| abstract |
The invention discloses a lignin-based diphenylmethane diisocyanate and a preparation method and application thereof. The lignin-based diphenylmethane diisocyanate is shown in formula I, and its preparation method is lignin cracking monomer compound II Hydroxyalkylation with carbonyl compound to obtain compound III, compound III and chloroacetamide through amination reaction to obtain compound IV, compound IV through Smiles rearrangement reaction to obtain compound V, compound V and carbonic acid group-containing compound to obtain formula I Lignin-based diphenylmethane diisocyanate shown. The product of the invention is used for the synthesis of polyurethane material instead of MDI, and the toughness, thermal stability and glass transition temperature of the polyurethane material are improved; when used in the application of polyurethane waterproof coating, the water absorption rate is obviously decreased, and the stability of the coating is also improved. |