Medical Adhesives and Sealants. Adhesion. Definition: The state at which two surfaces are held together by interfacial forces, which may consist of all known chemical attractive forces, as well as mechanical interlocking action or both. Adhesive.
Definition: The state at which two surfaces are held together by interfacial forces, which may consist of all known chemical attractive forces, as well as mechanical interlocking action or both.
Breaking strength is determined by:
A uniform stress pattern in an adhesive joint is seldom produced by the application of external force.
Degree of Cure ----->
Cyanoacrylate adhesives were first used on wounded soldiers in Vietnam: a quick spray over the wounds stopped bleeding and bought time until conventional surgery could be performed.
Methyl -cyanoacrylate monomer polymerizes in the presence of trace amounts of almost any electron-donor compound (the initiator) by anionic vinyl polymerization, examples include water, alcohols, amines, carboxylate ions, and electron rich olefins.
Medical grade products currently available contain either butyl, isobutyl or octyl esters. They are bacteriostatic and painless to apply, break down harmlessly in tissue by hydrolysis and are essentially inert once dry.
Substrate versatilityRapid cureAdhesion topolyolefins withprimers
Thermoplastic resinwhen curedPoor peel strength,rigidRefrigerationrequired
Catheter componentsTube-set bondingPolyolefin bonding
Substrate versatilityGood resistancepropertiesCure on demand
Capital expenditurefor light-cureequipment
Needle assemblyAnesthesia masksHeat exchangersOxygenatorsTube-set bonding
Substrate versatilitySuperior thermaland chemicalresistanceLow shrinkageHigh gap filling
Poor peel strength,rigidExothermic reactionTwo-part systemsrequire mixing
Needle assemblyDeep section potting
Substrate versatilityHigh peelGood resistanceproperties
Moisture sensitivityPrimers required forsome substratesTwo-part systemsrequire mixing
Deep section pottingBonding of tips ontovarious components