Waterproofing and Anticorrosion Engineering Materials for Animal Husbandry Buildings Based on Polymer Modification

Premature failure of waterproofing layers is a critical issue in the aggressive corrosive environment of intelligent pig houses. To overcome this challenge, a novel multiphase composite waterproofing and anticorrosion system was developed. The system comprised aliphatic anionic waterborne polyurethane as the polymer matrix, emulsified asphalt as the flexible phase, and heavy calcium carbonate as the inorganic reinforcing phase. The structure–property relationship of waterborne polyurethane was systematically investigated, and the optimal stable state of anionic aliphatic polyurethane in manure solution was identified for the first time. Then, a “polyurethane–emulsified asphalt–heavy calcium carbonate” multiphase synergistic design strategy was proposed. The composite exhibited optimal performance when the polyurethane content was 15% and heavy calcium carbonate, which was introduced with a 1:1 ratio of 400- and 800-mesh particles, accounted for 20%–30% of the total mass. The bonding strength reached 1.35 MPa, and the material retained adequate performance after simulated corrosion testing. Microscopic analysis revealed that a synergistic barrier mechanism, which combined crosslinking densification, flexible buffering, and inorganic passivation, effectively blocked the penetration of corrosive media.