Polymer Engineering Questions and Answers – Photo Initiaton of Polymerization

This set of Polymer Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Photo Initiaton of Polymerization”.

1. What is the mechanism of uncatalyzed photo-initiation of polymerization, when light of specific wavelength falls on monomer?
a) monomer directly decomposes to give radicals
b) monomer generates excites species by absorbing light quanta and then decompose into radicals by homolysis
c) photo-initiator is added to monomer and decomposes to radicals by photolysis
d) all of the mentioned
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2. What has the terms k_d[I] in the overall rate equation of uncatalyzed photo-polymerization been replaced by?
a) intensity of light radiation absorbed
b) intensity of incident light
c) number of pairs of chain radicals formed per quantum of light absorbed
d) monomer concentration
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3. What does the intensity of active radiation absorbed in uncatalyzed photo-polymerization, not depend on?
a) thickness of reaction mixture
b) intensity of incident radiation
c) monomer concentration
d) none of the mentioned
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4. How does the overall rate of uncatalyzed photo-polymerization vary, when the monomer concentration is quadrupled, rest all the terms remain same?
a) two fold increase
b) eight fold increase
c) remains same
d) two fold decrease
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5. Which of the following initiator system works on the mechanism of photo-activation?
a) hydrogen halide
b) nitrobenzene complexes
c) hydrogen sulphide
d) oxalate complex of transition metals
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6. Photo-activation allows the use of a wide range of chemicals as polymerization initiators in comparison to the thermal catalyzed process. State true or false.
a) true
b) false
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7. What is the expression for rate of initiation in catalyzed photo-polymerization? ( I0 and φ are the intensity of incident light and number of pairs of chain radicals formed per quantum of light absorbed, respectively and ε be the molar absorption coefficient )
a) 2φεI₀[I] 
b) φεI₀[M] 
c) 2φεI₀[M] 
d) φεI₀[I] 
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8. Which of the following is not true about photo-sensitizer in photo-polymerization?
a) easily gets excited on exposure to light
b) carries energy absorbed to initiator or monomer
c) helps in both catalyzed and uncatalyzed polymerizations
d) gets excited and decomposes to give radicals
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9. What happens to overall rate of catalyzed photo-polymerization, when the initiator concentration is quadrupled?
a) doubled
b) quadrupled
c) tripled
d) remains same
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Sanfoundry Global Education & Learning Series – Polymer Engineering.
To practice all areas of Polymer Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.