Visualization study on the dry devolatilization characteristics of styrene-butadiene-styrene block copolymers

Dry devolatilization is a promising method for saving energy, but understanding the devolatilization process has been challenging. A static devolatilizer was designed to study the devolatilization process of a Styrene-butadiene-styrene (SBS) block copolymer solution at different temperatures using visualization technology. The study found that temperature, Reynolds number, and heat flux are key factors influencing the devolatilization process. The optimal residence time was determined to be 196 s and the suitable feed coefficient is 0.17. Additionally, a new dimensionless parameter (the LZ number) was introduced. A value closer to 1 indicated a more effective devolatilization process. The obtained thermodynamic parameters and LZ number can guide the design of industrial devolatilization devices.