& nbsp Polyvinylidene fluoride (PVDF) resin mainly refers to the homopolymer of vinylidene fluoride or the copolymer of vinylidene fluoride with a small amount of fluorinated vinyl monomers, the relative density is 1.77-1.80g/cm3, the relative molecular weight is 40-800000, the melting point is 172-180 ℃, the thermal decomposition temperature is 350 ℃, the processing temperature from melting point to decomposition temperature is wide, the processing temperature is low, and the repeat units-CH2-CF2-,CH2- and CF2- units are arranged alternately. It has the characteristics of both fluorine resin and general resin, not only has good chemical corrosion resistance, high temperature resistance, oxidation resistance, weather resistance, ultraviolet resistance, radiation resistance, but also piezoelectric, thermoelectric and other special properties. At present, PVDF has become the second largest fluoroplastic only in polytetrafluoroethylene (PTFE), and has excellent properties different from other fluorinated resins represented by PTFE. It is widely used in chemical, electronic, electrical, architectural, military and other fields. It is a kind of thermoplastic engineering plastics with excellent comprehensive properties and various applications.
PVDF application
PVDF is mainly used in petrochemical, electronic and electrical and fluorocarbon coatings. It can be used as solar backplane membrane, filter membrane, wire, cable, pipeline, battery adhesive, coating and so on. Because of its good chemical resistance, processability and fatigue and creep resistance, it has incomparable advantages over other fluororesins in chemical corrosion protection. It is one of the best materials for pumps, valves, piping, pipe fittings, storage tanks and heat exchangers in the whole or lined fluid processing system of petrochemical equipment, and the equipment can meet the requirements of TOCS and flame retardant, so it can be used for the storage and transportation of high-purity chemicals in the semiconductor industry. PVDF is mostly used in the following aspects:
PVDF fluorocarbon paint
PVDF fluorocarbon coating can form a protective coating with excellent performance after curing at high temperature. the coating has the advantages of weather resistance, color retention, impact resistance and corrosion resistance. it can be used outdoors for a long time without maintenance. it is an ideal protective material and is widely used in metal materials in harsh environment, such as building exterior wall decoration, subway, chemical production area and so on.
Positive binder for lithium battery
PVDF has strong anti-oxidation and reduction ability, good thermal stability, and is easy to disperse in NMP solvent, so it is the best choice of positive binder for lithium battery. At the same time, it can also be used as battery separator material or coating layer to enhance the mechanical properties of the separator, enhance the liquid retention of the diaphragm to the electrolyte, and improve the high voltage stability of the diaphragm.
Hollow fiber membrane
PVDF can also be made into hollow fiber membrane with high packing density and high filtration precision, so it is widely used in drinking water treatment, printing and dyeing, food, medicine, sewage reuse and deep pretreatment of seawater desalination.
Photovoltaic backplane film
PVDF thin film has become the preferred material for photovoltaic backplane film because of its safety, reliability and good corrosion resistance, and its application in this field has been rapidly developed and widely recognized.
Market analysis
Affected by the demand of new energy vehicles, photovoltaic, 5G, lithium electricity market and other industries, PVDF and its upstream main raw materials R142b are in short supply in 2022, while the new capacity expansion time is long, the product technical barriers are high, the supply can not be effectively alleviated in a short time, and the price has been rising all the way. With the rapid rise of photovoltaic and lithium electricity market and the increasingly stringent wastewater discharge policy, the future market increment of PVDF is huge, and the major manufacturers have announced to expand production or build new capacity. Starting from the second half of 2022, with the gradual release of new production capacity and the cooling of the new energy industry, the PVDF market began to decline and PVDF prices began to return to rationality.
Under the background of the global "double carbon" goal and promoting the clean and low-carbon development of the energy system, photovoltaic power generation and power vehicles will be in a period of rapid development in the world, and the demand of PVDF in lithium batteries will continue to grow at a high speed. Source: Juhua shares