Hydrolysis of Polyphenyl-1,2,4-triazine and Polyphenyl-1,3,5-triazine in High Temperature Water

IntroductionThe evolution of contemporary science andtechnology has generated much need for polymericmaterials with good stabilities in high temperaturewater,where polymeric materials are used ascoatings,insulating materials,functional orstructural materi…

Hydrolysis of Polyphenyl-1,2,4-triazine and Polyphenyl-1,3,5-triazine in High Temperature Water

The hydrolysis of polyphenyl-1,2,4-triazine (As-PPT) and polyphenyl-1,3,5-triazine (S-PPT) in water at 250℃/ 3.97 MPa under nitrogen atmosphere has been investigated experimentally and theoretically. The hydrolysis reactions were monitored by Fourier transform-infrared (FT-IR) and ultra-violet-visible (UV-Vis) spectra. The results show that S-PPT is remarkably stable whereas As-PPT is easily hydrolyzed in water at 250℃. The identifications using FT-IR, high performance liquid chromatography (HPLC), nuclear magnetic resonance (1H-NMR) and mass spectrography (MS) confirm that terephthalic acid is the major hydrolysate of As-PPT. Two model compounds, 2,5,6-triphenyltriazine and 2,4,6-triphenyltriazine, were designed to simulate the local electronic structures of As-PPT and S-PPT, respectively. The electronic structures were given by ab initio calculations at the RHF/4-31G level. The calculational results indicate that the triazine rings are the hydrolytically active parts and the 1,2,4-triazine ring is easier to hydrolyze in comparison with the 1,3,5-triazine ring under the same condition.