Topics for Today  Back to PVC and Addition Polymers Stiff or Flexible? Plasticizers

Topics for Today  Orientation of the polymer Head-to-head? Head-to-tail?  What else is in plastic?

Readings for Today  Review 9.2 The Big Six 9.3 Addition Polymers

Topics for Friday

Exam #3! This Friday! Same format as always

Exam #3! Non-memory calculators OK. Please, no cell phones

Topics for Monday  Lipids, Fats, and Oils!

Topics for Monday  What is a fat? Fatty acid?  Saturated vs unsaturated fats  Animal versus plant

Readings For Monday  11.3 Fat & Oils: Part of the lipid family  11.4 Saturated and Unsaturated Fats & Oils

Figures Alive!

Topics for Today  Back to PVC and Addition Polymers Stiff or Flexible? Plasticizers

Where were we??

Condensation Polymers! Polyester Nylon

Summary… PET C O O C O OCC HH HH n Double Acid Double Alcohol ESTER Double Acid Double Alcohol ESTER Monomers ?

Summary… Nylon 6,6 n Double Acid Double Amine AMIDE Double Acid Double Amine AMIDE C O (CH 2 ) 4 C O N H (CH 2 ) 6 N H Monomers ?

Be able to write the overall reaction for production of a polyamide for ANY given diacid and diamine!!!! Same for the production of a polyester for ANY given diacid and dialcohol!!

Preview…

Equation 9.7 (p. 414) Built from amino acids!

Condensation Polymers  Nylon and PET (polyester) Can be built from one or two monomers A small molecule is released as a byproduct

Addition Polymers  PP, PS, HDPE, LDPE, PVC, Teflon 1 monomer No byproducts!

Polyethylene [ ]n]n –CH 2 –CH 2 – n C = C H HH H R·R· EXPAND!

Polyethylene -C C HHHHHHHHHHHHHHHHHHHHHH HHHHHHHHHHHHHHHHHHHHHH

Polypropylene n — C – C — n C = C CH 3 HH H R·R· H H H Does the orientation matter? Expand out…

-C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 -C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 Same or different?

-C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 -C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 -C C CH 3 HHH HHHHHHHH HH H HHH H HHH H H H HHHHH H HHH -C CH 3

Polyproylene n — C – C — n C = C CH 3 HH H R·R· H H H Does the orientation matter? HEADTAIL

-C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 -C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3

-C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 Polypropylene Head-to-Tail Any other options? = methyl = H

-C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 -C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 -C C CH 3 HHH HHHHHHHH HH H HHH H HHH H H H HHHHH H HHH -C CH 3 These are all head-to-tail!!

-C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 Polypropylene Head-to-Head Any other options? = methyl = H

-C C CH 3 H HH HHHHHHHH HHHHHHHHHHHHHHHHHHHHHH -C CH 3 Polypropylene - Random = methyl = H

Polystyrene Glassy and brittle

Polystyrene  Can be injected with a gas to make foam! We used to use CFCs!

Polystyrene? n — C – C — n C = C HH H R·R· H H H HEADTAIL

Polystyrene What orientation?

Polyvinyl Chloride (PVC)

CC Cl H H H vinyl chloride Polymerize!

Polyvinylchloride (PVC) n — C – C — n C = C Cl HH H R·R· H H H

PVC Cl Head-to-tail

PVC Cl Head-to-tail Has order – packs well

PVC Cl Head-to-tail Has order – packs well Rigid, stiff material

PVC Cl Head-to-head

PVC Cl Head-to-head Cl Has order – packs well Rigid, stiff material

PVC Cl Random

PVC Cl Random Less order – does not pack as well

PVC Cl Random Less order – does not pack as well Slightly softer

PVC comes in many forms!

PVC  Can be opaque and rigid

PVC  Can be opaque and rigid

PVC  Can be transparent and softer

often shiny

 Can also be shiny!

PVC Why not?

PVC PVC is usually not recyclable Why not?

Plasticizers  Big molecules added to soften a plastic Can often make- up about 30% of a plastic’s weight!

PVC Cl Random Less order – does not pack as well Slightly softer Still not soft enough for some uses…

Plasticizers Phthalates are commonly used Where have we seen phthlate-related compounds?

DEHP  Di(2-ethylhexyl)phthalate A double ester of phthalic acid!

Terephthalic Acid C HO O C OH O

Phthalic Acid C OH O C O

DEHP - Di(2-ethylhexyl)phthalate C O OH C O Phthalic Acid A double ester of phthalic acid! How do we make an ester?

Carboxylic Acid + Alcohol Ester + Water H+H+

DEHP - Di(2-ethylhexyl)phthalate C O OH C O Phthalic Acid How do we make an ester? React with an alcohol! Which one?

 Hexyl DEHP - Di(2-ethylhexyl)phthalate = 6 carbons CCCCCC HHHHHH HHHHHH HHO

 2-ethyl DEHP - Di(2-ethylhexyl)phthalate CCCCCC HHHHHH HHHHHH H Ethyl group on the 2 nd carbon! CH 2 CH 3 Carboxylic Acid + Alcohol Ester + Water H+H+ HO

2-ethyl-1-hexanol CCCCCC HHHHHH HHHHH H CH 2 CH 3 HO

New Notation!!  The “squiggly” notation

2-ethyl-1-hexanol CCCCCC HHHHHH HHHHH H CH 2 CH 3 HO

DEHP - Di(2-ethylhexyl)phthalate C O OH C O Phthalic Acid HO +

C O OH C O + OH

C O C O O DEHP - Di(2-ethylhexyl)phthalate +H2OH2O

HO Let’s add another one! C O C O OH O +H2OH2O

O C O C O O DEHP - Di(2-ethylhexyl)phthalate +H2OH2O +H2OH2O

 How do plasticizers soften plastic? “The elephant in the parade.”

 How do plasticizers soften plastic? “The elephant in the parade.” O C O C O O

 How do plasticizers soften plastic? “The elephant in the parade.” O C O C O O Creates more space between the polymer branches

Plasticizers Leading to a more flexible plastic

PVC Has been primarily replaced with PET Why? PVC used to be used to house food items.

Plasticizers slowly leach from the plastic and into solutions More likely to leach into polar or nonpolar solutions?

Where do we find plasticizers?

intravenous (IV) bags and tubing umbilical artery catheters blood bags and infusion tubing enteral nutrition feeding bags nasogastric tubes peritoneal dialysis bags and tubing tubing used in cardiopulmonary bypass (CPB) procedures tubing used during hemodialysis Over 1 billion lbs of DEHP used worldwide

Health Risks of DEHP?

In lab animals… Liver Damage Carcinogen (Causes Cancer)

In people… Controversial … What to do?

European Union  “…the exposure of the general population is well below (at least 280 times) levels at which their health might be put at risk.”  “no risk reduction measures are needed…”

2003  California Assembly  Bill to ban DEHP in medical devices (except where no alternative)

Exposure to DEHP increased with increased “use.” This is NOT a reason to discontinue medical treatment!!! DEHP leaches out extremely slowly in polar solutions

Topics for Monday  Lipids, Fats, and Oils! Are fats polar or nonpolar?