Synthesis Of Waterborne Polyurethane And Its Application In Anti-crease Finishing On Viscose Fabric

Viscose fabric has excellent performance in the application,however,it is difficult to Improve the anti-wrinkle properties because of its structure.Waterbome polyurethane was prepared with water as the dispersion medium.it was safe and environmental,good compatibility, and convenient to use.Fabric,which has been finished by waterborne polyurethane,will has good resilience and tensile properties for elasticity and toughness properties of waterborne polyurethane.Polyurethane’s elasticity properties could be changed by adjusting the polyurethane polymer structure.In this paper,series of waterborne polyurethane were prepared with IPDI,DMPA and dihydric alcohol by "pre-polymerizing, hydrophilic-extending, micromolecule-extending, water-extending,water-dispersing."process.The effects of different polyhydric-alcohols,polyol molecular weights,different dihydric alcohol and molar ratio of NCO/OH on waterborne polyurethane emulsion and adhesive film were investigated.Combined with waterborne polyurethane’s effect on viscose fabric crease resistant finishing,we determined the components of waterborne polyurethane which we needed in this paper.Then,we optimized the formulation and process of viscose fabric crease resistant finishing with the waterborne polyurethane.At last,we got a low formaldehyde nondestructive anti-wrinkle finishing agent which is compound with2D resin and waterborne polyurethane.The following was the specific research contents and results.Part l:The relationship between different structure and properties of waterborne polyurethane.Compared with PU prepared with PPG and polyester polyols,Emulsion of PU prepared with PTMG is more stable,its average particle size is smaller and its viscosity is lower. The latex film of PU with PTMG is softer and more tough.It is proved that the micro phase separation degree of PU prepared with PTMG is higher by TGA and DSC analysis.We found that,using DMA analysis,the micro phase separation degree of PU prepared with PTMG is high, but with the temperature increases, the micro phase separation degree reduced.With the increase of the molecular weight of PTMG, its average particle size is larger and its viscosity is higher.The latex film of PU with PTMG is softer and more tough. We found the structure of chain extender has little influence on viscosity,while it has some influence on average particle size,breaking strength and elongation at break of waterborne polyurethane.The less carbon of chain extension agent, the less the side chain, the smaller size of the side chain,the particle size of emulsions is smaller.The shorter the main chain of the chain extender, the neat structure, the strength of the polyurethane film is greater.We found r value increases, the average particle size of emulsion increases slightly.The viscosity of emulsions with excessed-OH is higher than emulsions with excessed-NCO,and it has little influence on the viscosity of emulsions when-NCO is excessed.The greater the r value, the polyurethane stress is greater.The smaller the r value,the creep of polyurethane is stronger.Part2:The determination of waterborne polyurethane components.Through analysing the effects of different structure of waterborne polyurethane on waterborne polyurethane performance and fabric wrinkle resistant finishing, we choose PTMG-1800as macromolecular polyol agent,PD-9as small molecule chain extension agent, and determine emulsion r value as1.3.Part3:The application of the waterborne polyurethane anti-wrinkle finishing agent is studied.The conditions were appropriate when concentration of finishing agent is90-110g/L,baking temperature is140℃,baking time is3min.The crease resistant finishing of viscose fabric using the complex of2D resin and waterborne polyurethane was researched while reducing.dosage of2D resin.We found the WRA of the finished viscose fabric increased nearly60°,fracture strength increased nearly20N and elongation at break increased almost15%.The results of project showed that aliphatic waterborne polyurethane prepared by Pre-polymers hybrid method with PTMG and IPDI as main monomers,DMPA as hydrophilic chain extender,PD-9as chain extender has high micro phase separation degree and excellent excellent performance.The crease resistant finishing of viscose fabric using the complex of2D resin and waterborne polyurethane was researched while reducing.dosage of2D resin.We found the WRA of the finished viscose fabric increased nearly60°,fracture strength increased nearly20N and elongation at break increased almost15%.Low formaldehyde nondestructive finishing agent has been realized basically.