Trimerization of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) - RAPID COMMUNICATION
Polimery 2001, No 2, 131
Trimerization of IPDI was studied in relation to catalyst type and reaction temperature. 2,4,6-tris(Dimethylaminomethyl)phenol (DMP-30), potassium acetate (K 64), 1,4-diazabicyclo[2.2.2]octane (DABCO), tetrabutyl orthotitanate (TBT), and a DMP-30/K 64 binary system were used as catalysts (used in 1, 2 or 5% based on IPDI weight). When dissolved in butyl acetate and stirred for 1 h at 80 °C with 5% of DMP-30, IPDI yielded a trimer melting at 286-289 °C (Table 1). The most active catalyst was K 64 (added 1 % by wt., as a solution in ethyl acetate containing 15% of K): in 1 h at 80 oC, a trimer was obtained in 98% yield. TBT (1%, 5%), DMP-30 (1%), DABCO, and K 64 (1%, 23°C) proved to be inactive as catalysts. In the binary system studied, the DMP-30 was found to inhibit the catalytic action of the K 64 consistuent.
Keywords: diisocyanate, trimerization, trimerization catalyst, isophorone diisocyanate (3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate)