A. Protect rubber goods from attack by oxygen & ozone present in the atmosphere
B. Reduce its viscosity to permit easier processing
C. Reduce the time of vulcanisation and quantity of vulcanising agent
D. Increase its viscosity
Related Mcqs:
- Antioxidants are added to rubber to protect it from the attack of light, heat & atmospheric ozone. Which of the following is an antioxidant used in rubber ?
A. Carbon
B. Alkylated diphenyl amine
C. Thiokol
D. Magnesium - Natural rubber is obtained from latex, which is a colloidal dispersion of rubber in water. Which of the following is used as a coagulant in latex ?
A. Ammonium alum
B. Potassium alum
C. Both A. & B.
D. Neither A. nor B. - Styrene butadiene rubber (SBR) as compared to natural rubber has_______________?
A. Poor tensile strength
B. Poorer resistance
C. Greater amount of heat build up heavy loading
D. All A., B. and C. - Which of the following is the most important rubber compounding ingredient which is used to improve wearing qualities of both natural rubber & SBR by imparting toughness ?
A. Phosphorous
B. Carbon black
C. Pine oil
D. Rosin - Fillers such as zinc oxide and carbon black are added to the crude natural rubber before vulcanisation in order to improve its_________________?
A. Elasticity
B. Strength
C. Plasticity
D. Weathering characteristics - Diphenylamine is added to rubber to_________________?
A. Vulcanise it
B. Protect it from deterioration on exposure to air
C. Make it non-inflammable
D. Make it thermosetting - Temperature and gage pressure maintained during the manufacture of hot SBR (styrene butadiene rubber) are____________________?
A. 50°C and 3 – 4 kg/cm2
B. 50°C and 1 kgf/cm2
C. 250°C and 10 kgf/cm2
D. 250°C and 1 kgf/cm2 - The rate controlling step in the manufacture of silicone rubber is the_________________?
A. Polymer termination step
B. Condensation of siloxane to silicone
C. Initial hydrolysis of silicone monomer
D. None of these - The monomer of natural rubber is A. DMT ______________________?
B. Isoprene
C. 2 methyl-1 propane
D. Both B. and C. - Styrene butadiene rubber (SBR) is never used for making__________________?
A. Coated fabrics
B. Front wheel tyres of aeroplanes (i.e., heavy duty tyres)
C. Gaskets
D. Soles of shoes