Synthesis of low free TDI trimer Toluene diisocyanate (TDI) can undergo trimerization under catalytic action to form trimers containing isocyanurate rings. TDI trimer has the advantages of low volatility, low toxicity, high functionality, good thermal stability, good corrosion resistance, etc. It is often used as a polyurethane curing agent in coatings and adhesives. In the...