Synthesis And Application Of Waterborne Polyurethane Wet Rubbing Improving Agent

With regard to poor wet rubbing fastness of cotton fabric with reactive dyes,waterborne polyurethane dispersion was synthesized by neutralization emulsificationmethod, with isophorone diisocyanate(IPDI), polyether(polyethylene glycol1000andpolypropylene glycol1000),2,2-dimethylol propionic acid(DMPA),triethylamine(TEA) and diethylene triamine(DETA) as raw materials. Then,waterborne polyurethane wet rubbing fastness improving agent was prepared byadding epoxy chloropropane into waterborne polyurethane under certain conditions,and the application processes were optimized.The effects of the factors，such as content of raw materials and syntheticconditions on waterborne polyurethane dispersion and emulsion-cast film werediscussed in the synthesis of waterborne polyurethane wet rubbing fastness improvingagent. The results indicated that prepolymerization temperature and time are70℃and120min, chain extending temperature and time are75℃and150min, R value(molratio of-NCO/-OH)2.1, n(PEG-1000)/n(PPG-1000)1:1, DMPA3.5%(on weight ofprepolymer), neutralization degree100%, diethylene triamine5.24%(on weight ofprepolymer), epoxy chloropropane1.1(mol ratio to diethylene triamine), modifiedtemperature and time are70℃and90min, waterborne polyurethane wet fastnessimproving agent with good rubbing fastness was synthesized.The effects of the factors，such as processes of padding and dipping on dry andwet rubbing fastness, color fastness to water and color fastness to perspiration werestudied in the application of waterborne polyurethane wet rubbing fastness improvingagent, the processes were settled. The results indicated that dry and wet rubbingfastness enhances evidently of the cotton fabrics after treatment, especially the wetrubbing fastness which improves1.5~2grades, can basically reach the requirement ofindustrial production. Furthermore, the product provides better color fastness to waterand color fastness to perspiration.Analysis methods were utilized to test the structure, thermal perfotmance andvitrification temperature of waterborne polyurethane wet rubbing fastness improving agent, such as spectroscopic analysis (FT-IR), thermogravimetric analysis (TG),differential scanning calorimetry(DSC). The analysis of FT-IR indicated that thesynthesized product is just the waterborne polyurethane wet rubbing fastnessimproving agent. The analysis of TG indicated that the thermal degradation ofpolyurethane begins in260-280℃, the thermal stability is good. The scanningelectron microscope(SEM) indicated that continuous film is formed on the surface offabric with excellent washability. The test showed non-formaldehyde on the fabricstreated with waterborne polyurethane wet rubbing fastness improving agent.In this paper, waterborne polyurethane was modified with cation by introductingreactive radical, the dispersion is stable and the mechanical property of emulsion-castfilm is good, the product is nontoxic and enviromental production. When applied tothe cotton fabric dyed by reactive dyes, dry rubbing fastness reaches more than4grades, while wet rubbing fastness reaches3~4grades with excellent washability.This research is theoretical significant to productive practice.