| HS Code | 370756 |
| Product | SELVOL Polyvinyl Alcohol 504 |
| Chemicalname | Poly(vinyl alcohol) |
| Casnumber | 9002-89-5 |
| Appearance | White to cream free-flowing powder |
| Degreeofhydrolysis | 87.0 to 89.0 mole % |
| Viscosity | 4.5 to 5.5 mPa·s (cP) as a 4% aqueous solution at 20°C |
| Ph | 5.0 to 7.0 for a 4% aqueous solution at 20°C |
| Ashcontent | 0.9% maximum |
| Volatilecontent | 5.0% maximum |
| Solubility | Soluble in hot and cold water; insoluble in common organic solvents |
| Bulkdensity | 0.40 to 0.60 g/cm³ |
| Specificgravity | 1.27 |
| Meltingpoint | Approximately 190°C |
| Glasstransitiontemperature | Approximately 58°C |
| Refractiveindex | Approximately 1.51 as a film |
| Ioniccharge | Nonionic |
As an accredited SELVOL Polyvinyl Alcohol 504 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SELVOL Polyvinyl Alcohol 504 supplied in 25 kg multi-wall paper bags with polyethylene liner. |
| Container Loading (20′ FCL) | 20' FCL container loading of SELVOL Polyvinyl Alcohol 504, palletized and secured, ensuring safe, efficient transport. |
| Shipping | SELVOL Polyvinyl Alcohol 504 ships as a dry granular solid in multi-layer paper bags or fiber drums. Keep containers sealed, dry, and away from moisture, heat, and incompatible oxidizers. Handle with dust control and static precautions. Transport in covered vehicles to prevent exposure. No dangerous goods classification under standard conditions. |
| Storage | Store SELVOL Polyvinyl Alcohol 504 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and open flames. Keep containers tightly sealed to prevent moisture absorption, as the product is water-soluble. Avoid contact with oxidizing agents and strong acids. Maintain moderate temperatures to preserve quality and prevent caking or degradation. |
| Shelf Life | Shelf life is typically two years from manufacture when stored unopened in a cool, dry area away from moisture. |
SELVOL Polyvinyl Alcohol 504, a partially hydrolysed grade of 87–89 mol% hydrolysis and Brookfield viscosity of 4.0–5.0 cP for a 4 wt% aqueous solution at 20 °C, enters vinyl acetate-ethylene (VAE) and polyvinyl acetate (PVAc) latex polymerisation as the primary protective colloid. The charge is 2.0–5.0 phm for VAE and 3.0–6.0 phm for PVAc homopolymer in batch reactors. The grade is pre-dissolved in demineralised water to a 15 wt% stock solution at 90 °C for 45–60 min, cooled to 40 °C, and metered into the reactor before initiator feed begins. Brookfield viscosity of the stock solution is confirmed by ISO 2555 using a Brookfield LV, spindle 2, at 12 rpm and 20 °C. The partially hydrolysed structure maintains interfacial surface excess at the monomer-swollen polymer particle, restricting particle coalescence during the constant-rate nucleation window. In 50–100 m³ batch reactors with anchor impellers operated at 40–80 rpm, semi-continuous addition of vinyl acetate monomer over 3–5 h yields latex median particle sizes from 800 nm to 1.8 µm; the final diameter depends on the initiator system and seed concentration. Excessive charge above 6 phm raises latex viscosity above 5000 mPa·s and can destabilise the reactor during monomer stripping. Coagulum is assessed on a 150 µm sieve after steam distillation, and residual vinyl acetate monomer is controlled below 500 ppm by combined vacuum and purge. For indirect food packaging adhesive applications, latex formulated with SELVOL 504 may be reviewed under 21 CFR 175.105 and 21 CFR 176.170. In formulations requiring wet tack and fast setting on paper, SELVOL 504 is partially replaced with fully hydrolysed grades; complete replacement in water-resistant adhesives is not recommended because acetate-rich chain segments remain sensitive to humid peel.
For water-soluble packaging films used in detergent unit doses and agrochemical sachets, SELVOL 504 is formulated at 100 parts by dry weight with glycerol at 12–18 phr, sorbitol at 5–8 phr, and a silicone-free defoamer at 0.1–0.3 phr. The aqueous dope is prepared at 18–22 wt% total solids and heated to 85–90 °C for 60 min under low-shear mixing, then deaerated under 200–400 mbar vacuum before being cast onto a polyethylene terephthalate belt with a slot die. Because the grade has 87–89 mol% hydrolysis, residual acetate groups break intra-chain hydrogen bonding and permit film disintegration in deionised water at 5 °C without an alkali wash. Cast webs are dried in three zones: 70 °C for setting, 95–110 °C for evaporative drying, and 40 °C for conditioning to 8–12 wt% residual moisture. The dry film is converted by kiss cutting; edge trimming is reprocessed as regrind at up to 20 wt% without blocking the slot die. Tensile properties are evaluated by ASTM D882; the absence of plasticizer exudation is checked after 7 days at 40 °C and 75% RH. In-line thickness is controlled to ±2 µm by beta gauge. When relative humidity in converting exceeds 60%, the film absorbs surface moisture and blocks on the rewinder; preconditioning of the slitting room below 45% RH is therefore mandatory. Combination with amine-based additives is avoided because alkaline amine residues accelerate acetate hydrolysis and reduce shelf stability. Published data for dissolution time specific to SELVOL 504 in finished unit-dose film is limited; converting lines therefore set disintegration windows using an internal protocol at 5 °C in deionised water before commercial release.
Remoistenable envelope flap coatings rely on the fast re-wetting and tack development of partially hydrolysed PVOH when a low-viscosity grade carries a high solids loading without stringing during roll transfer. A converting formulation typically combines SELVOL 504 at 100 parts, glycerol or polyethylene glycol 400 at 5–10 phr, and a modified starch extender at 0–20 phr. The adhesive is prepared at 30–38 wt% solids and held at 45–55 °C in a jacketed tank. Application proceeds by reverse gravure or smooth roll at coat weights of 0.8–2.5 g/m² dry. The coating is dried with forced air at 80–110 °C to a moisture content below 6 wt% before rewinding. Because the grade contains acetate groups at 12–13 mol% of the repeating unit, the film rehydrates on a wet sponge without elevated temperature on standard white wove envelope paper; published data for specific SELVOL 504 re-wetting kinetics is limited. Bond performance is quantified by ASTM D1876 T-peel on conditioned substrates at 23 °C and 50% RH, with fibre tear required for acceptable converting. High relative humidity above 70% causes pre-activation of the dry adhesive and early blocking in stacked blanks. The formulation must not be stored with borax or amine-containing wetting agents because borate crosslinking raises the re-wetting time and amine residues shift the pH above 6.5, accelerating ester hydrolysis in storage.
In vinyl chloride suspension polymerisation, SELVOL 504 is metered as the secondary suspending agent at 0.05–0.25 g/L of aqueous phase alongside a primary fully hydrolysed PVOH at 0.30–0.60 g/L. The distinction is functional: the high hydrolysis grade controls vinyl chloride monomer droplet coalescence, while the partial grade lowers interfacial tension at the reacting monomer-PVC particle and moderates free-radical entry into the growing grain. The ratio of primary to secondary PVOH is maintained between 2:1 and 4:1 by mass, depending on the target K value and cold plasticizer absorption of the PVC resin. In 50–120 m³ autoclaves with turbine agitators, tip speed is held at 1.5–3.0 m/s and polymerisation temperature at 55–65 °C; heat removal is controlled by reflux condenser and jacket. SELVOL 504 is charged before the monomer phase to avoid localised high-viscosity pockets that would generate fine particles below 50 µm. The suspension is monitored by in-situ focused beam reflectance measurement, with volume median droplet size kept within 100–160 µm for pipe-grade PVC. Final resin particle size distribution is measured by dry sieving under ISO 1624, and K value by ISO 1628-2. Excess secondary PVOH above 0.30 g/L reduces grain size, raises fines, and depresses plasticizer absorption below specification. The same grade cannot be used as the sole suspending agent because the partially hydrolysed molecule lacks sufficient graft stabilisation to prevent droplet coalescence at high conversion.
Textile warp sizing of ring-spun polyester/cotton blends uses SELVOL 504 in a size bath at 6–12 wt% solids supplemented with a fatty acid wax at 2–5 wt% of the PVOH dry weight and a defoamer at 0.05–0.10 wt%. The size is prepared in a pressure cooker at 110–130 °C for 30–40 min to dissolve the PVOH completely, then transferred to the slasher box at 80–85 °C. A double-box slasher with Teflon-coated squeeze rolls applies the size to warp yarns at 10–14 kN nip load; add-on on cotton-rich yarns is controlled at 8–12 wt% dry on yarn, while polyester-rich yarns are sized to 6–10 wt%. If slasher speed exceeds 250 m/min, bath viscosity must be reduced toward the lower end of the working range to prevent size splash, doctor blade deposit, and uneven transfer. Yarn abrasion resistance is evaluated on a Zweigle abrasion tester; tensile strength and elongation at break are measured by ASTM D2256. Desizing is carried out in enzyme-free hot water at 70–80 °C for cotton blends, with complete removal assessed by iodine stain. SELVOL 504 is not appropriate as the sole size for high-twist continuous polyester filament because the partial hydrolysis grade gives lower adhesion to hydrophobic filament than fully hydrolysed or modified PVOH grades. The material must be protected from high-humidity storage; caked size flakes above 60% RH form lumps that block the pressure cooker feed screw.
| Application | Standard or regulatory reference |
|---|---|
| Emulsion polymerisation | ISO 2555, ASTM D2196, 21 CFR 175.105, 21 CFR 176.170 |
| Cold-water film | ASTM D882 |
| Remoistenable adhesive | ASTM D1876 |
| PVC suspension polymerisation | ISO 1624, ISO 1628-2 |
| Textile warp sizing | ASTM D2256 |
In blade-coated paper and paperboard finishes, SELVOL 504 serves as a co-binder and water retention modifier in pigmented coatings at 0.5–2.0 parts per 100 parts dry pigment. The grade is pre-dissolved at 15–20 wt% solids and metered into the coating colour after starch cooking but before pigment slurry addition; injection into hot starch above 85 °C is avoided because localised thermal stress can form microgels. The coating formulation is run at 58–65 wt% solids with Brookfield viscosity measured by ISO 2555; high-shear viscosity must be matched to the blade coater model and backing roll speed. The PVOH improves surface strength, dry pick resistance, and optical brightening agent retention without the water-retention drop observed with low-molecular-weight starch alone. Coated sheet is printed on an IGT pick tester; wet pick strength is judged by the number of passes before blistering on a heated web. Because the grade is partially hydrolysed and carries residual acetate groups, it interacts less strongly with borate than fully hydrolysed PVOH, but glyoxal and zirconium ammonium carbonate insolubilizers must be dosed after pH stabilisation to avoid premature crosslinking. At addition levels above 2.5 parts, the coating colour shifts into the dilatant regime and blade scratches appear on high-speed coaters. The use of 0.05–0.10 parts of an anionic dispersant before PVOH addition prevents pigment shock and agglomeration.
Competitive SELVOL Polyvinyl Alcohol 504 prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615380400285 or mail to sales2@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8615380400285
Email: sales2@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
SELVOL Polyvinyl Alcohol 504 is positioned as a medium-viscosity partially hydrolyzed polyvinyl alcohol supplied as a granular solid that hydrates into clear aqueous solutions. The standard release envelope for this model lists a 4 % aqueous solution viscosity of 4.0–5.0 cP at 20 °C, hydrolysis between 87.0 mol% and 89.0 mol%, pH of 4.5–6.5, volatile content not exceeding 5.0 wt%, and ash content not exceeding 0.5 wt%. Primary industrial placements include emulsion polymerization as a protective colloid, textile warp sizing, paper surface sizing, remoistenable adhesive compounding, and temporary water-soluble film formation. The grade differs from fully hydrolyzed polyvinyl alcohol by retaining more residual acetate functionality, which suppresses interchain crystallinity and lowers the temperature needed for complete dissolution. It differs from lower-viscosity partially hydrolyzed products such as SELVOL 502 by building higher wet-film viscosity at equivalent solids, and it differs from higher-viscosity partially hydrolyzed products such as SELVOL 508 by offering easier solution make-up and more uniform transfer on certain coating lines.
Hydrolysis level governs the frequency of pendant acetate groups along the polyvinyl alcohol backbone. In SELVOL 504, the residual acetate moieties interrupt interchain hydrogen bonding and reduce crystalline packing relative to fully hydrolyzed grades in the 98–99 mol% range. That structural disruption permits dissolution in cold or tepid water under moderate agitation, whereas fully hydrolyzed PVOH often requires heating above 70–80 °C. The same acetate groups increase affinity for hydrophobic polymer surfaces, including corona-treated polyolefins and polyester film, which supports selection in tie-coat and sizing operations where wetting must occur before film consolidation.
Films cast from SELVOL 504 typically exhibit lower tensile modulus and higher elongation than equivalent fully hydrolyzed materials when conditioned at 23 °C and 50 % RH and evaluated by ISO 527-3. Published single-point data for this exact grade are limited; film mechanical response must be confirmed against the intended end use because plasticizer type, residual moisture, and drying history shift stress-strain behavior. Residual acetate groups also reduce wet strength after dry-film formation, so substituting SELVOL 504 into a fully hydrolyzed barrier application without re-qualifying water resistance is not recommended.
Residual acetate content also shifts solubility-parameter and interfacial-tension behavior, allowing stable aqueous emulsions to be produced with lower total emulsifier demand in certain nonionic surfactant systems. This response is used in emulsion polymerization but requires control because excess acetate in the final film can increase re-wettability and reduce blocking resistance in stacked coated sheets. Blocking evaluations are frequently performed at 40 °C and 70 % RH for 24 h using converter-specific protocols.
In emulsion polymerization, the grade is charged as a pre-dissolved protective colloid or added into the aqueous phase before monomer delay feed begins. Trials on jacketed stainless-steel reactors with turbine agitation indicate that the polymer disperses more uniformly when pre-slurried in cold water, heated to approximately 90 °C for full dissolution, and cooled before initiation. During polymerization, the colloid stabilizes vinyl acetate homopolymer and vinyl acetate-ethylene dispersions through adsorption at the polymer-water interface and through continuous-phase viscosity development. Moving from SELVOL 502 to SELVOL 504 raises latex viscosity and shifts particle size distribution; therefore solids, initiator feed rate, and agitation speed are adjusted to maintain target rheology. The molecular weight of SELVOL 504 is below that of SELVOL 508 or SELVOL 513, which reduces shear-thinning at equivalent solids while maintaining sufficient film coalescence for lamination. Process boundaries include maintaining pH between 4.5 and 6.5 and excluding borate ions from the reactor. Borate-diol complexation can produce a sharp viscosity increase and gel aggregates that foul impeller blades and heat-transfer surfaces.
The protective-colloid mechanism proceeds through grafting of vinyl acetate onto the PVOH chain during free-radical initiation, producing an amphiphilic graft copolymer that anchors the particle and improves shear stability. Graft density is sensitive to initiator selection; hydrogen peroxide-ascorbic acid redox initiation can produce different graft architecture than persulfate initiation at comparable addition rates. For this reason, reactor operators changing from another PVOH grade to SELVOL 504 should hold the initiation profile constant during grade evaluation, because graft density affects latex filterability, coagulum generation, and clean-in-place frequency. On production lines using diaphragm or lobe pumps, high shear at low temperature can create stable foam that carries into monomer stripping; antifoam dosing or pressure filtration may be required.
The specification table below summarizes typical control parameters used to establish lot-to-lot consistency for SELVOL Polyvinyl Alcohol 504. The viscosity control point is determined on a 4 % aqueous solution at 20 °C using a falling-ball viscometer; moisture and volatile content are controlled by loss on drying.
| Characteristic | Control Range or Typical Value | Basis |
|---|---|---|
| Viscosity, 4 % aqueous solution at 20 °C | 4.0–5.0 cP | Falling-ball viscometer; process control method |
| Hydrolysis | 87.0–89.0 mol% | Residual acetate titration |
| pH, 4 % aqueous solution | 4.5–6.5 | Direct pH electrode |
| Volatile content | ≤5.0 wt% | Loss on drying |
| Ash content | ≤0.5 wt% | Residue on ignition |
| Methanol residue | ≤1.0 wt% | Headspace gas chromatography |
Where food-contact compliance is claimed, converters commonly evaluate SELVOL 504 under FDA 21 CFR 175.105 for adhesives or FDA 21 CFR 176.170 and 176.180 for paper and paperboard. European use requires verification under EU 10/2011 for the intended food-simulant and migration-test conditions. These references are application-specific and do not replace migration testing on the finished article.
Grade substitution is usually driven by solution viscosity and wet-film build. The comparative table below places SELVOL 504 within the partially hydrolyzed product series; hydrolysis is held within a narrow window while solution viscosity increases with molecular weight.
| Grade | 4 % Aqueous Viscosity at 20 °C | Hydrolysis | Typical Compounding Effect |
|---|---|---|---|
| SELVOL 502 | 2.5–3.5 cP | 87.0–89.0 mol% | Lower solution viscosity; easier pumping; reduced wet-film thickness at equal solids |
| SELVOL 504 | 4.0–5.0 cP | 87.0–89.0 mol% | Balanced solution viscosity and film strength; medium-viscosity grade for general compounding |
| SELVOL 508 | 7.0–9.0 cP | 87.0–89.0 mol% | Higher solution viscosity; improved dry-film toughness; slower dissolution and lower leveling |
At equal solids, moving from SELVOL 502 to SELVOL 504 increases wet-film thickness and initial tack development but also raises mixing torque in high-shear mixing units and increases drying load in multi-zone ovens. Moving from SELVOL 504 to SELVOL 508 can improve dry-film tensile strength but narrows the working window for knife-over-roll coating because higher solution viscosity reduces leveling. Validation should include viscosity measurement per DIN 53015, solids determination by refractive index, and adhesive shear strength per ASTM D905 or the finished-article standard specified by the converter.
Viscosity boundaries are not absolute performance thresholds; they represent the release window for lot-to-lot consistency. A formulator using lots at 4.0 cP and 5.0 cP may need to adjust coating solids, but the adjustment is nonlinear because PVOH solution viscosity rises steeply at higher solids. In adhesive compounding, a shift from the lower to upper end of the viscosity window can alter transfer on two-roll applicators and change final coat weight, so gravimetric coat-weight checks should be performed at lot changes.
In textile warp sizing, SELVOL 504 is cooked with waxes and lubricants in jacketed starch cookers. Typical PVOH concentrations of 8–12 wt% are applied on slasher lines. The grade provides lower film stiffness than fully hydrolyzed products and is removed more readily during desizing, which reduces warp break risk on high-speed looms. The 87.0–89.0 mol% hydrolysis level reduces redeposition on drying cylinders and improves splitting at lease rods. Desizing efficiency after weaving can be assessed by weight loss or colorimetric test methods; the partially hydrolyzed film typically shows faster enzymatic or oxidative removal than fully hydrolyzed size films. Published data for this exact grade on a specific fabric construction are limited.
For paper surface sizing, size-press solids of 2–5 wt% are common. The low solution temperature of SELVOL 504 allows preparation at ambient-to-warm water temperatures, lowering steam demand compared with fully hydrolyzed PVOH. Surface strength after size-press application is typically evaluated by TAPPI T 459 or ISO 3783; results depend on base-sheet porosity, starch ratio, and drying profile. The grade contributes to film formation and pick resistance, but final performance is determined by the entire surface-sizing formulation.
Solution make-up for roll coating and size-press operations generally uses a jacketed tank with a high-shear disperser. The powder is added slowly to a cold-water vortex at moderate tip speed to disperse without fish-eye agglomerates, then heated to 90–95 °C for 30–60 min with continued agitation. Batch-to-batch viscosity control improves when the solution is cooled to 25 °C before final volumetric adjustment because PVOH viscosity is strongly temperature-dependent. Inline viscosity readings should be temperature-compensated against the 20 °C control basis.
Dry storage in unopened bags under ≤30 °C and ≤65 % RH is recommended to prevent caking and moisture uptake. Once dissolved, aqueous solutions should be cooled below 40 °C before preservative addition because prolonged warm storage promotes microbial growth. The polymer should not be combined with borate-releasing additives, concentrated strong mineral acids, or incompatible polyvalent salts in concentrated solution due to gelation or precipitation. For melt processing or compounding into polar polymer matrices, pre-drying to ≤0.5 wt% moisture is advisable, and processing above 200 °C should be justified by plasticizer thermal stabilization because degradation can accelerate beyond that threshold. Torque rheometry and melt-flow analysis are recommended before scale-up of melt-processed formulations containing SELVOL 504.
