Question

How would you explain to a young science student how to decide whether a given compound might be useful as a monomer for addition polymerization? Condensation polymerization?

Short answer

In summary, to decide whether a given compound might be useful as a monomer for addition polymerization or condensation polymerization, look for the following key characteristics: - For addition polymerization: 1. Presence of double or triple bonds. 2. Stability and low reactivity before polymerization. - For condensation polymerization: 1. Presence of two or more reactive functional groups, such as alcohol (-OH), carboxylic acid (-COOH), or amine (-NH2). 2. Yielding a small molecule as a byproduct, such as water or methanol, when combined with another monomer. Compare the compound's characteristics with the requirements for each polymerization type to determine its suitability for either process.

Step-by-step solution

Understanding Addition Polymerization

Addition polymerization involves the formation of large molecules (polymers) from small molecules (monomers) without any loss of atoms or molecules. This type of polymerization occurs through the linking of monomers with double or triple bonds. These double or triple bonds break, creating single bonds that can link with other monomers, forming a long polymer chain.

Identifying Monomers for Addition Polymerization

In order to determine if a given compound is useful as a monomer for addition polymerization, look for these characteristics: 1. The compound must have at least one double or triple bond, allowing the bond to break and form single bonds with other monomers. 2. The compound must be relatively stable and not reactive with other compounds before the polymerization process begins. Examples of monomers used in addition polymerization include ethylene (C2H4), styrene (C8H8), and vinyl chloride (C2H3Cl).

Understanding Condensation Polymerization

Condensation polymerization involves the joining of monomers with the elimination of a small molecule, such as water or methanol. This type of polymerization occurs when monomers with two or more reactive functional groups react together to form a polymer chain and eliminating a small molecule in the process.

Identifying Monomers for Condensation Polymerization

In order to determine if a given compound is useful as a monomer for condensation polymerization, look for these characteristics: 1. The compound must have two or more reactive functional groups, such as alcohol (-OH), carboxylic acid (-COOH), or amine (-NH2) groups, which can react with other monomers to form a polymer chain. 2. The compound, when combined with another monomer, must yield a small molecule as a byproduct, such as water or methanol. Examples of monomers used in condensation polymerization include glycols (HO-R-OH), diacids (HOOC-R-COOH), and diamines (H2N-R-NH2).

Comparing the Compound with Monomers for Each Polymerization Type

To decide whether a given compound is suitable for addition or condensation polymerization, compare its characteristics with the key features of monomers suitable for each type of polymerization mentioned in Steps 2 and 4. If the compound closely matches the characteristics of monomers for addition polymerization, it is more likely to be useful as a monomer for that process. Similarly, if the compound closely matches the characteristics of monomers for condensation polymerization, it is more likely to be useful as a monomer for that process.