POLYMER TECHNOLOGY
POLYMER TECHNOLOGY SYLLABUS
(These syllabus may change from time to time. Please check with the relevant Public Service Commission websites for any changes in the syllabus)
- Raw materials, monomers, homopolymers, copolymers
- Vinyl polymers, polymer chemistry, primary and secondary bonds
- Properties affected by primary bonds; physical properties affected by secondary bonds
- Free radical polymerization: reaction and termination rates using physical chemistry models; ionic, condensation and mixed mode polymerization
- Physical structure of polymers: semi-crystalline, amorphous, and rubbery states. Chain branching, networking in polymers.
- Iso-free volume theory: deformation of polymers - glassy and viscoelastic; molecular statistics of rubbery states
- Tensile, shear, compression and impact properties
- Effect of temperature and strain rates in polymers.
- Rheology: relationship between molecular weight, temperature and shear rates.
- Effect of additives.
- Structure-property correlation in glassy, semicrystalline and oriented polymers
- Polymer manufacturing and applications. Commodity and specialty plastics; Nanopolymers, conducting polymers.
POLYMER TECHNOLOGY MCQs
1. Which of the following is a trifunctional monomer?
A:-Propylene
B:-Butadiene
C:-Glycerol
D:-Glycol
Correct Answer:- Option-C
2. Polymer molecular weight is equal to repeat unit molecular weight times n, where n is
A:-Degree of polymerization
B:-Functionality
C:-Molecular weight distribution
D:-Extent of polymerization
Correct Answer:- Option-A
3. Below the glass transition temperature the free volume is
A:-Maximum
B:-Zero
C:-One
D:-Minimum
Correct Answer:- Option-D
4. Which of the following is a first order process?
A:-Solidification
B:-Vapourization
C:-Melting
D:-All of these
Correct Answer:- Option-D
5. Glass transition temperature of polyisoprene is
A:-Below room temperature
B:-Above room temperature
C:-Zero
D:-None of these
Correct Answer:- Option-A
6. A SBR is an example of
A:-Graft copolymer
B:-Random copolymer
C:-Block copolymer
D:-Homopolymer
Correct Answer:- Option-B
7. Hilderbrand is the unit of
A:-Flory interaction parameter
B:-Enthalpy
C:-Solubility parameter
D:-None of these
Correct Answer:- Option-C
8. For a polymer prepared by free radical polymerization
A:-Mw > Mn
B:-Mw < Mn
C:-Mz < Mn
D:-Mn = Mw = Mz
Correct Answer:- Option-A
9. Polydispersity index is said to be 1 when
A:-Mw = Mn
B:-Mw > Mz
C:-Mz > Mz+1
D:-None of these
Correct Answer:- Option-A
10. Thermoplastic polyurethane is a
A:-Thermoplastic
B:-Elastomer
C:-Thermoplastic elastomer
D:-Thermoset
Correct Answer:- Option-C
11. For EPDM the unsaturation is in the
A:-Main chain
B:-Branches
C:-Pendent groups
D:-All of these
Correct Answer:- Option-C
12. The monomers of butyl rubber are
A:-Butadiene and isoprene
B:-Butadiene and 1-butene
C:-Isoprene and 1-butene
D:-None of these
Correct Answer:- Option-D
13. The property that is lowered by increasing CN content of NBR is
A:-Oil resistance
B:-Low temperature flexibility
C:-High temperature resistance
D:-None of these
Correct Answer:- Option-B
14. The EPM is not cured by
A:-Sulphur
B:-Peroxide
C:-Radiation
D:-Oxime
Correct Answer:- Option-A
15. Fluorocarbons are known for
A:-High temperature resistance
B:-Ozone resistance
C:-Oil resistance
D:-All of these
Correct Answer:- Option-D
16. Nylon 66 melts at (deg C)
A:-219
B:-249
C:-269
D:-289
Correct Answer:- Option-C
17. In unsaturated polyester the monomer that is commonly used to give crosslinking sites is
A:-Fumaric acid
B:-Terephthalic acid
C:-Itaconic acid
D:-Maleic anhydride
Correct Answer:- Option-D
18. Neoprene is commonly cured with
A:-Sulphur
B:-Metal oxide
C:-Peroxide
D:-Radiation
Correct Answer:- Option-B
19. An example of amorphous polymer is
A:-UPVC
B:-PMMA
C:-Polystyrene
D:-All of these
Correct Answer:- Option-D
20. For polymer containing OH group a major absorption peak is expected at (wave number)
A:-3400
B:-3000
C:-2450
D:-1700
Correct Answer:- Option-A
21. Which of the following is commonly use to estimate crystallinity?
A:-NMR
B:-TGA
C:-X ray
D:-TMA
Correct Answer:- Option-C
22. Tan delta is defined as
A:-Loss modulus / storage modulus
B:-Storage modulus / loss modulus
C:-Logarithmic decay / phase angle
D:-Phase angle / storage modulus
Correct Answer:- Option-A
23. Resilience is inversely related to
A:-Compression set
B:-Heat build up
C:-Tension set
D:-All of these
Correct Answer:- Option-B
24. Tear strength is optimum at
A:-Optimum cure
B:-Slight under cure
C:-Slight over cure
D:-None of these
Correct Answer:- Option-B
25. A high value of tan delta indicates
A:-good traction
B:-good mileage
C:-low heat build up
D:-All of these
Correct Answer:- Option-A
A:-Propylene
B:-Butadiene
C:-Glycerol
D:-Glycol
Correct Answer:- Option-C
2. Polymer molecular weight is equal to repeat unit molecular weight times n, where n is
A:-Degree of polymerization
B:-Functionality
C:-Molecular weight distribution
D:-Extent of polymerization
Correct Answer:- Option-A
3. Below the glass transition temperature the free volume is
A:-Maximum
B:-Zero
C:-One
D:-Minimum
Correct Answer:- Option-D
4. Which of the following is a first order process?
A:-Solidification
B:-Vapourization
C:-Melting
D:-All of these
Correct Answer:- Option-D
5. Glass transition temperature of polyisoprene is
A:-Below room temperature
B:-Above room temperature
C:-Zero
D:-None of these
Correct Answer:- Option-A
6. A SBR is an example of
A:-Graft copolymer
B:-Random copolymer
C:-Block copolymer
D:-Homopolymer
Correct Answer:- Option-B
7. Hilderbrand is the unit of
A:-Flory interaction parameter
B:-Enthalpy
C:-Solubility parameter
D:-None of these
Correct Answer:- Option-C
8. For a polymer prepared by free radical polymerization
A:-Mw > Mn
B:-Mw < Mn
C:-Mz < Mn
D:-Mn = Mw = Mz
Correct Answer:- Option-A
9. Polydispersity index is said to be 1 when
A:-Mw = Mn
B:-Mw > Mz
C:-Mz > Mz+1
D:-None of these
Correct Answer:- Option-A
10. Thermoplastic polyurethane is a
A:-Thermoplastic
B:-Elastomer
C:-Thermoplastic elastomer
D:-Thermoset
Correct Answer:- Option-C
11. For EPDM the unsaturation is in the
A:-Main chain
B:-Branches
C:-Pendent groups
D:-All of these
Correct Answer:- Option-C
12. The monomers of butyl rubber are
A:-Butadiene and isoprene
B:-Butadiene and 1-butene
C:-Isoprene and 1-butene
D:-None of these
Correct Answer:- Option-D
13. The property that is lowered by increasing CN content of NBR is
A:-Oil resistance
B:-Low temperature flexibility
C:-High temperature resistance
D:-None of these
Correct Answer:- Option-B
14. The EPM is not cured by
A:-Sulphur
B:-Peroxide
C:-Radiation
D:-Oxime
Correct Answer:- Option-A
15. Fluorocarbons are known for
A:-High temperature resistance
B:-Ozone resistance
C:-Oil resistance
D:-All of these
Correct Answer:- Option-D
16. Nylon 66 melts at (deg C)
A:-219
B:-249
C:-269
D:-289
Correct Answer:- Option-C
17. In unsaturated polyester the monomer that is commonly used to give crosslinking sites is
A:-Fumaric acid
B:-Terephthalic acid
C:-Itaconic acid
D:-Maleic anhydride
Correct Answer:- Option-D
18. Neoprene is commonly cured with
A:-Sulphur
B:-Metal oxide
C:-Peroxide
D:-Radiation
Correct Answer:- Option-B
19. An example of amorphous polymer is
A:-UPVC
B:-PMMA
C:-Polystyrene
D:-All of these
Correct Answer:- Option-D
20. For polymer containing OH group a major absorption peak is expected at (wave number)
A:-3400
B:-3000
C:-2450
D:-1700
Correct Answer:- Option-A
21. Which of the following is commonly use to estimate crystallinity?
A:-NMR
B:-TGA
C:-X ray
D:-TMA
Correct Answer:- Option-C
22. Tan delta is defined as
A:-Loss modulus / storage modulus
B:-Storage modulus / loss modulus
C:-Logarithmic decay / phase angle
D:-Phase angle / storage modulus
Correct Answer:- Option-A
23. Resilience is inversely related to
A:-Compression set
B:-Heat build up
C:-Tension set
D:-All of these
Correct Answer:- Option-B
24. Tear strength is optimum at
A:-Optimum cure
B:-Slight under cure
C:-Slight over cure
D:-None of these
Correct Answer:- Option-B
25. A high value of tan delta indicates
A:-good traction
B:-good mileage
C:-low heat build up
D:-All of these
Correct Answer:- Option-A
26. Which rubber gives high tear resistance?
A:-PBD
B:-SBR
C:-IIR
D:-NR
Correct Answer:- Option-D
27. A DSC can measure
A:-Heat capacity
B:-Glass transition temperature
C:-Melting point
D:-All of these
Correct Answer:- Option-D
28. A parison is used in
A:-Blow moulding
B:-Transfer moulding
C:-Compression moulding
D:-None of these
Correct Answer:- Option-A
29. PET is not used in extrusion blow moulding because
A:-High viscosity
B:-High die swell
C:-Low melt strength
D:-Shark skin effect
Correct Answer:- Option-C
30. Which of the following is amenable to reaction injection moulding?
A:-PET
B:-TPU
C:-NYLON
D:-PU
Correct Answer:- Option-D
31. RRIM is used when
A:-Good strength is needed
B:-Fast reaction is needed
C:-High volume output is needed
D:-None of these
Correct Answer:- Option-A
32. In a two roll mill the shear rate is adjusted by
A:-reducing nip gap
B:-increasing roll speed ratio
C:-both of these
D:-none of these
Correct Answer:- Option-C
33. The effect of roll bending in calendaring operation is reduced by
A:-Roll crossing
B:-Roll crowning
C:-Roll bending
D:-All of these
Correct Answer:- Option-D
34. The role of a plug in a plug-assisted thermoforming is to help
A:-Maintain uniform thickness
B:-Permit deep drawing
C:-Both of these
D:-None of these
Correct Answer:- Option-C
35. Which of the following is not good for thermoforming?
A:-PP
B:-PE
C:-PF
D:-PS
Correct Answer:- Option-C
36. Which of the following is the best for uniform filler dispersion?
A:-Two roll mill
B:-Banbury
C:-Intermix
D:-Kneader
Correct Answer:- Option-A
37. Viscosity has the unit
A:-Pa. S
B:-N / sq. m
C:-Mpa
D:-dN.m.s
Correct Answer:- Option-A
38. Decrease of viscosity with increasing shear rate is known as
A:-Newtonian behaviour
B:-Bingham plastics
C:-Dilatant behaviour
D:-Pseudoplastic behaviour
Correct Answer:- Option-D
39. The unit of shear rate is
A:-meter per second
B:-Per second
C:-meter per second square
D:-Newton per second
Correct Answer:- Option-B
40. Yield stress is shown by
A:-Pseudoplastic materials
B:-Dilatant materials
C:-Bingham plastics
D:-Newtonian liquids
Correct Answer:- Option-C
41. Thixotropy is associated with reduction in viscosity
A:-With time at constant shear rate
B:-With shear rate
C:-With time and shear rate
D:-With shear stress
Correct Answer:- Option-A
42. In rheology relaxation time is defined as
A:-Viscosity / modulus
B:-Modulus / yield stress
C:-Time for 50% reduction in viscosity
D:-Time for extrudate to recover
Correct Answer:- Option-A
43. Bagley correction is done to account for
A:-Exit effect
B:-Slip at wall
C:-Stick-slip effect
D:-Entry effect
Correct Answer:- Option-D
44. Apparent shear rate for a capillary flow is related to
A:-Volume flow rate and l/d ratio
B:-Volume flow rate and capillary diameter
C:-Shear stress and capillary diameter
D:-None of these
Correct Answer:- Option-B
45. In an isometric creep curve
A:-Stress is plot against strain
B:-Strain is plotted against time
C:-Stress is plotted against log time
D:-Strain is plotted against log time
Correct Answer:- Option-C
46. Which of the following involves the use of a rotor?
A:-MDR
B:-Mooney viscometer
C:-Rubber process analyzer
D:-All of these
Correct Answer:- Option-B
47. The ply angle in radial tyres is close to ________ degrees.
A:-37
B:-45
C:-55
D:-90
Correct Answer:- Option-D
48. Which of the following is a slow accelerator?
A:-DPG
B:-MBS
C:-MBTS
D:-MBT
Correct Answer:- Option-A
49. Caprolactam disulphide is a
A:-Activator
B:-Monomer
C:-Sulphur donor
D:-Accelerator
Correct Answer:- Option-C
50. Chemical mastication is operational after (deg. Centigrade)
A:-100
B:-120
C:-140
D:-150
Correct Answer:- Option-B
51. Transmissibility is defined as
A:-Output amplitude / input amplitude
B:-Output frequency / input frequency
C:-Loss modulus / storage modulus
D:-None of these
Correct Answer:- Option-A
52. For good vibration isolation
A:-Transmissibility must be > 1
B:-Natural frequency must be high
C:-Natural frequency must be low
D:-Damping must be high
Correct Answer:- Option-C
53. DBP number is used to measure
A:-C black particle size
B:-C black surface area
C:-Surface functional group
D:-C black structure
Correct Answer:- Option-D
54. BET method uses ________ gas to measure surface area.
A:-Oxygen
B:-Helium
C:-Nitrogen
D:-Argon
Correct Answer:- Option-C
55. Si 69 is a
A:-Coupling agent
B:-Bonding agent
C:-Tackifier
D:-None of these
Correct Answer:- Option-A
56. Azodicarbonamide is a
A:-Accelerator
B:-Blowing agent
C:-Peptizer
D:-Activator
Correct Answer:- Option-B
57. The primary criterion for choosing blend components is
A:-Tg must be same
B:-Tg must be close
C:-Cohesive energy density > 1
D:-Solubility parameter must be close
Correct Answer:- Option-D
58. Blend miscibility is studied using a
A:-DMA
B:-DSC
C:-Both of these
D:-None of these
Correct Answer:- Option-C
59. Anisotropy is defined as
A:-Time dependent creep
B:-Strain dependent stress relaxation
C:-Temperature dependent modulus
D:-Direction dependent properties
Correct Answer:- Option-D
60. In short fiber composite extrusion, fibers are oriented circumferentially in a
A:-Diverging die
B:-Converging die
C:-Capillary die
D:-Ribbon die
Correct Answer:- Option-A
61. In blends UCST stands for
A:-Unit component surface thickness
B:-Upper critical solution temperature
C:-Unifiber composite sheet thickness
D:-None of these
Correct Answer:- Option-B
62. Spherulites are related to
A:-Polymer composites
B:-Polymer blends
C:-Polymer crystals
D:-Polymer coatings
Correct Answer:- Option-C
63. For a 70/30 NR/PE blend which phase morphology is more probable?
A:-NR is continuous phase
B:-PE is continuous phase
C:-They form IPN
D:-NR & PE form continuous phase
Correct Answer:- Option-A
64. Which one has molecular level mixing?
A:-Blend
B:-Composite
C:-Alloy
D:-All of these
Correct Answer:- Option-C
65. The membrane on rubber particles is
A:-proteinic
B:-lipoproteinic
C:-phospholipoproteinic
D:-phosphoproteinic
Correct Answer:- Option-C
66. Which of the following statements is true?
A:-TSC > DRC
B:-TSC < DRC
C:-TSC = DRC
D:-TSC-DRC < 1
Correct Answer:- Option-A
67. Mechanical stability test is done on
A:-Latex
B:-Unvulcanised rubber
C:-Vulcanised rubber
D:-Aged rubber
Correct Answer:- Option-A
68. The major metal present in sludge removed from latex is
A:-Fe
B:-Mg
C:-Mn
D:-None of these
Correct Answer:- Option-B
69. Which of the following is a VFA?
A:-Stearic acid
B:-Acetic acid
C:-Palmitic acid
D:-Oleic acid
Correct Answer:- Option-B
70. Which of the following cannot destabilize latex?
A:-Ammonia
B:-Acid
C:-Metal ion
D:-Positively charged electrode
Correct Answer:- Option-A
71. Potassium oleate is used in NR foam manufacture as
A:-Foam stabilizer
B:-Activator
C:-Foam promoter
D:-Antioxidant
Correct Answer:- Option-C
72. The foaming agent used in NR foam is
A:-DNPT
B:-Nitrogen
C:-Air
D:-All of these
Correct Answer:- Option-C
73. For making thick walled dipped products the preferred method is
A:-Coacervant dipping
B:-Heat sensitised dipping
C:-Straight dipping
D:-Multiple dipping
Correct Answer:- Option-B
74. In electrodeposition the rubber is deposited on
A:-Positive electrode
B:-Semi permeable membrane
C:-Negative electrode
D:-All of these
Correct Answer:- Option-A
A:-PBD
B:-SBR
C:-IIR
D:-NR
Correct Answer:- Option-D
27. A DSC can measure
A:-Heat capacity
B:-Glass transition temperature
C:-Melting point
D:-All of these
Correct Answer:- Option-D
28. A parison is used in
A:-Blow moulding
B:-Transfer moulding
C:-Compression moulding
D:-None of these
Correct Answer:- Option-A
29. PET is not used in extrusion blow moulding because
A:-High viscosity
B:-High die swell
C:-Low melt strength
D:-Shark skin effect
Correct Answer:- Option-C
30. Which of the following is amenable to reaction injection moulding?
A:-PET
B:-TPU
C:-NYLON
D:-PU
Correct Answer:- Option-D
31. RRIM is used when
A:-Good strength is needed
B:-Fast reaction is needed
C:-High volume output is needed
D:-None of these
Correct Answer:- Option-A
32. In a two roll mill the shear rate is adjusted by
A:-reducing nip gap
B:-increasing roll speed ratio
C:-both of these
D:-none of these
Correct Answer:- Option-C
33. The effect of roll bending in calendaring operation is reduced by
A:-Roll crossing
B:-Roll crowning
C:-Roll bending
D:-All of these
Correct Answer:- Option-D
34. The role of a plug in a plug-assisted thermoforming is to help
A:-Maintain uniform thickness
B:-Permit deep drawing
C:-Both of these
D:-None of these
Correct Answer:- Option-C
35. Which of the following is not good for thermoforming?
A:-PP
B:-PE
C:-PF
D:-PS
Correct Answer:- Option-C
36. Which of the following is the best for uniform filler dispersion?
A:-Two roll mill
B:-Banbury
C:-Intermix
D:-Kneader
Correct Answer:- Option-A
37. Viscosity has the unit
A:-Pa. S
B:-N / sq. m
C:-Mpa
D:-dN.m.s
Correct Answer:- Option-A
38. Decrease of viscosity with increasing shear rate is known as
A:-Newtonian behaviour
B:-Bingham plastics
C:-Dilatant behaviour
D:-Pseudoplastic behaviour
Correct Answer:- Option-D
39. The unit of shear rate is
A:-meter per second
B:-Per second
C:-meter per second square
D:-Newton per second
Correct Answer:- Option-B
40. Yield stress is shown by
A:-Pseudoplastic materials
B:-Dilatant materials
C:-Bingham plastics
D:-Newtonian liquids
Correct Answer:- Option-C
41. Thixotropy is associated with reduction in viscosity
A:-With time at constant shear rate
B:-With shear rate
C:-With time and shear rate
D:-With shear stress
Correct Answer:- Option-A
42. In rheology relaxation time is defined as
A:-Viscosity / modulus
B:-Modulus / yield stress
C:-Time for 50% reduction in viscosity
D:-Time for extrudate to recover
Correct Answer:- Option-A
43. Bagley correction is done to account for
A:-Exit effect
B:-Slip at wall
C:-Stick-slip effect
D:-Entry effect
Correct Answer:- Option-D
44. Apparent shear rate for a capillary flow is related to
A:-Volume flow rate and l/d ratio
B:-Volume flow rate and capillary diameter
C:-Shear stress and capillary diameter
D:-None of these
Correct Answer:- Option-B
45. In an isometric creep curve
A:-Stress is plot against strain
B:-Strain is plotted against time
C:-Stress is plotted against log time
D:-Strain is plotted against log time
Correct Answer:- Option-C
46. Which of the following involves the use of a rotor?
A:-MDR
B:-Mooney viscometer
C:-Rubber process analyzer
D:-All of these
Correct Answer:- Option-B
47. The ply angle in radial tyres is close to ________ degrees.
A:-37
B:-45
C:-55
D:-90
Correct Answer:- Option-D
48. Which of the following is a slow accelerator?
A:-DPG
B:-MBS
C:-MBTS
D:-MBT
Correct Answer:- Option-A
49. Caprolactam disulphide is a
A:-Activator
B:-Monomer
C:-Sulphur donor
D:-Accelerator
Correct Answer:- Option-C
50. Chemical mastication is operational after (deg. Centigrade)
A:-100
B:-120
C:-140
D:-150
Correct Answer:- Option-B
51. Transmissibility is defined as
A:-Output amplitude / input amplitude
B:-Output frequency / input frequency
C:-Loss modulus / storage modulus
D:-None of these
Correct Answer:- Option-A
52. For good vibration isolation
A:-Transmissibility must be > 1
B:-Natural frequency must be high
C:-Natural frequency must be low
D:-Damping must be high
Correct Answer:- Option-C
53. DBP number is used to measure
A:-C black particle size
B:-C black surface area
C:-Surface functional group
D:-C black structure
Correct Answer:- Option-D
54. BET method uses ________ gas to measure surface area.
A:-Oxygen
B:-Helium
C:-Nitrogen
D:-Argon
Correct Answer:- Option-C
55. Si 69 is a
A:-Coupling agent
B:-Bonding agent
C:-Tackifier
D:-None of these
Correct Answer:- Option-A
56. Azodicarbonamide is a
A:-Accelerator
B:-Blowing agent
C:-Peptizer
D:-Activator
Correct Answer:- Option-B
57. The primary criterion for choosing blend components is
A:-Tg must be same
B:-Tg must be close
C:-Cohesive energy density > 1
D:-Solubility parameter must be close
Correct Answer:- Option-D
58. Blend miscibility is studied using a
A:-DMA
B:-DSC
C:-Both of these
D:-None of these
Correct Answer:- Option-C
59. Anisotropy is defined as
A:-Time dependent creep
B:-Strain dependent stress relaxation
C:-Temperature dependent modulus
D:-Direction dependent properties
Correct Answer:- Option-D
60. In short fiber composite extrusion, fibers are oriented circumferentially in a
A:-Diverging die
B:-Converging die
C:-Capillary die
D:-Ribbon die
Correct Answer:- Option-A
61. In blends UCST stands for
A:-Unit component surface thickness
B:-Upper critical solution temperature
C:-Unifiber composite sheet thickness
D:-None of these
Correct Answer:- Option-B
62. Spherulites are related to
A:-Polymer composites
B:-Polymer blends
C:-Polymer crystals
D:-Polymer coatings
Correct Answer:- Option-C
63. For a 70/30 NR/PE blend which phase morphology is more probable?
A:-NR is continuous phase
B:-PE is continuous phase
C:-They form IPN
D:-NR & PE form continuous phase
Correct Answer:- Option-A
64. Which one has molecular level mixing?
A:-Blend
B:-Composite
C:-Alloy
D:-All of these
Correct Answer:- Option-C
65. The membrane on rubber particles is
A:-proteinic
B:-lipoproteinic
C:-phospholipoproteinic
D:-phosphoproteinic
Correct Answer:- Option-C
66. Which of the following statements is true?
A:-TSC > DRC
B:-TSC < DRC
C:-TSC = DRC
D:-TSC-DRC < 1
Correct Answer:- Option-A
67. Mechanical stability test is done on
A:-Latex
B:-Unvulcanised rubber
C:-Vulcanised rubber
D:-Aged rubber
Correct Answer:- Option-A
68. The major metal present in sludge removed from latex is
A:-Fe
B:-Mg
C:-Mn
D:-None of these
Correct Answer:- Option-B
69. Which of the following is a VFA?
A:-Stearic acid
B:-Acetic acid
C:-Palmitic acid
D:-Oleic acid
Correct Answer:- Option-B
70. Which of the following cannot destabilize latex?
A:-Ammonia
B:-Acid
C:-Metal ion
D:-Positively charged electrode
Correct Answer:- Option-A
71. Potassium oleate is used in NR foam manufacture as
A:-Foam stabilizer
B:-Activator
C:-Foam promoter
D:-Antioxidant
Correct Answer:- Option-C
72. The foaming agent used in NR foam is
A:-DNPT
B:-Nitrogen
C:-Air
D:-All of these
Correct Answer:- Option-C
73. For making thick walled dipped products the preferred method is
A:-Coacervant dipping
B:-Heat sensitised dipping
C:-Straight dipping
D:-Multiple dipping
Correct Answer:- Option-B
74. In electrodeposition the rubber is deposited on
A:-Positive electrode
B:-Semi permeable membrane
C:-Negative electrode
D:-All of these
Correct Answer:- Option-A