Problem 44 - Chemistry The Molecular Nature of Matter

Question

What is the difference between an addition polymer and condensation polymer?

Step-by-Step Solution

Answer

The difference is that addition polymers are formed by adding monomers without losing any atoms, while condensation polymers form by losing small molecules like water during the reaction.

Step 1: Understanding Addition Polymers

Addition polymers are formed by the repeated addition of monomer molecules with unsaturated carbon-carbon bonds (double or triple bonds). These polymers are formed without the loss of any small molecules.

Step 2: Understanding Condensation Polymers

Condensation polymers are formed by the repeated condensation reactions between monomer molecules where each reaction results in the loss of a small molecule, such as water or methanol, as a byproduct.

Step 3: Identifying the Key Difference

The main difference between addition and condensation polymers lies in their polymerization process. Addition polymerization involves simply adding monomers together without the loss of any atom, whereas condensation polymerization involves the loss of small molecules in the process of creating the polymer.

Key Concepts

Addition Polymerization

Addition polymerization is a type of polymerization process where monomers add together to form a polymer without producing any byproducts. The monomer molecules typically have unsaturated carbon-carbon bonds, such as double or triple bonds, which open up to join with other monomers. This process is like a chain reaction, where one monomer triggers the addition of another, and the chain grows in length.

This type of polymerization typically requires an initiator, a compound that starts the reaction, under specific conditions of temperature and pressure. Polymers produced by this process include polyethylene and polystyrene, which are common in various industries due to their desirable properties such as flexibility and resistance to moisture.

Condensation Polymerization

Condensation polymerization, on the other hand, is a process where monomer molecules combine with the elimination of small molecules like water, methanol, or hydrogen chloride. These monomer units usually contain at least two functional groups important for the chemical reaction, such as -OH, -COOH, or -NH2.

Common Characteristics

• Requires two different types of monomers.
• Often performed at higher temperatures.
• Produces a small molecule as a side product.

Examples of condensation polymers include nylon and polyester, both of which are integral to the textile industry. Disposal and recycling of such polymers can be more complex due to their varied composition.

Polymer Chemistry

Polymer chemistry is the study of the chemical synthesis and properties of polymers which are large molecules composed of repeated subunits known as monomers. This area of chemistry is crucial because it allows scientists to design and create new materials with specific characteristics for diverse applications ranging from packaging to biomedical devices.

Understanding both addition and condensation polymerization processes is essential in creating different types of polymers. The chemistry involved dictates not only the physical properties of the polymer, such as strength, elasticity, and durability, but also its thermal resistance and solubility, which are critical for its intended use.

Monomer Molecules

Monomer molecules are the basic building blocks of polymers. Each monomer has the capability to chemically bond to other monomers to form a polymer chain through polymerization processes. Monomers can be simple molecules like ethylene (used to make polyethylene) or more complex ones with several functional groups, like terephthalic acid (used to make polyester).

For addition polymerization, monomers must contain unsaturated bonds, which allow them to connect seamlessly. In condensation polymerization, monomers require two or more reactive functional groups to facilitate the release of byproducts and form the polymer backbone. The nature of these monomers decides the final properties of the polymer, influencing its application in everyday life.