PVAc, or polyvinyl acetate, is a synthetic polymer that is commonly used in a variety of applications, including adhesives, coatings, and textile finishes. The production process for PVAc involves the following steps:
- Vinyl acetate monomer (VAM) is produced by reacting ethylene with acetic acid. This reaction is typically carried out in the presence of a catalyst such as palladium or rhodium.
- The VAM is then polymerized using a free radical initiator, such as a peroxide or azo compound. The polymerization process can be carried out using a variety of techniques, including emulsion, suspension, or solution polymerization.
- The resulting PVAc polymer is typically recovered by precipitation, filtration, and drying. The properties of the polymer can be controlled by adjusting the reaction conditions, such as the temperature, pressure, and catalyst used.
- In some cases, the PVAc polymer may be further modified by adding plasticizers, crosslinkers, or other additives to improve its properties for specific applications.
Overall, the production of PVAc polymer is a complex process that requires careful control of the reaction conditions to ensure the desired properties of the polymer are achieved.
Which plasticizers are available for PVAC?
Plasticizers are commonly added to polyvinyl acetate (PVAc) polymers to improve their flexibility, toughness, and durability. Some common plasticizers for PVAc include:
- Diethyl phthalate (DEP): This is one of the most commonly used plasticizers for PVAc. It is a clear, colorless liquid that is compatible with PVAc and provides good flexibility and low-temperature performance.
- Dibutyl phthalate (DBP): This plasticizer is similar to DEP but is slightly more viscous and provides improved low-temperature flexibility.
- Butyl benzyl phthalate (BBP): This plasticizer is used in applications where improved resistance to heat and chemicals is required.
- Triacetin: This is a clear, colorless liquid that is used as a plasticizer for PVAc in applications such as coatings and adhesives.
- Epoxidized soybean oil (ESBO): This is a bio-based plasticizer that is derived from soybean oil. It is compatible with PVAc and provides good low-temperature flexibility.
The choice of plasticizer depends on the specific application requirements and desired properties of the PVAc polymer. It is important to note that the use of plasticizers can affect the long-term performance of the polymer, and proper formulation and testing are necessary to ensure that the desired properties are maintained over time.
VAE is a form of stable plasticized PVAC
VAE (vinyl acetate-ethylene) copolymers are related to PVAc (polyvinyl acetate) but they are not the same. VAE copolymers contain both vinyl acetate and ethylene monomers, while PVAc is a homopolymer of vinyl acetate. VAE copolymers are often used as binders in coatings, paints, and adhesives due to their improved water resistance and higher adhesive strength compared to PVAc.
VAE copolymers may or may not be plasticized, depending on the specific formulation and application. Like PVAc, VAE copolymers can be plasticized with a variety of compounds, including diethyl phthalate (DEP), dibutyl phthalate (DBP), and triacetin, among others. The choice of plasticizer for VAE copolymers, like PVAc, depends on the specific application requirements and desired properties. The plasticizer selection can have a significant impact on the performance of the VAE copolymer, such as its flexibility, adhesion, and durability.