Abstract ▼ AI-Helper

Polyurethanes (PUs) and styrene-butadiene-styrene block copolymers (SBS) are very efficient damping materials and frequently they need to be combined for mechanical parts with adhesives. Parts of PUs are usually prepared by casting and reactive adhesives for the joining of PUs and SBS via covalent b...

Polyurethanes (PUs) and styrene-butadiene-styrene block copolymers (SBS) are very efficient damping materials and frequently they need to be combined for mechanical parts with adhesives. Parts of PUs are usually prepared by casting and reactive adhesives for the joining of PUs and SBS via covalent bonds are desired for reliable adhesion of the parts in harsh environments. Reactive adhesives based on hydroxy terminated polybutadiene (HTPB) and amine terminated acrylonitrile butadiene rubber (ATBN) diluted with vinyl monomers were investigated as adhesives for PUs and SBS. Functional groups such as hydroxyl group and amine group in HTPB and ATBN respectively were expected to take part in the polyurethane formation reaction at the interface. Vinyl monomers with HTPB or ATBN may penetrate into SBS and crosslinked structures between adhesives and the rubber can be also formed during the casting process of PUs. The reactive adhesives properly designed based on swelling properties of SBS and contact angle on SBS showed cohesive failure at PU part in the 90° peel adhesion tests. Vinyl acetate and methyl acrylate were studied as reactive diluent of the adhesives as their solubility parameters are similar to toluene, the best solvent for SBS. Increasing the concentration of vinyl monomers resulted in the reduction of viscosity and decrease of contact angle of adhesives on SBS. It was found that 20 phr of vinyl monomers in HTPB showed the strongest adhesive strength in the test where cohesive failure at PU was confirmed. Mixtures of HTPB and ATBN did not show advantages as adhesives for PU and SBS. The reactive adhesives are expected to join PU and vulcanized rubbers as well as PU and SBS.

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