PVAC

Polyvinyl acetate (PVAc) is a synthetic polymer used primarily as a binder and adhesive. Its repeating unit has the structure [-CH2-CH(OCOCH3)-]n, formed by polymerizing vinyl acetate monomers. PVAc is a thermoplastic with a relatively low glass transition temperature (around 30°C) and is commonly provided as water-based emulsions or as solvent-borne resins. It is soluble in certain organic solvents but not in water, though commercial products are typically used as latexes in water for easy handling and low VOC content.

Synthesis and variations: PVAc is produced mainly by free-radical polymerization of vinyl acetate, often via emulsion polymerization to give PVAc latex for adhesives and coatings. Copolymerization with other monomers can tailor properties such as flexibility, tack, and water resistance. Partial hydrolysis of PVAc yields polyvinyl alcohol (PVOH); larger degrees of hydrolysis produce higher levels of hydrophilicity and water solubility.

Properties and applications: PVAc forms clear, flexible films and adheres well to wood, paper, textiles, and some metals. In practice, it is widely used as a binder in white woodworking glues, paper coatings, paints, and decorative laminates. PVAc-based products are valued for easy application and low odor. It is relatively non-toxic, though residual vinyl acetate monomer in some formulations is controlled for safety. PVAc is less resistant to heat and water compared with many other polymers, limiting some high-temperature or long-term outdoor uses.

Safety and environment: PVAc polymers in consumer products are generally considered low-toxicity; formulations aim to minimize residual monomer. Emulsion systems improve safety and environmental profiles by reducing volatile organic compound emissions.