Question

(questions about polyamide)

1-write the chemical structure of monomer , repeating unit and polymer ? and iupac name , common name , trade name and obbreviation.
2- what are the importance properties for the polymer?
3- when this polymer was discovered and commercialized . give the short history of polymer ?
4- how it can be polymerized . which polymerization process and what are the mostly used processing method !. which companies produces and how much produces this polymer!?
5- how it's characterized ? choose 3 different characterization tool and find examples from literature ? why these characterization methods are used?! what are the results for polyamide!?
6- what are the common applications of polyamide?
7-how polyamide can be modified?
8- what are the common copolymers , composites or nanocomposites of polyamide? ( give at least one important example each )
9-what are the recycling properties of polyamide?

Answer 1

polyamide:

A polymer in which each monomer unit is joined to the next by an amide bond (-CO-NH- ), for
example, nylon 66.

1-

Hexanedioic acid (Adipic acid) + 1,6-Hexanediamine (Hexamethylenediamine) ==>Nylon 66

n HOOC-(CH2)4-COOH + n H2N-(CH2)6-NH2 → [-OC-( CH2)4-CO-NH-(CH2)6-NH-]n + (2n-1) H2O
2-

Hydrogen bonds between adjacent polymer chains provide
additional tensile strength and stiffness to the fibers. The physical properties of the fiber are dramatic ( tensile
strength and stiffness).
3

In 1934, Carothers synthesized nylon 66, the first purely synthetic fiber. Nylon 66 is so
named because it is synthesized from two different monomers, each containing six carbon atoms.
4

The current raw material base for the production of nylon 66 is benzene, which
is derived almost entirely from catalytic cracking and reforming of petroleum. Catalytic
reduction of benzene to cyclohexane followed by catalyzed air oxidation gives a
mixture of cyclohexanol and cyclohexanone. Oxidation of this mixture by nitric acid
gives adipic acid.

Adipic acid, in turn, is a starting material for the synthesis of hexamethylenediamine.
Treatment of adipic acid with ammonia gives an ammonium salt, which when heated,
gives adipamide. Catalytic reduction of adipamide gives hexamethylenediamine.
Thus, carbon sources for the production of nylon 66 are derived entirely from petroleum.