7 Most VSAQ’s of Polymers Chapter in Inter 2nd Year Chemistry (TS/AP)
2 Marks
VSAQ-1 : What is PHBV? How is it useful to man?
PHBV (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)) is a biodegradable polymer with significant benefits for humans. It is fully biodegradable, reducing plastic waste and environmental pollution. PHBV’s biocompatibility makes it suitable for medical implants and drug delivery systems, minimizing the need for additional surgeries. It is also used in eco-friendly packaging materials, extending the shelf life of food products while reducing plastic waste in the food industry. In agriculture, PHBV-based mulch films enhance crop growth and eliminate the need for plastic mulch removal. Additionally, PHBV serves as a drug carrier for controlled release in pharmaceuticals. Its biodegradability aids in environmental conservation, reducing plastic pollution in ecosystems. Ongoing research and development in bioplastics, including PHBV, contribute to sustainable solutions across various industries.
VSAQ-2 : What is vulcanization of rubber?
Vulcanization of rubber is a chemical process that involves adding sulfur to rubber to improve its properties. During vulcanization, sulfur forms cross-links between rubber polymer chains, creating a three-dimensional network. This process enhances rubber’s elasticity, tensile strength, durability, and resistance to factors like heat, water, chemicals, and aging. Vulcanized rubber is widely used in applications such as tire manufacturing and footwear production due to its improved performance characteristics.
VSAQ-3 : What is polymerization? Give an example of polymerization reaction.
Polymerization is a chemical process where monomers (small molecules) join together to form polymers (large molecules). An example of polymerization is the polymerization of ethylene to produce polyethylene. In this reaction, multiple ethylene molecules (C2H4) combine to create a polymer chain, represented as (C2H4)n, where ‘n’ denotes the number of repeated ethylene units. Polyethylene is a widely used plastic known for its flexibility, durability, and resistance to moisture and chemicals, making it suitable for various applications like plastic bags and containers. Polymerization is fundamental in the production of synthetic materials and plastics.
VSAQ-4 : What are copolymers? Give example.
Copolymers are polymers formed by polymerizing two or more different types of monomers together in the same polymer chain. These monomers can be combined in various ratios, allowing for a wide range of compositions and properties in the resulting copolymer.
Example of a copolymer: Styrene-butadiene rubber (SBR)
SBR is a copolymer made by polymerizing two monomers, styrene and butadiene, in a specific ratio. Styrene contributes to hardness and wear resistance, while butadiene provides elasticity and low-temperature flexibility. SBR is commonly used in tire manufacturing due to its balanced properties, including good grip and abrasion resistance. Copolymers like SBR showcase the ability to tailor polymer properties by combining different monomers in a single polymer chain.
VSAQ-5 : What are the repeating monomeric units of Nylon 6 and Nylon 6,6? What are the monomers present in the Nylon 2 – Nylon 6?
- Nylon 6 is composed of repeating monomeric units derived from caprolactam, which has six carbon atoms, hence the name “Nylon 6.”
- Nylon 6,6 consists of repeating monomeric units from two different compounds: hexamethylenediamine and adipic acid, both containing six carbon atoms each, resulting in the “6,6” designation.
- Nylon 2 – Nylon 6 represents a copolymer containing various nylon monomers with different carbon atom numbers in their structures, such as nylon 2, nylon 4, and nylon 6. This results in a polymer with a blend of properties suitable for specific applications.
VSAQ-6 : What is biodegradable polymer? Give one example of biodegradable polyester?
A biodegradable polymer is a type of polymer that undergoes natural degradation through biological processes, reducing its environmental impact. An example of a biodegradable polyester is Polylactic Acid (PLA), which is derived from renewable sources like corn starch or sugarcane. PLA is used in applications such as food packaging and 3D printing and can be composted, breaking down into environmentally friendly components like water and carbon dioxide. Biodegradable polymers like PLA contribute to reducing plastic pollution and promoting sustainability.
VSAQ-7 : What is PDI (poly Dispersity Index)?
Polydispersity Index (PDI), also known as Polydispersity Coefficient, is a numerical measure used to describe the distribution of molecular weights within a polymer sample. It is calculated by dividing the weight-average molecular weight (Mw) by the number-average molecular weight (Mn) of the polymer. A PDI greater than 1 indicates a broader range of molecular weights and greater heterogeneity in the sample, while a PDI of 1 signifies a more uniform distribution with all polymer chains having the same molecular weight. PDI is a crucial parameter in polymer characterization as it influences the properties and performance of polymers in various applications.