| HS Code | 563143 |
| Product Name | Polymer Grade VAM HQ 14–17 ppm (Standard PVA Resin Raw Material) |
| Chemical Name | Vinyl acetate monomer |
| Chemical Formula | C4H6O2 |
| Molecular Weight G Mol | 86.09 |
| Appearance | Clear colorless liquid |
| Purity Wt Percent | >= 99.9 |
| Inhibitor Type | Hydroquinone (HQ) |
| Inhibitor Content Ppm | 14–17 |
| Boiling Point Celsius | 72.7 |
| Freezing Point Celsius | -93 |
| Flash Point Celsius Closed Cup | -8 |
| Specific Gravity 20 20 | 0.932 |
| Refractive Index At 20c | 1.3953 |
| Vapor Pressure Kpa At 20c | 11.5 |
| Viscosity Cp At 20c | 0.4 |
| Solubility In Water At 20c | Slightly soluble (approx. 20 g/L) |
| Autoignition Temperature Celsius | 427 |
| Explosion Limit Volume Percent Lower Upper | 2.6–13.4 |
As an accredited Polymer Grade VAM HQ 14–17 ppm (Standard PVA Resin Raw Material) factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Polymer Grade VAM HQ 14–17 ppm is packaged in 190 kg steel drums, 1,000 kg IBCs, or bulk ISO tanks. |
| Container Loading (20′ FCL) | Polymer Grade VAM HQ loaded into 20′ FCL container, securely stowed, protected from moisture, ensuring safe transport as PVA resin raw material. |
| Shipping | Ship as stabilized flammable liquid in sealed, properly grounded containers. Keep away from heat, sparks, and sunlight to prevent polymerization. Use ventilation and compatible materials. Label as Vinyl Acetate Monomer, inhibited (14–17 ppm HQ). Follow IMDG/ADR regulations for safe transport. |
| Storage | Store Polymer Grade VAM (Vinyl Acetate Monomer) with HQ inhibitor (14–17 ppm) in tightly sealed, corrosion-resistant containers under a nitrogen blanket. Keep in a cool, dry, well-ventilated area away from heat, sparks, open flames, and oxidizing agents. Maintain moderate temperatures to prevent polymerization; regularly verify inhibitor concentration. Use grounded equipment and follow all safety protocols. |
| Shelf Life | Store below 20°C, away from light and oxygen; shelf life typically 12 months, maintaining inhibitor effectiveness for PVA resin production. |
In single-stage batch emulsion polymerisation for woodworking adhesive stock, the 14–17 ppm hydroquinone level is normally offset by an ammonium persulfate/sodium metabisulfite redox couple rather than by pre-stripping monomer. A control recipe uses 100 parts VAM, 90–110 parts deionised water, 3–6 parts polyvinyl alcohol protective colloid, 0.2–0.5 parts ammonium persulfate, and 0.1–0.3 parts sodium metabisulfite. The reactor jacket is held at 65–75°C, agitation is set at 180–250 rpm, and the cooling loop is engaged when the exotherm rate exceeds 5–8°C/min. Hydroquinone consumes primary radicals during the induction period; if the inhibitor load is not compensated, delayed nucleation can broaden particle-size distribution above 2 µm D[4,3] and reduce sedimentation stability. Finished dispersions are adjusted to 50–55% solids and 3000–5000 mPa·s Brookfield viscosity at 25°C using RV spindle #5 at 10 rpm. The adhesive is then compounded with 3–8 phr plasticiser and 0.2–0.5 wt% defoamer before hardwood application. Bond performance is assessed under EN 204 D3 and ASTM D905; D3-grade formulations must survive water immersion but not boiling water. Terminal products include door stiles, engineered wood edge-banding, and furniture assembly cold-pressed for 15–45 min at 20–25°C. A practical limitation is that high-HQ monomer batches can delay exotherm onset; the exact redox correction is derived from plant-specific induction curves rather than a universal coefficient.
Vinyl acetate-ethylene emulsions for low-odour architectural coatings are polymerised in high-pressure stirred autoclaves where ethylene partial pressure is the primary variable controlling glass transition and minimum film-forming temperature. A typical VAE binder for interior wall paint uses 70–85 wt% VAM and 15–30 wt% ethylene, with reactor pressure maintained at 50–100 bar and temperature at 60–90°C. The VAM feed containing 14–17 ppm hydroquinone is pre-emulsified with water, hydroxyethyl cellulose or polyvinyl alcohol colloid, and a persulfate-redox initiator system. Ethylene is charged into the headspace and consumed as pressure decays; the vinyl acetate fraction is fed over 3–5 h to control compositional drift. The resulting polymer develops a Tg from -10 to +5°C and an MFFT below 0–5°C, permitting binder formulation at 55–60% PVC in flat and satin interior paints without excessive coalescent demand. End products are low-VOC interior wall paints, carpet backing compounds, and some pressure-sensitive adhesive bases. Compliance is verified by ISO 3251 for solids, ISO 2555 for Brookfield viscosity, and ISO 11890-2 for residual VOC, with typical unpigmented binder VOC below 1 g/L. The main operational boundary is that hydroquinone accumulation in recycled ethylene vents can raise phenolic residue in the latex and shift storage yellowness upward if the monomer is not distilled before use.Ethylene-vinyl acetate copolymer resin for photovoltaic encapsulation is produced by high-pressure autoclave or tubular polymerisation at a vinyl acetate content of 28–33 wt%. The VAM feed in this route is inhibited at 14–17 ppm hydroquinone, low enough to limit yellowing of the EVA film but high enough to require a defined oxygen/initiator balance in the high-pressure train. The copolymer is pelletised and then compounded into a film formulation containing 0.8–1.2 phr of a peroxide such as tert-butyl peroxy-2-ethylhexanoate, 0.3–0.5 phr vinyltrimethoxysilane coupling agent, 0.05–0.15 phr hindered amine light stabiliser, and 0.1–0.3 phr antioxidant. Compounding is run below 100°C to prevent premature crosslinking. Lamination against glass and backsheet is conducted at 145–160°C for 10–18 min in a vacuum laminator; the crosslinked film reaches a gel content of 75–90% under ASTM D2765. Optical transmission above 91% in the 400–1100 nm range is checked by ASTM D1003, and volume resistivity above 1×10¹⁴ Ω·cm is verified by ASTM D257. Terminal products include encapsulated monocrystalline and polycrystalline photovoltaic modules. A defined process boundary is that hydroquinone-derived chromophores increase yellowness if the EVA is held above 160°C for longer than 25 min, so the lamination profile must be locked tightly.
Ethylene-vinyl alcohol barrier resins originate from the same VAM monomer specification but require the intermediate EVA copolymer to be saponified to high ethylene-vinyl alcohol conversion with low residual acetate. Commercial ethylene boundaries include 27, 32, 38, and 44 mol% because gas-barrier properties and melt processability move in opposite directions as ethylene increases. In coextruded multilayer structures, a 20 µm EVOH layer has an oxygen transmission rate below 1 cm³/m²·day·atm at 20°C and 65% RH when measured by ASTM D3985. The polymer is highly moisture-sensitive: at 90% RH, oxygen permeability can be 5–10 times higher than at 50% RH, so the EVOH layer is positioned between moisture-resistant polyolefin skins. The 14–17 ppm hydroquinone in VAM does not transfer directly to EVOH at measurable levels if the EVA intermediate is washed with methanol and water after saponification; acetaldehyde and water are more critical monomer-quality parameters because they affect colour and gel formation. End products include flexible packaging films for processed meat and cheese, blow-moulded bottles for sauces, and fuel-tank inner layers. Compliance for food-contact uses is resolved through migration testing under EU 10/2011 and applicable national implementations, with the final article judged on overall migration and organoleptic transfer rather than a single monomer limit.Suspension copolymerisation of vinyl chloride with vinyl acetate uses VAM at 5–15 wt% in the monomer feed to reduce crystallinity and raise solubility in ketone and ester solvents used in maintenance coatings and gravure inks. Polymerisation is conducted in aqueous suspension at 50–70°C with a free-radical initiator such as di(2-ethylhexyl) peroxydicarbonate or azobisisobutyronitrile. Protective colloids include hydroxypropyl methylcellulose and partially hydrolysed polyvinyl alcohol at 0.03–0.15 wt% based on water. Hydroquinone at 14–17 ppm in VAM is partially extracted into the aqueous phase before polymerisation, so its effect is batch-history dependent and weaker than in bulk or solution polymerisation. Industrial lines therefore evacuate the reactor to below 0.5 bar absolute before monomer charging and hold dissolved oxygen below 2 ppm in the aqueous phase. Final VC-VAc resins have K-values between 45 and 62 depending on chain-transfer agent dosage and are formulated at 15–30% solids in methyl isobutyl ketone or toluene/ethyl acetate blends. End products include high-solids anticorrosion coatings, screen-printing inks, and vinyl floor covering wear layers. The limitation is that VAM content above 15 wt% lowers heat deflection and narrows the solvent-release window during forced drying at 60–80°C.
Redispersible polymer powders for cementitious tile adhesives and skim coats are produced by spray drying vinyl acetate-ethylene or vinyl acetate-VeoVa copolymer dispersions made with the same 14–17 ppm HQ VAM feed. The waterborne dispersion is polymerised to 50–55% solids and then compounded with 5–10 wt% polyvinyl alcohol hard protective colloid, 0.5–2 wt% anti-caking agent such as calcium carbonate or kaolin, and optionally a small amount of melamine-formaldehyde condensate stabiliser. Spray drying uses inlet air at 160–180°C and outlet air at 75–85°C; powder particle size is controlled to a D50 of 50–120 µm to balance redispersibility and silo flow. In a C2TE or D2TE tile adhesive, the RDP dosage is 1.5–4 wt% of dry-mix mass, with total polymer content in the mixed mortar from 2.0 to 5.5 wt%. The powder re-emulsifies during mixing at 500–1000 rpm; adhesion after water immersion and heat ageing is tested under ISO 13007 and EN 12004. End products include flexible tile adhesives, external thermal insulation composite systems, and self-levelling underlayments. The powder must be stored below 35°C and below 60% RH; above that range, the polyvinyl alcohol colloid plasticises and particles coalesce irreversibly, causing grit formation and loss of redispersibility.For paper saturation and nonwoven textile binding, vinyl acetate homopolymer or vinyl acetate-acrylate copolymer lattices are used with VAM content from 60 to 100 wt% in the polymer backbone. The latex is synthesised by semicontinuous emulsion polymerisation at 70–80°C; the 14–17 ppm hydroquinone in the VAM feed is stripped or complexed before the delayed monomer feed starts because phenolic residues can cause yellowness in saturated papers and nonwoven interlinings. Terminal applications include print paper saturation, tissue and towelling binders, and disposable nonwoven garment interlining. In paper saturation, the latex is applied at 20–45% solids and oven-cured at 100–130°C to reach machine-direction tensile strength above 1.5 kN/m when tested by ISO 1924-2. In textile binding, the binder add-on is 10–25 wt% on fibre weight and is applied by foam or kiss-roll methods to avoid surface film formation. The limitation is that hard homopolymer PVAc lattices with Tg above 30°C give high tensile strength but low wet-and-dry flexibility; softer acrylate-containing compositions reduce Tg to 0–15°C by adding 10–30 wt% acrylate but raise tackiness and blocking during storage.
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Vinyl acetate monomer is a reactive unsaturated ester feedstock for polyvinyl acetate and polyvinyl alcohol synthesis. The product designated Polymer Grade VAM HQ 14–17 ppm (Standard PVA Resin Raw Material) is specified by a hydroquinone concentration of 14–17 ppm and by polymer-grade limits for water, acidity, acetaldehyde, and colour. The stabilizer package is selected for methanol solution polymerization trains and subsequent saponification to polyvinyl alcohol resin. It differs from technical-grade and low-inhibitor VAM in that the inhibitor band is narrow enough to support reproducible radical initiation without monomer pre-distillation in many standard PVA resin production units. Principal downstream uses include standard PVA resins for textile sizing, paper coating binders, adhesive intermediates, and film-forming grades in which residual colour and erratic induction periods are controlled. The product is not a formulated resin; it is the monomer precursor from which polyvinyl acetate and polyvinyl alcohol are built.
The monomer is identified by CAS 108-05-4 and EINECS 203-545-4; the molecular formula C4H6O2 corresponds to a molar mass of 86.09 g/mol. The model designation “Polymer Grade VAM HQ 14–17 ppm” refers to hydroquinone content measured by ASTM D2193; no additional stabilizer is specified. Certificates of analysis are normally organized against ASTM D2190-07, the standard specification for vinyl acetate. The table below lists the standard quality boundaries for polymer-grade PVA feedstock. Each lot is also tested for appearance because haze or suspended polymer seed is a practical indicator of storage history.
| Parameter | Test Method | Specification |
|---|---|---|
| Vinyl acetate assay | ASTM D2192 | ≥99.9 wt% |
| Hydroquinone inhibitor | ASTM D2193 | 14–17 ppm |
| Acetaldehyde | ASTM D2191 | ≤0.005 wt% |
| Water | ASTM D2194 | ≤0.05 wt% |
| Acidity as acetic acid | ASTM D2086 | ≤0.005 wt% |
| Colour, Pt-Co | ASTM D1209 | ≤5 |
| Distillation range | ASTM D1078 | 72.0–73.0°C |
At railcar or isotank receipt, a top sample is not sufficient. Hydroquinone can stratify after long static storage; the receiving protocol therefore circulates the tank for 30–60 minutes before sampling from the recirculation loop. The sample is tested by ASTM D2193 for hydroquinone, by ASTM D2191 for acetaldehyde, and by ASTM D2194 for water. Appearance is checked against a clear liquid standard; visible haze or polymer seed triggers quarantine. The product is then transferred through a filter specified by the polymerization unit to protect downstream metering pumps. Because the specification window is narrow, analytical agreement between supplier and receiver is part of the product transfer. Interlaboratory bias in hydroquinone determination can occur if calibration standards are not exchanged. A top sample may understate bulk hydroquinone after static storage, while a bottom sample may overstate it. Poorly designed top-entry lines are a common source of batch-to-batch variance, and this operational detail is separate from the analytical precision of ASTM D2193.
Hydroquinone functions as a radical scavenger. During storage, it intercepts thermally generated radicals and prevents polymer seed formation. During polymerization, the same mechanism consumes initiator radicals until the inhibitor is exhausted. At 14–17 ppm, the inhibitor concentration is low enough that standard initiator feed adjustments can compensate for the induction period, but high enough to stabilize the monomer in normal tank logistics. The induction period is not a fixed constant; it depends on reactor temperature, agitation, oxygen ingress, initiator half-life, and trace metal concentration. In a typical methanol solution polymerization at 60–70°C using an azo-type initiator, the hydroquinone is consumed before the main propagation phase; the inhibition reaction is irreversible and produces quinone species that are not active chain carriers. Residual hydroquinone or its oxidized quinone can carry over into recovered monomer and may accumulate in recycle loops. Published data for this specific inhibitor band across all initiator systems is limited, so process qualification is performed in the actual polymerization vessel.
In suspension and solution polymerizations, the monomer is typically charged to a jacketed stirred-tank reactor with reflux condensation. The hydroquinone is not removed in many standard PVA resin lines; instead, the radical initiator precharge and continuous feed are adjusted to consume the inhibitor. Unreacted vinyl acetate is recovered by distillation after 50–70% conversion and recycled. The polyvinyl acetate in methanol is then saponified with sodium hydroxide to polyvinyl alcohol having a controlled degree of hydrolysis, commonly 86–99 mol%, and a 4% aqueous solution viscosity characterized by JIS K6726. Residual hydroquinone that survives polymerization can appear as colour bodies in the final PVA resin and can influence thermal stability; the 14–17 ppm band is therefore verified at receiving, after tank homogenization, and before charging to avoid lot-to-lot induction drift.
Fully hydrolyzed PVA with degree of hydrolysis above 98 mol% is used in textile sizing and paper coating where cold-water solubility is lower and film tensile strength is higher. Partially hydrolyzed PVA with degree of hydrolysis 87–89 mol% is used in adhesives and emulsion polymerization protective colloids where cold-water solubility and surface activity are required. The choice of VAM inhibitor band indirectly affects these grades because residual hydroquinone oxidation products can increase yellowness index in cast film; the 14–17 ppm band is selected to reduce that contribution without introducing the storage instability of lower-inhibitor feedstock. Film tensile strength is characterized by ISO 527-3 or ASTM D882-18, and film yellowness is monitored by ASTM E313 or equivalent.
Acetaldehyde and water in VAM are not inert spectators during PVA resin production. Water in the monomer is carried into the polyvinyl acetate solution and later consumes sodium hydroxide during saponification, increasing sodium acetate ash in the final PVA resin. Acetaldehyde contributes to colour formation through aldol condensation in the alkaline methanolysis medium. The polymer-grade specification of ≤0.05 wt% water and ≤0.005 wt% acetaldehyde reduces these effects. Acetic acid, if present above 0.005 wt%, reacts with sodium hydroxide in methanolysis and can shift the hydrolysis end point, requiring alkali adjustment. Recovered methanol and unreacted VAM recycle these impurities, so a lot with apparently acceptable single-pass values can accumulate carbonyls and water over multiple recycles. This is a production-scale bottleneck observed on continuous PVA lines with closed recovery loops.
Chain transfer to monomer in vinyl acetate polymerization is high; the molecular weight of polyvinyl acetate is therefore governed by reactor temperature, initiator concentration, and chain-transfer impurities rather than by conversion alone. Acetaldehyde acts as a chain-transfer agent and can lower the degree of polymerization. The polymer grade VAM HQ 14–17 ppm product limits acetaldehyde to ≤0.005 wt% and water to ≤0.05 wt%; these values support reproducible molecular weight in standard PVA resin recipes. Published data for the quantitative effect of hydroquinone in the 14–17 ppm band on final PVA degree of polymerization is limited, because the inhibitor is consumed early in the polymerization and the main determinants of molecular weight are initiator concentration and temperature.
An excursion below 14 ppm is generally observed as a shortened induction period and higher initial exotherm. The more significant risk is not immediate runaway but the slow formation of polymer seeds in storage and fouling in the monomer recovery column. An excursion above 17 ppm usually appears as a reduction in conversion per pass under the same initiator feed, followed by an increase in polymer solution viscosity when the operator compensates with additional initiator. The operational boundary is therefore established at the receiving tank, not at the reactor. If hydroquinone exceeds 17 ppm, direct feeding without initiator compensation can alter the molecular weight distribution, saponification rate, and sodium acetate ash content in the final PVA resin. Re-blending with low-inhibitor product may be permitted under supplier authorization, provided the resulting batch is re-analyzed by ASTM D2193 and the polymerization recipe is recalculated.
General-purpose vinyl acetate can carry an inhibitor concentration as low as 3–7 ppm for rapid initiation or as high as 25–30 ppm for extended tank storage. Low-inhibitor grades reduce the initial inhibitor consumption in the polymerization reactor but require stricter oxygen exclusion and lower transit temperatures; a single tank heel of water or rust can accelerate peroxide formation. High-inhibitor grades extend shelf life but may force the PVA producer to install monomer purification or to increase initiator dosing, which can raise the concentration of initiating fragments and affect chain-end structure. The polymer grade HQ 14–17 ppm product is specified between these levels. Compared with other VAM sources, the polymer grade also imposes tighter acetaldehyde and acidity controls because carbonyl and acid impurities influence final PVA colour and the methanolysis mass balance. In addition, the product is differentiated from inhibitor-free VAM by predictable storage stability and from other phenolic-stabilized grades outside the 14–17 ppm band by its suitability for standard PVA resin reactors without additional stabilizer removal. Published data for specific low-inhibitor configurations is limited; therefore, side-by-side reactor qualification is required when changing from one stabilizer package to another.
| Inhibitor band | Process observation | Typical control action |
|---|---|---|
| 3–7 ppm | Short induction period; greater sensitivity to oxygen and storage temperature | Low-temperature storage, oxygen exclusion, frequent peroxide and inhibitor analysis |
| 14–17 ppm | Reference band for standard PVA resin monomer; induction corrected by initiator feed | Receiving analysis by ASTM D2193, tank homogenization, standard recipe |
| 20–30 ppm | Extended shelf life; potential residual colour and initiator demand increase | Higher initiator feed or monomer purification; PVA colour qualification |
Vinyl acetate-ethylene emulsion polymerization and vinyl acetate-acrylic ester pressure-sensitive adhesive production may require different inhibitor packages or additional monomer purification. The 14–17 ppm hydroquinone band may be acceptable in these systems, but published data for specific copolymer configurations is limited. The polymer-grade specification should not be assumed to cover oxygen-reduced or redox emulsion polymerization without laboratory induction testing.
The product is stored in carbon steel or stainless steel tanks under a nitrogen blanket with oxygen content below 5 vol%. Moisture ingress is controlled because water above 0.05 wt% can hydrolyze vinyl acetate to acetaldehyde and acetic acid, shifting acidity and consuming inhibitor. Contact with copper alloys, strong bases, strong acids, oxidizing agents, and free-radical initiators is avoided. Storage temperature is maintained below 30°C because vapor pressure and thermal polymerization rates increase with temperature. For prolonged storage, the hydroquinone level is re-verified at intervals not exceeding 30 days by ASTM D2193. Transfer lines are designed with grounding and bonding to prevent static discharge; the flash point of vinyl acetate is approximately −8°C closed cup, and the explosive limits in air are 2.6–13.4 vol%. Any receiving tank that has been idle for more than 72 hours is circulated and sampled before transfer to the polymerization day tank.
