# Preparation of High-Performance Polyaspartic Polyurea and Application in Hydraulic Concrete Protection

## TL;DR

This study develops a high-performance polyurea coating that protects hydraulic concrete from water, chloride ions, and carbonation, showing great potential for infrastructure durability.

## Contribution

The novel design of PAE-PTMEG coating with tailored soft segments significantly improves reactivity, mechanical strength, and environmental resistance.

## Key findings

- PAE-PTMEG coating achieved high tensile strength (43.8 MPa) and elongation (646.1%) due to its microphase-separated structure.
- The coating showed excellent water resistance (<1% absorption) and exceptional chloride ion resistance (1.3 × 10−4 mg·cm−2·d−1).
- PAE-C paint demonstrated complete carbonation resistance and high frost resistance (200 cycles).

## Abstract

The long-term durability of hydraulic concrete infrastructure is severely compromised by water penetration, carbonation, and chloride ion erosion, necessitating the development of high-performance protective coatings. This study designed two polyaspartic ester polyurea coatings, PAE-PTMEG and PAE-PPG, derived from isocyanate prepolymers with polytetramethylene ether glycol (PTMEG) and polypropylene glycol (PPG) soft segments, respectively. The results demonstrated that the PTMEG-based prepolymer exhibited higher reactivity, leading to shorter curing times. The resulting PAE-PTMEG coating showed outstanding mechanical properties (tensile strength: 43.8 Mpa; elongation: 646.1%) and excellent water resistance (<1% absorption), attributable to its well-defined microphase-separated structure. When formulated into a practical paint (PAE-C), it surpassed mechanical standards for waterproofing and demonstrated exceptional resistance to chloride ion penetration (1.3 × 10−4 mg·cm−2·d−1), complete carbonation resistance, and high frost resistance (200 cycles). This work confirms that tailoring the soft segment structure is a crucial strategy for developing durable polyurea coatings, with PAE-PTMEG showing significant potential for protecting critical water conservancy infrastructure.