Synthesis Of Waterborne Fluorinated Polyurethane And Application In Waterpro Of And Breathable Fabric

Waterproof and breathable fabric is a kind of functional fabric with outstanding waterproofness,moisture permeable properties and ventilation properties. At present, the demand of waterproof andbreathable fabric is gradually increasing in market, owing to its excellent performance. Even inextreme conditions, waterproof and breathable fabric can resist the wind, rain and chemical reagentshaving adverse effect on the human body. At the same time, it also can have good air permeability.Furthermore its application is not limited to traditional military supplies and professional medicalprotective products, it can also use in daily life like outdoor leisure sports clothing. The traditionalwaterproof and breathable fabric has excellent performance of waterproof and windproof, but itsmoisture permeability is low, which leads to people’s discomfort feel for the clothing. Waterproofand breathable properties are both two important performances indexes of waterproof andbreathable fabric. Therefore, it has an important significance for develop waterproof and breathablefabric which has excellent waterproof performance and high moisture levels.Electrospinning has become widely applied technique to fabricate polymer fibers in diametersof tens of nanometers to micrometers. The advent of novel technique such as electrospinning mayraise the level of air permeability while maintaining the high level of water protection. But in theprocess will use a large amount of organic solvent, which will result in environmental pollution.Therefore, we use our synthesis waterborne fluorinated polyurethane to modify electrospun fibermembrane, and then has good waterproof and breathable permeability. The waterborne fluorinatedpolyurethane has advantages of two-phase microstructure of soft and hard segment structure andlow surface energy, heat hydrolysis resistance and other excellent properties. At the same time,because of the fluorinated chain segment is short, there is no bioaccumulation and biologicalmigration, and the degradation product is non-toxic harmless, which accord with the environmentalprotection development direction.The subject synthesis waterborne fluorinated polyurethane use TEOH-6, MDI, PTMG, DMPA and TEG as raw materials, and then pull-in fluorinated groups to the end of polymer chain. Wecharacterize the waterborne fluorinated polyurethane structure by FT-IR, NMR and study the effectof-NCO/OH content, hydrophilic and hydrophobic groups content on hydrophobicity, particle size,storage stability and thermal stability. The results show that waterborne fluorinated polyurethanehas good hydrophobic properties and best particle size stability, when-NCO/-OH is1.0, the contentof DMPA is8.0wt%and the content of TEOH-6is12wt%.Creating an efficient and cost-effective approach that can provide advanced microporousmembranes with high waterproofness and good breathability has proved to be an tremendouschallenging. This work responds to these challenges by designing, fabricating and evaluating anelectrospun polyacrylonitrile fibrous membrane which were modified with waterborne fluorinatedpolyurethane to achieve high waterproof and breathable performances. Polyacrylonitrile fibrousmembrane is hydrophilic nanofiber membrane, which cannot use as waterproof and breathablefabric. But through the waterborne fluorinated polyurethane modification, the pristinepolyacrylonitrile fibrous membranes possessed remarkable superhydrophobicity with an advancingwater contact angle of159°. At the same time, due to the introduction of fluorinated waterbornepolyurethane makes a large number of adhesion structure between adjacent fibers, changes the porestructure of polyacrylonitrile fiber membrane, which makes the modified polyacrylonitrile fibermembrane having excellent waterproof and moisture permeable properties. Furthermore, theresultant membranes could present a high waterproofness to83.4kPa, large water vaportransmission rate over9.2kg/m2/d, good air permeability over5.9L/m2/s, excellent mechanicalproperties of14.4MPa. Therefore, the modified fibrous membrane has great potential applicationsin protective clothing, biological separation, membrane distillation, tissue engineering,pharmaceutical engineering and other fields.