Question

Nylon 6,10 is prepared by polymerization of a diamine and a diacid chloride. Draw a structural formula for each reactant and for the repeat unit in this polymer.

Short answer

Answer: The reactants involved in the production of Nylon 6,10 are hexamethylene diamine (H2N(CH2)_6NH2) and sebacoyl chloride (ClOC(CH2)_8COCl). The structural formula for the repeat unit in the Nylon 6,10 polymer is -(NH(CH2)_6NHCO(CH2)_8CO)-.

Step-by-step solution

Understand the naming of nylon

Nylon 6,10 is a type of nylon named based on the number of carbon atoms in the diamine and diacid chlorides that react to form the polymer. In the case of nylon 6,10, the diamine has six carbon atoms, and the diacid chloride has ten carbon atoms.

Draw the structural formula for the diamine

The diamine has six carbon atoms, with an amine (-NH2) group attached at each end. The general formula for the diamine is H2N(CH2)_6NH2, and the specific compound is called hexamethylene diamine.

Draw the structural formula for the diacid chloride

The diacid chloride has ten carbon atoms, with an acid chloride (-COCl) group attached at each end. The general formula for the diacid chloride is ClOC(CH2)_8COCl, and the specific compound is called sebacoyl chloride.

Understand how the diamine and diacid chloride react

When the two reactants come together to create the polymer, a molecule of HCl (hydrogen chloride) is released as a byproduct. The amine group of the hexamethylene diamine will react with the acid chloride group of the sebacoyl chloride to create an amide linkage (-CONH-) between the two groups. This reaction continues to propagate along the length of the polymer chain.

Draw the structural formula of the repeat unit in the polymer

The repeat unit in the polymer will consist of both the hexamethylene diamine and sebacoyl chloride components, with the amide linkage between them. The formula for the repeat unit is -(NH(CH2)_6NHCO(CH2)_8CO)-.

Key concepts

Structural Formula

When we discuss organic compounds and polymers, understanding structural formulas is key. For nylon 6,10, the structural formula represents how atoms are organized and bonded in both the reactants and the final polymer. A structural formula is more detailed than a molecular formula, as it reveals the exact arrangement of the atoms.

For example, the diamine used in nylon 6,10 is hexamethylene diamine, with the formula \( H_2N(CH_2)_6NH_2 \). It shows that there are six carbon atoms (represented by \( CH_2 \) groups) connecting two amine groups (\( -NH_2 \)). Similarly, sebacoyl chloride has the formula \( ClOC(CH_2)_8COCl \), which denotes a ten carbon chain with two acid chloride groups at each end. This level of detail helps chemists visualize the reactions and the structure of the resulting polymer.

Polymer Chemistry

Polymer chemistry delves into the study and manipulation of polymers, which are long chains of repeating units called monomers. It's a fascinating area of chemistry that explains how various materials we use daily, from fabrics to plastics, are created. In the example of nylon 6,10, two different types of monomers – a diamine and a diacid chloride – react to form a copolymer.

In polymer chemistry, not just the identification of reactants is important, but also understanding how they transform under specific conditions. The creation of nylon 6,10 employs condensation polymerization, where each linking of monomers releases a small molecule (in this case, HCl) and forms a strong bond. Grasping these concepts helps in predicting the properties of the resultant polymer, such as its strength, durability, and other physical characteristics.

Amide Linkage

The amide linkage, represented by the group \( -CONH- \), is a distinctive feature of proteins and synthetic polymers like nylon. It forms when an amine group from one molecule reacts with a carboxylic acid derivative from another. This bond is pivotal because it defines the backbone of the polymer structure in nylons.

In nylon 6,10, each amide linkage results from the reaction between the amine group of hexamethylene diamine and the acid chloride group of sebacoyl chloride. The durability and resilience of nylon fabrics are partly due to the strong nature of the amide bonds, which provide excellent thermal and chemical resistance. Understanding the role of amide linkages in substances tells us a lot about their behavior and potential applications.

Condensation Polymerization

Condensation polymerization is a chemical process often used to synthesize polymers like nylon 6,10. It involves the repeated joining of monomers, with the simultaneous elimination of small molecules such as water or HCl. The removed small molecule is a byproduct of the formation of the new bond, hence the name 'condensation,' as the process typically involves the condensation of two molecules.

In our textbook case, each time the diamine and diacid chloride monomers link, they release a molecule of hydrogen chloride (HCl). This process not only extends the polymer chain but also ensures each new bond strengthens the polymer's structure. Understanding this process is crucial for students, as it explains the mechanics behind creating many of the materials they interact with every day, whether in personal products or industrial applications.