Structure and properties of new aqueous dispersion polysiloxane-polyuretane copolymers

A series of new aqueous dispersion polysiloxane-polyurethane (DHPDMS-PU) copolymers using dihydroxybutyl-terminated polydimethysiloxane (DHPDMS) as the part of soft segment were synthesized. Analysis of FT-IR and NMR shows that DHPDMS has been incorporated into the copolymer chains. It is found that siloxane segment transferred to the film surface, introduced the increase of siloxane content and brought the good surface property by comparing the transmitted FT-IR with ATR spectra. With the increase the DHPDMS content, the water contact angle of DHPDMS-PU film increases while the surface free energy decreases. When the content of DHPDMS is over 7%, the contact angle tends to a constant gradually. The results also indicate that the content of hydrogen bonded N-H decreases with the increase of DHPDMS.