Typical Formulation Ingredients
Ingredient
Parts by weight
SEBS Elastomer (Kraton G-1652, Kraton)
Crosslinked butyl (Kalar 5214, Hardman, Inc.)
Tackifier (Eastotac H-130E resin, Eastman)
Polybutene (Indopol H-300, Amoco Chemical)
Antioxidant (Irganox, 1010, Ciba-Geigy)
Amorphous polyolefin (Eastoflex P1023 APP, Eastman)
(Source: Eastman Chemical Company)
Typical Properties
Penetration hardness, ASTM D1321, dmm
Peel adhesion, ASTM C794 modified, pli
Canvas-to-cold rolled steel failure
Resulting Properties
SEBS thermoplastic elastomers are best known for their high heat resistance, high tear strength, and good tensile strength and elongation. Sealants have good adhesion to glass and aluminum along with excellent mechanical properties. It also has a low moisture vapor transmission rate along with excellent UV and thermal stability.
In some applications, however, stress is carried by the sealants, such that the material is in essence considered to be an adhesive-sealant. SBC copolymers can be formulated to meet the requirements of either kind of sealant. Because of their lower cost, SBS block copolymers are usually chosen for this type of application, but in roofing and paving applications, the SEBS block copolymers are also used because of better long-term aging resistance. The table above shows a starting formulation for a low viscosity SEBS hot melt sealant.