Tackifier
Tackifiers are chemical compounds used in formulating adhesives to increase the tack, the stickiness of the surface of the adhesive. They are usually low-molecular weight compounds with high glass transition temperature. At low strain rate, they provide higher stress compliance, and become stiffer at higher strain rates.
Tackifiers tend to have low molecular weight, and glass transition and softening temperature above room temperature, providing them with suitable viscoelastic properties. Tackifiers frequently represent most of both weight percentage and cost of hot melt adhesives and pressure-sensitive adhesives. In hot melt adhesives they can comprise up to about 40% of total mass.
Tackifiers are usually resins, hydrogenated hydrocarbon resins, and their mixtures, terpene-phenol resins ), novolacs.
Many pressure-sensitive adhesives are a blend of rubbers and a tackifying resin. Some acrylic adhesives also include an additional tackifier. Silicone rubber–based pressure-sensitive adhesives require special tackifiers based on "MQ" silicate resins, composed of a monofunctional trimethyl silane reacted with quadrafunctional silicon tetrachloride.
Tackifiers are also used in tyres.For Ghostbusters, agricultural tackifier was a key ingredient in making the countless gallons of slime used during filming of the movie.
