Self-polycondensation reaction of polyurethane isocyanate

——CarbodiimideUnder organic phosphine catalyst and heating conditions, isocyanate can undergo self-condensation polymerization reaction. Compounds containing carbodiimino groups (—NCN—) are generated. This reaction is another important autopolymerization reaction besides isocyanate trimerization and dimerization. Organophosphine catalysts include 1-phenyl-3-methylphosphine-1-oxide (structural formula as follows), triethyl phosphate, triphenylphosphine oxide, etc. The pentacyclic phosphine oxygen type catalyst has good effect and…