| HS Code | |
| Productname | Vinyl Acetate Monomer (VAM) |
| Iupacname | Ethenyl acetate |
| Chemicalformula | C4H6O2 |
| Molecularweight | 86.09 g/mol |
| Casregistrynumber | 108-05-4 |
| Ecnumber | 203-545-4 |
| Unnumber | 1301 |
| Appearance | Colorless liquid |
| Odor | Sweet, fruity, pungent |
| Boilingpoint | 72.7 °C |
| Meltingpoint | -93.2 °C |
| Density | 0.932 g/cm³ at 20 °C |
| Vapordensity | 3.0 (air = 1) |
| Vaporpressure | 88 mmHg at 20 °C |
| Flashpoint | -8 °C (closed cup) |
| Autoignitiontemperature | 402 °C |
| Explosivelimits | 2.6% to 13.4% by volume in air |
| Solubilityinwater | 23 g/L at 20 °C |
| Logp | 0.73 |
| Refractiveindex | 1.395 at 20 °C |
| Viscosity | 0.43 mPa·s at 20 °C |
| Polymerization | Readily polymerizes; typically inhibited with hydroquinone |
As an accredited Vinyl Acetate (VAM) factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Vinyl Acetate (VAM) is supplied in 200 L steel drums and 1,000 L IBCs, labeled flammable liquid, UN 1301. |
| Container Loading (20′ FCL) | Vinyl Acetate (VAM) loaded in a 20-foot FCL container, typically drummed or IBC-packed, secured, labeled, and handled as flammable hazardous cargo. |
| Shipping | Vinyl acetate (VAM) is shipped as a stabilized, flammable liquid under UN 1301, Class 3, Packing Group II. It requires approved drums or tank containers, flammable-liquid labels and placards, inhibitor monitoring, and compliance with IMDG/IATA/ADR rules. Keep cool, ventilated, and away from ignition sources to prevent polymerization. |
| Storage | Store Vinyl Acetate Monomer (VAM) in a cool, dry, well-ventilated, fireproof area away from heat, sparks, open flames, and direct sunlight. Keep containers closed, grounded, and made of compatible materials (e.g., stainless steel, carbon steel). Maintain inhibitor and dissolved oxygen; do not inert-blanket. Separate from oxidizers, acids, bases, and peroxides. Use explosion-proof equipment and follow local regulations. |
| Shelf Life | Vinyl acetate monomer shelf life: typically 6–12 months when inhibited, stored cool, dry, and protected from heat, light, and polymerization initiators. |
When residual vinyl acetate monomer in a homopolymer woodworking emulsion is held below 0.1 wt% and Brookfield RVT viscosity at 23 °C shifts more than 20% within 72 h, the batch is diverted from D3/D4 adhesive filling under EN 204:2016. This is because immersion durability depends on the distribution of polyvinyl alcohol protective colloid over the polyvinyl acetate particle surface, not on total solids alone. Coagulum accumulation on the reactor thermowell after six consecutive production batches typically traces to agitator tip speed above 3.0 m/s or to initiator addition before the monomer emulsion has reached 65 °C.
The monomer feed for the homopolymer emulsion contains 85–100 parts vinyl acetate per 100 parts total monomer; the balance, when present, is butyl acrylate or 2-ethylhexyl acrylate at 0–15 parts. Polyvinyl alcohol protective colloid is charged at 3–6 parts per 100 parts monomer, and triacetin plasticizer is post-added at 5–8 phr only for flexible bond-line specifications. Polymerization is run in a jacketed stainless steel reactor equipped with an anchor agitator and baffled cooling jacket at 65–80 °C, with potassium persulfate initiation at 0.2–0.5 wt% of monomer and pH maintained between 4.0 and 5.5 using sodium bicarbonate or phosphate buffer. Post-polymerization vacuum stripping at 60–80 °C and 150–300 mbar lowers residual vinyl acetate below 0.1 wt%; the cooled emulsion is filtered through a 180 µm sieve before drumming.
Compliance is evaluated under EN 204:2016 categories D2, D3, and D4, with shear bond strength measured by ASTM D905 and adhesive specification controls under ASTM D3930. The terminal products are D2 interior wood assembly adhesives, D3/D4 water-resistant woodworking adhesives, paper tube winding compounds, and laminating emulsions. Alkaline additives that raise pH above 7.0 should be excluded because polyvinyl acetate hydrolyzes to polyvinyl alcohol and loses viscosity; open assembly time typically falls below 5 min when relative humidity exceeds 70%.
In vinyl acetate-ethylene copolymer emulsion production for dry-mix mortars, the first variable to isolate after excessive sieve residue retention on a 0.8 mm screen is the spray dryer outlet temperature. The emulsion is synthesized in a high-pressure stirred reactor at 30–70 bar ethylene partial pressure, using a monomer feed of 70–85 wt% vinyl acetate and 15–30 wt% ethylene. Polymerization proceeds at 50–70 °C with a solids target of 50–55 wt%, pH between 4.0 and 5.5, and Brookfield viscosity from 400 mPa·s to 3,000 mPa·s depending on protective colloid molecular weight and chain architecture.
The emulsion is converted to redispersible polymer powder by co-current spray drying in a pressure-nozzle dryer at inlet temperature 160–190 °C and outlet temperature 60–80 °C. Polyvinyl alcohol protective colloid is present at 5–12 wt% of polymer solids, and inorganic anti-caking agent is metered at 0.5–2.0 wt% of powder. Outlet temperature below 55 °C raises residual moisture above 1.5 wt% and produces silo bridging; inlet temperature above 200 °C can crosslink the polyvinyl alcohol shell, producing a film residue above 2% and impaired redispersion in water. The powder is blended into dry-mix mortar at 1.5–4.0 wt% of the total formulation, while cement CEM I 52.5 occupies 35–40 wt%, siliceous sand 0.1–0.5 mm at 55–60 wt%, and cellulose ether at 0.3–0.5 wt%.
Table 1. Dry-mortar formulation gradient for C2 tile adhesive
| Component | Mass fraction range | Critical parameter | Test method |
|---|---|---|---|
| Redispersible polymer powder | 1.5–4.0 wt% | Tensile adhesion after water immersion | EN 1348 |
| Cellulose ether | 0.3–0.5 wt% | Open time and slip resistance | ISO 13007-1 |
| CEM I 52.5 cement | 35–40 wt% | Compressive strength | ASTM C109/C109M |
| Siliceous sand 0.1–0.5 mm | 55–60 wt% | Particle packing and shrinkage | EN 12808-4 |
The terminal products are C1 and C2 ceramic tile adhesives, exterior thermal insulation composite system base coats, self-leveling underlayments, and repair mortars. Adhesion after water immersion and after heat ageing is measured by EN 1348 and classified under EN 12004, with product designation under ISO 13007-1; compressive strength is verified by ASTM C109/C109M. In twin-shaft paddle mixers, batch-to-batch variance in redispersible polymer powder distribution increases if the powder is added after more than 60% of the liquid water has been metered; therefore the dry-mix sequence interleaves powder and cement before water contact.
In photovoltaic module laminators where the heated platen is held at 145–155 °C, encapsulation-grade ethylene-vinyl acetate copolymer requires a vinyl acetate content of 28–33 wt% and a melt mass-flow rate of 10–45 g/10 min under ISO 1133-1:2022 at 190 °C and 2.16 kg. The film is cast at 0.45–0.50 mm thickness on a chill roll maintained between 35 °C and 60 °C, with extruder melt temperature held below 100 °C to avoid peroxide scorch. Per 100 phr of EVA base resin, the compounding masterbatch includes organic peroxide at 0.5–1.0 phr, vinyl silane coupling agent at 0.3–0.8 phr, and a UV-stabilizer/HALS package at 0.2–0.5 phr.
After lamination, gel content of the cured encapsulant is measured by ASTM D2765 and is controlled between 75% and 90%; optical transmittance is evaluated by ASTM D1003, and tensile properties are verified under ASTM D638. Terminal product is the photovoltaic module encapsulant interlayer between front glass and backsheet. Resin pellets are dried to below 0.02 wt% moisture before cast film extrusion because free water consumes silane and generates haze; if predrying is interrupted and ambient humidity exceeds 60% RH, edge bubble defects become probable, although published data for this specific configuration is limited.
Continuous saponification of vinyl acetate-derived polyvinyl acetate is controlled less by residence time alone than by local mixing in the methanol solution and by the concentration of sodium hydroxide or sodium methoxide. Polyvinyl acetate is first produced from vinyl acetate by free-radical polymerization in methanol at 30–50 wt% solids and reactor temperature below 70 °C, with molecular weight adjusted by solvent ratio rather than by temperature only. In the belt saponifier or kneader, the catalyst is metered to yield a hydrolysis degree of 86.5–89.0 mol% for partially hydrolyzed polyvinyl alcohol or 98.0–99.3 mol% for fully hydrolyzed grades. The aqueous 4% solution viscosity is measured at 20 °C and ranges from 3 mPa·s to 70 mPa·s, corresponding to grades used in water-soluble film, textile sizing, and paper coating.
For warp sizing, the size bath is prepared with 6–12 wt% polyvinyl alcohol, and size add-on is maintained at 8–14% of warp yarn mass; where starch is used as a co-binder, polyvinyl alcohol replacement is 20–40% of the dry polymer mass. The terminal products are detergent unit-dose water-soluble film, textile warp size, and paper coating binder. Compliance standards include ISO 15023-1 for designation, FDA 21 CFR 177.1670 for polyvinyl alcohol film in food contact, and EU Regulation 10/2011 for plastic food-contact materials. Residual sodium acetate above 2.0 wt% reduces cold-water solubility of partially hydrolyzed film grades and increases haze in cast film.
Vinyl chloride-vinyl acetate copolymer resins for gravure ink binders are produced by suspension polymerization with a vinyl acetate fraction of 10–15 wt% in the monomer charge; the incorporation of vinyl acetate lowers the glass transition temperature into the 60–75 °C range and improves solubility in ketone-ester solvent blends compared with straight polyvinyl chloride. The resin is dissolved at 10–15 wt% in methyl ethyl ketone-toluene or ethyl acetate-ethanol combinations, while the pigment concentrate is milled separately and let down to a final ink containing 20–30 wt% pigment, 40–60 wt% solvent, and 1–3 wt% adhesion promoter. Gravure printing on vinyl film coil is run at 80–150 m/min with cylinder engraving depth selected to deposit 1.5–3.0 g/m² dry film. Terminal products include packaging inks, metal can exterior coatings, and vinyl flooring wear-layer coatings. Compliance for food-contact can coatings is assessed under FDA 21 CFR 175.300 and EU Regulation 10/2011; solvent emissions are classified under EU Directive 2004/42/EC.
For low-VOC interior flat paints formulated below a pigment volume concentration of 55%, vinyl acetate-acrylic copolymer latex with a monomer feed of 75–85 wt% vinyl acetate, 15–25 wt% butyl acrylate, and 1–2 wt% acrylic acid provides a minimum film-forming temperature below 5 °C without high coalescent demand. The finished paint contains latex at 20–35 wt%, rutile titanium dioxide at 15–22 wt%, extender pigment at 10–15 wt%, and rheology modifier at 0.5–1.5 wt%. Pigment deagglomeration is performed in a high-speed disperser, and the latex is introduced under low-shear let-down at 24–28 °C to avoid destabilization. Scrub resistance is measured by ASTM D2486 and ISO 11998, and VOC content is classified under EU Directive 2004/42/EC. Terminal products are interior wall paints, primer systems, and ceiling paints.
Competitive Vinyl Acetate (VAM) prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618136850665 or mail to admin@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8618136850665
Email: admin@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Vinyl Acetate (VAM), CAS 108-05-4, is the vinyl ester of acetic acid with molecular formula C4H6O2 and molar mass 86.09 g mol−1. At 20 °C it is a mobile, colourless liquid with density 0.934 g cm−3, boiling point 72.7 °C, flash point closed cup −8 °C, lower explosion limit 2.6 vol%, upper explosion limit 13.4 vol%, vapour pressure 11.8 kPa, and relative vapour density approximately 3.0 compared with air. Commercial polymerization-grade material is supplied as an inhibited liquid, typically using hydroquinone at 3–20 ppm to extend the induction period during storage and transfer. The dominant industrial route is gas-phase acetoxylation of ethylene with acetic acid and oxygen over a supported palladium–gold catalyst; the older acetylene-based route is confined to a limited number of legacy plants. Major derivative chains include poly(vinyl acetate), poly(vinyl alcohol), ethylene–vinyl acetate copolymers, vinyl acetate–ethylene dispersions, and vinyl chloride–vinyl acetate solution resins.
Storage and transfer of VAM are governed primarily by flammability and radical chain polymerization potential. Closed storage tanks of stainless steel 316L or 304L are standard; carbon steel is acceptable only when internally rust-free because dissolved iron and particulate oxide can promote redox decomposition of the hydroquinone inhibitor. Copper and copper-rich alloys are excluded from VAM service because copper ions catalyse colour-forming degradation and can destabilize the inhibitor package. Industrial handling guidance generally maintains a small dissolved oxygen concentration, typically in the range 1–5 ppm, because hydroquinone-type inhibitors can be less effective in fully inert atmospheres. Nitrogen blanketing therefore requires oxygen trim supply or direct inhibitor monitoring to avoid spontaneous exothermic polymerization during extended storage above 40 °C. Transfer pumps are normally sealless magnetic-drive or double mechanical seal types; pump speeds are commonly limited to 1750 min−1 to reduce local frictional heating. Storage vents are fitted with flame arresters and pressure/vacuum relief setpoints near 10 mbar. Distillation of VAM should not be taken to dryness because monomer heel residues can become thermally unstable and accelerate radical polymerisation. For drumming and sampling stations, local exhaust ventilation is required; the ACGIH TLV-TWA is 10 ppm, and vapour accumulating in pits or sumps must be monitored because VAM vapour is heavier than air.
Industrial fixed-bed reactors for ethylene acetoxylation are multitubular designs with tube inner diameters of 25–40 mm and molten-salt cooling. The catalyst is a supported palladium–gold shell type promoted with potassium acetate on silica. Feed consists of ethylene, acetic acid, oxygen, and carbon dioxide or nitrogen diluent. Inlet oxygen is held below 8–9 vol% at operating pressure 0.5–0.8 MPa to remain outside the flammability envelope. Reactor effluent contains VAM, water, unreacted acetic acid, ethylene, carbon dioxide, and trace ethyl acetate. Separation is performed by chilled acetic acid absorption followed by distillation; the VAM–water azeotrope is broken by pressure distillation or extractive distillation. Carbon dioxide is the principal side product from ethylene combustion, and selectivity to VAM based on ethylene generally exceeds 90%. Acetic acid recovery in closed-loop drying towers is typically greater than 99%. A known production bottleneck is potassium acetate migration from the catalyst surface during extended operation; progressive potassium loss raises carbon dioxide selectivity and lowers VAM output. Production units therefore monitor effluent carbon dioxide-to-VAM ratio as a leading indicator of catalyst ageing. Field experience with fixed-bed reactors of 25–40 mm tube diameter shows that pressure drop rises gradually as catalyst fines accumulate; catalyst replacement is often scheduled when pressure drop exceeds 0.3 bar above clean-bed baseline.
VAM is not a drop-in replacement for acrylate monomers in waterborne binders because of differences in hydrolysis chemistry, glass transition temperature, and outdoor weathering behaviour. Poly(vinyl acetate) homopolymer has a glass transition temperature of 28–32 °C, while poly(ethyl acrylate) and poly(butyl acrylate) have glass transition temperatures of −24 °C and −54 °C, respectively. Consequently, VAM imparts film hardness and adhesion to polar surfaces such as paper, wood, and concrete but requires external or internal plasticization for low-temperature flexibility. In waterborne binder formulations, vinyl acetate is frequently copolymerized with ethylene or butyl acrylate to obtain film-forming temperatures below 10 °C; the VAM fraction improves polar wetting, while the ethylene or acrylate fraction reduces surface tack and improves elongation. Hydrolytic stability of VAM copolymers is lower than that of pure acrylics. Under elevated pH and sustained humidity, acetate ester groups hydrolyse to hydroxyl groups with release of acetic acid, reducing alkali resistance and long-term ultraviolet durability. For exterior architectural coatings, VAM-based emulsions are therefore typically restricted to sheltered or non-south-facing substrates unless formulated with high-ethylene content or acrylic topcoats. Table 1 compares VAM with common comonomers on the basis of homopolymer glass transition temperature and boiling point.
| Monomer | CAS number | Homopolymer Tg (°C) | Boiling point at 101.3 kPa (°C) |
|---|---|---|---|
| Vinyl acetate | 108-05-4 | 28–32 | 72.7 |
| Ethyl acrylate | 140-88-5 | −24 | 99.4 |
| Butyl acrylate | 141-32-2 | −54 | 145 |
| Methyl methacrylate | 80-62-6 | 105 | 100 |
| Vinyl chloride | 75-01-4 | 82 | −13.4 |
Processing differences between VAM and methyl methacrylate are also significant in emulsion polymerization. VAM has a water solubility of 2.0 g/100 g at 20 °C, which supports homogeneous nucleation and fine particle formation; methyl methacrylate and butyl acrylate are less water-soluble and follow micellar nucleation more strongly in the presence of anionic surfactants. VAM undergoes chain transfer to polymer, leading to branched poly(vinyl acetate) and gel fraction in high-conversion latexes. Mercaptan chain-transfer agents are commonly dosed at 0.05–0.5 wt% on monomer to control molecular weight and reduce microgel. Unlike acrylate-rich systems, VAM emulsions are prone to pH drift during polymerization because acetate groups hydrolyse under acidic or alkaline conditions. Buffer systems based on sodium acetate and acetic acid are required to maintain pH 4.5–5.5 in batch and semi-batch emulsion processes. In contrast, methyl methacrylate and styrene copolymerizations tolerate a wider pH range, giving acrylic formulators greater flexibility in anionic surfactant selection.
ASTM D2190 establishes the main specification framework for vinyl acetate monomer. Typical polymerization-grade values are consolidated in Table 2. The specification does not normally include acetaldehyde, but internal quality systems for poly(vinyl alcohol) feedstock commonly control acetaldehyde below 50 ppm because it acts as a chain-transfer agent and can depress poly(vinyl alcohol) molecular weight. Water and acetic acid are controlled because both poison alcoholysis catalysts and increase ester hydrolysis during storage. Colour above 10 Pt-Co indicates oxidation or inhibitor degradation products. Inhibitor content is verified by iodometric or ultraviolet detection; lower inhibitor concentrations shorten induction time and can create runaway risk in clean steel vessels at 50 °C. Purity is determined by gas chromatography with flame ionization detection, water by Karl Fischer coulometry, and acidity by potentiometric titration.
| Property | Typical range | Test method |
|---|---|---|
| Purity | ≥99.9 wt% | ASTM D2190 gas chromatography |
| Water | ≤0.05 wt% | ASTM D2190 Karl Fischer |
| Acidity as acetic acid | ≤0.020 wt% | ASTM D2190 titrimetric |
| Colour | ≤10 Pt-Co | ASTM D1209 |
| Inhibitor as hydroquinone | 3–20 ppm | ASTM D2190 |
Commercial models are differentiated by inhibitor type and trace impurity profile rather than by chemical identity. Polymerization-grade VAM meeting ASTM D2190 is the base commercial model. Low-water, low-aldehyde material is specified for poly(vinyl alcohol) manufacture because water and acetaldehyde affect alcoholysis stoichiometry and polymer molecular weight. Low-inhibitor or uninhibited VAM is used in high-pressure ethylene copolymerization and certain captive emulsion plants; uninhibited VAM is not recommended for storage exceeding 8 h at 50 °C because the induction period falls below safe control limits.
For poly(vinyl alcohol) production, VAM is polymerized to poly(vinyl acetate), and the acetate groups are subsequently saponified using sodium hydroxide or sodium methylate in methanol. Degree of hydrolysis is controlled between 87–89 mol% for cold-water-soluble partially hydrolysed grades and 98–99 mol% for fully hydrolysed water-resistant grades. The molecular weight is set by polymerization temperature and chain-transfer agent addition; residual VAM in the polymer feed is stripped to below 0.05 wt% to avoid odour and methanol contamination in the alcoholysis process. On production-scale lines, stripping is performed in thin-film or wiped-film evaporators at 80–90 °C under reduced pressure; batch-to-batch variability in residual monomer is controlled by pH and agitation in the holding reactor. Poly(vinyl alcohol) derived from VAM is then used in textile warp sizing, paper surface sizing, water-soluble films, and as a protective colloid for subsequent vinyl acetate emulsion polymerization.
Vinyl chloride–vinyl acetate copolymers contain VAM levels of 5–15 wt% to reduce the glass transition temperature of the copolymer relative to unplasticized poly(vinyl chloride). These solution-grade resins are used in gravure and screen inks, coil coatings, and historically in phonograph records. VAM is a liquid at ambient pressure, unlike vinyl chloride, which is a gas with boiling point −13.4 °C; this simplifies weighing and reactor charging in batch suspension or solution copolymerization. The presence of VAM lowers thermal stability relative to poly(vinyl chloride) because acetate groups can undergo ester pyrolysis and dehydrochlorination at processing temperatures above 140 °C; calcium–zinc or organotin stabilizers are required. In comparison with vinyl chloride homopolymer, vinyl chloride–VAM copolymers show better adhesion to metal and paper, lower melt viscosity, and broader solvent solubility in ketones and esters.
Two copolymer families exploit VAM with ethylene under different mechanisms. Low-density ethylene–vinyl acetate is produced in high-pressure autoclave or tubular radical polymerizers at 150–300 MPa and 180–300 °C, with VAM content typically 5–40 wt%. The VAM units interrupt polyethylene crystallinity, increase optical clarity, improve heat-seal strength, and lower flexural modulus. Encapsulant grades for photovoltaic modules typically contain 28–33 wt% VAM and are crosslinked with organic peroxides; the VAM content provides transparency and adhesion to glass. Vinyl acetate–ethylene emulsion copolymers are produced at low pressure in aqueous emulsion, with ethylene content typically 5–30 wt%. These dispersions replace poly(vinyl acetate) homopolymer in low-VOC interior paints, carpet backing, and nonwoven binders. In vinyl acetate–ethylene emulsion production, ethylene lowers the film-forming temperature relative to homopolymer poly(vinyl acetate); many formulations film-form at 4 °C without coalescents when ethylene content is sufficient to depress the latex glass transition temperature below 5 °C.
