TUNING PROPERTIES AND MORPHOLOGY IN HIGH VINYL CONTENT SBS BLOCK COPOLYMER, A THERMOPLASTIC ELASTOMER VIA THIOL-ENE MODIFICATION

ABSTRACT Thiol-ene modification of high vinyl content thermoplastic elastomeric styrene butadiene styrene (SBS) block copolymer (BCP) was carried out using different thiolating agents in toluene at 70 °C. 1H NMR analysis confirmed the participation of vinyl double bond in the thiol-ene modification reaction of SBS. Surface morphology of the block copolymers evaluated by atomic force microscopy analysis showed higher roughness after the thiol-ene reaction. The thiol-modified SBS block copolymer showed better adhesion strength and oil resistance properties than the pristine SBS.

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CURE KINETICS AND FINAL PERFORMANCE OF STYRENE BUTADIENE STYRENE BLOCK COPOLYMER/SILICA NANOCOMPOSITES

Rubber Chemistry and Technology ◽

10.5254/rct.14.85974 ◽

2015 ◽

Vol 88 (1) ◽

pp. 53-64 ◽

Cited By ~ 3

Author(s):

Ahmad Moaddab ◽

Mohammadreza Kalaee ◽

Saeedeh Mazinani ◽

Ali Aghajani ◽

Mohammad M. Rajab

Keyword(s):

Block Copolymer ◽

Silica Nanoparticle ◽

Cure Kinetics ◽

Test Methods ◽

Force Microscopy ◽

Silica Nanocomposites ◽

Final Performance ◽

Styrene Butadiene Styrene ◽

Styrene Butadiene ◽

Butadiene Styrene

ABSTRACT Cure kinetics and the final performance of styrene–butadiene–styrene block copolymer (SBS)/silica nanocomposites followed by vulcanization are analyzed. The results indicated that the presence of silica affects the curing reaction of SBS, and additional heating is required for complete vulcanization of SBS/silica nanocomposites due to their higher activation energy. The samples were characterized using scanning electron microscopy/energy dispersive X-ray spectroscopy, atomic force microscopy, and tensile test methods. The tensile strength, hardness, and wear resistance of SBS/silica nanocomposites show considerable increases by incorporating different silica nanoparticle contents in the SBS matrix; however, silica nanoparticles cause a decrease in modulus and elongation at break compared to cured neat SBS.

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Influence of Ultraviolet Radiation on Mechanical Properties of a Photoinitiator Compounded High Vinyl Styrene–Butadiene–Styrene Block Copolymer

Polymers ◽

10.3390/polym13081287 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1287

Author(s):

Sanjoy Datta ◽

Radek Stocek ◽

Kinsuk Naskar

Keyword(s):

Mechanical Properties ◽

Block Copolymer ◽

Ultraviolet Radiation ◽

Thermoplastic Elastomer ◽

Labile Hydrogen ◽

Hydrogen Atoms ◽

Time Saving ◽

Styrene Butadiene Styrene ◽

Styrene Butadiene ◽

Butadiene Styrene

Ultraviolet curing of elastomers is a special curing technique that has gained importance over the conventional chemical crosslinking method, because the former process is faster, and thus, time-saving. Usually, a suitable photoinitiator is required to initiate the process. Ultraviolet radiation of required frequency and intensity excites the photoinitiator which abstracts labile hydrogen atoms from the polymer with the generation of free radicals. These radicals result in crosslinking of elastomers via radical–radical coupling. In the process, some photodegradation may also take place. In the present work, a high vinyl (~50%) styrene–butadiene–styrene (SBS) block copolymer which is a thermoplastic elastomer was used as the base polymer. An attempt was made to see the effect of ultraviolet radiation on the mechanical properties of the block copolymer. The process variables were time of exposure and photoinitiator concentration. Mechanical properties like tensile strength, elongation at break, modulus at different elongations and hardness of the irradiated samples were studied and compared with those of unirradiated ones. In this S-B-S block copolymer, a relatively low exposure time and low photoinitiator concentration were effective in obtaining optimized mechanical properties. Infrared spectroscopy, contact angle and scanning electron microscopy were used to characterize the results obtained from mechanical measurements.

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