Styrenics, or styrenic block copolymers are the most widely used of all TPE's. They combine well with other materials as well as fillers and modifiers. SEBS (styrene-ethylene/butylene-styrene) is characterized by hard and soft domains within individual polymer strands. The end-blocks are crystalline styrene while the mid-blocs are soft ethylene-butylene blocks. At higher temperatures these materials soften and become fluid. When cooled, the strands join at the styrene end-blocks forming a physical cross-link and providing a rubber like elasticity. Clarity and FDA approval make SEBS an excellent option for high-end applictions.
SEBS can improve performance in pressure-sensitive and other adhesive applications. Some of the more common applications include a variety of tapes, labels, plasters, construction adhesives, medical dressings, sealants, coatings and road marking paints.
SEBS can be compounded to produce materials which improve the grip, feel, appearance and convenience of various applications. Sports and leisure, toys, hygiene, packaging, automotive, and molded and extruded technical goods are some common examples.
SEBS can be used in combination with various fillers. Compounders will add these fillers if enhanced oil absorption, cost reduction, improved surface feel, or additional stabilization is required over pure SEBS.
Probably the most common filler for SEBS is oil. These oils are either paraffinic, naphthenic, or aromatic. These oils will be chosen depending on specific application requirements. Adding aromatic oil softens the PS blocks by plasticizing which decreases hardness and physical properties. Oils make the products softer and also act as processing aids. Paraffinic oils are preferred because they are more compatible with the EB center block. Aromatic oils are generally avoided because they intrude into and plasticize the polystyrene domains.
SEBS can enhance high styrene applications, films, bags, stretch film and disposable packaging. They can improve the performance of polyolefins for use in extreme temperatures, improve clarity and scratch resistance, and enhance elasticity.
KRATON FG1901, a functionalized styrene-ethylene/butylene-styrene (SEBS), give improved impact performance in highly polar materials. Formulators can vary the amount maleic anhydride (MA) content to obtain the desired impact-flow balance. Higher levels of MA improve dispersion and impact but have a negative effect on flow.
- G1643 (was MD6932)
- G1645 (was MD6945)