Abstract: A preparation method for a salt-spray-resistant polyaspartic acid ester includes mixing polyaspartic acid ester, cardanol resin and a catalyst together for transesterification reaction, and controlling a temperature at 100-130° C. and a relative vacuum degree at ?0.095 MPa-?0.1 MPa, and stirring for reaction for 2-5 h to obtain the salt-spray-resistant polyaspartic acid ester; in particular, a molar ratio of the polyaspartic acid ester to the cardanol resin to the catalyst is polyaspartic acid ester:the cardanol resin:the catalyst=1:0.1-0.3:0.001-0.003, and the catalyst is tetraisopropyl titanate or dibutyltin oxide.

Abstract: The present disclosure discloses a contact angle measuring device, including a light source, a container, a photodetector, a bubble generating unit, and a processing unit. The container includes a first and a second side walls that are opposite. The first side wall is made of a light-transmitting material, the container is filled with a liquid with light transmission inside. The monochromatic light emitted by the light source passes through the first side wall and enters an interface between the first side wall and the liquid. The bubble generating unit is configured for generating a bubble that is in contact with an inner surface of the first side wall. The photodetector is configured for detecting light intensity distribution of the monochromatic light through the liquid.

Abstract: The present disclosure discloses a contact angle measuring device, including a light source, a container, a photodetector, a bubble generating unit, and a processing unit. The container includes a first and a second side walls that are opposite. The first side wall is made of a light-transmitting material, the container is filled with a liquid with light transmission inside. The monochromatic light emitted by the light source passes through the first side wall and enters an interface between the first side wall and the liquid. The bubble generating unit is configured for generating a bubble that is in contact with an inner surface of the first side wall. The photodetector is configured for detecting light intensity distribution of the monochromatic light through the liquid.