Polyvinyl Chloride, also known as vinyl, is a cheap and flexible thermoplastic polymer that has numerous applications in the construction industry. It is used to make a wide variety of products, including window and door profiles, water and sewage pipes, cable insulation, medical equipment, and many other things. In terms of volume, it is only surpassed by polyethylene and polypropylene as the third most common thermoplastic.
Simple PVC Structures
Flexible and rigid varieties of polyvinyl chloride pvc film are commercially available. However, there are other variations, such as CPVC, PVC-O, and PVC-M. The physical properties of bi-axially orientated PVC are improved like stiffness, etc.
PVC that has been PVC (Density: 1.1-1.35 g/cm3): To create flexible PVC, PVC is combined with plasticizers that reduce its crystallinity, making the material more malleable. These plasticizers function similarly to lubricants, making the final plastic much more transparent and malleable. It’s possible you’ve heard this PVC referred to as PVC-P.
Hard, or unplasticized, PVC
Rigid PVC has a strong resistance to impact, water, weather, chemicals, and corrosive conditions, and it is also quite inexpensive. You may also hear it referred to as UPVC,or uPVC. In order to create it, PVC-amorphous U’s structure is reorganised into a layered one. The physical properties of bi-axially orientated PVC are improved like stiffness, fatigue resistance, lightweight, etc.
To make it, PVC resin is chlorinated. Superior strength, chemical stability, and fire resistance are the results of a high chlorine content. CPVC has a greater temperature tolerance than other plastics. PVC-O, or oriented polyvinyl chloride, is a novel type of PVC.
Vinyl chloride (PVC-M)
It’s a PVC alloy with increased toughness and impact resistance thanks to the use of modifying chemicals. The chlorine content of chlorinated polyvinyl chloride (CPVC) is increased from 56% to roughly 66% throughout production. The attractive forces between PVC’s molecular chains are
Chlorination of ethylene and subsequent pyrolysis of the resulting EDC in a cracking unit yields vinyl chloride monomer (VCM). Polymerization of vinyl chloride monomer results in PVC, which has a glass transition temperature of 70°C. Suspension PVC is one of the more used commercial PVC production processes. Powder or Liquid (E-PVC)
Process of Suspending Polyvinyl Chloride (S-PVC)
The monomer is combined with the polymerization initiator and any other necessary ingredients in a pressurised reactor. The PVC resin is kept in suspension and of consistent particle size by continuously stirring the contents of the reaction tank.
To achieve this, the vinyl chloride monomer is dissolved in water with the use of surfactants (soaps). Soap micelles serve as a protective barrier for the monomer during polymerization with water-soluble initiators.
Improvements to PVC Properties
The polymerization process results in PVC resin with low temperature stability and high melt viscosity, making it very unstable. Before it can be used to make completed goods, it must undergo some sort of transformation. Some of the additives that can be used to improve or alter its qualities are heat stabilisers, UV stabilisers, plasticizers, impact modifiers, fillers, flame retardants, colours, and so on.