Synthesis, Modification Of Dimer Acid Diisocyanate And It's Application On Fabric Finishing

Dimer fatty acid diisocyanate (DDI) has low toxicity, low vapor pressure and insensitive to water. When used as the material of polyurethane coatings and textile auxiliaries, it can supply the good weather resistance, abrasion resistance and aging resistant property. In this dissertation, using dimeric fatty acid, sodium azide, triphenylphosphine and N-chloro succinimide as raw material, DDI was synthesized via staudinger rearrangement reaction. The structure of DDI was confirmed by FT-IR, 1H NMR and MS. The purity of the product was identified by isocyanate value test to be more then 11.5.DDI were terminated with oxime compounds and the reaction was monitored by FT-IR . The terminated DDI was emulsified and applied on cotton fabric finishing. The application results showed that the finishing agent can afford good water repellency with the level of water repellent reached level 3, the surface contact angle reached 111.0o and 113.1o respectively, and softness grade reached level 2. The water repellency of fabrics remained unchanged after ten times of washing, which indicated the finished fabric had good washing fastness.Using amino silane coupling agent as modification reagent, DDI was modified. The structure of products was confirmed by FT-IR. The amino-silane modified DDI were applied on cotton fabric finishing and the comprehensive performance were determined through application experimental. The results showed that the finished fabrics have good water repellency, the level of water repellency reached level 3, and the strength of finished fabrics improved about 20%.The pre-polymer was prepared by dimeric fatty acid diisocyanate (DDI), polyether polyol, dimethylol propionic acid (DMPA) using methyl ethyl ketone pre-polymer process. The aliphaic waterbome polyurethane emulsion (PU emulsion) was prepared in the present of emulsifier, and the products were applied on cotton fabric finishing. The finished fabrics have good softness and wrinkle resistance with the level of softness reached level 4, the wrinkle recovery angle of cotton fabrics increased from 170.1o to 260.6o.