Synthesis and properties of polysiloxane graft waterborne polyurethane modified with α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane

Abstract

Abstract In this study, α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane was used to prepare waterborne polyurethane-polysiloxane graft copolymer dispersions. α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane was synthesized via hydroxyl protection, alkylation, anionic ring-opening polymerization, hydrosilylation, and deprotection. Waterborne polyurethane-polysiloxane graft copolymers were prepared by the reaction of poly propylene glycol (PPG), toluene diisocyanate (TDI), 2,2-dimethylol propionic acid (DMPA), 1,4-butanediol (BDO), and α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane. The water absorption of copolymer films decreased from 163.9 to 17.3% when polysiloxane content increased from 0 to 5%. The tensile strength of the copolymer films increased from 14.0 MPa to 26.3 MPa and decreased when polysiloxane content was more than 3%. The results revealed that the properties of waterborne polyurethane-polysiloxane graft copolymer dispersions and films were improved by grafting polysiloxane chains to polyurethanes.