped isoimide oligomers were synthesized using 2,3,3′,4′-biphenyltetracarboxylic dianhydride and aromatic diamines as the monomers, 4-phenylethynyl phthalic anhydride as the end-capping reagent, and trifluoroacetic anhydride as the dehydrating agent; then high performance thermosetting polyimides and composites were produced from these oligomers via the thermal crosslinking reaction of the phenylethylnyl group and the material properties were fully investigated. A series of isoimide oligomers with different mol. weights and a variety of chem. architectures were prepared by polycondensation of 3,4′-BPDA, 4-PEPA, and aromatic diamines including m-phenylenediamine (m-PDA), 2,2′-bis(trifluoromethyl)benzidine and 3,4′-oxydianiline followed by cyclization with trifluoroacetic anhydride. Compared to their imide analogs, isoimide oligomers showed much higher solubility in low b.p. solvents, and slightly lower melt viscosity, which can be attributed to their unique asym. architecture. These resins were formulated into thermosetting polyimides and composites by thermal crosslinking of the phenylethynyl group and conversion from isoimide to imide at elevated temperatures The properties of the thermosets and composites were studied using mech. property measurements, dynamic mech. thermal anal. and thermogravimetric anal. The polyimide/quartz fiber composites possessed excellent high temperature mech. properties due to the high glass transition temperatures of matrix resins. And 3-(4-Aminophenoxy)aniline (cas: 2657-87-6) was used in the research process.
3-(4-Aminophenoxy)aniline is one of ethers-buliding-blocks. Ethers lack the hydroxyl groups of alcohols. Without the strongly polarized O―H bond, ether molecules cannot engage in hydrogen bonding with each other. Application of 2657-87-6Ethers do have nonbonding electron pairs on their oxygen atoms, however, and they can form hydrogen bonds with other molecules (alcohols, amines, etc.) that have O―H or N―H bonds.
Reference:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem