Duan, Chunjian;Cui, Yu;Wang, Chao;Tao, Liming;Wang, Qihua;Xie, Hai;Wang, Tingmei published 《High temperature tribological properties of thermosetting polyimide》 in 2017. The article was appeared in 《Mocaxue Xuebao》. They have made some progress in their research.Safety of 3-(4-Aminophenoxy)aniline The article mentions the following:
Thermosetting polyimide oligomers with different diamines (isomers) was synthesized with 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), 4,4′-diaminodiphenyl ether (4,4′-ODA), 3,4′-diaminodiphenyl ether (3,4′-ODA) and 4-phenylethynylphthalide (4-PEPA). Furthermore, dry sliding tests were performed at 25°C, 100°C, 200°C, 250°C, 300°C and 350°C on a ball-on-disk wear tester. Mechanisms of friction and wear were studied in detail by scanning electron microscope and energy dispersive X-ray spectroscopy. At elevated temperature, exptl. results demonstrated that the wear rate increased first, then decreased and finally increased. However, average coefficient of friction showed a tendency to plummet with temperature range from 25°C to 350°C. This trend was attributed to changes in the mech. properties of the polymer surface. The wear mechanisms at elevated temperatures were different. At 25 and 100°C, fatigue wear and abrasive wear prevailed. From 100°C to 200°C, a dense of transfer film generated and the thickness increased due to adequate shearing motion of mol. chain. Hence, mild abrasive wear played a major role. Above 250°C, wear rate rapidly increased with damage of interaction between the mol. chain and polyimide was peeled on worn surface under the lasted load, adhesive wear was dominant. As a general guideline, higher ambient temperature rendered a greater wear rate. The experimental procedure involved many compounds, such as 3-(4-Aminophenoxy)aniline (cas: 2657-87-6) .
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. Safety of 3-(4-Aminophenoxy)aniline 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