Synthesis and properties of polyether-polyester mixed waterborne polyurethane

A series of polyether-polyester mixed waterborne polyurethane(WPU) dispersions were synthesized from hexamethylene diisocyanate(HDI),poly 1,4-butylene adipate(PBA),polypropylene oxide glycol(PPG),dimethylolpropionic acid(DMPA).The effects of the polyester /polyether ratio and molecular weight on the properties of waterborne polyurethane emulsion and mechanical properties were discussed.Results indicated that with the increase of polyester content in the soft segment,the strength of polyurethane film increases,and polyurethane film with the soft segment containing pure polyester or polyether exhibits better elongation ratio.The tensile strength of polyether polyurethane film decreases as the molecular weight of soft segments increase,but the tensile strength of polyester polyurethane film increases.