Preparation And Fixing Property Of Thermal Reactive Waterborne Polyurethane

In recent years,reactive dyes has been widely used in many kinds of fabrics because of its complete chromatography and low cost,but the dyed fabrics still have the problem of easy dye shedding or staining.In order to solve this problem,the dyed fabrics need to be treated with color fixation.Among them,waterborne polyurethane color fixing agent has the advantages of energy saving,environmental protection,safety and reliability,simple operation and so on,which is widely used in the dyeing treatment of fabrics.In this paper,according to the deficiency of the color fixing properties of the existing straight-chain polyurethane fixers,from the design of the molecular structure of polyurethane,the thermal reactive waterborne polyurethane with internal crosslinking structure and hyperbranched structure was prepared.By changing the type of hydrophilic chain extender,the thermal reactive waterborne polyurethane with different ion types was obtained.The influence of different variables in the formulation and preparation process on the color fixation property was investigated.Specific research contents are as follows:（1）Using IPDI and mixed PPG-1000/TMPEG-1000 as the main raw materials to synthesize the prepolymer,N-MDEA as the hydrophilic chain extender,TMP as the cross-linking agent,MEKO as the ending agent to synthesize the thermal reaction cationic waterborne polyurethane（TRCWPU）with internal cross-linking structure.The results show that when n（PPG-1000）:n（TMPEG-1000）is 8:2,N-MDEA dosage is 6%,TMP dosage is 3.5%,sealing rate is 50%,total R value is 1.17,the emulsion has good stability and moderate viscosity,the film feel soft and non-sticky,good water resistance.In this case,the tensile strength of the film is 1.58MPa,and the elongation at break can reach 1569%.The initial release temperature and thermogravimetric decomposition temperature of the film were 129℃and 244.5℃,respectively.The thermal stability of the film was good.When the emulsion dosage is 60g/L,the baking temperature is 160℃,and the baking time is 180s,the color fixation performance is better,and the dry and wet rubbing fastness of the dyed fabric is increased by 2 grades after the color fixation.（2）Using non-ionic polyol TMPEG-1000 as hydrophilic chain extender and TMP as cross-linking agent,a thermal reaction non-ionic waterborne polyurethane（TRNWPU）with internal cross-linking structure was synthesized by introducing different small molecule chain extenders.The results show that when 1,4-butaneglycol is used as small molecule chain extender,WTMP/WBDO=1:1,sealing rate 75%,R value is 1.3 before sealing end,R value is 1.06 after sealing end,the comprehensive performance of emulsion and film is good.After thermodynamic test,the initial unsealing temperature was 125℃,and the thermogravimetric decomposition temperature was 246.5℃.The thermal stability was good.When the emulsion dosage is 60g/L,the baking temperature is 160℃,and the baking time is 180s,the color fastness to dry friction of dyed fabric is increased by 2 grades and the color fastness to wet friction is increased by 1.5 grades.Moreover,the non-ionic color fastness has good color fastness in the p H range of 4～8.（3）With TMP as the"core",using the reaction functional group heteromonomer synthesis method（A₂+B₃）,IPDI,PTMG-1000,DMPA,MEKO as the main raw materials to synthesize thermal reactive waterborne polyurethane（TRHBWPU）with hyperoverrun structure.The results show that when n（IPDI）/n（TMP）=4.62,the sealing rate is 75%,the total R value is 1.08,and the amount of DMPA is 4%,the emulsion has good appearance and stability,and the film feel is hard.The tensile strength of the film was 3.01Mpa,and the elongation at break was 532%.The initial decapsulation temperature and thermogravimetric decomposition temperature of the film were 128℃and 273.7℃,respectively.The thermal stability of the film was good.When the emulsion dosage is 40g/L,the baking temperature is 140℃,and the baking time is 120s,the dry and wet rubbing fastness of the dyed fabric is increased by 2 levels after color fixing,but the feel of the fabric is decreased.