Scientific Name: Polyvinyl Alcohol English Name: Polyvinyl Alcohol English Abbreviation: PVA
Polyvinyl Alcohol (PVA) is a versatile polymer derived from vinyl acetate through polymerization and alcoholysis. This white, stable, and non-toxic water-soluble polymer is available in the form of powder, flakes, or flocculent solids. The physical properties of polyvinyl alcohol: Solubility: Polyvinyl alcohol powder exhibits excellent solubility in water. At room temperature, PVA resin with an alcoholysis degree of less than 95% can dissolve in water. In contrast, PVA resin with an alcoholysis degree exceeding 99.5% requires hot water above 95°C for complete dissolution.
Thermal stability: When subjected to heat, polyvinyl alcohol softens without significant changes occurring below 40°C. Its glass transition temperature ranges from 75°C to 85°C. However, as the temperature surpasses 100°C, PVA gradually changes color and becomes brittle. Prolonged heating beyond 160°C leads to coloration, dehydration, etherification, and a loss of solubility. At temperatures exceeding 220°C, decomposition occurs, resulting in the formation of water, acetic acid, acetaldehyde, and crotonaldehyde. Beyond 250°C, it transforms into a polymer compound containing conjugated double bonds.
Chemical resistance: PVA exhibits remarkable resistance to weak acids, weak bases, and organic solvents. Moreover, it possesses high oil resistance, making it suitable for various applications.
Storage stability: Polyvinyl alcohol is a low-viscosity polymer, and its aqueous solution remains highly stable at room temperature. This ensures that the solution does not deteriorate during storage, maintaining its integrity and usability.
Film-forming properties: Due to the strong adhesion between PVA molecules, it effortlessly forms films. These films are colorless, transparent, and boast excellent mechanical strength. Moreover, they possess a smooth surface with no stickiness and display resistance to solvents. PVA films also exhibit favorable properties such as good light transmission, high moisture permeability, minimal charge accumulation, resistance to dust absorption, and excellent printability.
The chemical properties of polyvinyl alcohol: Polyvinyl alcohol(PVA) resin can be regarded as a linear polymer featuring secondary hydroxyl groups. The high reactivity of the hydroxyl groups allows PVA to engage in typical chemical reactions exhibited by low alcohols. These reactions include esterification, etherification, acetalization, and other similar processes. Furthermore, PVA can react with a wide range of inorganic and organic compounds, expanding its potential applications.
Packaging, Transportation, and Storage Considerations: When it comes to packaging, transportation, and storage, it is important to ensure the proper handling of polyvinyl alcohol. Here are some key points to consider: Packaging: Polyvinyl alcohol is typically packaged in white flocculent, flaky, or powdery solid forms. It is classified as a non-dangerous, non-explosive, non-oxidizing, non-corrosive, non-radioactive, and non-toxic product. Packaging options include plastic woven bags or paper bags weighing 12.5kg, 20kg, or 25kg. Alternatively, larger quantities can be stored in plastic woven jumbo bags ranging from 750kg to 1000kg.
Transportation: During transportation, it is essential to employ clean means of transport to prevent moisture, rain, and excessive exposure to sunlight. Careful handling is crucial to avoid scratching or damaging the packaging.
Storage: To maintain the quality of polyvinyl alcohol, it should be stored in a dry and well-ventilated room with a temperature ranging between 5°C and 30°C. It is imperative to keep it away from heat sources, moisture, and direct sunlight. Additionally, storing PVA together with volatile chemicals should be strictly avoided to prevent adsorption and potential deterioration.
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