Synthesis Of Environmental Friendly Waterborne Polyurethanes And Their Applications On Cotton Fabrics

Waterborne polyurethane is dispersible in water medium, which is environmental friendly and possesses the advantages of low volatile organic compounds (VOC) emission. So it has attracted increasing attention and is widely used in producing environment friendly agents of coating, textile finishing and so on. With the improvement of people's living standard, environmental friendly and multi-functional waterborne polyurethanes will become the main trend.Starting from BBMO, we designed and synthesized the Clickable monomers BAMO, BPMO and three fluorinated monomers FOx-C1/C3, AFOx-C1. Four kinds of co-polyether diols and four kinds of homo-polyether diols were obtained via ring-opening polymerization of these monomers and characterized by FT-IR, NMR and GPC.In this paper we modified the clickable polyether diols by introduction of phosphate-containing groups to give PEG1-DEP-C1, PEG1-DEP/DFP-C3 and PEG2-DEP/DFP-C1. Meanwhile, we obtained PEG1-POSS-C1 by grafting the POSS-A to clickable polyether diols. These modified polyether diols were characterized by FT-IR, NMR and GPC.These modified polyether diols were then condensed with IPDI to form waterborne polyurethanes CFPU-C1-E1, CPU-C1-E2, APU-C1-E3, AFPU-C1-E4, APU-C3-E6, APU-C1-E11 and APU-C1-E14 respectively. APU-C3-E8, APU-C3-E9, APU-C3-E10 and APU-C3-E12 were modified functionally at the hard segment by using BHPP as the chain extender. In order to improve the stability of the emulsions, we designed and prepared APU-C3-E5, APU-C1-E7-1, APU-C1-E7-2 and APU-C3-E10 which contained fluorinated polyether diols and PPG-2000 within the soft segment. These obtained waterborne polyurethanes have linear structures with solid content between 15～20%.In comparison with these linear polyurethanes, we started from trihydroxolethylamine to form the core structure and reacted with PEG1-POSS-Cl or PEG3-A-C1 to form hyper branched polyurethane APU-C1-E15 or APU-C1-E13. APU-C1-E13 was grafted further with perfluorohexyl group to give hyper branched polyurethane APU-F which had the highest content of fluorine.These emulsions were applied on cotton fabrics by pad-dry-cure process. The water-, oil-repellent and flame retardant properties of the treated cotton fabrics were then studied. Cotton fabrics treated with waterborne polyurethanes emulsions showed good water repellent properties with the contact angles of over 130°, and the one treated with polyurethanes containing POSS reached over 140°. However, only fabric treated with APU-F had good oil repellent property as rated in Grade 5, and others were showed no obvious oil repellent property. The polyurethanes containing phosphonate groups in both hard and soft segments possessed slight flame retardant properties with LOI over 20%. Fabrics treated APU-C3-E9 had LOI of 22.7%. Other polyurethanes showed no obvious flame retardant properties.