VISIOMER® Methacrylate monomers FOR HIGH- PERFORMANCE ADHESIVES AND SEALANTS
VISIOMER® methacrylate monomers can be found as a raw material in various adhesive and sealant formulations. Most popular are reactive adhesives based on methacrylates, though pressure-sensitive adhesives and sealants, e.g. for construction applications, also contain our VISIOMER® products.
VISIOMER® offers adhesive and sealant formulators a versatile toolbox for tuning their adhesive formulations to optimize adhesion and cohesion properties. Adhesion and cohesion properties typically obtained with the different methacrylate monomers can be drawn from the table below.
It's really up to you! Stretch the possibilities for improving your acrylic adhesive formulation with our functional methacrylate monomers.
Anaerobic acrylic adhesives are well known for their superior properties in fixing and sealing metal joints, for example. With anaerobic adhesives, adhesion is provided by hydroxyl functionalized monomers like VISIOMER® HEMA or VISIOMER® HPMA. On the other hand, multifunctional methacrylates, such as VISIOMER® PEG200DMA and VISIOMER® TRGDMA, provide cohesive strength.
Structural acrylic adhesives are used in the transportation industry for OEM assembly and in marine applications. For structural methacrylic adhesives, the choice of monomers largely depends on the substrate to be bonded. Usually, no surface preparation is needed for this type of reactive adhesives – one of the major advantages of methacrylic-based adhesives. To increase adhesion to metal, polar functionalized monomers, such as VISIOMER® GMAA (methacrylic acid), and the hydroxyesters VISIOMER® HEMA and HPMA are typically used. Crosslinking monomers – e.g. VISIOMER® HEMATMDI – can increase adhesion to polar surfaces as well. Crosslinkers are important for ensuring the necessary cohesion strength. Evonik proposes a variety of di- or trifunctional crosslinking monomers. For high crosslinking densities, our VISIOMER® TMPTMA, a trifunctional monomer, is recommended. Difunctional crosslinkers, such as VISIOMER® EGDMA, TRGDMA and 1,4 BDDMA, vary in their chain length and have an impact on final mechanical properties. For non-polar surfaces, the long-chain alkyl methacrylates are the preferred choice of monomer. Improvement adhesion to low-energy surfaces can be achieved with VISIOMER® IDMA or VISIOMER® C13-MA, for instance. Using VISIOMER® THFMA or VISIOMER® IBOMA, for example, will enhance the mechanical performance of methacrylate adhesives. Substituting VISIOMER® MMA for VISIOMER® THFMA in adhesive formulations will improve elongation properties at comparable Young's moduli.
PRESSURE SENSITIVE ADHESIVES
Methacrylate monomers are used as comonomers mainly in binders for water-based PSAs, but also for acrylic hot melt systems. They are added to improve mechanical properties and provide additional functionalities like adhesion promotion. Acrylic PSAs are mainly used as adhesives for labels, tapes or lamination, especially in the packaging industry.