Question

Which of the following materials is used in production of terylene?

• A. PMMA
• B. DMT
• C. Glycerol
• D. Bisphenol

Hint:

PET can be synthesized using either DMT or terephthalic acid as the acid component.

Answer 1

The Correct Option is B

Step 1: Understanding terylene production.
Terylene is the trade name for polyethylene terephthalate (PET), which is produced by condensation polymerization.
Step 2: Raw materials involved.
Terylene is manufactured using dimethyl terephthalate (DMT) or terephthalic acid along with ethylene glycol. DMT reacts with ethylene glycol to form PET.
Step 3: Analysis of options.
(A) PMMA: It is itself a polymer, not a raw material for PET.
(B) DMT: Correct — A key monomer used in terylene production.
(C) Glycerol: Used in alkyd resins, not PET.
(D) Bisphenol: Used in polycarbonate synthesis.
Step 4: Conclusion.
Dimethyl terephthalate (DMT) is used in the production of terylene, hence option (B) is correct.

Answer 2

Terylene (PET) forms by joining a diol with a dicarboxylic acid (or its ester), releasing a small molecule at each linkage. The correct raw material must therefore carry two reactive ester/acid-forming groups that can pair up with ethylene glycol's two -OH groups.

1. PMMA: Polymethyl methacrylate is already a fully formed polymer with only one type of repeating methacrylate unit; it has no free difunctional group available to react with ethylene glycol, so it cannot serve as a monomer feeding into PET synthesis.
2. DMT: Dimethyl terephthalate carries two methyl ester groups, one at each end of the terephthalate ring. In transesterification with ethylene glycol, each methyl ester group is displaced by the glycol's -OH group, releasing methanol and forming the ester linkages that build up the PET chain - exactly the two-ended reactivity needed to build a linear condensation polymer with a diol.
3. Glycerol: Glycerol carries three -OH groups (a triol), which would introduce branching/crosslinking into any condensation polymer rather than the strictly linear chain that makes up Terylene's structure; it is used instead in alkyd resins where branching is desirable.
4. Bisphenol: Bisphenol A carries two phenolic -OH groups but is used to react with phosgene or diphenyl carbonate to form polycarbonate, a completely different linkage chemistry (carbonate, not ester-from-terephthalate) than what builds PET.

Only DMT provides the correctly-matched two ester-forming ends needed to pair with ethylene glycol and build the linear PET (Terylene) chain.

Therefore, the correct answer is DMT.