Food Packaging Technology Interview Questions and Answers on “Factors Influencing Polymer Structure and Related Properties”.
1. Polyethylene is a polymer of __________
a) C2H4
b) C4H6
c) CH4
d) C2H2
Answer: a
Clarification: Polyethylene (PE) is a polymer of Ethylene (C2H4). It’s IUPAC name is polyethene or Poly(methylene). It was first synthesized by a German chemist Hans von Pechman in 1898.
2. Which of the following is called poison plastic?
a) PP
b) PET
c) PVC
d) LDPE
Answer: c
Clarification: PVC, Polyvinyl Chloride is called poison plastic. It releases many chemicals such as- dioxins, lead, ethylene dichloride, vinyl chloride, which is very harmful for health. High exposure to these chemicals causes diseases such as asthma and other respiratory ailments.
3. Which of the following is not a step in Addition polymerization?
a) Propagation
b) Condensation
c) Termination
d) Initiation
Answer: b
Clarification: Condensation is not a step in addition polymerization. Addition polymerization includes three steps, via- initiation, propagation and termination. Condensation polymerization is another kind of polymerization reaction, which includes- joining of two compounds by losing a small molecule (generally a water molecule).
4. Condensation Polymerization is called Chain growth polymerization?
a) True
b) False
Answer: b
Clarification: Condensation polymerization is called Step Growth Polymerization. Addition polymerization is called chain growth polymerization. Hence, the answer is false.
5. Styrene is also called as ___________
a) Ethylbenzene
b) Phenylphrene
c) Methylbenzene
d) Vinylpyridine
Answer: a
Clarification: Styrene is also known as ethylbenzene. Its chemical formula is C6H5CH=CH2. The polymerization of styrene via addition mechanism. It finds many uses in packaging industry due to some of its attributes like, clarity, hardness and brittleness.
6. Which of the following has greater density?
a) Polypropylene
b) High Density Polyethlene
c) Polystyrene
d) Polyvinyl chloride
Answer: d
Clarification: Amongst the given, PVC (Polyvinyl Chloride) has the greatest density. Density of Polypropylene is 0.946 g/cm3. Density of High Density Polyethlene is 0.970 g/cm3. Density of polystyrene ranges from 0.96 – 1.04 g/cm3. Density of Polyvinyl chloride ranges from 1.3 – 1.45 g/cm3.
7. Which of the following is the strongest plastic?
a) Teflon
b) High Density Polyethylene
c) Polystyrene
d) Polycarbonate
Answer: d
Clarification: Polycarbonate is the strongest plastic. It has properties such as high impact strength, high flexibility, durability – which make it very suitable for construction purposes.
8. Which of the following is microwave safe plastic?
a) PET
b) PVC
c) PP
d) PS
Answer: c
Clarification: Polypropylene (PP) is microwave safe plastic. It is produced from addition polymerization of propylene. Its melting point is about 160°C.
9. Which of the following plastics has identification number 6?
a) PS
b) HDPE
c) LDPE
d) PET
Answer: a
Clarification: Polystyrene (PS) has identification number 6. The identification number ranges from 1-7, plastics being, PET, HDPE, PVC, LDPE, PP, PS and others respectively.
10. Which of the following is used for juice bottles?
a) HDPE
b) PP
c) PET
d) PS
Answer: a
Clarification: HDPE (High Density Polyethylene) is used for making juice bottles. It is a thermoplastic polymer made by polymerization of ethylene. It has a high strength-to-density ratio.
11. Which of the following is used as imitation glassware?
a) PS
b) PVC
c) PET
d) HDPE
Answer: a
Clarification: Polystyrene is used for manufacture of imitation glassware. It is a clear, hard and brittle polymer, making it suitable for making imitation glassware. It is also used as a container for yogurt and jelly.
12. Which of the following is used in making carrier bags?
a) PP
b) LDPE
c) PVC
d) PET
Answer: b
Clarification: LDPE-Low Density Polyethylene is used in the manufacture of carrier bags. It is made by free radical polymerization of ethylene. LDPE has lesser branching, which is responsible for its lower density.