SEBS PROPERTIES AND APPLICATIONS
Styrene-ethylene-butylene-styrene, also known as SEBS, is an important thermoplastic elastomer (TPE) whose behavior is similar to that of rubber without vulcanization. SEBS is strong and flexible, with excellent heat resistance and ultraviolet resistance, and easy to process. It is produced by partial and selective hydrogenation of styrene-butadiene-styrene copolymer (SBS), which can improve the thermal stability, weather resistance and oil resistance, and make SEBS steam sterilized. However, hydrogenation also reduces the mechanical properties and increases the cost of polymer. SEBS elastomer is usually mixed with other polymers to enhance its performance. They are used as impact modifiers for engineering thermoplastics and tougheners/tougheners for transparent polypropylene (PP). Usually, oil and filler are added to reduce the cost and/or further modify the performance. Important applications include hot-melt pressure-sensitive adhesive, sole of toy products and TPE modified asphalt products for road paving and roofing applications.
1, wire and cable sheath and insulation tape
SEBS is an excellent material for making wire and cable sheaths and insulation tapes because of its excellent electrical insulation, weather resistance and aging resistance, good flexibility and high strength, and wide range of application temperature. The amount used in this area is relatively large in the United States.
Its cost is lower than that of polyester or polyurethane thermoplastic elastomer. SEBS can replace vulcanized rubber, PVC, cross-linked polyethylene, etc., and it has excellent performance in battery cable, transformer cable insulation sheath, instrument wire, etc. SEBS has a broad application prospect in electric wires, showing strong competitiveness.
2. Application of SEBS in plastic modification
SEBS can blend and modify many plastics, and obviously improve the comprehensive properties of plastics. For example, it can be blended with polypropylene, polycarbonate, polyvinyl chloride, nylon polyoxymethylene, etc., so as to obtain high polymer alloy with excellent performance.
In recent years, the automobile is developing towards light weight and good safety. SEBS has been widely used in automobile manufacturing industry in developed countries such as the United States, such as dashboard, steering wheel protective layer, seals, ventilation pipes, etc. Compared with polyurethane and polyolefin thermoplastic elastomer, SEBS has advantages in performance and total production cost.
3. Food devices and medical products
Because SEBS has the characteristics of good air tightness and high-temperature steam sterilization, it is non-toxic and very in line with the standards issued by the Food and Drug Administration (FDA). It is suitable for making medical devices, injection needles, emulsion tubes, food packaging materials, valves, water heater parts, etc.
SESB has good solubility, can be dissolved in common solvents, can be blended with many polymers, and can be filled with oil commonly used in rubber industry, such as naphthenic oil or alkane oil. SEBS is suitable for producing hot-melt pressure-sensitive adhesive with good heat resistance and high temperature resistance. The adhesive has good oxygen resistance and ultraviolet resistance, and has no peeling phenomenon and no obvious change in viscosity after being placed at 177℃ for 7 days.
In addition, the application of SEBS in the field of adhesives and sealants has the following advantages: processing: easy operation, recycling of leftover materials, no need for vulcanization, hot melting, easy to stick with many additives evenly, soluble in conventional solvents, fast dissolving speed and high solid content. Performance: High strength, high elasticity, good elasticity at low temperature, acid and alkali resistance, and can be made into products with required performance.
5. Lubricating oil additives
Adding a small amount of SEBS into the lubricating oil can stabilize the viscosity index of the lubricating oil, so that the viscosity of the lubricating oil will not be obviously affected by the temperature change. It has been reported in the literature that after adding 0.7.3% SEBS into the lubricating oil of the aircraft engine, it has been tested for 201 hours, which proves that the effect is very good.