Polymerization MCQs With Answer

Polymerization MCQs With Answer

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Polymerization MCQs With Answer is a focused review designed for B.Pharm students to master polymer chemistry concepts applied in pharmaceuticals. Understanding polymerization is essential because polymers act as excipients, drug carriers, coatings and biomedical materials. This set covers chain-growth and step-growth mechanisms, free radical and ionic initiation, condensation and ring-opening polymerizations, controlled/living techniques, molecular weight parameters (Mn, Mw), polydispersity, kinetics, copolymerization, crosslinking and degradation. Emphasis is placed on catalysts (Ziegler–Natta, coordination), characterization (GPC, viscometry), and pharmaceutical relevance including hydrogels, PEG and HPMC. These MCQs are tailored to B.Pharm curricula and emphasize problem-solving in formulation science. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is polymerization?

  • The process of separating monomers into individual molecules
  • The chemical reaction in which monomers link to form polymers
  • The physical blending of two polymers without chemical bonding
  • The degradation of polymers into monomers

Correct Answer: The chemical reaction in which monomers link to form polymers

Q2. Which statement best distinguishes chain-growth from step-growth polymerization?

  • Chain-growth forms polymers only by condensation with loss of small molecules
  • Step-growth links monomers by gradual reaction between functional groups, while chain-growth involves active centers adding monomer units rapidly
  • Chain-growth always yields polymers with higher polydispersity than step-growth
  • Step-growth requires free-radical initiators exclusively

Correct Answer: Step-growth links monomers by gradual reaction between functional groups, while chain-growth involves active centers adding monomer units rapidly

Q3. Which initiator is commonly used for free-radical polymerization in the laboratory?

  • Ziegler–Natta catalyst
  • Benzoyl peroxide
  • Sodium hydroxide
  • Titanium tetrachloride

Correct Answer: Benzoyl peroxide

Q4. Condensation polymerization is characterized by which feature?

  • Polymer chains grow by addition of monomers without by-products
  • Each step produces small molecules such as water or methanol as by-products
  • It only occurs in the presence of radical initiators
  • It exclusively forms linear polymers with no branching

Correct Answer: Each step produces small molecules such as water or methanol as by-products

Q5. Degree of polymerization (DP) refers to:

  • The number of polymer chains in a sample
  • The average number of repeating units in a polymer chain
  • The molecular weight measured by light scattering only
  • The temperature at which a polymer softens

Correct Answer: The average number of repeating units in a polymer chain

Q6. Mn and Mw denote:

  • Mn is number-average molecular weight; Mw is weight-average molecular weight
  • Mn is weight-average; Mw is number-average molecular weight
  • Both are identical for all polymers
  • They refer to melting and glass transition temperatures respectively

Correct Answer: Mn is number-average molecular weight; Mw is weight-average molecular weight

Q7. Polydispersity index (PDI) is defined as:

  • Mn × Mw
  • Mn / Mw
  • Mw / Mn
  • Mn + Mw

Correct Answer: Mw / Mn

Q8. Chain transfer reactions in radical polymerization primarily affect:

  • The tacticity of the polymer chain
  • The rate of initiation only
  • The molecular weight and molecular weight distribution
  • The glass transition temperature directly

Correct Answer: The molecular weight and molecular weight distribution

Q9. Termination by combination in free-radical polymerization results in:

  • Two chains joining to form one longer chain
  • A chain losing its active center but not joining another chain
  • The formation of monomers from polymers
  • Transfer of radical to monomer without chain growth

Correct Answer: Two chains joining to form one longer chain

Q10. Ziegler–Natta catalysts are particularly important for producing:

  • Polyesters by condensation
  • Stereoregular polyolefins such as isotactic polypropylene
  • Polymers by free-radical emulsion only
  • Hydrogels for drug delivery

Correct Answer: Stereoregular polyolefins such as isotactic polypropylene

Q11. A key feature of living polymerization is:

  • Immediate and irreversible termination of all chains
  • Absence of chain transfer and reversible chain ends allowing narrow PDI growth
  • Production of polymers only by condensation
  • Degradation of polymer during synthesis

Correct Answer: Absence of chain transfer and reversible chain ends allowing narrow PDI growth

Q12. Ring-opening polymerization (ROP) is commonly used to synthesize which pharmaceutical polymer?

  • Polyethylene (PE)
  • Nylon-6 from caprolactam
  • Polystyrene by free-radical addition
  • Polyvinyl chloride (PVC)

Correct Answer: Nylon-6 from caprolactam

Q13. Which polymerization method uses no solvent and relies on monomer bulk?

  • Solution polymerization
  • Emulsion polymerization
  • Bulk polymerization
  • Suspension polymerization

Correct Answer: Bulk polymerization

Q14. Emulsion polymerization typically involves:

  • Polymerization entirely in the gas phase
  • Monomers dispersed as droplets in water with surfactant-stabilized micelles
  • Polymerization in pure organic solvent without water
  • Formation of polymers by ionic precipitation only

Correct Answer: Monomers dispersed as droplets in water with surfactant-stabilized micelles

Q15. An inhibitor in radical polymerization acts to:

  • Accelerate chain propagation
  • Scavenge radicals and prevent polymerization
  • Increase molecular weight by promoting combination
  • Convert step-growth into chain-growth polymerization

Correct Answer: Scavenge radicals and prevent polymerization

Q16. RAFT and ATRP are examples of:

  • Conventional uncontrolled free-radical polymerization
  • Controlled/”living” radical polymerization techniques
  • Step-growth condensation reactions
  • Thermal degradation processes

Correct Answer: Controlled/”living” radical polymerization techniques

Q17. Which copolymer type has distinct blocks of different monomers along the chain?

  • Random copolymer
  • Graft copolymer
  • Block copolymer
  • Alternating copolymer

Correct Answer: Block copolymer

Q18. Reactivity ratios in copolymerization describe:

  • Thermal stability of copolymers
  • Relative tendency of each monomer to add to its own or the other monomer
  • The solubility of monomers in water
  • The molecular weight distribution after polymerization

Correct Answer: Relative tendency of each monomer to add to its own or the other monomer

Q19. Glass transition temperature (Tg) refers to:

  • The temperature at which a crystalline polymer melts
  • The reversible transition where an amorphous polymer softens from a glassy to rubbery state
  • The decomposition temperature of a polymer
  • The temperature at which crosslinking begins

Correct Answer: The reversible transition where an amorphous polymer softens from a glassy to rubbery state

Q20. Crosslinking in polymers generally results in:

  • Lower thermal stability and easier solubility
  • Formation of a three-dimensional network that reduces solubility and can increase modulus
  • Conversion of polymers into monomers
  • Reduction of molecular weight without affecting mechanical strength

Correct Answer: Formation of a three-dimensional network that reduces solubility and can increase modulus

Q21. Which polymer is most susceptible to hydrolytic degradation in aqueous environments?

  • Polyethylene (PE)
  • Polylactic acid (PLA)
  • Polystyrene (PS)
  • Polypropylene (PP)

Correct Answer: Polylactic acid (PLA)

Q22. Gel permeation chromatography (GPC) is used to measure:

  • Thermal transitions like Tg and Tm
  • Molecular weight distribution and average molecular weights
  • Chemical composition by NMR only
  • Mechanical properties like tensile strength

Correct Answer: Molecular weight distribution and average molecular weights

Q23. The Mark–Houwink equation relates intrinsic viscosity to:

  • Glass transition temperature
  • Molecular weight of the polymer
  • Degree of crystallinity
  • Solubility parameter

Correct Answer: Molecular weight of the polymer

Q24. Tacticity in polymers refers to:

  • The degree of crosslinking in a network
  • The stereochemical arrangement of pendant groups along the polymer chain
  • The number of chain ends per molecule
  • The solubility class of a polymer

Correct Answer: The stereochemical arrangement of pendant groups along the polymer chain

Q25. A common radical initiator used in free-radical polymerization of styrene is:

  • Benzoyl peroxide
  • Hydrochloric acid
  • Sodium borohydride
  • Phosphoric acid

Correct Answer: Benzoyl peroxide

Q26. Gamma irradiation of polymers during sterilization can cause:

  • Only beneficial crosslinking with no adverse effects
  • Chain scission, crosslinking, or both depending on polymer structure
  • Complete conversion to monomers immediately
  • No chemical changes because radiation does not affect polymers

Correct Answer: Chain scission, crosslinking, or both depending on polymer structure

Q27. Plasticizers are added to polymer formulations to:

  • Increase Tg and make polymers more brittle
  • Decrease Tg and increase flexibility
  • Cause immediate polymer degradation
  • Convert thermoplastics into thermosets

Correct Answer: Decrease Tg and increase flexibility

Q28. Which polymer is frequently used as a water-soluble excipient in pharmaceuticals?

  • Polyethylene (PE)
  • Polyvinyl alcohol (PVA)
  • Polystyrene (PS)
  • Polypropylene (PP)

Correct Answer: Polyvinyl alcohol (PVA)

Q29. Hydrogels used in drug delivery are primarily characterized by:

  • Hydrophobic, non-swelling networks
  • Crosslinked, hydrophilic networks that swell in water
  • Linear non-crosslinked polymers soluble in water
  • Polymers that melt at body temperature without swelling

Correct Answer: Crosslinked, hydrophilic networks that swell in water

Q30. A perfectly monodisperse polymer sample would have a PDI of:

  • 0
  • 0.5
  • 1
  • Greater than 2

Correct Answer: 1

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