Polyvinyl ethers are either viscous oils or soft and tacky rubbery materials depending on the structure and molecular weight. Their glass transition temperature is well below room temperature. They are known for their elasticity and excellent resistance to hydrolysis (being ether-based, PVEs do not hydrolyze). They also have fairly good weatherability and heat resistance since they do not have double bonds in the backbone. They are miscible with water and are soluble in many solvents. They are usually none hazardous substances and not irritants to skin.
Vinylether monomers have unique properties. Due to the presence of the neighboring oxygen atom, the double bond is highly electronegative. For this reason, they easily undergo (living / controlled) cationic polymerization. This makes them very versatile curing agents. The reactivity of the vinyl ethers in cationic polymerization depends on both the initiator used and the structure of the vinyl ether itself. In general, vinyl ethers possessing highly branched alkyl groups are more reactive than those bearing straight-chain alkyl groups.
Free-radical copolymerization of vinyl ethers is also possible; it can be initiated with peroxide, azo, and redox initiators. However, the polymerization under free radical conditions gives only low-molecular-weight oligomers and only copolymers can be synthesized. Furthermore, in the presence of water they readily hydrolyse to acetaldehyde and alcohol below pH of about 5.5 which makes emulsion polymerization with certain monomers like vinyl acetate difficult unless the pH is carefully controlled.
Some commercially important vinyl ethers include ethyl, n-butyl, isobutyl, ethylhexyl, dodecyl, octadecyl, and cyclohexyl vinylether.
The Main manufacturer of vinyl ether monomers and resins is BASF. Other manufacturers of vinyl ether polymers and copolymers are Ashland, and Idemitsu Kosan.
Poly(vinyl ethers) and their copolymers find many applications such as adhesives, release and surface coatings, lubricants, greases, elastomers, anticorrosion agents, molding compounds, personal care products, fiber and textile finishes.
Polyvinyl ethers are widely used in adhesive and coating formulations. Due to their efficiency as reactive diluents and their ability to undergo both cationic homopolymerization and free-radical copolymerization, vinylether monomers are excellent co-reactants for silicone release coatings and silicone pressure sensitive adhesives. Some benefits of the addition of vinylethers to commercial (UV curable) epoxysilicone release coatings include improved cationic photoinitiator miscibility, viscosity reduction, and lower raw material costs. Vinylether monomers are not inexpensive, however, they are less costly than epoxy silicone polymers and hence, lower raw material costs. Vinylethers are also known to be effective reactive diluents for acrylate oligomers in free radical and hybrid adhesives. Like acrylic polymers, they provide pressure sensitive adhesives with a high degree of tack, hence, no tackifier resins have to be added. Due to their high(er) cost, but excellent compabiltiy with acrylic resins, they are ususally blended with acrylic polymers/oligomers to improve certain characteristics of the PSA. Due to their good adhesion to skin and high water permeability, they are sometimes used for medical pressure sensitive tapes and dressings.
Polyvinyl ethers are also used as synthetic lubricants, mainly as refrigerant oils. The synthetic vinyl ether oils (PVE) have excellent lubricating properties. However, they provide not better lubrication than petroleum-based lubricants such as mineral oils, but they do have a narrow molecular weight distribution which gives the oil very consistent physical properties. Furthermore, the polymer-based chemical structure and controllable synthesis makes it possible to tailor the PVE oil with different viscosity and miscibility properties. Compared with polyolester oils (POE), they are more chemically stable since carbon-oxygen double bonds are absent.