| HS Code | 932053 |
| Product Name | SELVOL Polyvinyl Alcohol 125 |
| Chemical Name | Polyvinyl Alcohol |
| Cas Number | 9002-89-5 |
| Chemical Formula | (C2H4O)n |
| Appearance | White granular powder |
| Degree Of Hydrolysis | 98.5 - 99.5 mol% |
| Viscosity 4 Solution At 20 C | 26 - 30 mPa·s |
| Ph 4 Solution | 5.0 - 7.0 |
| Ash Content | ≤ 1.0% |
| Volatile Matter Moisture | ≤ 5.0% |
| Bulk Density | 0.4 - 0.6 g/cm³ |
| Density | 1.19 - 1.31 g/cm³ |
| Melting Point | 220 - 240 °C |
| Glass Transition Temperature | 75 - 85 °C |
| Solubility | Soluble in hot water; insoluble in most organic solvents |
As an accredited SELVOL Polyvinyl Alcohol 125 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SELVOL Polyvinyl Alcohol 125 is supplied as a white powder in 25 kg multiwall paper bags. |
| Container Loading (20′ FCL) | 20′ FCL containing SELVOL Polyvinyl Alcohol 125, bagged and palletized, securely loaded for safe, efficient transport. |
| Shipping | SELVOL Polyvinyl Alcohol 125 ships as a dry, water-soluble powder in multi-wall paper bags or fiber drums. Ensure containers are sealed and stored in a cool, dry area. Non-hazardous per DOT, but avoid dust inhalation and moisture exposure during transport. |
| Storage | Store SELVOL Polyvinyl Alcohol 125 in its original, tightly sealed container in a cool, dry, well-ventilated area away from direct sunlight and moisture. Avoid high humidity, as PVA is hygroscopic. Maintain moderate temperatures and keep away from incompatible materials. Proper storage preserves product quality, flow, and shelf life. |
| Shelf Life | Shelf life is approximately two years from manufacture when stored unopened in a cool, dry environment away from moisture. |
Aqueous-phase preparation of SELVOL Polyvinyl Alcohol 125 in a vinyl acetate–ethylene (VAE) pressure reactor is typically set at 2.0–5.0 wt% on total monomer feed. The 88 mol% degree of hydrolysis and 12–15 cP viscosity, measured as a 4% aqueous solution at 20°C, produce stable steric barriers around polymerising latex particles without the excessive grafting observed with fully hydrolysed grades. Pre-dissolution requires a jacketed stainless steel vessel held at 85–90°C for 60–90 min, followed by cooling to 40–50°C and filtration through a 100–150 μm mesh before introduction into the seed stage. In a semi-batch train with persulfate initiators, the unimodal particle size is maintained between 0.8–1.2 μm; lower protective-colloid additions near 2.0 wt% increase coarse grit in the kettle, while dosages above 5.0 wt% elevate dry-film water whitening and reduce adhesion to polar substrates. The resulting emulsion viscosity is commonly adjusted to 2,000–4,000 mPa·s at 25°C for wood bonding and packaging lamination. Compliance for indirect food-contact adhesives is evaluated under FDA 21 CFR 175.105, and migration testing may be required under EN 1186-1:2002. Batch-to-batch variance in PVOH ash content, typically below 0.5%, should be monitored because sodium acetate residues can shift persulfate decomposition rates and final latex pH.
Thermochemical starch cooking at 120–130°C in a jet cooker supplies the main sizing solids, while SELVOL Polyvinyl Alcohol 125 is prepared separately as a 10–15% aqueous solution and blended into the size press feed. Replacement of starch at 10–25% dry-weight equivalent raises surface strength and reduces dusting on high-speed paper machines. The low viscosity of PVOH 125, 12–15 cP at 4% solids, permits size press solids up to 8–10% without overloading film-transfer rolls. At replacement ratios above 30%, porosity decreases and drying demand increases. Surface sizing performance is assessed by ISO 535 Cobb water absorptivity and by IGT pick resistance according to ISO 3783. For food-contact paperboard, the formulation falls under FDA 21 CFR 176.170 or 176.180 depending on the food type. Process control requires continuous viscosity monitoring at the size press; boric acid should not be used in the same circulation loop because it crosslinks PVOH and can cause gel deposition on doctor blades.
On a multi-cylinder slasher running 65/35 polyester/cotton warp yarns, SELVOL Polyvinyl Alcohol 125 is blended into a size mix at 8–12% solids. A typical formula contains 1 part PVOH 125 to 0.25–0.40 part acrylic size, with 0.02–0.05 part wax lubricant based on dry solids. The size box temperature is held at 60–70°C to keep the film flexible during yarn separation at the lease rods. Dry can temperatures are staged from 90°C to 120°C; final moisture on the warp should remain near 7–8%. Partially hydrolysed PVOH provides lower film strength than fully hydrolysed grades but easier hot-water desizing. Warp tensile retention and abrasion resistance are evaluated under ASTM D2256 and ASTM D3884. High-humidity weaving sheds above 85% RH can soften the size film and reduce loom efficiency, while dry sheds below 40% RH may cause size shedding at the drop wires. Desizing uses water at 70–80°C plus amylase when starch is present; PVOH 125 alone is removed without enzymatic treatment. This track has fewer kinetic conflicts than emulsion polymerisation, but its cost-benefit depends on reclamation of size liquor through ultrafiltration.
Solution casting of SELVOL Polyvinyl Alcohol 125 into water-soluble packaging film requires plasticiser addition to avoid brittle failure at high line speeds. A typical casting dope contains 18–22% total solids, with 10–15 wt% glycerol or sorbitol on dry PVOH, 0.5–1.5 wt% nonionic surfactant, and the balance PVOH 125. The solution is degassed under vacuum at 50–60°C before slot-die coating onto a chromium-plated belt or chill roll. Drying is staged from 90°C to 110°C, yielding film thickness between 35–75 μm. Partially hydrolysed grades dissolve faster in cold water than fully hydrolysed grades, but film tensile strength is lower. Extrusion of this grade without plasticiser is not processable; thermal degradation initiates near 200°C. The film is used for hospital laundry bags, agrochemical sachets, and dye-transfer inhibitor sheets. For packaging not regulated as food contact, mechanical and solubility specifications are often verified by supplier-internal methods. Regulatory compliance for packaging waste is assessed under EN 13432 for compostability where applicable, though water-soluble PVOH film is not a compost packaging solution. Residual moisture in the film must remain below 3% to prevent blocking on the reel.
Spray drying of VAE dispersions stabilised with SELVOL Polyvinyl Alcohol 125 uses a rotary atomiser or pressure nozzle. Feed solids are adjusted to 45–50%, with PVOH 125 added at 8–12 wt% on dry polymer before drying. Inlet air temperature is set at 130–170°C, and outlet air is controlled at 65–75°C to avoid exceeding the glass transition of the secondary protective colloid layer. Powder rewetting and redispersion are checked in a standard cylinder test; acceptable powders produce a smooth dispersion without visible grit after 30 min stirring at 500 rpm. In a C2TE/S1 cementitious tile adhesive, the redispersible polymer powder is added at 2.5–4.0 wt% of total dry mortar. Adhesion after water immersion and heat ageing is measured according to ISO 13007-2. The primary risk is nozzle blockage when feed viscosity exceeds 500 mPa·s; defoamer selection must be neutral to PVOH 125 because silicone-based defoamers can destabilise the redispersed latex and lower tensile adhesion. The final mortar must be stored at <50% RH to prevent powder caking.
Release barrier coats for open-mould composite lamination are produced from a 5–8% aqueous solution of SELVOL Polyvinyl Alcohol 125 applied at 30–50°C by spray or brush. The dried film, typically 20–40 μm, forms a water-soluble membrane between the tool gelcoat and the polyester or vinyl ester laminate. It prevents styrene migration into the tool surface and permits clean demoulding without silicone contamination that would interfere with post-mould painting. Spray application uses an air-assisted spray gun at 2.0–3.0 bar; brushing requires multiple passes to avoid pinholes. The principal operational limit is re-dissolution in humid workshops or when moulds are washed with water; the barrier coat is not suitable for outdoor mandrels exposed to rain. Film uniformity is verified by dry film thickness measurement, and adhesion is assessed by the tape snap test according to ASTM D3359. This application has a broad process window and the critical variable is drying time rather than polymer chemistry.
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Product designation SELVOL Polyvinyl Alcohol 125 identifies a partially hydrolysed polyvinyl alcohol resin supplied as white, free-flowing granules. The resin is manufactured through controlled methanolysis of polyvinyl acetate and is specified by a 4% aqueous solution viscosity of 5.0–6.0 mPa·s at 20°C and a hydrolysis degree of 86.0–89.0 mol %. Residual volatile matter is held to ≤5.0 wt % following 3 h drying at 105°C; ash as sodium oxide is ≤0.5 wt %; and the pH of a 4% solution is 4.5–6.5. Bulk density typically ranges from 0.55 g/cm³ to 0.70 g/cm³. The grade is differentiated from fully hydrolysed PVOH of comparable molecular weight by its approximately 12 mol % residual acetate functionality, which lowers the dissolution temperature, reduces crystallinity, and modifies surface activity in aqueous protective-colloid and adhesive applications.
Procurement specifications should reference JIS K6726:1994 or ISO 15023-2:2019 for viscosity and hydrolysis. The 4% solution is prepared with distilled water and heated to 90–95°C for 30–60 min, then cooled to 20°C before determination with a Brookfield LV/RV viscometer. Hydrolysis is determined by residual acetate titration. Ash is determined after combustion at 700°C and reported as sodium oxide. The following certificate-of-analysis benchmarks are used for release.
| Property | Test method | Release specification |
|---|---|---|
| Viscosity, 4% aqueous solution | JIS K6726 / ISO 15023-2, 20°C | 5.0–6.0 mPa·s |
| Hydrolysis degree | JIS K6726, residual acetate titration | 86.0–89.0 mol % |
| Volatile matter | 105°C, 3 h | ≤5.0 wt % |
| Ash as Na₂O | 700°C combustion | ≤0.5 wt % |
| pH, 4% solution | JIS K6726 | 4.5–6.5 |
At ambient plant conditions exceeding 60% RH, granules pick up moisture and should be pre-dried at 40–50°C to below 5.0 wt % before gravimetric dispensing. Dissolution is conducted by dispersing the resin in cold water under agitation, heating to 85–95°C for 30–60 min, and holding at temperature until the solution clears. Prolonged holding above 95°C accelerates hydrolysis and yellowing. Storage of non-preserved solutions beyond 24 h requires a compatible biocide because PVOH is biodegradable in aqueous systems. The resin should not be blended with strong oxidising agents or with borate salts unless controlled crosslinking is intended.
Partially hydrolysed PVOH 125 is used as a protective colloid in emulsion polymerisation of vinyl acetate and vinyl acetate-ethylene copolymers. The residual acetate groups increase interfacial activity relative to fully hydrolysed grades, allowing lower surfactant demand and promoting stable particle nucleation. Typical loading in batch and continuous stirred-tank reactors is 2–5 wt % on monomer, with the PVOH pre-dissolved to 5–10% solids. Process control at production scale hinges on viscosity of the aqueous phase; at 20°C, a 4% solution at 5.0–6.0 mPa·s still shows shear-thinning behaviour under high-shear transfer pumps. For reactor surveillance, emulsion viscosity can be monitored by ISO 2555 or ASTM D2196 Brookfield methods; particle size distribution is measured by laser diffraction under ISO 13320. Coagulum in the reactor is reduced when the PVOH is fully hydrated before monomer addition; incomplete hydration leaves gel nuclei that raise filter blockage. Published data for this specific configuration is limited when reactors operate above pH 6.5 because hydrolysis of polyvinyl acetate may generate acetic acid and drift the pH downward.
For paper surface sizing, a 2–6% solids solution of SELVOL 125 is applied at 50–60°C in a size press or film coater. Oil and grease resistance develops as the resin fills pore voids and forms a continuous film; Kit values can be measured by TAPPI T 559 cm-12. Surface strength improvement is monitored by TAPPI T 459 or ISO 3783. Paper machine runnability depends on solution viscosity stability under shear; the low 4% viscosity of 5.0–6.0 mPa·s permits higher solids at equivalent machine-application viscosity than higher-viscosity grades, reducing the drying load.
In water-activatable and remoistenable adhesives, SELVOL 125 provides a balance of wet tack and set speed because the partially hydrolysed structure swells rapidly at ambient temperature while still forming a heat-sealable film. Formulation with plasticisers such as glycerol or pentaerythritol at 5–30 wt % on resin reduces film brittleness; borax addition at 0.5–2.0 wt % on dry resin produces a reversible coordinate crosslink that raises high-shear viscosity but can gel the batch above pH 9.0. Mixing characteristics depend on the low-shear viscosity of the cooked PVOH solution; a 4% solution at 5.0–6.0 mPa·s can be transferred through lobe pumps without cavitation, while high-shear mixing should be limited to ≤60°C to avoid shear-induced molecular weight loss. Adhesive film tensile properties can be tested according to ASTM D882; peel adhesion on paper is commonly evaluated by ASTM D1876 or equivalent. When the formulation includes fully hydrolysed PVOH grades, the user typically observes lower cold-water solubility but improved water resistance; when it includes low-viscosity partially hydrolysed grades, wet tack declines but machine cleanability improves. Formulated adhesive viscosity is controlled by ASTM D1084 or ASTM D2196, and pH is measured by ASTM E70.
The selected grade differs from fully hydrolysed polyvinyl alcohol grades in three practical respects. First, the residual acetate content lowers the dissolution temperature from approximately 96°C for fully hydrolysed grades to 85–95°C for SELVOL 125. Second, the lower crystallinity yields films with higher water sensitivity and lower tensile modulus; a fully hydrolysed grade of equivalent viscosity typically provides higher water resistance and barrier under humid conditions. Third, the partially hydrolysed structure reduces the minimum film-forming temperature in aqueous formulations and permits higher solids at equal process viscosity. Against lower-viscosity partially hydrolysed grades, SELVOL 125 provides greater green strength in adhesive applications but demands longer hydration and higher mixing torque. Against higher-viscosity partially hydrolysed grades, SELVOL 125 is preferred when spray drying or high-speed coating requires lower Brookfield viscosity.
PVOH 125 can be incorporated in water-based barrier coatings for paper and board. At dry coat weights of 2–10 g/m², the oxygen transmission rate declines relative to uncoated board when measured at 23°C and 0% RH according to ASTM D3985; performance at 80% RH decreases sharply because the polymer plasticises with moisture. The resin may be used in food-contact structures under FDA 21 CFR 177.1670 for polyvinyl alcohol film, provided end-use testing addresses migration limits of residual vinyl acetate monomer and processing aids. Where EU food-contact compliance is required, the finished article must be evaluated against Commission Regulation (EU) No 10/2011 for overall migration and any applicable specific migration limits. The material is not suitable for direct contact with liquid water without co-binders, because the partially hydrolysed grade swells and loses barrier function under sustained wet exposure. Thermoplastic processing of PVOH 125 on a twin-screw extruder with L/D 44:1 and barrel temperature profile 120–180°C is feasible only with sufficient plasticiser and pre-dried resin; the melt rheology is shear-sensitive and residence time should be held below 5 min to avoid discolouration. Published data for this specific configuration is limited.
