Organic Chemistry Multiple Choice Questions on “Copolymerisation”.
1. Which of the following is true about copolymerisation?
a) radical, coordination, anionic, or cationic polymerization, depending on the type of initiation
b) addition of monomer to a metal complex, propagation is by successive insertion of monomer at the metal, and termination occurs when the metal complex separates from the polymer
c) monomers react by eliminating small molecules like H2O, NH3, CH2O and NaCl in a repetitive manner, Indefinite growth of the polymer occurs at both ends
d) a mixture of more than one (or different) monomeric species is allowed to polymerize
Answer: d
Clarification: When two or more different monomers unite together to polymerize, the product is called a copolymer and the process is called copolymerization. If M and N are present together, Random type MM MN NNN MM N M MM N N…… and Alternating type M N M N M N M N M ………
2. Gradient copolymer comers under which of the following copolymer category?
a) Linked copolymer
b) Branched copolymer
c) Terepolymer
d) Brush copolymer
Answer: a
Clarification: Linear copolymers consist of a single main chain and gradient copolymers are single chain of polymer in which the monomer composition changes gradually along the chain.
3. Which of the following copolymers is the copolymer with regular alternating A and B units?
a) Alternating copolymer
b) Periodic copolymer
c) Statistical copolymer
d) Block copolymer
Answer: a
Clarification: Alternating copolymers are with regular alternating A and B units, as shown below. This sequence will not change.
—- A-B-A-B-A-B-A-B-A-B-A-B-A-B-A-B-A-B—-
4. Which of the following copolymers is the copolymer with A and B units arranged in a repeating sequence?
a) Alternating copolymer
b) Periodic copolymer
c) Statistical copolymer
d) Block copolymer
Answer: b
Clarification: Copolymers with A and B units arranged in a repeating sequence are periodic polymers as shown below. This sequence will repeat itself to form a polymer.
(A-B-A-B-B-A-A-A-A-B-B-B)n
5. Which of the following copolymers is the copolymer with sequence of monomer residues follows a statistical rule?
a) Alternating copolymer
b) Periodic copolymer
c) Statistical copolymer
d) Block copolymer
Answer: c
Clarification: Copolymers with sequence of monomer residues follows a statistical rule, are called as statistical copolymer, as shown in below. This sequence will not change.
—- A-B-B-B-A-B-A-B-A-B-A-A-B-B-B-A-A-B—-
6. Which of the following copolymers is the copolymer which comprises two or more homopolymer subunits linked by covalent bonds?
a) Alternating copolymer
b) Periodic copolymer
c) Statistical copolymer
d) Block copolymer
Answer: d
Clarification: Copolymers which comprises two or more homopolymer subunits linked by covalent bonds, are called as block copolymer, as shown in below. This sequence will not change.
—- B-B-B-B-B-A-A-A-A-A-B-B-B-B-B—-
