| Código SH | 643758 |
| Nome Químico | álcool polivinílico |
| Número Cas | 9002-89-5 |
| Aparência | Produto pulverulento granulado branco a ligeiramente amarelo |
| Grau De Hidrólise | 86,5 - 89,0 mol% (parcialmente saponificado) |
| Grau De Polimerização | Aproximadamente 500 |
| 4 De Solução Aquosa A 20c | 20 - 28 mPa · s |
| Ph 4 Solução Aquosa | 5 - 7 |
| Conteúdo Volátil | Max 5.0% em peso |
| Conteúdo De Cinzas | Máximo 0,5% em peso |
| Densidade Aparente | 0,4 - 0,6 g/cm³ |
| Solubilidade | Solúvel em água |
| Tamanho De Partícula | Produto pulverulento fino, gama típica 150 - 350 µm |
Como uma fábrica acreditada GOHSENOL EG-22P, aplicamos protocolos de qualidade rigorosos - cada lote é submetido a testes rigorosos para garantir padrões de eficácia e segurança consistentes.
| Embalagem | GOHSENOL EG-22P é fornecido como um pó granular branco em sacos de papel multicamadas de 20 kg com um forro de polietileno. |
| Carga de contêiner (20' FCL) | Carga FCL de 20 “de GOHSENOL EG-22P: sacos de 25 kg em paletes, embalados em contração, presos para evitar danos por umidade e deslocamento durante o trânsito. |
| Envio | GOHSENOL EG-22P, um pó de álcool polivinílico, é enviado como um material não perigoso em papel multicamadas selado ou sacos forrados com PE. Mantenha seco, evite a geração de umidade e poeira. Transporte em recipientes ventilados em temperaturas ambientes, protegendo de danos físicos e oxidantes incompatíveis. |
| Armazenamento | Guarde GOHSENOL EG-22P em seu recipiente original bem fechado em uma área fria, seca e bem ventilada. Proteja da umidade, umidade, luz solar direta e calor excessivo. Evite o contato com agentes oxidantes. Mantenha longe de fontes de ignição e alimentos. Sob condições adequadas, o material permanece estável por um longo período. |
| Prazo de validade | GOHSENOL EG-22P tem uma vida útil típica de dois anos quando armazenado em local fresco e seco. |
Preços competitivos GOHSENOL EG-22P que se encaixam no seu orçamento - termos flexíveis e orçamentos personalizados para cada pedido.
Para amostras, preços ou mais informações, entre em contato conosco em +8615380400285 Ou envie para sales2@liwei-chem.com.
Responderemos a você o mais rápido possível.
Telefone: +8615380400285
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Pagamento flexível, preço competitivo, serviço premium - Consulte-nos agora!
GOHSENOL EG-22P is a partially hydrolyzed polyvinyl alcohol powder manufactured under the GOHSENOL product line. The resin carries a nominal hydrolysis range of 86.5–89.0 mol% and an aqueous solution viscosity of 20.5–24.5 mPa·s when measured as a 4% solution at 20°C according to JIS K6726. Because the degree of hydrolysis remains below 90 mol%, residual acetyl groups are present in sufficient quantity to modify aqueous surface activity, foam character, and adhesion to hydrophobic substrates. The grade designation “22P” identifies a medium-viscosity, powder-form PVOH in the EG series; published specification limits for volatile matter, ash, and pH appear in the accompanying table.
| Property | Test condition /method | Specification or typical value |
|---|---|---|
| Appearance | Visual inspection | White to pale-yellow powder or granules |
| Viscosity | 4% aqueous solution, 20°C, JIS K6726 | 20.5–24.5 mPa·s |
| Degree of hydrolysis | JIS K6726 | 86.5–89.0 mol% |
| pH | 4% aqueous solution, 20°C, JIS K6726 | 5.0–7.0 |
| Volatile matter | JIS K6726 | ≤5.0% |
| Ash as Na₂O | JIS K6726 | ≤0.5% |
The combination of medium viscosity and partial hydrolysis places EG-22P between low-viscosity, high-surface-activity grades such as EG-05P and high-viscosity PVOH used for film strength. Its high residual acetate concentration relative to fully hydrolyzed grades lowers the crystalline melting range and reduces gelation of aqueous solutions on cooling. This property supports use in applications requiring stable low-temperature solution behavior and moderate dried-film water solubility.
The first operational boundary in solution preparation is particle wetting and thermal energy input. In closed high-shear dissolution tanks, EG-22P powder is typically dispersed into ambient water at 20–30°C under agitation at 300–500 rpm using a sawtooth dispersing blade; the slurry is then heated to 85–90°C and held for 30–60 min at 1.0–2.0 bar absolute pressure to reduce surface foam. Under these conditions, a 10 wt% solution reaches Brookfield viscosity values approximately 150–400 mPa·s at 60°C as measured with spindle LV 2 at 30 rpm; published data for this specific configuration is limited and should be verified against site-specific mixing power. Direct polymer addition to hot water above 60°C produces a gelatinous outer layer on the particle and is a documented cause of undissolved fisheyes in subsequent coating. In pressure-rated tanks, nitrogen inerting is not required solely for dissolution but may be applied when the solution is held above 80°C for more than 8 h to inhibit oxidative discoloration. The solution should be cooled below 50°C before transferring to storage because prolonged exposure to iron or copper surfaces at elevated temperature can catalyze degradation. At relative humidity above 60%, the powder may absorb moisture and caking occurs; pre-drying at 60°C for 1 h is normally sufficient before feeding to loss-in-weight hoppers.
Polymerisation of vinyl acetate and vinyl acetate–ethylene (VAE) emulsions uses partially hydrolyzed PVOH as protective colloid to control particle nucleation, emulsion viscosity, and mechanical stability. EG-22P is dosed at 2–6 wt% of monomer mass, normally as a 10–12 wt% aqueous solution. The medium solution viscosity of EG-22P produces a higher continuous-phase viscosity than EG-05P at equivalent solids, which can shift the particle size distribution toward coarser particles and increase finished emulsion viscosity. Laboratory-scale reactors of 2 L with anchor agitators at 150–250 rpm produce final VAE emulsions with solids near 55–60%; Brookfield RVT viscosity at 20 rpm and 25°C typically spans 1,000–5,000 mPa·s for grades containing higher PVOH content. In full-scale plants, circulation through an external heat exchanger and half-pipe coil reactors with turbulent flow is used to remove the exotherm; thermal control at 70–80°C is maintained to prevent destabilization. The residual acetyl groups in EG-22P contribute interfacial activity and reduce the need for high levels of nonionic surfactant, although this does not eliminate the need for surfactant in high-ethylene VAE formulations. Published data for this specific grade in high-pressure ethylene polymerisation is limited; formulators generally validate low-pressure vinyl acetate homopolymer and low-ethylene VAE first.
In paper surface sizing and pigmented size-press formulations, GOHSENOL EG-22P is incorporated at 2–8 wt% in 55–65°C aqueous solution. At these concentrations, the 4% solution viscosity of 20.5–24.5 mPa·s translates to runnable size-press viscosity without forcing excessive starch dilution. Cationic starch co-binder ratios of 60:40 to 80:20 starch:PVOH are typical in publication grades; the 86.5–89.0 mol% hydrolysis of EG-22P reduces excessive inter-fiber hydrogen bonding, maintaining sheet caliper after calendering. Cobb values measured according to ISO 535 may be higher than those obtained with fully hydrolyzed PVOH unless a crosslinker such as ammonium zirconium carbonate at 0.5–2.0 wt% of PVOH solids is added. The use of borax or boric acid is contraindicated in size-press formulations above 50°C because pH-sensitive PVOH–borate gelation can form insoluble deposits on rolls and doctor blades. For pigmented coatings, high-shear viscosity response should be checked with a capillary viscometer at 10,000–100,000 s⁻¹; EG-22P contributes more shear stress than low-molecular-weight grades but remains below the level associated with blade-actuated scratches.
Remoistenable adhesive systems rely on dried PVOH films that rehydrate on demand yet retain sufficient cohesion before drying. EG-22P is used at this boundary because its partially hydrolyzed structure dissolves more readily in cold water than fully hydrolyzed PVOH. In aqueous adhesive compounding, 10–25 wt% EG-22P solutions are combined with plasticizers such as glycerol or sorbitol at 5–15 wt% of PVOH solids. Boric acid and borax are commonly used as rheology modifiers at 0.1–1.0 wt%; however, the interaction between borate ions and the hydroxyl groups of PVOH produces a pH-sensitive crosslinked network. If levels exceed 1.0 wt%, the solution may gel above 50°C or at neutral pH, blocking transfer lines. In adhesive formulations where borate is incompatible due to pH control or rewetting requirements, alternative crosslinkers such as glyoxal at 0.05–0.2 wt% of PVOH solids produce a lower degree of irreversible gelation. Adhesive open time is measured on coated paperstock at 23°C and 50% relative humidity; films from EG-22P retain tack for 5–15 s after rewetting, depending on plasticizer type. The film tensile strength is lower than that of fully hydrolyzed PVOH, which must be considered when adhesive bond strength exceeds 2 N/15 mm in peel testing.
Comparison of EG-22P against other GOHSENOL PVOH grades clarifies the practical consequences of viscosity and hydrolysis differences. All EG-series grades in the table share the same partial hydrolysis range; the principal variable is solution viscosity, which correlates with average molecular weight and therefore with film cohesion, emulsion thickening, and dissolution time.
| Grade | Hydrolysis range | 4% viscosity at 20°C | Typical distinction |
|---|---|---|---|
| EG-05P | 86.5–89.0 mol% | 4.8–5.8 mPa·s | Lower solution viscosity, faster dissolution, lower finished emulsion viscosity |
| EG-22P | 86.5–89.0 mol% | 20.5–24.5 mPa·s | Medium viscosity, balance between dispersant activity and film strength |
| EG-30P | 86.5–89.0 mol% | 27.0–33.0 mPa·s | Higher viscosity, increased cohesion, slower cold-water dissolution |
| EG-40P | 86.5–89.0 mol% | 40.0–46.0 mPa·s | Highest EG-series viscosity, more shear stress in coating and adhesive systems |
| Fully hydrolyzed PVOH representative | 98.0–99.0 mol% | 20.0–30.0 mPa·s | Lower cold-water solubility, greater water resistance, higher crystallinity |
The critical difference between EG-22P and fully hydrolyzed PVOH is not solution viscosity but the residual acetyl content. At 86.5–89.0 mol% hydrolysis, EG-22P retains sufficient acetate to weaken interchain hydrogen bonding, lower the crystal melting range, and increase solubility in cold water. This reduces equilibrium water resistance of the dried film unless crosslinked. Fully hydrolyzed grades with 98.0–99.0 mol% hydrolysis form denser, more crystalline films and are preferred where low water solubility is required. In paper applications, EG-22P tends to generate more stable size-press rheology but higher Cobb values than fully hydrolyzed PVOH at equal coat weight.
In suspension polymerisation of vinyl chloride, GOHSENOL EG-22P functions as a secondary dispersing agent when combined with lower hydrolysis PVOH grades. The medium viscosity modifies interfacial tension and PVC grain porosity. Typical addition levels of 0.1–0.4 wt% on monomer are used in stainless-steel autoclaves at 50–65°C with peroxide initiators. The effect on grain morphology is monitored by sieve retention at 45 µm and 250 µm and by apparent bulk density measured according to ISO 60. Published data for this specific grade in vinyl chloride suspension polymerisation is limited; the addition level must be optimized against reactor fouling rate and plasticizer absorption of the dried PVC.
Bulk handling of EG-22P in silos requires dry air purging when ambient relative humidity exceeds 60%. The powder has a bulk density typically between 0.40–0.60 g/cm³ depending on particle size distribution and compaction; published data for this specific grade is limited. Conveyors should be sized for cohesive flow and equipped with hopper vibrators to avoid bridging. Absorption of moisture from air can increase the measured volatile content above the 5.0% specification limit and alter screw feeding accuracy on loss-in-weight systems. Dissolution plants may use eductor systems where powder is wetted by a water jet at 15–25°C before entering a high-shear mix tank; if the water temperature exceeds 30°C, lump formation increases. Long-term solution storage beyond 72 h at 40°C can promote microbial growth because diluted PVOH is biodegradable; a biocide compatible with nonionic or weakly anionic systems is required. The material is not compatible with concentrated strong acids or strong alkalis above pH 10 because chain scission and hydrolysis can occur. Aqueous solutions should not be exposed to copper, copper alloys, or unprotected iron surfaces at temperatures above 70°C because transition metal ions accelerate oxidative degradation.
