Preparation And Application Of The Anti-Crease Finishing Agent With Non-Formaldehyde And Low Strength-Loss

In general traditional anti-crease finishing agent is mainly N-hydroxymethyl reactive system. Formaldehyde will be released during the finishing process and even in the course of the storage and wear of the cotton fabrics treated with them.It not only pollute environment,but also do harms to the people's health.At the same time the strength loss of these cotton fabrics is serious. Waterborne polyurethane agent is a kind of promising and green anti-crease finishing agent because of its non-formaldehyde and low strength loss.In this thesis,series of waterborne polyurethane(WPU)were successfully prepared by pre-polymerizing-extending-blocking-dispersing etc.with polyol,isophorone diisocyanate(IPDI), dimethylolpropionic acid(DMPA)and other raw materials.The occurrence of polymerization was proofed by FTIR and DSC.The effects of synthesis process,different materials, DMPA content,the extent of neutralization and different blocking agents on WPU properties had been studied.Blocking process by NaHSO₃ had been investigated,the agent with good dispersion had been prepared,WPU formula had been optimized by application tests.The results showed that:The conditions were appropriate when the pre-polymerizing temperature was 95℃,the pre-polymerizing time was 4h,the neutralization temperature was 50℃.Neutralization could help to carry out the reaction after the completion of pre-polymerizing.DMPA mass fraction should be around 5.5 percent and the extent of neutralization should be 90%to 100%.The deblocking temperatures of the products with NaHSO₃ and MEKO were about 60℃and 120℃respectively. When the amount of ethyl acetate was 25%of prepolymer,W_NaHSO3/ W_H2O was 10%and ethanol volume was about 50%of solvent,the blocking efficiency was high.The WPU was suit for anti-crease finishing when the molecular weight of polyether diols was 1500,nNCO/nOH was 2.4,nNCO/nNH₂ was 2.6.The finished cotton fibers had been analyzed by FTIR and EMS and the process of WPU anti-crease finishing had been studied.The main results obtained were as follows:A certain extent chemical cross-linking occurred between WPU and cellulose.The wrinkle recovery angle(WRA) of the finished cotton fabric with WPU increased more than 65°and the strength retention rate reached 90%,other properties had no effect when the concentration of finishing agent was 130g/L, curing conditions was 160℃/3min.It was appropriate that the recruitment of WPU was 40g/ L and increase the WRA and strength retention of the finished fabric.The WPU prepared proved to be an excellent non-formaldehyde and low strength-loss anti-crease agent and would have great potential in market in future.