CNGNGE JOHN MCMURRY CHAPTER 27 Synthetic Polymers Organic Chemistry with Biological Applications
CHAPTER 27 Synthetic Polymers
Polymers Large molecules built up by repetitive bonding together of monomers Indicate repeating unit in parentheses H2C=CH CH2-CH-I Styrene Polystyrene
▪ Large molecules built up by repetitive bonding together of monomers ▪ Indicate repeating unit in parentheses Polymers
Why This Chapter? More comprehensive view of polymers to see: More detail about how polymers are made How polymer structure correlates with their physical properties
More comprehensive view of polymers to see: ▪ More detail about how polymers are made ▪ How polymer structure correlates with their physical properties Why This Chapter?
27-1 Chain-Growth Polymers Chain-growth polymers are produced by chain-reaction polymerization Benzoyl peroxide is used as common radical initiator Initiator (radical,acid,or anion)adds to a carbon- carbon double bond of an unsaturated substrate (a vinyl monomer)to yield a reactive intermediate that reacts with a second molecule of monomer and so on 2C02 Benzoyl peroxide Benzoyloxy Phenyl radical radical(Ph) Repeat Ph-CH2CH2. many times → Ph-(CH2CH2)nCH2CH2
Chain-growth polymers are produced by chain-reaction polymerization ▪ Benzoyl peroxide is used as common radical initiator ▪ Initiator (radical, acid, or anion) adds to a carbon– carbon double bond of an unsaturated substrate (a vinyl monomer) to yield a reactive intermediate that reacts with a second molecule of monomer and so on 27-1 Chain-Growth Polymers
27-1 Chain-Growth Polymers Acid-catalyzed (cationic)polymerization is effective only with vinyl monomers that contain an electron-donating group (EDG) n EDG stabilized the chain-carrying carbocation intermediate EDG EDG EDG EDG EDG EDG A H2C=CH H-CH2-CH+ H2C=CH CH3CH-CH2CH+ Repeat CH2-CH方 where EDG an electron-donating group Cengoge Learing.All Rights Poserved
Acid-catalyzed (cationic) polymerization is effective only with vinyl monomers that contain an electron-donating group (EDG) ▪ EDG stabilized the chain-carrying carbocation intermediate 27-1 Chain-Growth Polymers