High Performance Fibers and Polymers Quiz
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High Performance Fibers and Polymers Quiz

Created by
@LucidMemphis

Questions and Answers

What is the trade name of the high tenacity and modulus fiber developed by DuPont in 1971?

Kevlar

What is the aromatic co-polyamide that appeared on the market towards the end of the 1980s, similar to Kevlar?

Twaron

What technique is used to prepare the polymer Nomex by low-temperature solution polymerization?

Solution polymerization

What is the solvent used for interfacial polymerization in the production of Nomex?

<p>Solvent with limited water solubility</p> Signup and view all the answers

Why is it important to carry out the polymerization reaction of Nomex at low temperatures?

<p>To avoid side reactions that produce unreactive ends</p> Signup and view all the answers

What can high temperatures during the polymerization of Nomex lead to?

<p>Side reactions</p> Signup and view all the answers

What is the strength of Kevlar at cryogenic temperatures?

<p>Maintains its strength and resilience</p> Signup and view all the answers

How does the tensile strength of Kevlar change at higher temperatures?

<p>Reduced by about 10–20%</p> Signup and view all the answers

What happens to Kevlar's strength after 500 hours at 160°C (320°F)?

<p>10% reduction in strength</p> Signup and view all the answers

At what temperature does Kevlar experience a 50% strength reduction after 70 hours?

<p>260°C (500°F)</p> Signup and view all the answers

What are some applications of Para-aramids like Kevlar?

<p>Used in brake linings, tyre reinforcement, composites for aircraft and protective clothing</p> Signup and view all the answers

Where are PPTA fibers, like Kevlar, commonly used?

<p>In protective clothing like bulletproof vests and composites manufacturing</p> Signup and view all the answers

What is the basis for the high modulus versions of Kevlar and Twaron?

<p>High crystallinity</p> Signup and view all the answers

How is radial crystalline orientation achieved in Para-aramid fibers?

<p>Using the dry-jet wet-spinning process</p> Signup and view all the answers

What is the relationship between molecular orientation and fiber modulus in Para-aramid products?

<p>Almost directly proportional</p> Signup and view all the answers

What are some properties of Kevlar related to insulation?

<p>Good thermal insulation and electrical insulation</p> Signup and view all the answers

How does the strength of p-aramid fibers compare to steel?

<p>5 times stronger</p> Signup and view all the answers

What is the dimensional stability like for aramid fibers?

<p>Excellent</p> Signup and view all the answers

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