Epoxies give in to modification. Distinguish chemical and physical modification.
The first consists in change of structure of grid of polymer by addition of the connections which are building in structure of it. As the example — addition of laproksid (polyethers of the alcohols containing glycidyl groups, for example glycerin anhydride) depending on functionality and molecular weight gives to cured resin elasticity, due to increase in molecular weight of internodal fragment, but lowers its water resistance. Addition halogen - and organophosphorous connections gives to pitch big incombustibility. Addition of phenol - formaldehyde resins allows to cure epoxy direct heating without hardener, gives big rigidity, improves antifriction properties, but lowers impact strength.
Physical modification is reached by addition in pitch of the substances which are not entering chemical bond with binding. As the example — addition of rubber allows to increase the impact strength of cured resin. Addition of colloid titanium dioxide increases its index of refraction and gives property of opacity to ultra - violet radiation.
On the basis of epoxies the different materials applied in different areas of the industry are made. Carbon fiber and ES form coal plastic (it is used as constructive material in different areas: otaviastroyeniya (see the Boeing - 777) before automotive engineering). Composite on the basis of ES are used in fixing bolts of rockets of class the earth space. ES with kevlar fiber — material for creation of bullet - proof vests.
Often epoxies use as epoxy glue or impregnating material — together with fiber glass fabric for production and repair of the different body or performance of waterproofing of rooms and also as the most available way in life to make product of glass - fiber as at once ready after injecting into a mold, and with probability of further cutting and polishing.
With ES do the body of watercrafts bearing very strong blows, different details for cars and other vehicles of fiber glass fabric.
As filling (sealant) for different payments, devices and devices.
Also epoxies are used in construction (see Sydney Opera House).
From epoxies the most different objects and things are produced (we will tell, mouthpieces).
Epoxies use as household glue. It is quite simple to use epoxy glue. Mixing of epoxy with hardener as a rule is carried out in extremely small volumes (several grams) therefore hashing is made at the room temperature and does not cause difficulties, proportion accuracy pitch/hardener when mixing depends on the producer of epoxy or hardener, it is necessary to use only those proportions which are recommended by the producer as time of hardening and physical properties of the turned - out product depends on it (derogation from the necessary proportion as a rule leads to hardening delta time, in extreme cases it is possible to receive unsteady product). As hardeners apply: hardeners cold triethylene tetramine (TETA), polietilenpoliamin (PEPA), polysebacic anhydride and hot cure maleic anhydride (DETA). [4][5] Usually standard proportion makes from 10: 1 to 5: 1, but in certain cases can reach to 1: 1. It is forbidden to mix large amount of pitch with hardener without use of special devices for mixing in order to avoid boiling up at once.
