Question

Which is/are correct about PMMA here (I) It is called plexiglass (II) It is hard and transparent (III) For it's formation peroxide is used (IV) It is co-polymer (a) I, II (b) II, III (c) I, II, III (d) I, II, III, IV

Short answer

(c) I, II, III

Step-by-step solution

Understanding PMMA

PMMA stands for polymethyl methacrylate, which is commonly known as plexiglass. Therefore, statement (I) is correct. It is a transparent thermoplastic often used as a lightweight or shatter-resistant alternative to glass.

Evaluating Hardness and Transparency

PMMA is known for being hard and transparent, making it suitable for a wide range of applications such as lenses and windows. Thus, statement (II) is correct.

Analyzing Formation Process

The formation of PMMA involves the polymerization of methyl methacrylate. Peroxides are frequently used as initiators in the polymerization process of such monomers, so statement (III) is correct.

Checking Polymer Type

PMMA is not a copolymer; it is a homopolymer. A copolymer consists of two or more different types of monomers. Therefore, statement (IV) is incorrect.

Key concepts

plexiglass

Plexiglass is a popular name for polymethyl methacrylate (PMMA), a transparent thermoplastic often used as a lightweight alternative to traditional glass. The reason it's frequently utilized is due to its shatter-resistant properties, making it ideal for windows, display cases, and many other applications. This material is not only durable but also flexible in its uses, being sought after in industries ranging from architecture to retail display.
Plexiglass offers excellent clarity, which is why it's sometimes used in place of glass in aquariums and car windows. It's important to remember that while it's similar in appearance to glass, it has unique properties that set it apart. These include:

• Higher impact resistance compared to glass.
• Lighter weight, making it easier to handle and install.
• The ability to be molded, dyed, and shaped into various forms.

thermoplastic

Thermoplastics are a type of polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Unlike thermosetting plastics, which once set cannot be remelted, thermoplastics allow for reshaping and recycling. This makes them incredibly versatile and sustainable for many applications.
PMMA, or plexiglass, is a prime example of a thermoplastic. It can be melted down and reshaped without altering its inherent properties, which adds to its appeal in manufacturing. Key characteristics of thermoplastics include:

• Recyclability, which aids in reducing waste.
• Flexibility during processing and manufacturing.
• Varied applications owing to their ability to be easily molded.

polymerization process

The polymerization process is a chemical reaction in which small molecules, known as monomers, combine to form a complex chain or network, known as a polymer. In the case of PMMA, the monomer involved is methyl methacrylate. During polymerization, initiators such as peroxides are often used to kickstart the reaction, allowing the chains to grow and form the desired polymer.
Polymerization is key to creating the structure and properties of materials like plexiglass. It's an intricate process that can be finely controlled to produce polymers with specific characteristics, such as hardness and transparency. The process typically involves:

• Initiation, where initiators start the chain reaction.
• Propagation, in which monomers add to the growing chain.
• Termination, where the chain stops growing.

homopolymer

Homopolymers are a type of polymer that consists of only one kind of monomer. This is in contrast to copolymers, which are made from two or more different monomers. PMMA is classified as a homopolymer because it is derived solely from the polymerization of methyl methacrylate monomers.
Being a homopolymer means that PMMA has a uniform structure, which contributes to its clarity and strength. Homopolymers tend to display consistent properties throughout the material, allowing for predictability in its application and performance. Key features of homopolymers include:

• Simplicity in composition, leading to a uniform set of properties.
• Enhanced clarity and optical properties in materials like PMMA.
• Predictability in behavior under various conditions.