In recent years, people's awareness of environmental protection has been gradually strengthened. The environmental protection for the textile has become a focus of attention of producers and consumers. APEO content is an important indicator of environmental protection in international textile trade.

The types of environmental hormones produced by textile dyeing and finishing auxiliaries account for 37% of internationally recognized hormones. Among them, the content of alkyl phenol polyoxyethylene ether (APEO) is the highest in textile testing, ranging from 30 mg/kg to 100 mg/kg. At present, most of the raw materials used to prepare high temperature leveling agent contain APEO. Therefore, researchers have developed environmental friendly and high temperature leveling agent.

High-temperature leveling agents are divided into non-ionic high-temperature leveling agents, anionic high-temperature leveling agents and anion/non-ionic compound high-temperature leveling agents.

Non-ionic high-temperature leveling agent is mostly polyoxyethylene ether structure, and the polyoxyethylene ether chain segment has asymmetric amphiphilic structure, of which the ethoxy component has certain affinity to disperse dyes, binding with dyes in the dyeing process, which reduces the initial dyeing rate of the dyeing and achieves leveling purpose. For low cloud point non-ionic surfactants, dyes are easy to associate and coagulate at high temperature. Therefore, the non-ionic high temperature leveling agents are seldom used alone.

Anionic high-temperature leveling agent can form a strong negative charge layer on the surface of dye particles. Because of the strong electrostatic repulsion between charged dye particles, it can form a stable dispersion state. It has good dispersion and solubilization effect on disperse dyes, and can reduce the cohesion of dyes, and occupies a high proportion in the use of high-temperature leveling agent.

Anionic and nonionic complexes have synergistic effects and synergistic effects, which can improve cloud point, high temperature dispersion, solubilization and leveling. They are also commonly used in the preparation of high temperature leveling agents.