The invention relates to a preparation method of waterborne
polyurethane capable of selfreparing. The preparation method includes the steps that hydrophilic chain
extender is added to dihydric
alcohol, heating for
dehydration is conducted under a vacuum condition, the mixture is cooled to 70-85 DEG C, diisocyanate is added, stirring is conducted for a reaction, then the temperature is cooled to 50-55 DEG C,
butanone is added, then a catalyst and the chain
extender containing disulfide bonds are added, a reaction is conducted for 0.5-3 hours, then the temperature is cooled to 30-35 DEG C, neutralizer is added, then the mixture is cooled to 20-25 DEG C,
distilled water is added, the mixture is stirred till
emulsion and dispersion are achieved, ethidene
diamine is added, chain extension is conducted for 0.5-1 hour, the
butanone is removed, vacuum defomaing is conducted, and waterborne
polyurethane capable of being self-repaired is obtained. The waterborne
polyurethane prepared through the method can be self-repaired under the heating condition, the required condition is mild, the repairing effect is good,
emulsion dispersion stability is good, operation is simple, and environmental friendliness is good.