II. Analysis of Core Preparation Processes
Currently, the mainstream process for industrial production of PAM dry powder is the aqueous solution polymerization method. This process includes monomer preparation, polymerization, hydrolysis, granulation, drying, crushing, and screening.
1. Ultra-High Molecular Weight Control Technology
To achieve the required molecular weight of over 20 million for oil displacement applications, the polymerization conditions must be strictly controlled during synthesis. Modern processes typically employ a complex initiation system, utilizing the synergistic effect of redox initiators and azo initiators to initiate polymerization under low-temperature (10-25°C) adiabatic conditions. This slow, low-temperature polymerization helps form longer molecular chains, thereby significantly increasing the molecular weight.
2. Copolymerization and Hydrolysis Processes
For specific applications, such as high-temperature and high-salinity reservoirs, homopolymers of acrylamide alone are insufficient. Advanced production technologies currently use molecular structure design, introducing specific functional monomers and controlling their micro-sequence structure on the molecular chain to produce temperature-resistant and salt-tolerant products. Additionally, anionic polyacrylamide can be produced through the pre-alkalization co-hydrolysis process, giving the product better chain extension and flocculation performance.
3. Development of Fast-Dissolving Products
Traditional PAM powder has issues with slow dissolution speed and a tendency to clump (commonly known as “fish eyes”). To solve this problem, the key to developing fast-dissolving products lies in improving the later-stage physical processing techniques. By adjusting the drying and crushing processes to control the particle size distribution and specific surface area of the product, it can rapidly disperse and swell in water. The dissolution time for some fast-dissolving products has been shortened to less than half an hour.