@article{oai:nagasaki-u.repo.nii.ac.jp:00015918,
 author = {Furukawa, Mutsuhisa and Kawashita, Eizi and Yokoyama, Tetsuo},
 issue = {8},
 journal = {長崎大学工学部研究報告, Reports of the Faculty of Engineering, Nagasaki University},
 month = {Jan},
 note = {Amine degradation was studied for the network polyurethanes (PPG-TDI-BD) and model compounds of allophanate, urethane, and urea linkages (1,3-diphenyl methylallophanate, 4-methyl-m-phenylenedicarbamate, and 1,3-diphenylurea) in DMSO at a low temperature below 70℃. Among the model compounds, only the allophanate reacted with an equimolar amount of aliphatic primary amine to give urea and urethane. However, the other compounds did not react. It was found that the concentration of allophanate groups is determined by using H2S04-MeOH solution and bromphenol blue. By this method crosslinking densities of the network polyurethanes were determined and compared with those estimated from stoichiometric calculation and from rubber elasticity. The crosslinking densities determined by the amine degradation of po!yurethanes cured under air atmosphere were 22～48% of those estimated stoichiometrically. In contrast, both values of polyurethane cured under nitrogen atmosphere were in good agreement., 長崎大学工学部研究報告, (8), pp.67-76; 1977},
 pages = {67--76},
 title = {The Amine Degradation of Network Polyurethanes},
 year = {1977}
}