9 Jul 2019

Evonik has developed a monomer that is all in one

Specialty chemicals group Evonik has developed a monomer that is an all-in-one adhesion promoter, corrosion inhibitor and reactive flame retardant: VISIOMER® HEMA-P 70M.

What makes this innovative specialty methacrylate unique
is its versatility, which is apparent in a number of different
areas:

  • Adhesion: VISIOMER® HEMA-P 70M improves adhesion dramatically, even at low concentrations. In studies, shear strength was tripled in structural adhesives when 5% VISIOMER® HEMA-P 70M was added (Figure 1).
  • Corrosion protection: Effectively preventing corrosion has always been a major requirement for coatings. The trend toward waterborne systems, however, makes ensuring such anti-corrosion properties a challenge. Studies on acrylic emulsions with a low amount of VISIOMER® HEMA-P 70M demonstrate enhanced corrosion resistance compared to resins that feature no anti-corrosion agent. Panels coated with emulsion polymers containing VISIOMER® HEMA-P 70M withstood corrosion for up to 168 hours in a saltwater immersion test (Figure 2).
  • Flame-retardant properties: New regulations are driving industry interest towards alternatives to conventional halogen-based flame-retardants. Since VISIOMER® HEMA-P 70M acts as a reactive diluent or co-monomer which is bonded to the polymer backbone, it does not migrate like conventional flame retardants do. The product can be used to improve flame retardancy even further in combination with other standard flame retardants.
  • Processing and appearance: VISIOMER® HEMA-P 70M contains 70% phosphate compounds as well as 30% methyl methacrylate. It is particularly easy to process because of its low viscosity. In addition, and as a result of its low color index, the specialty monomer is also particularly well-suited for applications that demand high transparency and surface quality, e.g. acrylate and methacrylate systems.