One potential solution to minimize solvent usage and reduce energy consumption is performing solvent-free enzymatic synthesis in bulk. However, it is important to note that this approach also has certain limitations. The mild reaction temperatures required for enzymatic catalysis can lead to high viscosity and reduced fluidity within the reaction medium, making it difficult for reactants to move and hindering the progression of the reaction. Therefore, this method may only be successful when the synthesized polyesters have relatively low melting points, ensuring that the products remain molten during the reaction while preserving enzyme activity. Additionally, according to literature data, enzymatic synthesis in solvents such as diphenyl ether often yields materials with higher molecular weights, making this procedure preferable in many cases . While the bulk polycondensation method, compared to polycondensation in solvents, exhibits a lower E-factor, indicating reduced material consumption, energy requirements, and waste generation, it is crucial to ensure that the final product meets the required specifications. Therefore, the synthesis routes need to be evaluated not only from an environmental standpoint but also in terms of the quality and performance of the resulting material.