1. Uses of PVA

PVA is a versatile polymer with a wide range of industrial applications due to its unique properties. Here are some of the main uses of PVA in more detail:

1. Paper Coating

PVA is widely used in the paper industry as a coating material. When applied to paper, PVA forms a smooth, glossy, and hard surface that improves the paper's printability, durability, and barrier properties. PVA coatings provide excellent ink absorption, preventing the ink from spreading or bleeding. They also enhance the paper's resistance to moisture, grease, and solvents. PVA coated papers are used for high-quality printing applications such as magazines, brochures, and packaging materials[1].

1. Textile Sizing

PVA is used as a sizing agent in the textile industry to improve the weaving efficiency and the quality of the woven fabric. Sizing is the process of applying a protective coating to the warp yarns before weaving to reduce breakage and friction during the weaving process. PVA is an excellent sizing agent due to its film-forming properties, high viscosity, and adhesion to fibers. It forms a smooth, flexible coating on the yarns that reduces hairiness and improves the yarn's strength and abrasion resistance[2].

1. Adhesives

PVA is used as a base for adhesives due to its strong bonding properties, especially to porous materials like paper, wood, and cloth. PVA adhesives are water-based, non-toxic, and environmentally friendly. They form strong, flexible bonds that are resistant to moisture and heat. PVA adhesives are used in various applications such as paper bonding, wood gluing, bookbinding, and bag sealing. They are also used in the production of adhesive tapes and labels[3].

1. Emulsifier and Protective Colloid

PVA is an excellent emulsifier and protective colloid due to its hydrophilic nature and ability to stabilize emulsions. It is widely used in emulsion polymerization to produce water-based polymers such as polyvinyl acetate, acrylic resins, and polyvinyl chloride. PVA adsorbs on the surface of the polymer particles and prevents them from coagulating, resulting in stable emulsions with small particle sizes. PVA also acts as a thickener, increasing the viscosity of the emulsion and improving its stability and flow properties[4].

1. Films

PVA films have excellent mechanical and barrier properties, making them useful for various packaging applications. PVA films are clear, flexible, and tough, with high tensile strength and tear resistance. They have good oxygen and aroma barrier properties, making them suitable for packaging food products that are sensitive to oxidation and odors. PVA films are also resistant to oils, greases, and solvents, making them useful for packaging oily or greasy products. PVA films are biodegradable and water-soluble, making them an environmentally friendly alternative to traditional plastic films[5].

1. Polyvinyl Butyral

PVA is the raw material for the production of polyvinyl butyral (PVB), a specialty polymer used in safety glass laminates for automobile windshields and architectural glass. PVB is produced by the condensation reaction between PVA and butyraldehyde. The resulting polymer has excellent adhesion to glass, high tensile strength, and good impact resistance. When laminated between two sheets of glass, PVB acts as a shock absorber, preventing the glass from shattering and causing injuries in case of impact[6].
References
1. Shen, Z., et al., Improving the Barrier Properties of Packaging Paper by Polyvinyl Alcohol Based Polymer Coating-Effect of the Base Paper and Nanoclay. Polymers (Basel), 2021. 13(8).
2. Ahmed, T., et al., Evaluation of sizing parameters on cotton using the modified sizing agent. Cleaner Engineering and Technology, 2021. 5: p. 100320.
3. Ebnesajjad, S. and A.H. Landrock, Chapter 5 - Characteristics of Adhesive Materials, in Adhesives Technology Handbook (Third Edition), S. Ebnesajjad and A.H. Landrock, Editors. 2015, William Andrew Publishing: Boston. p. 84-159.
4. Carrà, S., et al., Grafting and Adsorption of Poly(vinyl) Alcohol in Vinyl Emulsion Polymerization. Polymer, 2005. 46: p. 1379-1384.
5. Park, N., M.A. Friest, and L. Liu, Enhancing the Properties of Polyvinyl Alcohol Films by Blending with Corn Stover-Derived Cellulose Nanocrystals and Beeswax. Polymers, 2023. 15(21): p. 4321.
6. Nikitakos, V., et al., An Integrated Characterization Strategy on Board for Recycling of poly(vinyl butyral) (PVB) from Laminated Glass Wastes. Polymers, 2024. 16(1): p. 10.