Tokyo – Liquid polybutadiene with a higher content of 1,2-vinyl units can be produced by the living-anion polymerisation method, sets out Nippon Soda in a recently supplied technical paper.
The product, it notes, is used as an additive for various rubber products such as EPDM, SBS, and HNBR, as the 1,2-vinyl units crosslink to create a network that contributes to the improvement of hardness, elasticity and oil-resistance in finished rubber products.
For a study detailed in the paper, Nippon Soda carried out an evaluation of 1,2-epoxidised PB as an additive in the formulation of chlorosulfonated polyethylene (CSM) rubber.
The resulting product offered "excellent resistance against liquids tested in this evaluation, in addition to equivalent or superior mechanical properties such as tensile strength, hardness and compression set."
The results are said to indicate that 1,2-epoxidised PB can be used, not only as a modifier for mechanical properties, but also as an acid acceptor for halogenated rubber formulations instead of lead monoxide, which has seen stricter regulations by the amendment of REACH and RoHS.
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