Advances in acrylic structural adhesives

Over the past decade, structural acrylic adhesives have advanced significantly in market applications. Where once disadvantages such as odor, odd mix ratios, and flammability were thought to be limiting factors in use, the increase in applications with mixed material bonding and/or high-performance requirements have driven growth in structural acrylic adhesives. New monomers have been introduced to address flammability issues and reduce odor issues. Particularly odiferous formulation additives have been replaced to also reduce odor issues. Meter mix dispense equipment is capable of delivering consistent mix ratio performance, reducing the risk of utilizing a two-component adhesive in manufacturing. The rapid rise in the electric vehicle market has led to a sharp rise in the need for structural adhesives capable of bonding metal to plastic and metal to various coatings at room temperature with performance capable of handling crash forces. Structural acrylic adhesives are well placed to meet these requirements. This chapter will briefly review the historical background of structural acrylic adhesives, market growth over the past decade, the use of higher molecular weight monomers, manufacturing trends, and some key customer applications.