Study on water-borne polyurethane modified with two-hydroxypropyl-terminated polysiloxane for wood coatings

The block copolymer of water-born polyurethane and polysiloxane was synthesized by IPDI,PCDL,DMPA,HO-PDMS and other materials. A series of structure testings were done for the modified aqueous polyurethane. And through the comparison of performance between modified and unmodified emulsions,the HO-PDMS can markedly enhance the water resistance of the polyurethane. When the mass content of the HO-PDMS is at 3%,the modified films display well performance,but hardness decreased slightly.