Food Packaging Technology Multiple Choice Questions & Answers (MCQs) on “Additives in Plastics”.
1. Which of the following is not a plastic colorant?
a) Diarylide
b) Tartrazine
c) Sudan stain
d) Oil blue A
Answer: b
Clarification: Tartrazine is not a plastic colorant. It is an artificial dye (Lemon yellow colored) used in foods. Sudan stain and Oil blue A are dyes and Diarylide is a pigment. Colorants are added to plastic to give it a desired colour.
2. What is the function of biostabilizers?
a) To regulate hardness
b) Obtain better impact resistance
c) Control surface tension
d) To prevent deterioration
Answer: d
Clarification: Biostabilizers helps to prevent deterioration of plastic. Biostabilizers are also called as antimicrobials because itdecreases susceptibility of plastic against microbial attack.
3. What is the function of fillers?
a) Increase conductance
b) Reduce sinkage
c) Increase stiffness and hardness
d) Improve ability to absorb shock
Answer: c
Clarification: Fillers help in increasing the stiffness and hardness of a plastic. Substances like photoinitiators increase electrical stability. Impact modifiers improve the ability to absorb shock. Blowing agents reduces sinkage.
4. Are foaming agents used in plastic?
a) True
b) False
Answer: a
Clarification: Foaming agents are also known as blowing agents. They are used during the process of blow moulding, to reduce or eliminate sink marks. It gives a foam structure to the plastic, hence the name foaming agent.
5. Which of the following is not a filler?
a) CaCo3
b) SbO3
c) Silica
d) Asbestos
Answer: b
Clarification: Antimony Trioxide (SbO3) is not filler. Rest of these are fillers used in plastics. Fillers provide rigidity to the plastic, thereby increasing its tensile strength and toughness. It also increases elastic modulus and wear resistance.
6. Which of the following is not a lubricant used in plastic?
a) Silicone oil
b) Low mol wt PE
c) Neoprene
d) Halogens
Answer: d
Clarification: Halogens are not lubricants; they are flame retarders. Silicone oil, low molecular weight polyethylene and neoprene are lubricants. Lubricants are used to prevent any damage caused to plastic during its processing (especially the moulding process).
7. UV Stabilizers are added to plastics?
a) True
b) False
Answer: a
Clarification: UV stabilizers are added to plastics to increase the life of plastics, especially when exposed to UV lights. The following UV stabilizers are generally used- benzotriazoles, alkylated hindered phenol, benzophenones, etc.
8. Anti-oxidants used in plastic.
a) True
b) False
Answer: a
Clarification: Anti-oxidants are used in plastic to prevent oxidation. Plastics deteriorate due to oxidation – unstable melt flow properties, brittleness, discoloration and loss of tensile properties. Following are the commonly used anti-oxidants used in plastics-arylamines, phenols, phosphites and various sulfur compounds.
9. What is the function of plasticizer?
a) Improve rheology
b) Lower glass transition temperature
c) Increase electrical stability
d) Improve strength
Answer: b
Clarification: Plasticizers lower the glass transition temperature of plastics. Therefore, it helps to make the plastic more flexible. It does so by decreasing its viscosity in a way. Rheology is improved by lubricants. Substances like photoinitiators increase electrical stability and fillers improve strength.
10. Which among the following is a UV light absorber?
a) Phosphate esters
b) Quaternary ammonium compounds
c) Polyethylene glycol esters
d) Benzophenones
Answer: d
Clarification: Benzophenone is an additive used in plastics as a UV light absorber. These are used to increase the life of plastic and stabilize its color, mainly caused due to its exposure to sunlight – UV spectrum.
11. Halogens are used as _______ in plastics.
a) Flame retardant
b) UV light absorber
c) Antimicrobial
d) Antistatic agents
Answer: a
Clarification: Halogens are used as fire retardant in plastics. Halogens are generally added to thermoplastics to provide insulation, coat base plastic to exclude oxygen and create an endothermic cooling reaction.
12. Adipate diesters are _________
a) Flame retardant
b) Antimicrobial
c) UV light absorber
d) Plasticizers
Answer: d
Clarification: Adipate diesters are plasticizers used in plastic. Plasticizers are lubricants, which work by decreasing physical boding of the molecules and overcoming forces of attraction amongst them.