| HS Code | 817140 |
| Product Name | Shuangxin 26-99 PVA (PVA 100-70) |
| Cas Number | 9002-89-5 |
| Appearance | White granular powder |
| Degree Of Polymerization | 2600 |
| Degree Of Hydrolysis | 99.8 - 100.0 mol% |
| Viscosity 4 Aqueous Solution 20 C | 60.0 - 70.0 mPa·s |
| Ph 4 Aqueous Solution | 5.0 - 7.0 |
| Ash Content | ≤ 1.0% |
| Volatile Content | ≤ 8.0% |
| Sodium Acetate Content | ≤ 2.0% |
As an accredited Shuangxin 26-99 PVA (PVA 100-70) factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Shuangxin 26-99 PVA (PVA 100-70) is supplied in 25 kg multi-walled paper bags with a polyethylene liner. |
| Container Loading (20′ FCL) | Shuangxin 26-99 PVA (PVA 100-70) is loaded in a 20′ FCL, with bags palletized and secured for safe transport. |
| Shipping | Shuangxin 26-99 PVA (PVA 100-70) ships as a non-hazardous, water-soluble powder in sealed multi-layer bags or 25 kg sacks. Keep dry, palletized, and protected from moisture, heat, and direct sunlight during transit. Standard freight handling applies; avoid compression to preserve flow and dissolution properties. |
| Storage | Store in a cool, dry, well-ventilated area, away from direct sunlight, heat, and ignition sources. Keep the original container tightly sealed to prevent moisture absorption and contamination. Avoid generating dust; keep separated from oxidizing agents. Ensure proper labeling and access restricted to trained personnel. |
| Shelf Life | Shelf life is typically 12 months from manufacture when stored unopened in a cool, dry, well-ventilated area. |
Shuangxin 26-99 PVA (equivalent designation PVA 100-70) is introduced into warp size formulations for high-density cotton/polyester weaving lines because the 99 mol% hydrolysis level limits cold-water sensitivity after regenerated film formation, while the degree of polymerisation of 2600 contributes film tensile strength values from 40 MPa to 60 MPa when measured on cast films according to ISO 527-3:2018 after conditioning at 23 °C and 50% RH. In blended starch/PVA size mixtures, the dry PVA addition ratio ranges from 8 wt% to 12 wt% of total size solids for high-count polyester/cotton warp yarns; single-component PVA formulations are applied at an aqueous concentration of 5 wt% to 10 wt%. Size preparation on production-scale lines uses a high-shear jet cooker at 95 °C to 98 °C for 45 min to 60 min, followed by holding at 75 °C to 80 °C. Application through a size box with squeeze roller pressure of 20 kN/m to 40 kN/m is followed by multi-zone hot-air drying with zone temperatures from 110 °C to 130 °C, after which warp yarn regain is held at 4% to 6% to avoid blocking on loom beams. Compliance for this segment is evaluated under ZDHC MRSL v3.1 and OEKO-TEX Standard 100 Annex 6; desizing effluent can be handled with hot-water extraction at 80 °C to 90 °C followed by ultrafiltration recovery. Terminal greige articles include twill, poplin, and workwear woven fabrics. The operational boundary is that final moisture content below 3% increases brittleness and above 7% induces beam blocking in humid weave rooms.
In the size press of a fine paper machine running above 800 m/min, substitution of oxidised starch with a fully hydrolysed polyvinyl alcohol at an addition level of 0.5 wt% to 1.5 wt% dry PVA on dry paper reduces Cobb water absorptiveness below 30 g/m2 when tested according to ISO 535:2014 and supports grease resistance ratings under ISO 16532-1:2008 without fluorochemical wet-end chemicals. The size press formulation is prepared at 6 wt% to 9 wt% total solids with a PVA-to-starch dry solids ratio of 10:90 to 30:70; the circulating size pump must maintain Brookfield viscosity below 200 mPa·s at 65 °C to avoid rod marks and transfer defects on film press applicators. Production uses a film press or metering rod size press with circulating temperature control at 65 °C to 70 °C, followed by infrared pre-drying and cylinder drying with surface temperatures of 100 °C to 110 °C. For food-contact paper and board, the formulation falls under FDA 21 CFR 176.170 as a paper and paperboard component when good manufacturing practices are documented. Terminal grades include grease-resistant sandwich wrap, bakery bags, and linerboard for dry foods. The operational boundary is that exceeding 9 wt% size press solids may create transfer defects on high-speed machines, and retention of the water-soluble PVA in the broke system must be controlled to avoid deposit accumulation on dryer felts.
Because residual ash and trace chloride in the polyvinyl alcohol backbone become incorporated into the interlayer during PVB synthesis, low ash content below 0.3 wt% and a high degree of polymerisation of 2600 determine the suitability of the 26-99 grade as a feedstock for polyvinyl butyral resin, where the aqueous PVA solution is acetalized with n-butyraldehyde in the presence of an acid catalyst. The initial PVA concentration in the aqueous phase is maintained at 8 wt% to 12 wt%, and the molar ratio of n-butyraldehyde to vinyl alcohol units is controlled between 0.45 and 0.60 depending on target residual hydroxyl content. The reaction is conducted in a glass-lined reactor equipped with a high-turbulence impeller; dissolution of the 26-99 grade requires jacket temperatures of 90 °C to 95 °C and 30 min to 60 min holding to prevent gel particles, followed by cooling to 10 °C to 20 °C before aldehyde addition. Acetalization then proceeds under pH control from 1.0 to 2.0, and the precipitated PVB is neutralised and washed until residual chloride is below 100 ppm. Finished interlayer film is tested for tensile properties under ISO 527-3:2018 and for laminated safety glass performance under EN ISO 12543-2:2011. Terminal products include automotive and architectural laminated safety glass interlayers. Operational boundaries include exclusion of oxygen during dissolution to limit yellowing and avoidance of amine-based additives because acidic catalyst residues cause pH drift that shifts the degree of acetalization.
Cementitious tile adhesives and gypsum-based patching compounds formulated with water-soluble PVA 26-99 exhibit water retention and consistency control when the powder is dry-blended at 0.3 wt% to 0.8 wt% on total dry mortar solids, which corresponds to 0.5 kg to 1.5 kg per 100 kg of cementitious binder. The production process uses a single-shaft pan mixer operating at 15 rpm to 20 rpm for 10 min to 15 min before bagging, because higher shear can generate electrostatic fines and reduce batch uniformity. Site mixing is specified with a high-torque paddle mixer at 400 rpm to 600 rpm and a water-to-powder ratio of 1:4 until a lump-free ribbon is obtained. The hardened adhesive is tested for tensile adhesion strength after 28 days of dry conditioning under EN 12004:2007+A1:2012, while fresh mortar consistency is checked by the flow table method under EN 1015-3:1999/A1:2004. Terminal products include interior thin-bed ceramic tile adhesives, gypsum joint compounds, and skim coats. The operational boundary is that the grade is not equivalent to spray-dried VAE copolymer powders and is not recommended for exterior water-immersion exposure because the polyvinyl alcohol remains soluble and may leach under prolonged wet conditions.
In low-solids ceramic slurries, the 26-99 grade acts as a temporary binder at a dosage between 1.0 wt% and 3.0 wt% of ceramic powder mass for alumina and zirconia bodies; above 4.0 wt% the apparent viscosity at 10 s−1 exceeds 2000 mPa·s and vacuum degassing time increases beyond 60 min. The slurry is prepared by ball milling at 60 wt% solids for 12 h to 24 h, followed by deaeration under vacuum at 50 mbar and casting through a doctor blade gap of 0.5 mm to 1.0 mm. Drying is staged from 25 °C to 60 °C to avoid skinning, and green tape tensile strength is checked with a texture analyser equipped with a 50 N load cell rather than by an ASTM flexural standard because green body fracture is not equivalent to sintered advanced ceramics. Burnout behaviour is verified by thermogravimetry under ISO 11358-1:2014 and ash content of the binder by ISO 3451-1:2019; residual ash must remain below 0.3 wt% after 600 °C to avoid contamination of sintered parts. Terminal products include ceramic substrates, multilayer ceramic carrier plates, and extruded alumina bodies. The operational boundary is that sodium or ash above 0.5 wt% shifts the burnout onset and can generate surface defects on sintered ceramics.
When a remoistenable adhesive specification requires block-free dry film above 35 °C and rapid tack upon remoistening with water, the 26-99 grade is formulated at resin solids of 15 wt% to 25 wt% in aqueous solution together with glycerol plasticiser at 10 to 20 parts per 100 parts PVA dry solids and dextrin at 30 to 50 parts per 100 parts PVA dry solids where viscosity reduction is needed. The solution is batch-cooked at 80 °C to 85 °C for 20 min to 30 min and applied by reverse roll coater at a wet deposition of 50 g/m2 to 80 g/m2, followed by forced-air drying at 60 °C to 80 °C. Viscosity at 20 wt% solids is controlled by equipment selection because the grade can produce Brookfield readings above 2000 mPa·s at 25 °C, which falls outside the operating envelope of high-speed roller coaters without heated transfer lines. Compliance for indirect food-contact packaging adhesives is documented under FDA 21 CFR 175.105, and the dry adhesive film is evaluated for blocking resistance in a humidity cabinet at 50 °C and 50% RH for 24 h. Terminal products include remoistenable envelope front seals, stamp gumming, label adhesives, and spiral-tube winding gums. The operational boundary is that exposed dry film becomes tacky above 80% RH and should not be used where ambient humidity exceeds that threshold for extended storage.
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Shuangxin 26-99 PVA, also distributed under the sourcing synonym PVA 100-70 in certain supply chains, is a fully hydrolyzed, high-molecular-weight polyvinyl alcohol resin. The 26-99 designation denotes a nominal polymerization degree of 2600 and an alcoholysis degree of 99 mol%, placing the material in the upper segment of the producer’s homopolymer range. Typical certificate-of-analysis values for the 4 wt% aqueous solution viscosity at 20 °C fall within 56–66 mPa·s when determined in accordance with GB/T 12010.2-2010. Volatile matter is generally held below 5.0 wt%, ash below 0.7 wt%, and pH in a 5–7 range for the aqueous solution. The resin is supplied as white to off-white granules with a typical density of 1.26–1.30 g/cm³. Because the parenthetical descriptor PVA 100-70 is a distribution synonym, lot-specific values should be confirmed against the manufacturer certificate of analysis and ISO 15023-2:2019 classification practice.
Compared with lower-polymerization-degree fully hydrolyzed grades, 26-99 occupies the highest conventional viscosity class among the widely distributed 99-series products. The viscosity increase from 24-99 to 26-99 is approximately 15–25% at equal solids, primarily because of chain-length distribution rather than a shift in alcoholysis degree. In the entangled solution regime, low-shear viscosity rises as a power law of molecular weight, so a relatively small change in polymerization degree produces a conspicuous change in Brookfield readings and wet-film pickup. This nonlinearity is the central reason that 26-99 is reserved for applications where film cohesion, size-film toughness, or resistance to liquor penetration into porous substrates dominates processing decisions.
Table 1 compares the 4 wt% aqueous solution viscosity classes at 20 °C for fully hydrolyzed grades in the same producer series. The values are typical class ranges derived from manufacturer literature and GB/T 12010.2-2010 viscosity practice.
| Grade | 4 wt% aqueous viscosity at 20 °C (mPa·s) | Alcoholysis degree (mol%) | Relative viscosity build at equal solids vs 17-99 |
|---|---|---|---|
| 17-99 | 25–31 | 99.0–99.8 | 1.0× |
| 20-99 | 37–45 | 99.0–99.8 | 1.5× |
| 24-99 | 44–52 | 99.0–99.8 | 1.7× |
| 26-99 | 56–66 | 99.0–99.8 | 2.1× |
Partially hydrolyzed grades such as 17-88 and 24-88, with 88 mol% alcoholysis, dissolve more readily in cold water. At 20 °C, 17-88 can yield clear solutions above 10 wt% within 60 min under stirring, whereas 26-99 remains below 1 wt% dissolution after 2 h without heat. This solubility gap determines application selection: 26-99 is selected when the dried film must retain low cold-water sensitivity, while 17-88 is selected for cold-water-soluble packaging, release films, or emulsion polymerization protective colloid use. Film cast from 26-99 and conditioned at 23 °C/50% RH shows tensile strength in the 60–90 MPa range and elongation at break in the 80–150% range when tested under ISO 527-3; corresponding 88 mol% grades typically fall 20–40% lower in tensile strength at equal film thickness.
In vinyl acetate emulsion polymerization, 26-99 is not a first-choice primary protective colloid because its fully hydrolyzed character and high molecular weight generate higher latex viscosity and broader particle-size distribution at equivalent dosage. Partially hydrolyzed grades such as 17-88 or 24-88 at 2–4 wt% based on vinyl acetate provide more efficient stabilization and lower reactor viscosity. If 26-99 is used as a co-stabilizer, addition above 1 wt% of monomer is generally avoided to prevent mixer-torque excursions and a coarse latex fraction.
For a 4.0 wt% solution, the granules are first pre-slurried in deionized water at 25–30 °C under turbine agitation at 150–300 rpm. The slurry is then transferred to a jacketed dissolving vessel fitted with a low-shear three-blade agitator and heated to 90–95 °C. Complete dissolution is normally reached after 60–90 min at 90–95 °C, after which the solution is passed through a 150 μm filter bag before use. In a 500 L jacketed vessel with a side-entering turbine, 20 kg of 26-99 granules can be dissolved in 480 L of water within 90 min without vortexing if agitator speed is held at 250–350 rpm. Prolonged hold times above 100 °C should be limited to less than 4 h; extended heating promotes dehydration and acid-catalyzed chain scission, which lowers the 4 wt% viscosity and shifts solution color toward yellow.
Field experience on a single-station size press with a working width of 1,200 mm and line speeds of 120–180 m/min indicates that 4.0–5.0 wt% 26-99 size solutions generate a wet pickup of 3–6 g/m². Pickup above 8 g/m² typically creates drying-capacity bottlenecks and visible deposit on downstream doctor blades. The same production-scale configuration demonstrates that the high molecular weight of 26-99 reduces liquor migration into the base sheet, allowing the surface to retain a more continuous film at lower total add-on. This is a processing advantage on lightweight linerboard but requires accurate metering because the 56–66 mPa·s base viscosity is more sensitive to solids drift than lower-viscosity grades.
Addition of borax or boric acid above 0.1 wt% of solution should be avoided. Borate ion produces thermoreversible gelation with 1,3-diol segments in polyvinyl alcohol, causing viscosity spikes and filtration difficulties. Strong mineral acids, persulfates, and oxidizing agents should not be mixed with heated 26-99 solutions unless a controlled molecular-weight reduction step is intended; oxidative chain scission can reduce the 4 wt% viscosity below 40 mPa·s at 80 °C in less than 30 min in the presence of 0.5 wt% hydrogen peroxide. After dissolution, the solution pH should remain between 5 and 7.
For paper surface sizing, the solution is applied at 60–70 °C on a size press. On a 120 g/m² linerboard, a 4.0 wt% 26-99 pickup of 3–6 g/m² can shift Cobb60 water absorption from 32–38 g/m² to 18–24 g/m² when tested under ISO 535; the response typically flattens above 6 g/m². In textile warp sizing, 26-99 is blended with native or modified starch at 25–35 wt% PVA on dry size. The higher viscosity permits a reduction in total size add-on while maintaining abrasion resistance on high-speed looms. In water-remoistenable adhesive formulations, 26-99 is typically used at 6–8 wt% in the adhesive solution; the high molecular weight supplies wet tack at low solids, but open time is shorter than with 17-99 at the same film thickness.
A 10 wt% solution measured with a Brookfield RVT at 20 rpm and 25 °C typically reads 5,000–10,000 mPa·s; the same solution at 90 °C drops below 2,000 mPa·s. This thermal sensitivity means that high-shear mixing alone is not a substitute for thermal dissolution, and room-temperature applications above 8 wt% solids become difficult to pump and coat. For casting of high-strength film, the solution is typically prepared at 10–15 wt% solids, filtered, deaerated under vacuum, and coated onto a heated casting surface. Films dried from such solutions show the tensile response cited above and are substantially less cold-water-soluble than films produced from 88 mol% grades.
Fully hydrolyzed high-polymerization-degree PVA picks up atmospheric moisture. At storage relative humidity above 60%, granules can develop surface tack and caking. Pre-drying at 80 °C for 4 h is commonly applied before high-volume feeding into dry-mix adhesive or textile size systems; hopper moisture should be maintained below 1.0 wt% to avoid screw slippage and metering drift. In high-humidity coating rooms, solution concentration should be checked by refractive index or dry-content oven method because a 4 wt% solution left uncovered at 70% RH can lose 0.5–1.0 wt% water equivalent in 8 h, raising effective polymer concentration and changing wet-film pickup.
When reduced viscosity is required without changing total solids, part of the 26-99 fraction can be replaced by 17-99 at a ratio of roughly 1 part 26-99 to 1.5 parts 17-99 to maintain equivalent Brookfield viscosity at 10 wt% solids. The resulting blend has somewhat lower film strength and slightly faster cold-water response, which may be acceptable in low-porosity base papers or where open time must be extended. Where food-contact paper or paperboard is targeted, the finished article must be verified against 21 CFR §176.170 under the intended conditions of use; the raw resin documentation alone does not establish compliance for the converted article.
Thermogravimetric analysis in air at 10 °C/min shows the onset of mass loss around 220 °C for fully hydrolyzed high-DP polyvinyl alcohol, with discoloration accelerating above 250 °C. Melt processing without plasticizer is not recommended because thermal degradation and melt viscosity are not well separated. In compounding applications, the material is normally added as an aqueous solution or blended with plasticizers such as glycerol or trimethylolpropane at levels of 10–30 phr to permit extrusion below 200 °C. These boundaries are more restrictive than for low-hydrolysis PVA grades and must be included in any process-transfer calculation.
