Elastomer identification: which of the following is an elastomer (rubbery polymer)?
Chemical Engineering
Polymer Technology
Difficulty: Easy
Choose an option
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AThiokol (polysulfide rubber)
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BPhenol–formaldehyde resin
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CUrea–formaldehyde resin
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DPolystyrene
Answer
Correct Answer: Thiokol (polysulfide rubber)
Explanation
Introduction / Context:Elastomers display large reversible deformations. Among the listed materials, only polysulfide rubber (Thiokol) is an elastomer; the others are rigid thermosets or thermoplastics.
Concept / Approach:Phenolic and urea–formaldehyde are thermosets; polystyrene is a brittle thermoplastic at room temperature; Thiokol is a synthetic elastomer with notable fuel and solvent resistance.
Final Answer:Thiokol (polysulfide rubber)