Transcript organic chemistry

ORGANIC CHEMISTRY
Naming Saturated Hydrocarbons
• The International Union of Pure and Applied Chemistry (IUPAC)
names for the first 12 "straight-chain" or "normal" alkanes are:
Number of Carbons in chain
Prefix
C-C
C=C
C C
1
Meth-
Methane
2
Eth-
Ethane
Ethene
Ethyne
3
Prop-
Propane
Propene
Propyne
4
But-
Butane
Butene
Butyne
5
Pent-
Pentane
Pentene
Pentyne
6
Hex-
Hexane
Hexene
Hexyne
7
Hept-
Heptane
Heptene
Heptyne
8
Oct-
Octane
Octene
Octyne
9
Non-
Nonane
Nonene
Nonyne
10
Dec-
Decane
Decene
Decyne
11
Undec-
Undecane
Undecene
Undecyne
12
Dodec-
Dodecane
Dodecene
Dodecyne
Alkanes and Cycloalkanes
• The simplest saturated hydrocarbons are called alkanes.
• Methane, CH4, is the simplest alkane.
• The alkanes form a homologous series.
– Each member of the series differs by a specific number and
kind of atoms.
H
H C
H
H
H
C H
H
H
or CH4
Alkanes and Cycloalkanes
• The alkanes differ from each other by a CH2 or methylene group.
• All alkanes have this general formula.
CnH2n+2
• For example ethane, C2H6 , and propane, C3H8 , are the next two family
members.
H
H
H
C
C
H
H
C2H6
H
H
H
H
H
C
C
C
H
H
H
C3H8
H
Alkanes and Cycloalkanes
• Isomers are chemical compounds that have the same molecular
formulas but different structures.
• Two alkanes have the molecular formula C4H10.
– They are a specific type of isomer called structural
isomers.
•
Branched-chain alkanes are named by the following rules.
H
H
H
H
H
C
C
C
C
H
H
H
H
H
H
H
H
H
C
C
C
H
H
H
H
C
H
H
n-butane
2-methylpropane
Naming Saturated Hydrocarbons
1.
2
3
4
5
6
Choose the longest continuous chain of carbon atoms which gives the basic
name or stem.
Number each carbon atom in the basic chain, starting at the end that gives the
lowest number to the first group attached to the main chain (substituent).
For each substituent on the chain, we indicate the position in the chain (by an
Arabic numeric prefix) and the kind of substituent (by its name).
 The position of a substituent on the chain is indicated by the lowest number
possible. The number precedes the name of the substituent.
When there are two or more substituents of a given kind, use prefixes to indicate
the number of substituents.
 di = 2, tri = 3, tetra = 4, penta = 5, hexa = 6, hepta = 7, octa = 8, and so on.
The combined substituent numbers and names serve as a prefix for the basic
hydrocarbon name.
Separate numbers from numbers by commas and numbers from words by
hyphens.
 Words are "run together".
Naming Saturated Hydrocarbons
•
Alkyl groups (represented by the symbol R) are common substituents.
– Alkyl groups are fragments of alkanes in which one H atom has
been removed for the connection to the main chain.
– Alkyl groups have the general formula CnH2n+1.
•
In alkyl groups the -ane suffix in the name of the parent alkane is replaced by -yl.
– A one carbon group is named methyl.
– A two carbon group is named ethyl.
– A three carbon group is named propyl.
• Three alkanes have the formula C5H12.
– There are three structural isomers of pentane.
CH3
H2
H2
CH3
C
C
C
CH
CH3
H3C
C
CH3
H3C
CH3
H3C
C
H2
CH3
H2
n-pentane
2-methylbutane 2,2-dimethylpropane
Alkanes and Cycloalkanes
• There are five isomeric hexanes, C6H14.
H3C
H2
C
C
H2
H2
C
CH3
C
H2
CH3
C
H3C H C
H2
H2
C
CH3
n-hexane
2-methylpentane
CH3
C H2 CH3
C
H3C
CH3
CH3
C H CH3
H3C H C
2,2-dimethylbutane
2,3-dimethylbutane
H2
H2
C H C
CH3
C
H3C
CH3
3-methylpentane
CH3
•The number of structural isomers increases rapidly with
increasing numbers of carbon atoms.
•The boiling points of the alkanes increase with molecular weight.
Alkanes and Cycloalkanes
• Cyclic saturated hydrocarbons are called cycloalkanes.
– They have the general formula CnH2n.
• Some examples are:
H2
C
H 2C
H2C
CH 2
CH 2
H2
C
H2C
H2C
cyclopentane
CH 2
C
H2
H2 H2
C C
CH 2
cyclohexane
H2C
H2C
H2C
CH 2
CH 2
CH 2
cyclooctane
Alkenes
•
1.
2.
3.
•
The three classes of unsaturated hydrocarbons are:
alkenes and cycloalkenes, CnH2n
alkynes and cycloalkynes, CnH2n-2
aromatic hydrocarbons
The simplest alkenes contain one C=C bond per molecule.
– The general formula for simple alkenes is CnH2n.
• The first two alkenes are:
– ethene, C2H4 H
H – and propene, C3H6
H
C C
H
H
H
• Each doubly bonded C atom is sp2 hybridized.
• The sp2 hybrid consists of:
– two s bonds (single bonds) and
– one s and one p bond (double bond)
C
H
C
H
H
C
H
Alkenes
• The systematic naming system for alkenes uses the same stems as alkanes.
• In the IUPAC system, the -ane suffix for alkanes is changed to -ene.
– Common names for the alkenes have the same stem but use the suffix ylene is used.
• In chains of four or more C atoms, a numerical prefix shows the position of
the lowest-numbered doubly bonded C atom.
– Always choose the longest chain that contains the C=C bond.
• Polyenes contain two or more double
H
H
bonds per molecule.
H
H
H
H
• Indicate the number of double bondsH C C C C C H H C C C C C C
C
H
with suffixes:
H
H
H
H
H
H
H
– -adiene for two double bonds.
1,3,5-hexatriene
1,3-hexadiene
– -atriene for three double bonds,
H
etc.
H H C H H
• The positions of the substituents are H
C
C
C
C
C
C
H
indicated as for alkanes.
H
H H C H
• The position of the C=C bond(s)
H
is/are given the lowest number(s) 2,3-dimethyl-1,3,5-hexatriene
possible.
H
Cycloalkenes
• Cycloalkenes have the general formula CnH2n-2.
• Examples are:
• cyclopentene
• cyclohexene
H H
H
C
C C H
H
C C H
H
H
H
H
H
C
C
C
H
C H
C H
C
H
H
H H
Alkynes
•
•
Alkynes contain CC bonds.
The simplest alkyne is C2H2, ethyne, or acetylene.
– Alkynes with only one C  C bond have the formula CnH2n-2.
Each carbon atom in a C  C bond is sp hybridized.
•
– Each sp hybrid contains two  bonds and two  bonds.
– The carbon atom will have one single bond and one triple bond.
• Alkynes are named like the alkenes except that the suffix -yne is used with
the characteristic stem
– The alkyne stem is derived from the name of the alkane with the same
number of carbon atoms.
H
H
H
C
C
H
H
C
C
H
H
H
C
C
C
H
H
H
3-heptyne
H
H
H
C
H
C
C
H
H
H
H
H
C
C
C
C
C
H
H
H
H
H
2-octyne
H
Hydrocarbons: A Summary
Carbon Atom
Hybridization
C uses
C forms
Example
sp3
tetrahedral
4 sp3 hybrids
4  bonds
CH4
sp2
trigonal planar
3 sp2 hybrids &
1p orbital
3  bonds
1  bond
C2H4
sp linear
2 sp hybrids & 2
p orbitals
2  bonds
2  bonds
C2H2
Aromatic Hydrocarbons
• Historically, aromatic was used to describe pleasant smelling substances.
• Now it refers to benzene, C6H6, and derivatives of benzene.
– Other compounds that have similar chemical properties to benzene are
also called aromatic.
H
H
• The structure of benzene, C6H6, is:
H
C
C
C
C
C
C
H
H
H
• Coal tar is the common source of benzene and many other aromatic
compounds.
H
H
• Some aromatic hydrocarbons that
H
H
C
C
C
C
C
contain fused rings are:
• napthalene
C
C
C
H
C
C
H
H
H
Resonance in Benzene
• C–C single bond = 154 pm
• C=C bond = 134 pm
• CC bonds in benzene = 139 pm
• C6H6 has two resonance structures with alternating double bonds.
• The π electrons are delocalized over the ring.
H
H
H
H
C
H
C
H
C
H
H
H
C
C
C
C
C
C
HC
C
H
CH
H
C
CH
C
H
Resonance structures of benzene, C6 H6
HC
C
H
CH
Abbreviated representation
of resonance structures
π electrons delocalized
Other Aromatic Hydrocarbons
• Many aromatic hydrocarbons contain alkyl groups attached to benzene rings
(as well as to other aromatic rings).
• The positions of the substituents on benzene rings are indicated by the
prefixes:
– ortho(o-) for substituents on adjacent C atoms
– meta(m-) for substituents on C atoms 1 and 3
– para(p-) for substituents on C atoms 1 and 4
CH 3
CH 3
CH 3
CH 3
CH 3
m-xylene
CH 3
o-xylene
p-xylene
Organic Halides
• A halogen atom may replace almost any hydrogen atom in a hydrocarbon.
• The functional group is the halide (-X) group.
• Examples include:
– chloroform, CHCl3
• 1,2-dichloroethane, ClCH2CH2Cl
Cl
Cl
H Cl
C
H C C H
H
Cl
Cl
• para-dichlorobenzene
Cl
Cl H
Alcohols and Phenols
• The functional group in alcohols and phenols is the hydroxyl
(-OH) group.
• Alcohols and phenols can be considered derivatives of hydrocarbons in which
one or more H atoms have been replaced by -OH groups.
• Phenols are derivatives of benzene in which one H has been replaced by
replaced by -OH group.
• The stem for the parent hydrocarbon plus an -ol suffix is the
systematic name for an alcohol.
• A numeric prefix indicates the position of the -OH group in
alcohols with three or more C atoms.
• Common names are the name of the appropriate alkyl group plus
alcohol.
Alcohols and Phenols
• Ethyl alcohol (ethanol), C2H5OH, is the most familiar alcohol.
H
H
H
C
C
H
H
OH
• Phenol, C6H5OH, is the most familiar phenol.
OH
Alcohols and Phenols
•
1.
2.
•
3.
•
Alcohols can be classified into three classes:
Primary (1°) alcohols like ethanol have the -OH
group attached to a C atom that has one bond to
another C atom.
Secondary(2°) alcohols have the –OH group
attached to a C atom that has bonds to
2 other C atoms.
For example,2-propanol:
Tertiary (3°) alcohols have the –OH group
attached to a C atom that is bonded to 3
other C atoms.
For example, 2-methyl-2-propanol
H3C
C OH
H2
H3C
HC OH
H3C
OH
H3C C CH3
CH3
Alcohols and Phenols
•
•
Alcohols are named using the stem for the parent hydrocarbon plus an -ol suffix in
the systematic nomenclature.
A numeric prefix indicates the position of the -OH group in alcohols with three or
more C atoms.
– Common alcohol names are the name of the appropriate alkyl
group plus the word alcohol.
H2C
H2
C
OH
C
H2
H2
C
OH
CH3
1-pentanol
1-pentyl alcohol
C
H3C H C
H2
H2
C
CH3
2-pentanol
2-pentyl alcohol
H2
H2
C H C
H3C
C
CH3
OH
3-pentanol
3-pentyl alcohol
Alcohols and Phenols
• There are several isomeric monohydric acyclic (contains no rings) alcohols
that contain more than three C atoms.
• There are four isomeric four-carbon alcohols.
OH
H2
C
HO
H2
C
C
H2
CH
CH3
H3C
CH 3
1-butanol
2-butanol
OH
HO
CH 2
CH
H3C
CH 2
CH 3
2-methyl-1-propanol
H3C
C
CH 3
CH 3
2-methyl-2-propanol
Alcohols and Phenols
• There are eight isomeric five-carbon alcohols.
HO
C
H2
H2
C
C
H2
H2
C
OH
CH3
1-pentanol
C
H3C H C
H2
2-methyl-1-butanol
C
H3C H C
H2
H2
C
H3C
C
CH2
OH CH3
2-methyl-2-butanol
2
3-methyl-1-butanol
H3C
C
3-pentanol
CH3
CH3H
OH
H2
H2
C H C
CH3
C
H3C
OH
CH3
CH3
C
C
C H
H2
H2
CH3
CH3
2-pentanol
CH3
HO
H2
C
C
CH3 OH
2,2-dimethyl-1-propanol
C H CH3
H3C H C
OH
3-methyl-2-butanol
Alcohols and Phenols
• Polyhydric alcohols contain more than one -OH group per molecule.
OH
OH
C
H2C H CH2
OH
OH
glycerin
HO
OH
OH
C H C H CH2
C H C H C
H2
OH OH
sorbitol
Alcohols and Phenols
• Phenols are usually called by their common (trivial) names.
OH
OH
OH
OH
CH3
CH3
OH
resorcinol
o-cresol
m-cresol
CH3
p-cresol
Ethers
• Ethers may be thought of as derivatives of water in which both H atoms have
been replaced by alkyl or aryl groups.
H
O
H3C
H
water
O
H
H3C
an alcohol
O
CH3
an ether
• Ethers are not very polar and not very reactive.
• They are excellent solvents.
• Common names are used for most ethers.
H3C
O
C
H2
CH3
ethylmethyl ether
H3C
O
CH3
dimethyl ether
H2
C
H3C
O
H2
C
diethyl ether
CH3
Aldehydes and Ketones
• The functional group in aldehydes and ketones is the carbonyl group.
O
R1
R2 or H
carbonyl group
Aldehydes and Ketones
• Except for formaldehyde, aldehydes have one H atom and one organic group
bonded to a carbonyl group.
O
H3C
O
O
H
ethanal
or
acetaldehyde
H
H
methanal
or
formaldehyde
H 3C
C
H2
H
propanal
or
propionaldehyde
• Ketones have two organic groups bonded to a carbonyl group.
H3C
O
O
O
C
C
C
CH 3
propanone
or
acetone
H2C
CH 3
CH 3
2-butanone
or
ethylmethylketone
H 2C
CH 3
CH 2
CH 3
3-pentanone
or
diethylketone
Aldehydes and Ketones
• Common names for aldehydes are derived from the name of the acid with the
same number of C atoms.
• IUPAC names are derived from the parent hydrocarbon name by replacing -e with
-al.
H3C
C
H2
H2
C
O
C
H2
C
pentanal
or
pentyl aldehyde
H3C
H
H3C
C
O
O
C
C
H
H
CH3
2,3-dimethylproponal
or
2,3-dimethylpropionaldehyde
benzanal
or
benzyl aldehyde
Aldehydes and Ketones
• The IUPAC name for a ketone is the characteristic stem for the parent
hydrocarbon plus the suffix -one.
• A numeric prefix indicates the position of the carbonyl group in a chain or
on a ring.
O
H3C
C
H2
H2
C
O
C
H2
C
CH3
2-hexanone
or
methyl pentyl ketone
H3C
H2
C
O
C
H2
C
C
H2
C
CH3
CH3
3-hexanone
or
ethyl propyl ketone
acetophenone
or
methyl phenyl ketone
Amines
• Amines are derivatives of ammonia in which one or more H atoms have been
replaced by organic groups (aliphatic or aromatic or a mixture of both).
• There are three classes of amines.
H
N
H
H
ammonia
H3C
N
H
primary
amine
H
H3C
N
H
CH3
secondary
amine
H3C
N
CH3
CH3
tertiary
amine
Carboxylic Acids
O
• Carboxylic acids contain the carboxyl functional group.
C
OH
O
• The general formula for carboxylic acids is:
– R represents an alkyl or an aryl group
C
R1
OH
• IUPAC names for a carboxylic acid are derived from the name of the
parent hydrocarbon.
– The final -e is dropped from the name of the parent
hydrocarbon
– The suffix -oic is added followed by the word acid.
• Many organic acids are called by their common (trivial) names which
are derived from Greek or Latin.
Carboxylic Acids
O
O
C
C
H
H3C
OH
methanoic acid
or
formic acid
ethanoic acid
or
acetic acid
O
O
H3C
H2
C
C
C
H2
OH
OH
propanoic acid
or
propionic acid
H3C
C
C
H2
OH
butanoic acid
or
butyric acid
Carboxylic Acids
• Positions of substituents on carboxylic acid chains are indicated by
numeric prefixes as in other compounds
– Begin the counting scheme from the carboxyl group
carbon atom.
• They are also often indicated by lower case Greek letters.
–  = 1st C atom
–  = 2nd C atom
–  = 3rd C atom, etc.
O
H3C H C
C
OH
CH3
CH3
O
C
C
OH
H3C H C
H2
2-methylpropanoic acid 3-methylbutanoic acid
or
or
-methylpropanoic acid -methylbutanoic acid
O
H2
H3C H C
C
C
C
OH
H2
CH3
4-methylpentanoic acid
or
-methylpentanoic acid
Nomenclature of Carboxylic Acids
• Dicarboxylic acids contain two carboxyl groups per molecule.
O
OH
C C
HO
O
oxalic acid
HO
O
O
O
C
C
C
C
H2
OH
malonic acid
HO
C
H2
H2
C
C
O
succinic acid
OH
Carboxylic Acids
• Aromatic acids are usually called by their common names.
• Sometimes, they are named as derivatives of benzoic acid which is
considered to be the "parent" aromatic acid.
HO
HO
O
benzoic acid
HO
O
O
Cl
p-chlorobenzoic acid
OH
O
OH
CH3
p-toluic acid
O
phthalic acid
Some Derivatives of
Carboxylic Acids
R1
O
O
O
C
C
C
O
R1
acid anhydride
R1
acid chloride
O
O
R1
C
Cl
O
ester
R2
R1
C
NH2
amide
Alcohols and Phenols
•
•
•
The stem for the parent hydrocarbon plus an -ol suffix is the systematic name for an alcohol.
A numeric prefix indicates the position of the -OH group in alcohols with three or more C atoms.
Common names are the name of the appropriate alkyl group plus alcohol.
•
Common names are used for most ethers.
•
•
Common names for aldehydes are derived from the name of the acid with the same number of C atoms.
IUPAC names are derived from the parent hydrocarbon name by replacing -e with -al.
•
•
The IUPAC name for a ketone is the characteristic stem for the parent hydrocarbon plus the suffix -one.
A numeric prefix indicates the position of the carbonyl group in a chain or on a ring.
•
•
•
•
Ethers
Aldehydes and Ketones
Amines
Amines are derivatives of ammonia in which one or more H atoms have been replaced by organic
groups (aliphatic or aromatic or a mixture of both).
There are three classes of amines.
Carboxylic Acids
IUPAC names for a carboxylic acid are derived from the name of the parent hydrocarbon.
– The final -e is dropped from the name of the parent hydrocarbon
– The suffix -oic is added followed by the word acid.
Many organic acids are called by their common (trivial) names which are derived from Greek or Latin.
When compounds contain more than one functional group, the order of precedence determines
which groups are named with prefix or suffix forms. The highest precedence group takes the
suffix, with all others taking the prefix form. However, double and triple bonds only take suffix
form (-en and -yn) and are used with other suffixes.
Functional group
Formula
Prefix
Suffix
1
Cations
e.g. Ammonium
–NH4+
-onioammonio-
-onium
-ammonium
2
Carboxylic acids
–COOH
carboxy-
-oic acid*
3
Carboxylic acid derivatives
Esters
Acyl chlorides
Amides
–COOR
–COCl
–CONH2
R-oxycarbonylchloroformylcarbamoyl-
-oyl chloride*
-amide*
4
Nitrites
Isocyanides
–CN
–NC
cyanoisocyano-
-nitrile*
isocyanide
5
Aldehydes
Thioaldehydes
–CHO
–CHS
formylthioformyl-
-al*
-thial*
6
Ketones
Thioketones
>CO
>CS
oxothiono-
-one
-thione
7
Alcohols
Thiols
–OH
–SH
hydroxysulfanyl-
-ol
-thiol
8
Amines
–NH2
amino-
-amine
9
Ethers
Thioethers
–O–
–S–
-oxy-thio-
Priority
Isomerism
• Isomers have identical composition but different structures
• Two forms of isomerism
– Constitutional (or structural)
– Stereoisomerism
• Constitutional
– Same empirical formula but different atom-to-atom connections
• Stereoisomerism
– Same atom-to-atom connections but different arrangement in
space.
• Geometric - Geometric isomers can occur when there is a C=C
double bond.
• Optical - Optical isomers are molecules with non-superimposable
mirror images. Such molecules are called CHIRAL. Pairs of chiral
molecules are enantiomers. Chiral molecules in solution can rotate
the plane of plane polarized light.
Structural Isomers
Stereoisomers: Geometric
Geometric isomers can occur when there is a C=C double bond.
Cis-2-butene
Trans-2-butene
Stereoisomers: Optical
• Optical isomers are molecules with
non-superimposable mirror images.
• Such molecules are called CHIRAL
• Pairs of chiral molecules are
enantiomers.
• Chiral molecules in solution can
rotate the plane of plane polarized
light.
• Chirality generally occurs when
a C atom has 4 different groups
attached.
Lactic acid
Chirality: Handedness in Nature
These molecules are non-superimposable mirror images.
Sugars: Related to Alcohols
• Sugars are carbohydrates, compounds with the formula Cx(H2O)y.
CHO
H OH
4
HO
HO
5
3
H
H
OH
2
H
3
H
OH
4
H
OH
5
H
HO
2
HO
1
OH
OH
-D-glucose
H
1
CH2OH
H OH
4
HO
HO
5
HO
1
3
H
H
2
OH
H
OH
-D-glucose
Open chain form
What is the difference between a and b D-glucose?
Glycosidic bonds: The anomeric hydroxyl group (axial) and a hydroxyl
group of another sugar or some other compound can join together, splitting
out water to form a glycosidic bond.
R-OH + HO-R' --> R-O-R' + H2O
Carbohydrates (also referred to as glycans)
have the basic composition:
Monosaccharides - simple sugars, with multiple hydroxyl groups.
Based on the number of carbons (e.g., 3, 4, 5, or 6) a monosaccharide is a triose,
tetrose, pentose, or hexose, etc.
Disaccharides - two monosaccharides covalently linked
Oligosaccharides - a few monosaccharides covalently linked.
Polysaccharides - polymers consisting of chains of monosaccharide or
disaccharide units
Aldoses (e.g., glucose) have an aldehyde
at one end.
Ketoses (e.g., fructose) have a keto
group, usually at C #2.
Nomenclature for stereoisomers: D and L designations
are based on the configuration about the single asymmetric
carbon in glyceraldehyde.
For sugars with more than one chiral center, the D or L
designation refers to the asymmetric carbon farthest from
the aldehyde or keto group.
Most naturally occurring sugars are D isomers.
D & L sugars are mirror images of one another. They have
the same name. For example, D-glucose and L-glucose are
shown at right.
Haworth projections represent the cyclic sugars
as having essentially planar rings, with the OH at
the anomeric C1 extending either:
•below the ring (a)
•above the ring (b).
Sucrose and Ribose
H OH
HO
HO
HO
H
OH
O
H
OH
O
HO
H
H
H
CH2OH
-D-Glucose
H
HO
O
OH
Fructose
H
OH
H
H
H
Deoxyribose, the
sugar in the
DNA backbone.
H
CH2 OH
Sucrose, common table sugar, has a glycosidic bond linking the anomeric hydroxyls of
glucose and fructose. Because the configuration at the anomeric carbon of glucose is 
(O points down from the ring), the linkage is designated a(12). The full name is -Dglucopyranosyl-(12)b-D- fructopyranose.
Fats and Oils
H2 C
HC
H2 C
O
O CR
O
O CR
O
O CR
What is the
functional group in a
fat or oil?
R = organic group
with NO C=C bonds
C12 = Lauric acid
C16 = Palmitic acid
C18 = Stearic acid
R = organic group
with C=C bonds
C18 = oleic acid
H2 C
HC
H2 C
O
O CR
O
O CR
O
O CR
Fats and Oils
Fats with C=C bonds are usually LIQUDS
Oleic acid: a
monounsaturated
fatty acid
C=C bond
Trans Fatty Acids
•Oleic acid is a mono–unsaturated cisfatty acid
•Trans fatty acids have deleterious health
effects.
•Trans fatty acids raise plasma LDL
cholesterol and lower HDL levels.
C=C bond
Alpha-Amino Acids
H2N
H
O
C
C
OH
R
Amine
H
Alanine
H3C
C
Chiral -carbon
NH3
CO2
Acid
Peptides and Proteins
O
H 3N
OŠH CH3
Alanine
HOCH 2
H 3N
+
H
OŠ-
O
Serine
peptide bond
– H2O
H
HOCH2
H
H 3N
O
N
H
O
O
Š
CH3
Adding more peptide links ---> PROTEIN
Polymers
• Giant molecules made by joining many small molecules called
monomers
• Average production is 150 kg per person annually in the U.S.
Polymer Classifications
• Thermoplastics (polyethylene) soften and flow when heated
• Thermosetting plastics — soft initially but set to solid when
heated. Cannot be resoftened.
• Other classification: plastics, fibers, elastomers, coatings,
adhesives
National Liner is a premium cured-in-place pipe trenchless rehabilitation
system designed to repair sanitary and stormwater pipelines ranging
from to 120 in. in diameter. Made of non-woven, needled polyester felt
and saturated with a thermosetting resin, the liner is inserted into an
upstream manhole and expanded with a hydrostatic head of water to
press the liner tightly against the interior of the host pipe. Once in place,
the liner is heated to activate the resin system, causing the resin to cure,
and form a new structural pipe within the host pipe.
National Envirotech Group
Houston,TX
Tel:800-547-1235
Web:www.nationalliner.com
Polymer Preparation
• Addition polymers — directly adding monomer
units together
• Condensation polymers — combining monomer
units and splitting out a small water (water)
Types of Polyethylene
Linear, high density PE
(HDPE)
Branched, low density
PE, LDPE
Cross-linked PE, CLPE
Types of Polyethylene
Polymers based on Substituted Ethylenes, CH2=CHX
CH2CH
OH
CH2CH
n
polyvinyl alcohol
CH2CH
OCCH3 n
O
polyvinyl acetate
n
polystyrene
Table 11.12: others are PVC, acrylonitrile, polypropylene,
polymethyl methacrylate
Bubble Gum!
A copolymer
Styrene + butadiene
Condensation Polymers
O
n HOC
O
COH + n HOCH2CH2OH
terephthalic acid
O
C
ethylene glycol
O
COCH2CH2O
+ H2 O
n
Polyethylene terephthalate (PET), a polyester
Polyamides: Nylon
•Each monomer has 6 C atoms in its chain.
•A polyamide link forms on elmination of HCl
•Result = nylon 66
•Proteins are polyamides