PVA 173 is a specific grade of Polyvinyl Alcohol (PVA), a water-soluble polymer with diverse applications in various industries. This grade of PVA is often used for film formation, adhesive formulations, and coatings due to its excellent water solubility, flexibility, and adhesive properties. Like other grades of PVA, PVA 173 is produced by the hydrolysis of polyvinyl acetate, which gives it its water-soluble characteristics.
Properties of PVA 173 (Polyvinyl Alcohol):
- Molecular Formula: (C₂H₄O)ₙ
- CAS Number: 9002-89-5 (This is the general CAS number for PVA.)
- Appearance: PVA 173 typically appears as a white, odorless powder or granules.
- Molecular Weight: The molecular weight of PVA 173 typically ranges from 50,000 to 100,000 g/mol, though this can vary depending on the exact grade specifications.
- Degree of Hydrolysis: The degree of hydrolysis for PVA 173 is typically 87-89%, meaning it is partially hydrolyzed. This level of hydrolysis provides moderate water solubility and helps balance the film-forming properties with mechanical strength.
- Solubility: PVA 173 is soluble in water, with solubility increasing with temperature. It is insoluble in organic solvents like acetone, toluene, and chloroform. The polymer is partially soluble in cold water but dissolves more readily in hot water, especially in the form of a polymer solution.
- pH: The pH of an aqueous solution of PVA 173 is typically neutral to slightly alkaline, ranging from 7 to 8.
- Film-Forming Properties: PVA 173 is known for its excellent film-forming properties, producing flexible, durable films that are moisture-resistant and biodegradable, making it suitable for various packaging and coating applications.
- Viscosity: PVA 173 has a moderate viscosity, which allows for ease of processing and incorporation into various formulations, particularly those requiring water-based systems.
(As a polymer, PVA’s molecular weight varies depending on the degree of polymerization.)
Key Uses of Polyvinyl Alcohol (PVA 173):
1. Adhesives and Bonding Agents
Paper and Packaging Adhesives: PVA 173 is used extensively in the paper and packaging industries as an adhesive for paperboard, cardboard, and labels. Its moderate hydrolysis level provides sufficient water resistance for applications in packaging, especially for corrugated board and paper labels.
Textile Adhesives: In the textile industry, PVA 173 is used for bonding fibers and fabrics. It can be employed as an adhesive in applications such as fabric lamination or nonwoven fabric production.
Woodworking Adhesives: PVA 173 is used in wood adhesives for applications in the furniture and plywood industries. It provides a strong bond for wooden materials and is resistant to moisture and heat in many woodworking applications.
2. Textile Industry
Sizing Agent: PVA 173 is a widely used sizing agent in the textile industry, particularly for improving the strength and durability of yarns during the weaving process. It also provides a smooth surface, preventing friction and breakage of fibers.
Weaving: During the weaving process, PVA 173 acts as a coating on yarns, helping to reduce friction and increase the efficiency of the weaving operation, particularly in cotton and synthetic fibers.
Textile Coatings: PVA 173 is used in textile coatings to improve the smoothness, strength, and appearance of fabrics. It is useful for protective clothing, upholstery fabrics, and industrial textiles.
Dyeing and Printing: As a binder in the dyeing and printing process, PVA 173 helps to improve color fastness and evenness of dye application on fabrics. It is used in applications such as screen printing and rotary printing.
3. Water-Soluble Films
Single-Use Packaging: PVA 173 is used to produce water-soluble films, which are ideal for single-use packaging applications such as detergent pods, cleaning products, and food packaging. These films dissolve in water, leaving no residue and ensuring that the contents are released when needed.
- Detergent Pods: In the home care industry, PVA 173 is frequently used for the manufacture of laundry pods and dishwasher pods where the film dissolves in water, releasing the detergent inside.
- Food Packaging: The water-soluble nature of PVA 173 makes it suitable for food packaging applications, particularly for products where portion control and easy dissolution are required.
Controlled Release Applications: PVA 173 is used to create controlled release systems for pharmaceuticals, fertilizers, and pesticides. The film encapsulates the active ingredients and releases them gradually over time when exposed to water or moisture.
4. Pharmaceutical Applications
Tablet and Capsule Coatings: PVA 173 is used as a coating agent for tablets and capsules in the pharmaceutical industry. It serves as a protective barrier to mask the taste of the active ingredients and provide a smooth finish. Additionally, PVA 173 is used for creating extended-release formulations where the polymer helps control the release of active ingredients over time.
Wound Dressings: PVA 173 is used in the development of wound care products, such as hydrogel dressings. These products help promote moist wound healing by providing a protective, moist environment while delivering active ingredients like antibiotics or antiseptics.
5. Cosmetic and Personal Care
Film-Forming Agent: PVA 173 is used as a film-forming agent in a variety of cosmetic products such as face masks, shampoos, conditioners, hair sprays, and lip glosses. It forms a thin, flexible film on the skin or hair, improving texture, appearance, and moisture retention.
- Facial Masks: PVA 173 is used in peel-off facial masks, where it forms a film that adheres to the skin and can be peeled off easily, carrying away impurities.
- Hair Care Products: In hair sprays and styling gels, PVA 173 is used to improve the hold and shine of hair while providing a smooth texture.
- Moisturizing Products: PVA 173 helps to retain moisture on the skin by forming a thin, protective barrier that prevents water loss, which is beneficial in lotions and moisturizers.
6. Paints and Coatings
Emulsifier and Binder: PVA 173 is often used as an emulsifying agent and binder in the paint and coating industries. It helps to stabilize emulsions and improve the adhesion and durability of paints on various substrates.
- Water-Based Paints: In water-based paints, PVA 173 helps to provide excellent film formation and coverage, contributing to smooth, durable finishes.
- Coatings: It is used in protective coatings and industrial paints to ensure strong adhesion and resistance to wear and environmental factors.
7. Agricultural Applications
Controlled Release Fertilizers: PVA 173 is used in the development of controlled release fertilizers. It helps encapsulate the fertilizer and regulate the release of nutrients into the soil, improving the efficiency of fertilizer use and reducing environmental runoff.
Pesticide Encapsulation: PVA 173 is used to encapsulate pesticides and herbicides in a controlled manner. The polymer ensures that the active ingredients are gradually released over time, which increases their effectiveness while minimizing the environmental impact.
8. Paper and Pulp Industry
Paper Coatings: PVA 173 is used as a coating agent in the paper and cardboard industries. It helps improve the smoothness, brightness, and printability of paper, making it ideal for magazines, labels, and printed materials.
Paper Strengthening: In recycled paper production, PVA 173 is used as a binder to enhance the strength and durability of the paper product. It improves the overall quality of recycled and virgin paper products.
9. Other Industrial Applications
Rubber Coatings: PVA 173 can be used in rubber coatings to improve adhesion and durability. It is especially useful in applications that require a smooth finish and strong bond to metal, fabric, or plastic surfaces.
Ink and Printing: PVA 173 is used in inks and printing formulations as a binder and thickening agent, contributing to better print quality and adhesion to substrates like paper, cardboard, and textiles.