Vulcanization — Summer 2023

Define the given terms: (i)Vulcanization (ii)Vulcanizate (iii)Rate of Cure

Indentify drawbacks of unvulcanized rubber.

With schematic diagram, explain the major components of structure of rubber vulcanizate.

List out different allotropic forms of sulphur. Brief out any one.

Differentiate the Vulcanization properties of Natural Rubber (NR) and Synthetic Rubber (SR).

Explain the construction and working of Moving Die Rheometer (MDR).

Explain the limitations of vulcanization temperature.

What do you mean by sulphur donors? Give any two examples with their structure.

Which points are taken in account before selecting an accelerator system for manufacturer of particular rubber product?

Explain in detail about the sulphenamide type accelerators.

With schematic diagrams, show the role of retarder in vulcanization process.

Classify the accelerated sulphur vulcanization system. Also outline any one with suitable example.

Explain in detail about the amine type accelerators.

Which rubber is cured by metal oxide? Why?

Give the advantages of peroxide cure over sulphur curing.

Explain in detail about autoclave curing.

Which rubber is cured by phenolic resin? Why?

Give the advantages of superheated steam over saturated steam with respect to vulcanization process.

Explain in detail about fluidized bed vulcanization.

What do you mean by pressurized vulcanization technique? Also give it’s examples.

With labeled diagram, write about rotocure.

Explain in detail about microwave vulcanization technique.1

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What do you mean by pressure less vulcanization technique? Also give it’s examples.

Compare hot air vulcanization with steam vulcanization.

Explain in detail about electron beam vulcanization technique.