Polyvinyl Chloride (PVC)
The only major polymer that starts to destroy itself below its own processing temperature. PVC resin is never used as it arrives — it is a formulation ingredient, and the stabiliser is what makes it a material at all.
Molecular Structure
What is Polyvinyl Chloride (PVC)?
PVC is polymerised vinyl chloride — a carbon backbone with a chlorine on every second carbon. Those chlorines make the polymer polar, which gives it unusual compatibility with plasticisers, and they make it inherently flame-retardant, which is why cable and building applications favour it. Chlorine also accounts for 57% of the mass, so PVC is the only major polymer that is mostly not made from oil.
It arrives as a white powder rather than pellets, and it is never used neat. Every commercial PVC is a compound: resin plus heat stabiliser, lubricant, filler, impact modifier, pigment, and for flexible grades a plasticiser at anything up to half the total mass. Two products made from the same resin can have almost nothing in common.
The resin itself is specified by K-value, a viscosity measurement in dilute solution that tracks molecular weight. Low K-values flow easily and suit injection moulding and fittings; middle values go to pipe and profile; high values give the mechanical performance needed for flexible cable and paste applications. Suspension resin covers most of the market, with emulsion resin serving pastes and coatings.
PVC begins losing hydrogen chloride at temperatures below where it can be processed, and the HCl released catalyses further decomposition — the reaction accelerates itself. Without a heat stabiliser the polymer degrades in the extruder before it forms a part. No other commodity polymer depends on an additive this absolutely.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
A carbon backbone carrying a chlorine on every second atom. Those chlorines make the polymer polar and largely amorphous, give it inherent flame retardance, and provide the site from which hydrogen chloride is lost when the material is heated.
Chain architecture — chlorine on every second backbone carbon
Structural Identity
- PolymerPolyvinyl chloride
- Repeat unit(C₂H₃Cl)ₙ — vinyl chloride
- Repeat unit mass62.50 g/mol
- Chlorine content≈ 57 wt% — mostly not from oil
- MorphologyLargely amorphous, ≈10% crystalline
- Molecular weight measureFikentscher K-value
- Resin typesSuspension, emulsion, bulk
- Thermal behaviourDehydrochlorinates; autocatalytic
- Never used neatRequires stabiliser and lubricant
- CAS Number9002-86-2
- Specified byK-value, resin type, bulk density
Product Specifications
Chelora supplies Polyvinyl Chloride (PVC) in standard and custom grades. Contact us for specification sheets tailored to your process.
| Polymer | Polyvinyl chloride, suspension grade |
|---|---|
| CAS Number | 9002-86-2 |
| Repeat unit | (C₂H₃Cl)ₙ |
| K-value (Fikentscher) | 57 – 80 — specify for the application |
| Bulk density | 0.45 – 0.60 g/cm³ |
| Particle size, through 250 µm (min) | ≥ 99% |
| Particle size, retained on 63 µm | Grade dependent |
| Plasticiser absorption | 18 – 30 g per 100 g resin, grade dependent |
| Volatiles including moisture (max) | ≤ 0.30 wt% |
| Residual vinyl chloride monomer (max) | ≤ 1.0 ppm; ≤ 0.1 ppm for food grade |
| Fish eyes (max) | ≤ 20 per 100 cm² |
| Whiteness index (min) | ≥ 75 |
| Impurity / foreign particles (max) | ≤ 20 per 400 g |
| Apparent viscosity number | Per ISO 1628-2, reported with K-value |
| Ash / sulphated ash (max) | ≤ 0.10 wt% |
| pH of aqueous extract | 6.0 – 8.0 |
| Stabiliser | Not included — compound separately |
| Packaging | 25 kg bags, 500 – 1250 kg jumbo bags, bulk |
| Transport classification | Not regulated as dangerous goods |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of Polyvinyl Chloride (PVC).
Pipe & Fittings
The largest outlet. Unplasticised PVC pressure and drainage pipe, conduit and fittings for water, sewer and electrical, using K65–K68 suspension resin.
Window & Door Profile
Rigid extruded profile with impact modifier and titanium dioxide, giving multi-decade weathering performance with no maintenance coating.
Cable Insulation
Plasticised compound for wire and cable insulation and sheathing — inherent flame retardance from the chlorine content is the reason PVC holds this market.
Flooring & Membrane
Vinyl sheet and tile flooring, roofing and geomembrane, and wall covering, where wear resistance and formulation flexibility both matter.
Film, Sheet & Coating
Calendered rigid and flexible film for packaging, blister pack, credit cards, signage and banner, plus paste resin for coated fabric and wallcovering.
Medical Devices
Blood bags, IV sets and tubing, where clarity, flexibility, weldability and tolerance of radiation sterilisation are difficult to replicate at the price.
Why source Polyvinyl Chloride (PVC) through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation, with residual VCM certified on every lot — no grey-market supply.
Grade Flexibility
Suspension and emulsion resins supplied across the K-value range. We match on K-value, bulk density, porosity and plasticiser absorption, because those decide how the resin dry-blends and fuses rather than how it looks.
Full Documentation
CoA including residual VCM, SDS, REACH compliance, food-contact and potable water declarations, and destination-market certificates with every shipment.
Logistics Support
Experienced in powder resin logistics — 25 kg bags, jumbo bags and bulk silo delivery with dust control and moisture protection, for Indian and international delivery.
Storage & Handling Guidelines
Always refer to the full SDS before handling. The following is a summary of key requirements.
- Store dry and cool, out of direct sunlight, with bags off the ground and away from external walls. PVC resin picks up moisture from humid air, and moisture causes voids, poor fusion and surface defects in the extrudate.
- Manage powder dust as an explosion risk and a housekeeping problem in equal measure. Ground and bond conveying, control accumulation, and assess protection on silos and dust collectors.
- Never process without a heat stabiliser. This is not a quality recommendation — unstabilised PVC dehydrochlorinates in the extruder, the released HCl accelerates further decomposition, and the result is a scorched, corrosive mess in the machine.
- Purge equipment properly at shutdown. PVC left in a hot barrel continues to degrade, releasing hydrogen chloride that corrodes screws, barrels and dies. Cross-purging with a stable polymer is standard practice for a reason.
- Specify corrosion-resistant metallurgy for wetted parts and provide extraction at the die. Traces of HCl are released even from well-stabilised compound, and over years they attack tooling.
- Segregate resin grades and keep compounded material away from virgin resin. K-value and stabiliser system are invisible in a silo of white powder.
- Control residence time and dead spots in the screw and die. Local stagnation gives local degradation, which shows as black specks and yellowing in the product.
- Store away from oxidisers, strong bases and sources of ignition, and do not allow contact with hot surfaces above the processing range.
- Provide extraction and, where fire is a credible scenario, plan for hydrogen chloride release — PVC fires produce a corrosive acidic smoke that damages equipment well beyond the fire itself.
Hazard Summary
Classification: PVC resin is not classified as hazardous under CLP. The polymer is inert and stable at ambient temperature, and is used in potable water pipe and medical devices. The hazards arise from processing and from fire, not from the material as supplied.
Thermal decomposition releases hydrogen chloride: PVC begins dehydrochlorinating below its processing temperature, and the HCl released catalyses further decomposition, so the reaction accelerates once started. Overheating, stagnation in the screw or leaving material in a hot barrel all produce corrosive acid gas and irreversibly degraded polymer.
Stabiliser is not optional: no commercial PVC is processed without a heat stabiliser system. Calcium-zinc and organotin systems now predominate; lead-based stabilisers have been phased out in the EU and are restricted in many other markets. Confirm the stabiliser system your compound uses against the regulations of your destination market.
Residual monomer: vinyl chloride is a Category 1A human carcinogen, and modern suspension PVC is stripped to below 1 ppm residual VCM, with food-contact grades held far lower still. This is a legacy of the occupational disease clusters of the 1970s and is now routine. Residual VCM should be certified on every lot, and any resin without that figure on its certificate should be questioned.
Fire behaviour: PVC is self-extinguishing because of its chlorine content and will not sustain burning without an external flame. But when it does burn it produces dense smoke and hydrogen chloride, which is toxic to occupants and severely corrosive to electrical and metal assets — fire damage from a PVC fire routinely extends far beyond the burned area.
Dust: PVC powder forms combustible dust clouds and is a respiratory irritant. Control by enclosure and extraction rather than by respirators.
PPE minimum: safety glasses, gloves and dust protection for powder handling; heat-resistant gloves and face protection for work on hot equipment, plus respiratory protection for any purge or degradation event.
Consult the full SDS, the compound supplier's processing guidance and the applicable food-contact or potable water regulations before use.
Frequently Asked Questions
Technical and commercial questions about Polyvinyl Chloride (PVC) sourcing and specifications.
What is PVC used for?
Pipe and fittings for water, sewer and electrical conduit is the largest single outlet, followed by rigid window and door profile. Plasticised PVC covers cable insulation and sheathing, flooring, roofing membrane and coated fabric. Calendered film and sheet go into packaging, blister pack, credit cards and signage. Medical devices — blood bags, IV sets, tubing — are a smaller but demanding segment where PVC's combination of clarity, flexibility and sterilisation tolerance is hard to replace.
What is K-value and how do I choose one?
K-value is a Fikentscher constant derived from the viscosity of the resin in dilute solution, and it tracks molecular weight. Lower K means shorter chains, easier flow and lower mechanical performance; higher K means the reverse. As a rough guide, K57 to K60 suits injection moulded fittings and rigid applications needing flow, K65 to K68 covers pipe and profile extrusion, K70 to K71 goes to flexible and cable compound, and K75 and above is used for paste and plastisol applications where the resin is dispersed rather than melted. Choosing too high a K-value gives a compound you cannot fuse at reasonable temperature; too low, and the part will not meet its mechanical specification.
Why can PVC not be processed without a stabiliser?
Because it starts decomposing below the temperature it needs to be processed at. Heating PVC causes it to lose hydrogen chloride from the chain, leaving behind conjugated double bonds that discolour the polymer. The problem is that the HCl released catalyses the same reaction elsewhere, so the process is autocatalytic — once it starts it accelerates. A heat stabiliser works by scavenging that HCl and by capping the reactive sites where elimination begins. Without one, the resin would char in the extruder before it formed a part. This dependence on an additive is unique among the commodity polymers and it is why PVC is always discussed as a compound rather than a resin.
What is the difference between suspension and emulsion PVC?
The polymerisation process, and consequently the particle structure. Suspension PVC, which is around 80% of the market, is made by dispersing vinyl chloride droplets in water with a protective colloid; the resulting particles are porous, around 100 to 150 microns, and absorb plasticiser readily to make a dry blend that can be extruded or moulded. Emulsion or paste PVC is made with a surfactant and spray-dried, giving much finer particles that do not absorb plasticiser at ambient but disperse in it to form a stable liquid plastisol. That plastisol can be spread, dipped, sprayed or rotationally cast and then fused with heat, which is how coated fabric, wallcovering, dip-moulded gloves and automotive underbody sealant are made.
How much residual vinyl chloride is in PVC resin, and should I be concerned?
Modern suspension resin is stripped to below 1 part per million residual VCM, and food-contact grades to a fraction of that. The context matters: vinyl chloride is an established human carcinogen, and the occupational disease clusters found among PVC polymerisation workers in the early 1970s led directly to both the 1 ppm workplace exposure limit for the monomer and to the stripping technology that removes it from the resin. Those controls have been standard for decades, and residual VCM in current commercial resin is not a practical concern for converters or end users. What is worth doing is confirming the figure on the certificate of analysis for every lot, particularly for food-contact and medical applications, rather than assuming it.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis covering K-value, bulk density, particle size distribution, plasticiser absorption, volatiles, residual vinyl chloride monomer, fish eyes, whiteness index, foreign particles and ash; a Safety Data Sheet to GHS and REACH format; REACH polymer compliance confirmation; food-contact and potable water declarations where the grade supports them; confirmation that the resin is not regulated as dangerous goods; an origin certificate; and destination-market certificates where required.
Request a quote or specification sheet
Talk to Chelora's sourcing team about Polyvinyl Chloride (PVC) grade, volume, logistics, documentation, and lead times. We respond within one business day.
