Polyamides resins are linear condensation polymers with a high degree of crystallinity with repeating amide links in their molecular chain. They can either be based upon a single repeating monomer comprising an amine reactive group and a carboxylic acid group, or they are the product of a reaction of a diamine and a diacid. Polyamides are engineering polymers characterized by exceptional hardness, good impact strength, and high abrasion resistance. Reason for their excellent mechanical characteristics is the amide links leading to internal hydrogen bonds between the different polymer chains.
All polyamides are made by the formation of an amide function to link two molecules of monomer together. The monomers can be amides themselves (usually in the form of a cyclic lactam such as caprolactam), amino acids or a stoichiometric mixture of a diamine and a diacid. Both these kinds of precursors give a homopolymer. Polyamides are easily copolymerized, and thus many mixtures of monomers are possible which can in turn lead to many copolymers.
The main applications of polyamide resin are toothbrushes, wear pads, wheels, gloves, guitar strings and pics, tennis racket strings, medical implants, electrical connectors, fishing lines, tents, gears, and many more.
It can be used in the printing industry to produce solvent type printing ink for the soft palate, surface printing ink for plastic, and hot-melt adhesive.
Reactive polyamides are initially used as curing agents for epoxy resins.
Non Reactive polyamides are used largely. These are used in hot-melt adhesives and printing inks.
It is commonly used in almost every kind of metal and nonmetal. For example aluminum, steel, iron, ceramic, rubber, wood, glass, cement, glass-reinforced plastic along other epoxy resin.