Synthesis And Application Of Modified Waterborne Polyurethane Fixing Agent

In recent years,the demand for synthetic leather has been increasing,and the pursuit of quality has been continuously improved.However,the color fastness of dyed synthetic leather,especially poor wet rubbing fastness,often requires the use of color fixing agents for finishing.The study found that waterborne polyurethane(WPU)has a good effect on the fixing of dyed synthetic leather,which can effectively improve the rubbing fastness and discoloration of synthetic leather,and WPU has the advantages of non-toxic,green and environmental protection.Therefore,The research and development of WPU type fixing agent has a good broad application prospect and economic benefits.In this thesis,with polypropylene glycol(PPG-1000)and hexamethylene diisocyanate(HDI)as the main raw materials,and cationic and anionic WPU emulsions without organic solvents were prepared respectively.Orthogonal experimental design method was used to investigate the factors influencing the performance of WPU fixing agent.The effects of baking temperature and baking time on the fixing effect were discussed,a better synthesis and fixing process was explored.The study found that the performance of anionic WPU is better than that of cationic WPU.When epichlorohydrin(ECH)is an anionic WPU modified by an end-blocking crosslinking agent and its dosage is 92%,it can improve the dry and wet friction of PU leather by 2 grades.When the amount of hydrophilic chain extender is 5% and the mass mixing ratio of dimethylol propionic acid(DMPA)and dimethylol butyric acid(DMBA)is 1: 3,it can be improved PU leather dry rubbing fastness grade 2 and wet rubbing fastness grade 2 ? 3.Organic fluorine(F-HDIT)modified WPU,when the dosage is 7.5%,fixing PU leather,dry rubbing fastness increased by 2 ? 3.The wet rubbing fastness is improved by 3.