The synthesis of polyvinyl chloride PVC from vinyl chloride monomer VCM is typically carried out through a polymerization process called suspension polymerization. The optimum conditions for this process depend on various factors, such as the type of catalyst, the desired molecular weight of the PVC, and the specific requirements of the final product. However, some general guidelines can be provided.1. Temperature: The optimum temperature for the polymerization of VCM to PVC is typically in the range of 40-60C. At lower temperatures, the reaction rate is slower, leading to longer reaction times and lower yields. At higher temperatures, the reaction rate increases, but the risk of side reactions and thermal degradation also increases, which can negatively affect the properties of the final product.2. Catalyst concentration: The catalyst used in the polymerization of VCM is usually an initiator, such as an organic peroxide or an azo compound. The concentration of the catalyst affects the reaction rate and the molecular weight of the PVC. Higher catalyst concentrations lead to faster reaction rates and lower molecular weights, while lower concentrations result in slower reaction rates and higher molecular weights. The optimum catalyst concentration depends on the desired properties of the final product, but it is typically in the range of 0.01-0.1 wt% of the VCM.3. Reaction time: The reaction time required for the synthesis of PVC depends on the temperature, catalyst concentration, and the desired degree of polymerization. Generally, the reaction time is in the range of a few hours to several days. Longer reaction times can lead to higher yields and higher molecular weights, but they also increase the risk of side reactions and thermal degradation.Changing these parameters can affect the yield and properties of the final PVC product in various ways:- Increasing the temperature or catalyst concentration can increase the reaction rate and yield, but it can also lead to a lower molecular weight and potentially poorer mechanical properties.- Decreasing the temperature or catalyst concentration can result in a higher molecular weight and better mechanical properties, but it may also lead to longer reaction times and lower yields.- Adjusting the reaction time can help to control the degree of polymerization and the molecular weight of the PVC, but it should be balanced with the risk of side reactions and thermal degradation.In summary, the optimum conditions for the synthesis of PVC from VCM depend on the specific requirements of the final product and the type of catalyst used. By carefully adjusting the temperature, catalyst concentration, and reaction time, it is possible to achieve the desired yield and properties for the PVC product.