Rubber based adhesives generally offer higher adhesion and shear properties than acrylic or silicone adhesives. Based on natural or synthetic rubbers, these adhesives are mixtures that include ingredients such as tackifying resins and oils to improve wetting properties. They provide good to excellent initial tack and adhesion particularly in skin contact applications.
Because of their strong bonding characteristics, many of the adhesives used in surgical applications are rubber based. They provide the strength and moisture resistance required in challenging environments.
Acrylic monomer esters as a class, are polymerized to form polymer chains and are cross-linked to form high molecular weight polymers with the desired adhesive properties. Acrylic adhesives provide resistance to solvents.
Acrylic adhesives offer many advantages in medical applications. Lower initial tack allows for repositioning for optimum effectiveness. All medical adhesive applications are temporary in nature, from an hour to days of adhesion, so a permanent bond is not required. Ease of removal is also an important consideration.
In addition, polymerized acrylics are chemically inert so they typically cannot cause allergic reactions.
An acrylic adhesive is combined with tackifying resins to enhance bonding properties. They offer higher initial tack and improved bonding to low energy surfaces, but there is some loss of UV and solvent resistance.
For medical applications, hydrocarbon tackifiers, which are chemically inert and hypoallergenic, have been developed.
Silicone adhesives are used for specialty applications such as high oxygen/gas permeability, low pain upon removal, and adhesion to and removal from sensitive skin.