There are many kinds of adhesives, and the components a […]
There are many kinds of adhesives, and the components are different. Therefore, their uses are also different. Therefore, the classification method is also varied. What are the major classification methods?
1, according to the shape classification
Adhesives can be divided into: aqueous solution type, solution type, emulsion (latex) type, solvent-free type, solid-state type, and paste and putty.
2, according to chemical composition
1) Inorganic adhesives: including silicates, phosphates, borates, ceramics and low melting point metals.
2) Organic adhesives: including natural and synthetic systems. Natural systems include starches, protein systems, natural resin systems, natural rubber systems, and asphalt systems; synthetic systems include resins and rubbers (chloroprene rubber, nitrile rubber, styrene-butadiene rubber, butyl rubber, Polysulfide rubber, carboxy rubber, silicone rubber, thermoplastic rubber) and composite type. Among them, the resin types include thermoplastics (polyvinyl acetate, polyvinyl alcohol, polyvinyl acetals, polyacrylates, celluloses, saturated polyesters, polyurethanes, etc.) and thermosettings (urea-formaldehyde resins, melamine resins, phenolic aldehydes). Resins, resorcinol-formaldehyde resins, epoxy resins, unsaturated polyesters, etc.)
3, classified by source
Adhesives can be divided into natural adhesives and synthetic adhesives according to their source. The former, such as animal skins, bones, blood glues, plant starches, natural rubbers, and rosin gums, all belong to natural adhesives and have been developed and applied for thousands of years, but their strength is not ideal. The latter started after the emergence of synthetic polymers at the beginning of this century, and its performance is superior. It has formed urea-formaldehyde, phenolic aldehyde, melamine, polyvinyl acetate emulsion, synthetic rubber mortar, polyacrylate and other inexpensive large varieties and varieties with various characteristics. , and has been widely used and promoted.