Vultac® are sulfur donors and vulcanization agents for rubbers
Supplied by MLPC International, Vultac® grades are low molecular weight alkylphenol disulfide oligomers that contain between 20-31.5% of sulfur.
Vultac®, a chemically unique cross-linker and sulfur donor
Vultac® products are polymeric alkylphenoldisulfides, commonly used as nitrosamine-free curing agents. Vultac® acts both as sulfur donor and cross-linker in rubber compositions. With a distinctive combination of benefits, Vultac® products enable formulators to decrease their formulation costs while improving the performance of the finished articles.
Vultac® products act as special cross-linkers, forming both hybrid and traditional sulfur bridges, as shown in the figure. The hybrid bonds are composed of alkylphenol groups linked to the rubber chains by monosulfidic or disulfidic bridges.
Benefits and features of Vultac®
In rubbers, Vultac® grades as curing agents offer the advantages of:
- Thermal stability leading to better reversion and heat ageing resistance.
- A relative long hybrid cross-link, providing a better molecular flexibility and thus improving mechanical and dynamic properties
Others key benefits
- Tackifier enhancing adhesion
- Anti-oxidant behaviour
Vultac® products are particularly recommended in halobutyl rubber (CIIR, BIIR, BIMS) applications, but have been used successfully also in a wide range of rubber formulations, including IIR, EPDM, NR, SBR and NBR.
Automotive rubber applications :
- Tire innerliner
- Tread for green tire
- Sidewall for tire
- Damping blocks and motor mounts
- Shoulder, chafer and apex
- Solid tires
- Inner tubes
- Elastic threads
- Halobutyl rubbers
- Shoe sole