Polymerizatio Lab p. 1 Polymerizatio Lab Itroductio: Polymers (Greek-PLY...may ad MES...parts) have existed sice the begiig of life. Both "atural" ad "sythetic" polymers are a itegral part of our life. Most of the atural ad sythetic materials with which we come i cotact are wholly or partly polymeric i ature (arboyhydrates, cellulose, plastics, etc.). Polymers (plastics) are large molecules (macromolecules) made up of repeatig uits called "mers" or more correctly "moomers". These "uits" are chemical molecules. There are two polymerizatio mechaisms: additio ad codesatio. I this lab we ll be modelig both the additio mechaism ad the codesatio mechaism. odesatio polymerizatio occur accordig to mechaisms already described for ester formatio ad amide formatio. The steps of the additio mechaism are as follows: 1. Iitiatio 2. Propagatio 3. Termiatio Iitiatio: ree radicals are itroduced as iitiators to the polymerizatio process. The formatio of a sample radical ad its actio o a moomer may be described as: I the presece of UV light or other high eergy sources, a moomer may also form a radical. I this lab the iitiator ad moomer were cosidered as totally differet, but the moomer s double bod could be altered as it is struck by UV light. A popular example of a harmful radical is oe formed by the types of hloro-luoro-arbos that we use as refrigerat gases. The very reactive ozoe of the ozoe layer of the atmosphere may cause the same reactio, also formig ustable radicals. Propagatio: A free radical is used, but aother is produced ad the chai cotiues to grow util all of the moomer is used. a + 2 2 = 2 2 a- 2-2 Termiatio: ree radicals combie 2 a( 2-2 ) - 2-2 + 2-2 - ( 2-2 )a a( 2-2 ) - 2 - -a
Polymerizatio Lab p. 2 bjectives: 1. Lear to distiguish betwee additio ad codesatio polymers 2. Idetify repeatig uits ad moomers 3. Draw polymers formed, give moomers Part 1: Additio polymerizatio Procedures: 1) With your modelig kit costruct 3 ethee moomers by formig a double bod betwee two black carbo atoms with the sprig like double bods. Add the appropriate umber of hydroge atoms. a. Draw the structure of the moomer below (ot as it actually looks with symbols for the elemets ad lies for bods ) 2) Iitiatio: Usig a oxyge atom, i this case, represetig a free radical, iitiate the polymerizatio by breakig oe of the double bods ad coectig it to the oxyge free radical. a. emember that a free radical is a atom that has a upaired electro. So, of the two electros i the bod you just broke, oly oe was shared with the oxyge free radical. The other electro still belogs to the molecule, creatig a larger free radical which the reacts with aother ethee moomer. + 3) Propagatio: otiue the additio polymerizatio util you have used up all of your moomers. a. You should ote that the polymer you ve created is still capable of reactig sice it s still a free radical. 4) Termiatio: You will eed to fid a parter ad bod your two free radicals together. 5) Sketch the structure of your polymer below. (ot how it actually looks use letters for atoms, lies for bods). 6) Are there ay double bods i the polymer? 7) Additio polymers are made from molecules (moomers) with what fuctioal group? 8) Does the fuctioal group o the moomer appear i the polymer? If yes, circle it i your sketch above. If ot, explai why ot.
Polymerizatio Lab p. 3 9) The polymer you drew is called polyethylee. Is it amed after the moomer or the polymer? 10) Draw the polymer that would be made from 1,2-dibromoethee 11) I the polymers below, circle the repeatig uit, give the moomer used to make each oe ad ame the moomer. i. 3 3 3 3 ii. iii. iv. 12) Viyl ad ethylee are other ames for ethee. a you tell which of the above polymers is a. PVA (Poly viyl alcohol) b. PPE (Polypropylee) c. Teflo PTE (polytetrafluoroethylee) d. PV (Poly viyl chloride)
Polymerizatio Lab p. 4 Part 2: odesatio polymers 1) What are the products of a reactio betwee a carboxylic acid ad a alcohol? 2) What are the products of a reactio betwee a carboxylic acid ad a amie? Polymer A: Polyester 3) Begi by cuttig out all of the molecules for Polymer A. Make sure to oly cut alog the solid lies first save the dotted lie for later. 4) ow may fuctioal groups appear o each moomer? Are they the same or differet? 5) Ulike additio polymerizatio codesatio polymers ca propagate from both eds of the molecule. Gather together the moomers for Polymer A ad begi by cuttig alog the dotted lies o oe of the moomers. 6) ut alog the dotted lies o a secod moomer ad fit these two together. a. What fuctioal group was formed? 7) it together the parts that you cut out. What molecule was formed? 8) otiue to cut out ad fit together the moomers for polymer A 9) e you have completed these steps for Polymer A tape it together 10) ow are codesatio polymers differet from additio polymers i terms of? a. uctioal group chage b. Mechaism i. ow does iitiatio occur? ii. Does it matter from what ed you add the ext moomer? iii. ow does termiatio occur? c. Products
Polymerizatio Lab p. 5 11) Why wo t ethaoic acid ad ethaol form a polymer? 12) The polymer you ve created is called polyester. Why is it called that? 13) Draw the polymer formed from the followig moomers Moomer a. 3 3 Polymer b. hallege: c. 3 14) ircle the repeatig uit i the polymers below ad idetify the moomer that makes each oe Polymer Moomer a. l l l b. l l l Polymer B: Polyamide (ylo), a copolymer 15) Begi by cuttig out all of the molecules for Polymer B. Make sure to oly cut alog the solid lies first save the dotted lie for later. 16) a. ow may moomers are there? b. ow may fuctioal groups appear o each moomer? c. Are the fuctioal groups o each moomer the same or differet? 17) Gather together the moomers for Polymer B ad begi by cuttig alog the dotted lies o oe of the moomers. 18) ut alog the dotted lies o a secod moomer ad fit these two together. a. What fuctioal group was formed? 19) it together the parts that you cut out. What molecule was formed?
Polymerizatio Lab p. 6 20) otiue to cut out ad fit together the moomers for Polymer B. ce you have completed these steps for Polymer B tape it together Polymer : A opolymer polyester 21) Begi by cuttig out all of the molecules for Polymer. Make sure to oly cut alog the solid lies first save the dotted lie for later. 22) a. ow may moomers are there? b. ow may fuctioal groups appear o each moomer? c. Are the fuctioal groups o each moomer the same or differet? 23) Gather together the moomers for Polymer ad begi by cuttig alog the dotted lies o oe of the moomers. 24) ut alog the dotted lies o a secod moomer ad fit these two together. a. What fuctioal group was formed? 25) it together the parts that you cut out. What molecule was formed? 26) otiue to cut out ad fit together the moomers for Polymer. ce you have completed these steps for Polymer tape it together 27) ow is this polymer similar to Polymer A, but differet from Polymer B? 28) ow is this polymer differet from Polymer A, but similar to Polymer B? 29) Amio Acids are compouds that have a carboxylic acid ad a amie group. The structures of the 20 amio acids are give i your data booklet, which I ve provided a copy of. or each amio acid idetify the amie group ad the carboxylic acid group a. What makes the amio acids differet?
Polymerizatio Lab p. 7 b. Whe amio acids bod, a peptide bod is formed. What fuctioal group is formed whe two amio acids bod? c. Which polymer (A, B, or ) is similar to a polypeptide? d. Draw the polypeptide Lys-Val-Gly e. Proteis are a series of amio acids, but they are ot cosidered polymers because there is o repeatig uit. The sequece of amio acids is ot the same through out each protei. Explai how they are similar to polymers ad why oe might thik they are polymers. eview: 30) Describe, i your ow words, the differece betwee additio polymers ad codesatio polymers. 31) Look at the polymers that you taped together ad your drawig of the additio polymer. ow ca you distiguish betwee additio ad codesatio polymers? 32) ow ca you tell if the polymer is made of more tha oe type of moomer? 33) If you ca distiguish betwee additio ad codesatio polymers, the you ca figure out what the moomers are. Describe how you would do this for the three kids of polymers.
Polymerizatio Lab p. 8 34) Practice: i. Idetify the followig as a additio or codesatio polymer ii. ircle the repeatig uit iii. Idetify the moomer(s) Br Br Br a. 3 3 3 b. c. 3 3 3 d. 3 3 3 3 3 3 e. 3 3
Polymerizatio Lab p. 9 Polymer A
Polymerizatio Lab p. 10 Polymer B
Polymerizatio Lab p. 11 Polymer