Preparation And Research Of Superhydrophobic Coatings Based On Long Chain Alkyl Compounds

The water repellency of superhydrophobic coating makes it have good application prospects in self-cleaning,antibacterial,moisture-proof,oil-water separation and so on.As people pay more and more attention to the environmental problems,the green environmental degradable packaging is becoming a development trend.At present,paper packaging materials have the problem of poor moisture resistance and poor water resistance,and the application of superhydrophobic coating on the surface of paper packaging can effectively improve the above problems,endowing the hydrophilic materials with moisture resistance and water resistance.In this study,safe low-surface energy long-chain fatty acid substance—stearic acid is used to prepare superhydrophobic coating with good adhesion,and AKD superhydrophobic coating was prepared by all-water based process.The application of moisture-proof packaging paper prepared by superhydrophobic coating is studied,which expands the research practice of such superhydrophobic coating.The main contents and research results are as follows:(1)Micro-nano crystallization coarse microstructure of stearic acid/shellac/ethyl cellulose(STA/Lac/EC)superhydrophobic coating is prepared,induced by solvent evaporation.Single factor and orthogonal test are done to obtain the optimal formula and technology of the coating,which is 3 wt%stearic acid,4 wt%Lac,1 wt%ethyl cellulose,and 50?drying temperature,the contact Angle of the coating is 153.1°,sliding Angle is 6°,delimit fork method of adhesion of grade 4,which can be used in a variety of substrate surface.The coating has good stability.After a long time storage,its hydrophobicity remains unchanged,and it has hydrophobicity stability within the pH range of 1?7.It can withstand water immersion for 10 days and maintain superhydrophobicity.The water contact angle was maintained above 140°after 120 min water impact.(2)The AKD water-based superhydrophobic coating was prepared by sacrificial template method.Na Cl and Zn O nanoparticles were used as template particles,and the superhydrophobic coating was obtained by removing micro and nano particles from the AKD coating after pickling.When applied to the surface of paper substrate,the water contact Angle of the coating can reach 152.2°and the sliding Angle can reach 8°,which achieves superhydrophobicity.The superhydrophobicity of the coating is stable after long-term indoor storage,and the pH of the coating is stable within the range of 4?13.After the coating is immersed in water,the contact Angle decreases with the increase of soaking time.(3)Explores the STA/Lac/EC super hydrophobic paper wet moisture resistance performance and storage effect of jackfruit dried fruits and biodegradability,found that the moisture resistance of wet sex is better than that of uncoated paper,waxed paper,water vapor transmittance is 24.5g/(m~2·24h),the jackfruit dried fruit packing after 20 days of storage in high humidity environment,moisture rate was 2.5%,the hardness fell by 15.8%,the sensory quality changes is small,which is expected to be used for short-term bulk vegetables dry food packaging.Degradation test shows that the degradation half-life of STA/Lac/EC superhydrophobic coating paper is 113 days,which means that it is biodegradable.