Breve introduzione:
Polyvinyl Alcohol 20-88 (also known as PVA 2088 or 088-35) is a partially hydrolyzed grade polymer characterized by a unique medium-high viscosity range.
With a viscosity of 28.0 – 43.0 mPa.s, PVA 20-88 offers stronger initial tack and film thickness compared to standard 17-88 grades, while maintaining better flow properties than high-viscosity 24-88 grades. This balance makes it the preferred choice for industrial applications requiring precise rheological control, such as stiffening agents for abrasives and re-wettable adhesives.
Specifiche:
| Articolo | Specificazione |
|---|---|
| Degree of Alcoholysis (mol%) | 86.00 - 90.00 |
| Viscosity (mPa·s) | 28.0 - 43.0 |
| Volatile Content (wt%, max) | 5 |
| Purity (wt%, min) | 93.5 |
| Valore del pH | 5 ~ 7 |
| Ash Content (wt%, max) | 0.5 |
Main Characteristics:
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Solubilità: Easily soluble in water. While it can dissolve slowly at room temperature, it is recommended to dissolve in hot water above 85°C for efficiency.
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Processing Tip: Foam may be generated during dissolution; adding a defoaming agent is recommended.
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Punto di fusione: As a partially hydrolyzed grade, it begins to melt around 180-190°C and decomposes above 200°C.
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Adhesiveness: Exhibits excellent bonding strength not only to hydrophilic materials (cellulose, paper) but also to hydrophobic fibers.
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Film Properties: Forms flexible, tough films with excellent barrier properties against gases.
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Compatibilità: Compatible with starch, gums, and other emulsions.
Applicazioni:
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Coated Abrasives & Molds: Specifically used for base fabric stiffening and reinforcement in the abrasives industry (e.g., sandpaper backing).
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Adhesives: Ideal for formulating re-wettable adhesives (remoistening glues) used in postage stamps, envelopes, and paper tapes.
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Industria tessile: Used in fiber processing for short fibers and long filaments to improve weaving efficiency.
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Film Processing: Used as a raw material for manufacturing water-soluble films.
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Stabilizer: Functions as a protective colloid in the polymerization of Vinyl Acetate (PVAc) emulsions.
Imballaggio:
- Confezione: 25 kg per bag.
- Magazzinaggio: Store in a cool, dry, and well-ventilated area to prevent caking and moisture absorption.
Prodotto Magazzinaggio:
Keep in a dry, well-ventilated place to prevent moisture absorption.
FAQ:
Q: When should I choose PVA 20-88 over PVA 17-88?
A: You should choose PVA 20-88 when you need slightly higher viscosity (28-43 mPa.s) and stronger bonding strength than what 17-88 (19-32 mPa.s) can offer. It is ideal for applications where 17-88 is too thin or runny, such as in fabric stiffening or vertical adhesive applications.
Q: Does PVA 20-88 foam during dissolving?
A: Yes, like many partially hydrolyzed grades, it can generate foam during the dissolution process. We recommend adding a small amount of defoaming agent (antifoam) during the heating process to ensure a clear, bubble-free solution.
Q: What is the melting temperature of PVA 20-88?
A: Unlike fully hydrolyzed grades which melt at higher temperatures (~230°C), PVA 20-88 begins to melt at a lower range of 180-190°C. This lower melting point can be advantageous in certain thermoplastic processing applications.
Need Medium-High Viscosity PVA? Get a Quote. We supply premium Polyvinyl Alcohol 20-88 for specialized industrial applications.
