Question

Indicate whether the following statement is true or false: For an addition polymerization, there are no by-products of the reaction (assuming \(100 \%\) yield).

Short answer

The statement is \(True\). In an addition polymerization, monomers are directly bonded to each other without releasing any by-products, and as the reaction is assumed to have a 100% yield, no side reactions occur to generate any by-products.

Step-by-step solution

Defining Addition Polymerization

Addition polymerization, also known as chain-growth polymerization, is a type of polymerization in which monomers are added to the growing polymer chain one at a time, and no by-products are formed.

Addition polymerization mechanism

In an addition polymerization, the monomers contain a double bond (or sometimes a triple bond) that can be broken to create radicals or other reactive species in the presence of an initiator. These reactive species then add to the double bond of other monomers, thus initiating a chain reaction for the polymer formation.

Determining if there are any by-products

The key point of addition polymerization is that the monomers are directly bonded to each other without any molecules being released as by-products. If we have 100% yield, it means that all monomers react to form the polymer, and no other reaction occurs to generate any by-products.

Conclusion

Since addition polymerization is directly bonding the monomers, and it's assumed to be a 100% yield, which means that all the monomers form the polymer without any side reactions. Thus, there are no by-products formed during the reaction. Therefore, the statement is \(True\).

Key concepts

Chain-Growth Polymerization

Chain-Growth Polymerization is a fascinating process in polymer chemistry where small molecules called monomers join together to form large molecules known as polymers. Unlike step-growth polymerization, chain-growth polymerization involves adding individual monomers to an active site on a growing polymer chain one at a time.
This process generally requires an initiator to start the reaction, which can be a chemical compound that produces reactive species such as free radicals. These radicals react with unsaturated bonds in monomers, often involving double or triple carbon bonds, causing the chain reaction that leads to polymerization.
One of the defining characteristics of chain-growth polymerization is the absence of by-products. This means that every atom in the monomer becomes part of the polymer, assuming the reaction has a 100% yield. Chain-growth polymerization is used to produce a variety of important materials like polyethylene and polystyrene.

Polymer Chemistry

Polymer Chemistry is the branch of chemistry that studies polymers, their properties, and how they are formed. Polymers are large, complex molecules made by linking together thousands of smaller units known as monomers.
Addition polymerization is one of the fundamental types of reactions studied in this field. Chemists use various techniques and methods to understand and control the polymerization process, with the goal of designing materials that have the desired properties and functionalities.
In polymer chemistry, understanding the molecular structure and dynamics is crucial. For instance, chain-growth polymerization creates linear or branched polymers, depending on the conditions and the monomers used. Polymer chemists also explore the thermal and mechanical properties of polymers to determine suitable applications, ranging from plastics to biomedical devices. Tools like spectrometry and chromatography are often employed to analyze and verify the chemical structure of polymers.

Polymerization Mechanism

The Polymerization Mechanism is a detailed explanation of how monomers combine to form a polymer. In the case of addition polymerization, the process is generally initiated by an initiator that creates reactive sites on a monomer.
Initially, these reactive sites are often in the form of free radicals which are created by breaking a bond with the help of the initiator. These radicals attack the double bond in another monomer, opening it up and forming a new bond. This newly formed bond continues this process, adding more monomers and growing the chain.

• Initiation: Reactive species are generated.
• Propagation: Reactive sites react with monomers to grow the chain.
• Termination: The chain stops growing, often by combining with another reactive species.

Each step of this mechanism is essential for controlling the speed and length of the polymer chain. By understanding and manipulating the polymerization mechanism, chemists can produce polymers with specific characteristics tailored for diverse applications.