Example 5
2.60 grams of 1-(aziridin-1-yl)propan-2-ol, 0.02 grams of bismuth neodecanoate and 32 grams of dimethylformamide were charged to a reaction flask equipped with a thermometer. The mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere and heated to 50° C. A solution of 5.00 grams of Desmodur N 3600 in 32 grams of dimethylformamide was then added dropwise in 15 minutes to the reaction flask, where after the mixture was heated further to 70° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no NCO-stretch at 2200-2300 cm−1 was observed. The solvent was removed in vacuo to obtain an opaque highly viscous liquid. The calculated molecular weight of the theoretical main component was 807.52 Da, chemical structure is shown below.
Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=830.52 Da; Obs. [M+Na+]=830.47 Da.
15.0 grams of Desmodur N 3600, 7.09 grams of 1-(2-methylaziridin-1-yl)propan-2-ol, 8.21 grams of a poly(ethylene glycol) monomethyl ether with an average Mn of 1000 Da, 112 grams of dimethylformamide were charged to a reaction flask equipped with a thermometer. The mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere. The mixture was than heated to 50° C., 0.03 grams of dibutyltin dilaureate was added and after 15 minutes the mixture was heated further to 70° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no NCO-stretch at 2200-2300 cm−1 was observed. The solvent was removed in vacuo to obtain an opaque highly viscous liquid. The calculated molecular weights of the theoretical main components were 849.57 Da (three aziridines) and 1735.07 Da (two aziridines, 22 EG repeating units), chemical structures are shown below.
