Polyvinyylibutaalia

Polyvinyylibutaalia, commonly known as polyvinyl butyral (PVB), is a thermoplastic polymer produced by the acetalization of polyvinyl alcohol with butyraldehyde. The resulting material forms a flexible, transparent interlayer that combines good adhesion to glass with toughness and impact resistance.

PVB is most widely known for its role in laminated safety glass. When used as an interlayer between glass sheets, it binds the glass together and helps hold shards in place if the glass is broken, reducing the risk of injury. This property makes PVB a standard material in automotive windshields, architectural glazing, and security glazing. PVB films are usually plasticized to improve flexibility at room temperature, with plasticizers ranging from traditional phthalates to newer non-phthalate alternatives.

The polymer is supplied in films or sheets and can be processed by extrusion, calendering, or lamination. Its optical clarity is high, and it can be formulated with UV stabilizers, colorants, or additional additives to tailor performance. The mechanical properties and glass transition temperature depend on the degree of plasticization and the formulation, which influences handling, lamination temperatures, and long-term durability.

Environmental and safety considerations include the use of plasticizers, some of which (historically phthalates) have raised health and regulatory concerns, leading to the development of non-phthalate alternatives. PVB itself is relatively inert, but laminated glass recycling and end-of-life processing remain areas of ongoing development. See also laminated glass, interlayer materials, and safety glazing.