ADHESIVES, GLUES AND SEALANTS
Chemical adhesives are those adhesives which polymer chains are formed and joined together to form the adhesive through various chemical reactions also called polyreactions. Therefore a chemical reaction will be needed in order to produce the adhesive.
We can classify chemical reactions or polyreactions in 3 groups:
Chemical curing adhesives are based on a series of monomers which react chemically with them in order to produce polymers structures with thermoplastic, elastomers or thermosets properties.
Monomer: Basic units of the polymer that it found in the resin, catalyst, which reaction each monomers with other monomers in order to producer thermoplastic , elastomers or thermosets polymers.
Pre-polymers: polymer chains with small size, mainly used for adhesives such as polyurethane.
Loads or fillers: silica, clay, aluminum powder ...
Additives: Accelerators, inhibitors, adhesion promoters ...
Chemical curing adhesives have excellent chemical, mechanical and physical properties compare with physical curing adhesive that is the reason about the use of these types of adhesives to perform joins that requires certain levels of strength and security.
Resistance to high temperatures above 180 ° C, for silicone-based adhesives can reach 300 º C.
High resistance against fracture or impact loads, chemical adhesives can reach strength about 40MPa like epoxy adhesives.
High elongation before fracture, reaching elongation higher to 600% as polyurethane and silicone based adhesives.
Generally, chemical curing adhesives have good resistance to moisture and the environment.
Below there is a list of all the chemical curing adhesives are currently used:
Hot curing rubber adhesives
Polimerization adhesives :
Unsaturated polyester adhesives
Acrylates curing radiation
Epoxy curing radiation
Polycondensation adhesives :
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