Product Details of 2657-87-6《Structures and properties of closed-cell polyimide rigid foams》 was published in 2013. The authors were Wang, Leilei;Hu, Aijun;Fan, Lin;Yang, Shiyong, and the article was included in《Journal of Applied Polymer Science》. The author mentioned the following in the article:
Closed-cell polyimide rigid foams with different Calculated Mol. Weight (Calc’d Mn) and foam d. (ρ) have been prepared by thermal foaming of nadimide-endcapped imideoligomers (NAIO) powder. The NAIO powder was obtained by thermally treating of a PMR poly(amide ester) solution derived from the reaction of di-Et ester of 2,3,3′,4′-biphenyltetracarboxylic dianhydride (α-BPDE) and p-phenylenediamine (p-PDA) using monoethyl ester of cis-5-norbornene- endo-2,3-dicarboxylic acid (NE) as reactive endcapping agent in Et alc. Effect of Calc’d Mn and foam d. (ρ) on mech. and thermal properties of the polyimide rigid foams have been systematically investigated. It was found that the thermal foaming properties of NAIO powders were affected by the Calc’d Mn. The appreciate Calc’d Mn could yield polyimide foams with both high closed-cell content (Cc) (>80%) and outstanding mech. properties. Moreover, the thermal properties were reduced by increasing of Calc’d Mn and the mech. properties improved gradually by increasing foam densities. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013.3-(4-Aminophenoxy)aniline (cas: 2657-87-6) were involved in the experimental procedure.
3-(4-Aminophenoxy)aniline is one of ethers-buliding-blocks. Ethers feature bent C–O–C linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. Product Details of 2657-87-6 The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.
Reference:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem