1 / 20

An expert is someone who has made all of the possible mistakes in a very narrow field of study

Explore the history and chemistry behind the creation of nylon, from the announcement of a brand-new chemical textile fiber to its impact during WWII and beyond. Learn about the structures of nylon, polyurethanes, branching, networks, Bakelite, and crosslinking.

jeanettak
Download Presentation

An expert is someone who has made all of the possible mistakes in a very narrow field of study

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. An expert is someone who has made all of the possible mistakes in a very narrow field of study 
 – Niels Bohr

  2. H2N - (CH2)6 - NH2 + HO - C - (CH2)4 - C - OH Hexamethylene Diamine Adipic Acid O O O O H2N - (CH2)6 - N - C - (CH2)4 - C - OH + H2O Amide Group H Nylons

  3. Nylon 6,6 O O - N - (CH2)6 - N - C - (CH2)4 - C - n 6 6 H H “I am making the announcement of a brand new chemical textile fiber ---derivable from coal, air and water -- and characterized by extreme toughness and strength --” Charles Stine V.P. for research, Du Pont, 1938

  4. Nylon “I am making the announcement of a brand new chemical textile fiber ---derivable from coal, air and water -- and characterized by extreme toughness and strength --” Charles Stine V.P. for research, Du Pont, 1938

  5. Nylon May 15 1940 - “Nylon Day” Four million pairs go on sale throughout US Supply exhausted in 4 days.

  6. Nylon Parachute WWII

  7. Post WWII stocking sale, San Francisco

  8. O = C = N - (CH2)6 - N = C = O + HO - (CH2)2 - OH O Hexamethylene Diisocyanate Ethylene Glycol O = C = N - (CH2)6 - N - C - O - (CH2)2 - OH Urethane Linkage H Polyurethanes Reaction does not involve splitting out of a small molecule usw.

  9. Branched - short branches Linear & branched polymers ex: polyethylene Linear

  10. CH2 - CH2 ~~~CH2 - CH CH2 H .CH2 Formation of short chain branches in polyethylene CH2 - CH2 ~~~CH2 - CH CH2 . CH2H CH2 = CH2 C4H9 - ~~~CH2 - CH - CH2 - CH2. C4H9 - ~~~CH2 - CH - CH2 - CH2- CH2 - CH2. CH2 = CH2 Linear & branched polymers ex: polyethylene

  11. Low density polyethylene (LDPE) (short branches)

  12. Other types of branching short long star Branching suppresses or prevents chain movement & "crystallization" in polymers

  13. Branching Another way to make chains branch * * Use multifunctional (f>2) monomers * OH + CH O 2 OH OH OH CH CH CH 2 2 2 OH CH CH CH 2 2 2 OH OH OH CH 2 OH

  14. The phenol + formaldehyde rxn

  15. Network formation Further reaction under heat & pressure builds up densely cross-linked network. This is Bakelite, a thermosettingpolymer. Once reaction is complete, material cannot be reheated and/or reformed Bakelite

  16. Bakelite - Material of a Thousand Uses Bakelite telephone Clear Bakelite items Phenolic resin/celluloidclock Bakelite radio Bakelite microphone Bakelite camera

  17. Crosslinking Take linear polymer chains & link using covalent bonds

  18. - CH2 CH2 - CH2 CH2 - CH2 CH2 - - - - - - - C = C C = C C = C - - - - - - CH3 H CH3 H CH3 H Crosslinking Ex: rxn of natural rubber or poly(isoprene) with sulfur - interconnects the chains by reacting with the double bonds (vulcanization)

  19. Crosslinking

  20. Assignment: Review today's classnotes a. nylons b. polyurethanes c. branching d. networks e. Bakelite f. crosslinking g. vulcanization Read: chapter 14

More Related