9. High performance polymers Flashcards by Amalie Krebs

Q

Does the number of carbons in polyamide affect the Tg for nylons?

A

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Q

Which type of liquid crystalline behavior is important for the processing of Kevlar?

A

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Q

How can you modify the preparation of a polyurethane to improve the mechanical properties? (maintained stoichiometry)

A

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Q

What is a mesophase?

A

The ordered regions in liquid crystallines.

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Q

What is the difference between lyotropic and thermotropic liquid crystals?

A

Lyotropic is formed in solvent, thermotropic is formed in melts.

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Q

What type of polymer are nylons?

A

Polyamides.

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Q

What is the odd-even effect on melting temperature for nylons?

A

Even numbered carbon chain will give higher Tg, because it gives more hydrogen bonding.

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