Published July 2024
Polyvinylidene fluoride (PVDF) is one of the most widely used fluoropolymers available today. It is frequently employed as membrane and binder materials, and in pipes and cables. PVDF is now being investigated for its use in wastewater management, chemical engineering, biomedical research, and batteries. Because of its exceptional physicochemical qualities, PVDF is used in a majority of developing technologies. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is a copolymer formed by the emulsion polymerization of vinylidene fluoride (VDF) with hexafluoropropylene (HFP). The insertion of the HFP group in VDF polymer improves its characteristics since the fluorine segment is hydrophobic and has a low polarity. PVDF-HFP has higher solubility (particularly in organic solvents), hydrophobicity, mechanical strength, a lower glass transition temperature, reduced crystallinity, and a higher free volume than PVDF.
This study covers the semibatch emulsion polymerization process of PVDF-HFP copolymer, which is obtained from VDF with comonomer HFP, in an aqueous medium containing a non-fluorinated surfactant. Usually, an aqueous medium is used in a semibatch emulsion or suspension polymerization process to convert VDF into PVDF. A free-radical initiator, a fluorinated surfactant (such as ammonium perfluoro decanoate), and a chain transfer agent (CTA) are used in the polymerization operations. Fluorinated surfactants are stabilized compounds that are often costly and have a high degree of environmental persistence due to their high stability. Fluoroalkyl surfactants are resistant to chemical breakdown, and therefore, may build up in the environment and in living things. Additionally, the surfactant's high degree of fluorination prevents atoms from transferring from the surfactant to a developing polymer chain during polymerization, which will likely inhibit the reaction and lower the product's molecular weight.
This review addresses the technical and financial aspects of producing commercial-grade PVDF-HFP copolymer with a capacity of 22.05 MMlb/y (10,000 t/y) using the emulsion copolymerization of VDF with HFP (7.2 wt%). The process flow diagram, material balance, major equipment list with specifications, cost information for battery limits and offsites, variable costs, capital expenditure (capex) and operating expenditure (opex), the levelized cost of electricity (LCOE), and total production cost are included in this assessment. Process Economics Program (PEP)'s independent interpretation of the commercial process, based on data from publicly available sources, including technical articles and patents, is the basis for the economic evaluation provided in this review. It may not accurately depict the actual plant layout, either whole or in part.