Degree of Polymerization for 6,6-Nylon
Calculate the degree of polymerization if 6,6-nylon has a molecular weight of 120,000 g/mol.

Question

Accepted Answer

The reaction by which 6,6-nylon is produced was described in Example 16-3. Hexamethylene diamine and adipic acid combine and release a molecule of water. When a long chain forms, there is, on average, one water molecule released for each reacting molecule. The molecular weights are 116 g/mol for hexamethylene diamine, 146 g/mol for adipic acid, and 18 g/mol for water. The repeat unit for 6,6-nylon is

[latex]\begin{matrix} \ \ \ \ \ \underset{|}{H} \ \quad \underset{|}{H} \quad \underset{|}{H} \quad \underset{|}{H} \quad \underset{|}{H} \quad \underset{|}{H} \quad \ \underset{|}{H} \quad \ \underset{|}{H} \ \quad \underset{||}{O} \quad \underset{|}{H} \quad \ \underset{|}{H} \quad \underset{|}{H} \quad \underset{|}{H} \quad \ \underset{||}{O} \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ H-N-C-C-C-C-C-C-N-C-C-C-C-C-C-O-H \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \quad \overset{|}{H} \quad \overset{|}{H} \ \quad \overset{|}{H} \ \quad \overset{|}{H} \quad \overset{|}{H} \quad \overset{|}{H} \ \ \ \ \quad \quad \ \ \ \ \quad \ \overset{|}{H} \quad \overset{|}{H} \quad \overset{|}{H} \quad \ \overset{|}{H}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \end{matrix} [/latex]

The molecular weight of the repeat unit is the sum of the molecular weights of the two monomers, minus that of the two water molecules that are evolved:
[latex]M_{repeat \ unit}[/latex] = 116 + 146 - 2(18) = 226 g/mol
Degree of polymerization = [latex]\frac{120,000 \ g/mol}{226 \ g/mol} = 531 [/latex]
The degree of polymerization refers to the total number of repeat units in the chain.

Question 16.4: Degree of Polymerization for 6,6-Nylon Calculate the degree ......

Related Answered Questions

Condensation Polymerization of 6,6-Nylon Nylon was first reported by Wallace Hume Carothers of Du Pont^TM in about 1934. In 1939, Charles Stine, also from Du Pont^TM, reported the discovery of this first synthetic fiber to a group of 3000 women gathered for the New York World’s Fair. The first ...

Verified Answer:

Verified Answer:

Comparing Mechanical Properties of Thermoplastics Compare the mechanical properties of low-density (LD) polyethylene, high-density (HD) polyethylene, polyvinyl chloride, polypropylene, and polystyrene, and explain their differences in terms of their structures. ...

Verified Answer:

Impact Resistant Polyethylene A new grade of flexible, impact-resistant polyethylene for use as a thin film requires a density of 0.88 to 0.915 g/cm³. Design the polyethylene required to produce these properties. The density of amorphous polyethylene is about 0.87 g/cm³. ...

Verified Answer:

Design of a Polymer Insulation Material A storage tank for liquid hydrogen will be made from metal, but we wish to coat the metal with a 3-mm-thick polymer as an intermediate layer between the metal and additional insulation layers. The temperature of the intermediate layer may drop to -80°C. ...

Verified Answer:

Number and Weight Average Molecular Weights We have a polyethylene sample containing 4000 chains with molecular weights between 0 and 5000 g/mol, 8000 chains with molecular weights between 5000 and 10,000 g/mol, 7000 chains with molecular weights between 10,000 and 15,000 g/mol, and 2000 chains ...

Verified Answer:

Verified Answer:

Insulation Boards for Houses You want to design a material that can be used for making insulation boards that are approximately 4 ft wide and 8 ft tall. The material must provide good thermal insulation. What material would you choose? ...

Verified Answer:

Materials Selection for Polymer Components Discuss the type of polymer you might select for the following applications: a surgeon’s glove, a beverage container, and a pulley. ...

Verified Answer: