Synthesis And Application Of Anion Aqueous Polyurethane Anti-Pilling Agent

With the development of knitted products,the level of the request has been improved, specially the quality of products.Particularly in recent years,the knitwear,which is comfortable, natural,recreational and anti-pilling,is in many consumers’ good graces.So,great attention is paid to the study of wearing and fabric quality by the workers of dyeing and finishing.Anion waterborne polyurethane is dispersible in water medium,which has hydrophilic groups in the molecular chain,with strong affinity for water.Not only it has the excellent properties of solvent-borne polyurethane with good low temperature resistance,great adhesion,as well as outstanding toughness combined with energy conservation,environmental friendliness,and good film-forming breathability.In this paper,a variety of anionic waterborne polyurethanes with different structures were prepared and applied to improve the anti-pilling quality and the hand feeling of finishing fabrics. The stable aqueous polyurethane was prepared based on anionic self-emulsified process.The APU-1 were prepared using different types of polyols and 2,4-toluene diisocyanate(TDI). Reaction conditions such as the ratio of raw materials,reacting temperature,and reacting time were investigated.The influence of the addition method and dosage of the extending agent,the extending reaction temperature,and the degree of neutralization with acid on the properties of APU-1 dispersion,were also investigated.The results showed that firstly,the different structures of polyesterols resulted in different properties of polyurethane,such as particle size,viscosity of emulsions,tensile strength of films.Secondly,the phrase compatibility of soft-segments and hard-segments was improved when the contents of hard-segments increased by elevating the ratio of -NCO/-OH and the dosages of DMPA and extender.Thirdly,the average particle size of the anionic aqueous-based polyurethane dispersions increased with an increasing molar ratio of -NCO/-OH groups,decreasing DMPA content,or increasing degree of neutralization.Preparation worked out the best conditions:the anion waterborne polyurethane prepolymer was synthesized with polyether 3050、2,2-dimethylol propionic acid and 2,4-Diisocyanatotoluene for two and a half hours at 80℃.Then the prepolymer was terminated at 5℃with sodium bisulfite,regulated pH with triethylamine,the anion waterborne polyurethane emulsion was prepared.The products were used solely to improve the anti-pilling quality of knitted fabrics.The effects of the amount of APU-1,heating temperature,heating time and the soaking temperature、time、pH Value were also discussed.The pilling is greatly reduced when the fabric is done by APU-1,and it is flexible,strong sense of hair,soft,smooth,and wear-resistant,the effect of anti-pilling improves from grade 1.5 to grade 4.Finally,electron microscope scanning of the anti-pilling viscose knits indicates that there is polymer deposition on the surface of the fibers, gel-coated film,which makes relative sliding lower between fibers.These means the APU-1 can form a thin layer on fiber surface which with great scratch-resistance,high tensile strength,good elasticity and a certain hydrophilic property.This layer can also strengthen the adhesion between fabrics and improve the anti-pilling quality of wool knitted fabrics.Meanwhile, this agent also has an antistatic effect,which can improve the anti-pilling quality of the fabrics.