A PVC suspending agent is a type of polymer additive used during the suspension polymerization of vinyl chloride monomer (VCM) to produce polyvinyl chloride (PVC). Its main function is to stabilize the vinyl chloride droplets in the aqueous phase, preventing them from coalescing or settling before polymerization is complete. This ensures uniform particle size distribution and consistent resin quality, which is crucial for downstream processing and product performance. During the suspension polymerization process, VCM is dispersed in water using mechanical agitation. The suspending agent, typically a water-soluble polymer such as polyvinyl alcohol (PVA), methyl cellulose, hydroxypropyl methylcellulose (HPMC), or gelatin, acts as a protective colloid.