Transcript Organic Chemistry for Cosmetic Chemist

Organic Chemistry for
Cosmetic Chemists
Tony O’Lenick
Thomas O’Lenick, PhD
October 2015
S
Organic Chemistry
S Organic Chemistry however has profound effects upon our
formulations.
S This becomes clear when a formulator tries to substitute one
raw material for another.
S Armed with only INCI names this can be a best a frustration or
at worst a complete failure.
S Why is this the case?
Organic Chemistry
S Why is this the case?
1.
2.
3.
4.
Many of our raw materials come from different raw material
bases and despite common names are not identical.
Many manufacturers use different processes to make their
products.
These differing processes result in different % conversion, by
products and un-reacted raw materials.
Many manufacturers use processing aides, and other
additives.
Back the the Basics
S Before we dive into Organic chemistry or more commonly
called O-Chem we need the basics
S First off
Back the the Basics
S How do we draw Chemical Structures
CH3CH2CH3
S Hydrocarbons- All Carbon and Hydrogens
S
Alkanes
S
Alkenes
S
Alkynes
S
Cyclic
S Aromatic Compounds
Organic Chemistry
Structures and Naming
S
Hydrocarbon
S Hydrocarbons are organic compounds that are composed of
carbon and hydrogen.
S To start the naming process we need to start with the
simplest form.
S Compounds with all single Carbon-Carbon bonds.
S Hydrocarbons are named by identification of the longest
continuous carbon chain.
S They are named by the number of carbons in that chain
followed the suffix “-ane”
Hydrocarbons
S Now
Number
Name
Molecular
come
the memorizationFormula
part…
of Carbons
Structural
Formula
1
Methane
CH4
-
2
Ethane
C2H6
CH3CH3
3
Propane
C3H8
CH3CH2CH3
4
Butane
C4H10
CH3(CH2)2CH3
5
Pentane
C5H12
CH3(CH2)3CH3
6
Hexane
C6H14
CH3(CH2)4CH3
7
Heptane
C7H16
CH3(CH2)5CH3
8
Octane
C8H18
CH3(CH2)6CH3
9
Nonane
C9H20
CH3(CH2)7CH3
10
Decane
C10H22
CH3(CH2)8CH3
S The prefixes…
Isomers
S What are isomers?
S When you have two or more chemical structures that have the
same molecular formula but different structures.
S Example
S How many Isomers of pentane (C5H12) can you draw?
1
Pentane
2
2-Methyl Butane
3
2,2-Dimethyl Propane
Branching?
S When a carbon chain is handing off of the carbon chain but
is not part of the primary carbon chain, you name the
number of carbons, but add a –yl at the end.
4-Ethyl
3-Methyl
3-Methyl
3-Methyl
Heptane
4-Propyl
Heptane
Heptane
Octane
Cyclic Alkanes
S What about?
2
3
1
Pentane
CycloPentane
5
4
C5H10
S No it is not an isomer. It has 2 fewer hydrogens.
S Cyclic compounds have the same type naming but the word
Cyclo-
Alkenes
What about hydrocarbons
with Double Bonds?
S
Hydrocarbons
S Alkenes are:
S Compounds with at least one Carbon-Carbon double bond.
S Name them the same way you name alkanes, except:
1.
2.
You have to identify where the double bond is
Drop the –ane and replace it with –ene.
Number
of Carbons
Name
Molecular
Formula
Structural
Formula
2
Ethene
C2H4
CH2=CH2
3
Propene
C3H6
CH3CH=CH2
Alkenes
trans 2-Pentene
2-Pentene
Pentene
Pentane
cis 2-Pentene
Cyclic –enes?
CycloPentene
CycloPentane
3-Methyl
cyclopentene
Alkynes
S Alkynes are:
S Compounds with at least one Carbon-Carbon triple bond.
S Name them the same way you name alkanes, except:
1.
2.
You have to identify where the double bond is
Drop the –ane and replace it with –yne.
Number
of Carbons
Name
Molecular
Formula
Structural
Formula
2
Ethyne
C2H2
CHCH
3
Propyne
C3H6
CH3CCH
Alkynes
Pentane
Pentyne
S No Cis and Trans
S There are a limited number of cyclics.
2-Pentyne
Alkenes to Alkanes
S Hydrogenation involves hydrogen gas and a metal
Conjugation
S Conjugation as we have seen, leads to stability and if the
conditions are correct, aromatic compounds.
S There is another added benefit that we see a lot in cosmetic
chemistry….Absorption
S Before we discuss how conjugation, lets briefly discuss
absorption in organic molecules.
Resonance
S Lets review Alkenes
S Now we have a diene.
S When dienes are on adjacent carbons, they can have
resonance with each other.
−
+
Aromatic Compounds
S Aromatic Compounds, also known as arenes or aromatics,
are chemical compounds that contain conjugated planar
ring systems with delocalized π electron clouds instead of
discrete alternating single and double bonds. Typical
aromatic compounds are benzene and toluene. They should
satisfy Hückel’s rule.1
So….what does that really mean?
1. http://en.wikipedia.org/wiki/Category:Aromatic_compounds
Aromatic Compounds
http://en.wikipedia.org/wiki/Ouroboros
http://en.wikipedia.org/wiki/August_Kekulé
http://www.sparknotes.com/chemistry/organic1/covalentbonding/section2.rhtml
Benzene
Absorption of Organic Molecules
S Absorption can provide
information about organic
materials.
S There are 2 important
absorptions
S Infrared
S UV-Vis
S Infrared
S Tells us what kind of bonds are
involved.
http://ajwin.us/uvbnarrowband.com/index.php/the-blog/
Conjugation’s effect on
Absorption
S UV light has just the right amount of energy to cause an
electronic transition.
S It is the energy gap that determines what wavelength is
absorbed.
HOMO and LUMO
π*
π*
π
π
O
O
H3C
CH3
H3C
CH
CH2
Organic Filters
S s
Avobenzone
Homosalate
Octocrylene
Alcohol
Not just for drinking anymore…
S
Alcohol
S Alcohols are named by the functional hydoxyl group.
S - OH
S Alcohols can be branched or linear.
S
Oxygen prefers to have 2 bonds, so they are classified according to
what they are connected to.
Alcohols
Primary
CH3CH2OH
OH
1
Secondary
2
CH3CH(CH3)OH
OH
1
Tertiary
(CH3)3COH
3
2
OH
1
Amines
The original nitrogen…
S
Amines
S Amines are named based on this functional group.
S -NHx
S Nitrogen likes to make 3 bonds
S They are named based on how many non-hydrogen atoms are
bonded to the Nitrogen.
CH3
CH3NH2
Primary Amine
CH3
NH
CH3
Secondary Amine
CH3
+
N
CH3
TertiaryHAmine
Ethers
S Ethers are named based on this functional group.
R1-O-R2
S Oxygen likes to have 2 bonds, so ethers are typically non-
reactive
S They are named by their alkyl chains.
CH3
O
CH3
Dimethyl ether
CH3
O
CH2CH3
Methyl Ethyl ether
Carbonyl Group
The gateway drug…
S
Carbonyl Group
S There is a large subsection of functional groups that are
based on the Carbonyl group.
S The carbonyl groups is R2C=O
S The functional group is then based on what R is.
S The Carbon in the Carbonyl is reactive and is very
important in Organic synthesis.
Aldehyde
S Aldehyde is conforms to the following structure.
O
H
S They are named by their parent alkyl chain, but drop the –e
and replace it with –al.
O
H
H
Methanal
(Formaldehyde)
O
H
CH3
Ethanal
Ketones
S A ketone where the R group(s) are carbons.
O
R2
R1
S They are named by their parent alkyl chain, but drop the –e
and replace it with –one.
O
O
CH3
H3C
Dimethyl Keytone
(Acetone)
CH3CH2CH2
CH2CH3
3-Hexanone
Carboxylic Acid
S An Acid is a carboxyl with a C(O)OH.
O
R2
OH
S They are named by their parent alkyl chain, but drop the –e
and replace it with –ic acid
O
O
OH
H3C
Ethanoic Acid
(Acetic Acid)
CH3CH2CH2
OH
Hexonic acid
Esters
S An Ester is a carboxyl with a C(O)OR.
O
R2
OR1
S They are named by their parent alkyl chain with the
carbonyl, but drop the –e and replace it with –oate
O
O
OCH3
H3C
Methyl Ethanoate
(Methyl Acetate)
CH3CH2CH2
OCH2CH3
Ethyl Butanoate
Anhydrides
S Anhydrides are compounds that have the following
structure.
O
O
R2
O
R1
S They are named by their parent alkyl chain with the
carbonyl, but drop the –e and replace it with –oic anhydride
O
H3C
O
O
O
CH3
Ethanoic Anhydride
CH3CH2CH2
O
O
CH2CH3
Butanoic Propanoic anhydride
Epoxides, Alkyl Halides and
Acyl Halides
S Epoxides (oxarines) are 3 membered rings.
O
H2C
CH2
S Alkyl Halides
CH3CH2-X
X = Cl, Br, F, ect.
S Acyl Halides
O
R2
X
X = Cl, Br, F, ect.
Problems
Practice makes perfect…
S
Examples
S Identify the functional group(s):
1
2
3
4
5
6
Some Synthesis Concepts
S Umpolung
S
Is a rather obscure German word, it means “Group Reversal”.
S One of the most dramatic uses of this concept can be seen
in the making of esters.
S Lets do an example….
S Lets Draw
Stearyl Oleate & Oleyl Stearate
S
Umpolung
S Sometimes
1.
2.
3.
Lack of availability of technical data;
Multiple methods of naming;
Different raw materials
Cause confusion in using this concept
Melting Point, °C: 42
S
CAS 3234-84-2
Melting Point, °C: 43
Analogues and Homologues
S A very important concept that one needs to understand
the difference between an analogous series and a
homologous series
S Analogous series are those that differ only in the
functional group present.
S So, for example, sodium laureth-2-sulfate and sodium
laureth-2-phosphate are two analogues.
S Their common raw material is lauryl alcohol with two
moles of ethylene oxide.
Analogues
S The substantial difference in properties between these
analogues is due only to the different functional
groups.
S Changes within a analogous series generally result in
profound differences, including compatibility with
other ingredients.
Homologues
S If one varies the carbon chain in the group, a series of homologues is
prepared.
S Such a homologous pair is sodium lauryl (C12) sulfate and sodium
behenyl (C22) sulfate.
S The differences in the properties of these two surfactants are due to
the differing number of carbon atoms in the molecule.
S Changes within a homologous series generally result in different melt
points, foam, viscosity and conditioning effects
S
It is often advantageous to take into account such differences as these in order
to select a chemistry that will give the desired property. The process becomes
even more complicated when one considers modifications that change both
functionality and carbon chain distribution.
Raw Materials
S
Raw Materials
S There are many different “chemicals” out there to make
products from.
S Several componentsOrigins
go intoofpicking
the correct starting
Materials
materials.
Natural Oils
S
(Triglycerides)
Cost
Petroleum
(Crude Oil)
Minerals
(Quatz)
SMethyl
Availability
Esters
Ethylene Propylene Silicon
SFatty
Purity
Alcohols
Alpha Olefins
Chlorosilanes
Fatty Amines
Fatty Alcohols
Silicone
Glycerin
Fatty Amines
Organofunctional
Natural Oils Triglycerides
Petroleum-based
Alkanes,
Alkenes &
Alkynes
Alkanolamide
Methyl Ester
Acids
Ether Sulfate
Phosphate
Alcohol
Ethoxylates
Sulfate
Ether Ester
Sulfosuccinate
Guerbet
Alcohols
Phosphates
Esters
Sulfates
Ether
Phosphate
Ether
Sulfosuccinate
Ether
Carboylate
Natural Oils Triglycerides
Petroleum-based
Alkanes,
Alkenes &
Alkynes
Alkanolamide
Methyl Ester
Imidazoline
Acids
Amphoterics
Ethoxylated
Amines
Aminosulfosuccanate
Alcohol
Phophobetane
Sulfobetaine
Alkanolamide
Fatty Amine
Betaines
Betaines
Amphoteric
Quats
Triglycerides
The oil of nature…
S
Triglycerides
S Triglycerides are key raw materials
S Triglycerides are the fatty tri-ester of glycerin.
O
O
O
R2
O
R
R1
O
O
Triglyceride
S Typically there are 3 classes of Triglycerides
Class I
Products Rich in Components below C18
Class II
Products Rich in Unsaturated Components
Class
III
Products Rich in Components with Chain Lengths Higher than C18
S Why is this important?
Class I Oils
S
Coconut Oil
S Source:
Component
S Coconut oil is the most abundant processed
natural oil.
S Comes from the seeds of the cocs nucifera
plant.
S Is the major source of Lauric Acid (C12)
Concentratio
n
(% wt)
C8
8.0
C10
7.0
C12
48.0
C14
19.0
C16
8.0
C18
3.0
C18:1
5.0
C18:2
2.0
Class II Oils
Unsaturated C18 Triglycerides
S
Soybean Oil
S Source:
Component
S Comes from the soybean glycerin max.
Concentratio
n
(% wt)
C8
-
C10
-
C12
-
C14
-
C16
7.0
C18
4.0
C18:1
29.0
C18:2
54.0
C18:3
5.0
Class III Oils
S
Meadowfoam Oil
S Source:
S Derived from the herbaceous winter plant
(limnanthes alba).
Component
Concentratio
n
(% wt)
C20:1 (n = 5)
63.0
C20:2 (n = 5.13)
12.0
C22:1 (n = 5)
3.0
C22.1 (n = 13)
12.0
C22.2 (n = 5.13)
10.0
Carbon-Carbon Bonds?
S Double bonds or unsaturation tends to:
S Turn dark when heated
S Go rancid over time
Methyl Esters
OH
O
O
O
R2
O
OH
HO
R
R1
O
O
+ 3 CH3OH
O
3 x R2
OCH3
S Methyl esters are made by the reaction of a triglyceride with
methanol in the presence of a catalyst.
S Commercial manufacturing of methyl esters is
accomplished by using a continuous hydrogenolysis process.
S The Methyl ester is separated from the glycerin and distilled
to produce narrow fraction products useful as ram materials
for the preparation of surfactant products.
Reactions
And let the fun begin…
S
Organic Chemistry
S There are many reactions involved in organic chemistry….
S Instead of memorizing name reaction after name reaction, it
is much simpler to breakdown the reactions into simple
steps or trends.
S With the understanding of these trends, we can understand
the reaction without memorizing a bunch of reactions.
Reactions
S Rule number 1 when we start looking at reactions is
S ALWAYS PUSH ELECTRONS!!!
S Reactions always go from atoms with high electron content
to electron deficient atoms.
S The atoms with high electron content are called
Nucleophilies.
S Electron deficient atoms are called electophiles
Typical Nucleophilies
S Lone Pair Electrons:
S
O , N, S, Cl, Br, I
S
π-bonds
http://www.masterorganicchemistry.com/2011/03/04/the-three-classes-of-nucleophiles/
Nucleophilic
Substitution
WE now know what nucleophilic means…
S
Subsitution Reactions
S What is a “Subsitution Reaction”?
S Simply put a Subsitution reaction is replacing one group
with another, or subsituting one group for another.
S There are 2 basic Subsitution reactions:
1.
2.
S
SN1
SN2
Can be used to make
S
Amids, Esters, Quats, ECT..
Neclophillic Subsitution Reaction
SN1
S SN1 Reactions are a two step reaction.
S They are called SN1 because the rate of the reaction is based
on the carbocation.
rate= k[+]
3o > 2o NO 1o
S Step 1
Rate Limiting Material
Mixture of R and S
Neclophillic Subsitution Reaction
SN2
S SN2 Reactions are a One step reaction.
S They are called SN2 because the rate of the reaction is based
on the carbocation.
rate= k[Starting Material][Nuc]
1o > 2o Typically no 3o
Product inversion (R  S)
Elimination Reactions
They go hand and hand with the SNs…
S
Elimination Reactions
S Elimination reactions are just like the SN reactions, except
you get a double bond instead of a substitution.
-OH
H
CH2
H3C
H
Br
CH3
H3C
CH2
+
CH3
CH2
H
S Consider the reaction.
H3C
-Br
OH
CH3
-OH
CH2
H3C
CH3
E1 Mechanism
-OCH
3
+
+ -Cl
1
1
2
Elimination
-OCH
3
+ -Cl
E2 Mechanism
Cl
-OCH
3
E1
Cl
+
-OCH
3
E2
+
Esterification
S
Esters
S Esters are an important class of compounds made by
nuclephilic substitution.
S Esters are a diverse class of compounds that have a variety
of functional attributes useful to the cosmetic chemist.
S The functionality is determined by the structure. The ester
reaction in simple form.
Neclophillic Subsitution Reaction
@ SP2
O
O
R1
+
HOR2
HO
R1
+
HOH
O
O
R1
OR2
OR3
+
HOR2
R1
OR2
+
HOR3
Esters
S Reactants
S Acid & Base – High Acid Value & Hydroxyl value.
S Saponification value is low.
S Products
S Acid Value and Hydroxyl value are low
S Saponification value is High
S Structurally,
1. Direct esterification
2. Transesterification
Esters
Esters can be described by the process used to make them.
Direct Esterification
S This Ester is made from an Acid and Alcohol.
O
+
CH3CH2OH
O
HO
CH3(CH2)3
CH3(CH2)3
+
Isopropyl
Palmitic
Palmitate
Acid
OCH2CH3
HO
Isopropyl Alcohol
+ HOH
Trans-Esterification
S This type of ester is made from by reacting an Ester and Alcohol.
O
CH3CH2OH
O
CH3(CH2)3
+
OCH3
CH3(CH2)3
+ CH3OH
OCH2CH3
S You always get a mixture of Esters but can separate with packed
column.
Trans-Esterification
S This Ester is made from an Triglyceride and Alcohol.
CH2OH
CH3(CH2)10C(O)OCH2
|
|
CHOH
CH3(CH2)10C(O)OCH + 3 CH3(CH2)11OH -> CH3(CH2)10C(O)O(CH2)11CH3 + |
|
CH2OH
CH3(CH2)10C(O)OCH2
Triglyceride
Alcohol
Ester
Glycerin
Trans-Esterification
S Triglyceride and Alcohol.
S Esters may also be prepared by the reaction of a triglyceride
with a fatty alcohol, releasing glycerin. Glycerin is often
removed by allowing it to settle from the ester and
decantation. This reaction is generally conducted using acid
or metal catalyst.
Trans-Esterification
S Question
S How would an ester made from an acid, in the direct
process differ from the same ester made by
transesterification using either methyl ester or triglyceride?
Types of Esters
The structure of Esters fall into three categories:
1. Simple
2. Complex
3. Polyesters
Simple Ester
O
CH3(CH2)3
OR1
S This type of ester is made from a mono-acid and mono-
Alcohol
S Consider
O
CH3(CH2)8
S Name? IUPAC ? INCI?
OCH3
Simple Ester
O
CH3(CH2)8
OCH3
S Raw Materials?
1.
Find the weak spot of the molecule
2.
Break the molecule and see what it is
O
CH3(CH2)8
OCH
OH 3
HOCH3
Complex Esters
S Complex Esters are made from:
S Mono Acids & Poly Alcohols
S Poly Acids / Mono Alcohols
Complex Esters
O
CH2OH
O
|
HO-CH
O-CH2-C-CH3
|
CH3
O
R
Neopentyl glycol (NPG)
S You can have a mono-ester or a di-ester
R
Complex Esters
Trimethylol propane (TMP) 3 hydroxyl groups
CH2OH
|
HO-CH2-C-CH2CH3
|
CH2OH
Complex Esters
Glycerin 3 hydroxyl groups
CH2-OH
|
CH-OH
|
CH2-OH
Complex Esters
Pentaerythritol (PE) 4 hydroxyl groups
CH2OH
|
HO-CH2-C-CH2-OH
|
CH2OH
Complex Esters
Di-Pentaerythritol (DPE) 6 hydroxyl groups
CH2OH
CH2OH
|
|
HO-CH2-C-CH2-OCH2-C-CH2OH
|
|
CH2OH
CH2OH
An Example
O
(CH2)10CH3
CH2O
O
O
CH3(CH2)10 OCH2-C-CH2O
O
CH2O
(CH2)10CH3
(CH2)10CH3
S Name?
Pentaetyrthritol tetralaurate
S Why is the name Laurate?
Another Example
O
(CH2)10CH3
CH2O
O
CH3(CH2)10 OCH2-C-CH2OH
O
CH2O
(CH2)10CH3
S Name?
Pentaetyrthritol trilaurate
Question
S Now for the real question…..
S How would you expect the two to function differently in
formulations?
O
(CH2)10CH3
CH3(CH2)10
(CH2)10CH3
CH2O
OCH2-C-CH2OH
O
O
(CH2)10CH3
O
OCH2-C-CH2O
O
CH2O
O
O
CH3(CH2)10
(CH2)10CH3
CH2O
CH2O
(CH2)10CH3
Problem
S Lets make 200 g of Lauryl Stearate
O
CH3(CH2)16
O(CH2)11CH3
S Determine the Formula of the reactants
S Stearic Acid
CH3(CH2)16COOH
S Lauryl Alcohol CH3(CH2)11OH
Problem
Write a Balanced Equation
O
O
HO
CH3(CH2)16
+ HO-(CH2)11CH3
CH3(CH2)16
O(CH2)11CH3
+ HOH
Problem
S Determine MW Reactants
S Stearic Acid
C18*12 =216
CH3(CH2)16COOH
H36 1*36 =36
C18H36O2
O2 2*16= 32
216+36+32 = 284
S Lauryl Alcohol CH3(CH2)11OH
C12H24O
S C12*12 = 144
O 1*16= 16
H24 1*24 = 24
144+24+16 = 184
Problem
S Determine Mole Ratio and %
Material
MW
Stearic Acid
284
Lauryl Alcohol 184
Total
MR
1.0
1.0
MCH
284
184
468
%
Grams
60.6
121.2
39.4
78.8
100.0
200.0
In theory there will 3.8% Water generated and 96.2 % Ester at 100% Rxn
Amide
Amide
S Amides are an important class of compounds made by
nuclephilic substitution.
S Amides are a diverse class of compounds that have a variety
of functional attributes useful to the cosmetic chemist.
S Alkanolamides are a diverse class of compounds, used
commonly in personal care to alter the salt curve of
formulation and provide a thickening effect to the formulation
S The functionality is determined by the structure. The Amide
reaction in simple form.
Direct Amidation
S This Amide is made from an Acid and Amine.
O
O
HO
CH3(CH2)3
+
CH3CH2NH2
CH3(CH2)3
S Reactants
S Acid Value & Alkali Value are HIGH
S Products
S Acid Value & Alkali Value are LOW
S Saponification Value- Increases
NHCH2CH3
+ HOH
Amide Types
S Structurally amides fall into two categories based upon alkanolamine
type:
1.
2.
3.
Monohydroxy -amines (monoethanolamine, monoisopropanolamine)
Dihydroxyamines (diethanolamine, diisopropanolamine)
There are no amides based upon tertiary amines.
S Additionally, within each category amides can be classified by the fatty
raw materials and can be:
1.
2.
3.
4.
Saturated
Unsaturated
Branched
Guerbet
Amide from Methyl Esters
S Methyl ester is reacted with ethanolamines, releasing methanol.
S The use of the methyl ester for amid synthesis offers the most flexibility in
obtaining pure carbon numbers in the product. Methyl esters can be
fractionated easily and almost any carbon number methyl ester can be used
to make unique products.
S Methanol is removed by distillation leaving behind the amid. This reaction
is generally conducted using base catalyst. Methanol, a flammable liquid,
must be efficiently removed to obtain a high purity product. Air must be
excluded to prevent color formation.
Direct Amidation
S This Amide made from an Ester and Amine.
O
O
CH3(CH2)10
+
OCH3
Methyl Laurate
CH3CH2NH2
Ethylamine
CH3(CH2)10
NHCH2CH3
N-Ethyl Lauramide
+ HOCH3
Methanol
Specifications
S
Amine Value – Amine value is a measure of the unreacted amine content. It will drop as
the reaction proceeds.
S
GLC- The ratio of carbon distribution of the amid can be determined by GLC. The
distribution is critical to performance.
S
Color – This is a good indication of the way in which the product was made. Darker
colors generally indicate that the product was exposed to more heat and consequently
may have more oxidation.
S
FTIR – This instrumental method is a great method to develop a fingerprint for the
product. The availability of analytical programs to look at numerical comparisons to a
standard pre-approved lot offers the chemist a unique method of verifying batch-to-batch
variability.
S
Melt point – The melting temperature is an important property to check
S
% Glycerin – Even in instances where there is an acid value, it is critical to check
glycerin content to determine is the acid was added to a product made by reaction of a
triglyceride.
Lactams
S Are molecules that are cyclic amides
O
O
HO
H2N
NH +
Lactam
HOH
Amide from Fatty Acids
O
O
HO
CH3(CH2)10
+
CH3CH2NH2
CH3(CH2)10
NHCH2CH3
+ HOH
S Fatty Acid is reacted with an ethylamine, releasing water. Water
is removed by distillation leaving behind the amid. This reaction
is generally conducted without catalyst. . Water must be
efficiently removed to obtain a high purity product. Air must be
excluded to prevent color formation.
Amide from Fatty Acids
Specifications
Acid Value – Acid value measures added acid. Acid reacts with amine to form amid. In cases
of esters made by transesterification, there will be no acid value, unless the acid is post
added, that is added after the making of the product.
Amine Value – Amine value is a measure of the unreacted amine content. It will drop as the
reaction proceeds.
GLC- The ratio of carbon distribution of the amid can be determined by GLC. The
distribution is critical to performance.
Color – This is a good indication of the way in which the product was made. Darker colors
generally indicate that the product was exposed to more heat and consequently may have
more oxidation.
FTIR – This instrumental method is a great method to develop a fingerprint for the product.
The availability of analytical programs to look at numerical comparisons to a standard
pre-approved lot offers the chemist a unique method of verifying batch-to-batch
variability.
Amide from Triglycerides
S A triglyceride is reacted with an alkanolamine, releasing glycerin.
Glycerin is not removed and is left in the product in which it is
soluble. This reaction is generally conducted using a base catalyst.
Specifications
S
Acid Value – Acid value measures added acid. Acid reacts with amine to form amide. In cases
of esters made by transesterification, there will be no acid value, unless the acid is post added,
that is added after the making of the product.
S
Amine Value – Amine value is a measure of the unreacted amine content. It will drop as the
reaction proceeds.
S
GLC- The ratio of carbon distribution of the amid can be determined by GLC. The
distribution is critical to performance.
S
Oolor – This is a good indication of the way in which the product was made. Darker colors
generally indicate that the product was exposed to more heat and consequently may have more
oxidation.
S
FTIR – This instrumental method is a great method to develop a fingerprint for the product.
The availability of analytical programs to look at numerical comparisons to a standard preapproved lot offers the chemist a unique method of verifying batch-to-batch variability.
S
Melt point – The melting temperature is an important property to check.
S
% Glycerin – Even in instances where there is an acid value, it is critical to check glycerin
content to determine is the acid was added to a product made by reaction of a triglyceride.
Problem
S Lets Make 200 g of Lauramide DEA
O
CH3(CH2)10
NH(CH2)2OH
S Determine the Formula of the Reactants
S Lauric Acid
CH3(CH2)10COOH
S Diethanolamine N-(CH2CH2-OH)2
Problem
Write a Balanced Equation
O
O
HO
CH3(CH2)10
+
(HOCH2CH2)2
NH2
CH3(CH2)3
+ HOH
NH(CH2CH2OH)2
Problem
S Determine Emp Formula
S Lauric Acid
CH3(CH2)10COOH
S Diethanolamine N-(CH2CH2-OH)2
C12H24O2
C4H10N
Problem
S Determine MW Reactants
S Lauric Acid
CH3(CH2)10COOH
C12*12 = 144
C12H24O2
H24 1*24 = 24
O2 2*16= 32
144+24+32 = 200
S Diethanolamine N-(CH2CH2-OH)2
C12*4 = 48
H10 1*10 = 10
48+10+14+32 = 104
C4H10O2N
N 1*14= 14
O2*16 = 32
Problem
S Determine Mole Ratio and %
Material
Lauric Acid
DEA
Total
MW
200
104
MR
1.0
1.0
MCH
200
104
304
%
Grams
65.8
131.6
34.2
68.4
100.0
200.0
There will theoretically be 5.9 % water generated and 94.1% Amide,
if there is 100% reaction
Carboxylates
Soap from Methyl Ester
S Methyl Esters are saponified by reaction with KOH. The
methanol produced is generally distilled from the product.
O
O
CH3(CH2)10
+
OCH3
KOH
CH3(CH2)10
O-
Potassium Laurate
K+
+ HOCH3
Carboxylates
Soap from Methyl Ester
S Methyl Esters are saponified by reaction with KOH. The
methanol produced is generally distilled from the product.
O
O
CH3(CH2)10
+
OCH3
KOH
CH3(CH2)10
O-
K+
Potassium Laurate
+ CH3OH
Carboxylates
Soap from Triglycerides
S This reaction is used to produce the so-called glycerin soaps.
The reaction produces three moles of soap and one mole of
glycerin. The glycerin stays in the soap and alters hardness
of the soap giving the characteristic glycerin soap feel.
Soap Specifications
S
Acid Value – Acid value measures added acid. Acid reacts with base to form soap. In
cases of esters made by transesterification, there will be no acid value, unless the acid is
post added, that is added after the making of the product
S
Alkali Value – Alkali value is a measure of the unreacted base content, added to
saponify the oil. It will drop as the reaction proceeds.
S
Color – This is a good indication of the way in which the product was made. Darker
colors generally indicate that the product was exposed to more heat and consequently
may have more oxidation.
S
FTIR – This instrumental method is a great method to develop a fingerprint for the
product. The availability of analytical programs to look at numerical comparisons to a
standard pre-approved lot offers the chemist a unique method of verifying batch-to-batch
variability.
S
Melt point – The melting temperature is an important property to check
S
% Glycerin – Even in instances where there is an acid value, it is critical to check
glycerin content to determine is the acid was added to a product made by reaction of a
triglyceride.
Carboxylates
from Fatty Alcohols
S Sodium mono-chloroacetate is reacted with fatty alcohol or
fatty alcohol ethoxylate in the presence of sodium methylate
catalyst. Chloride ion is produced, which forms sodium
chloride. Sodium chloride, a crystalline solid, is filtered off.
Carboxylates
Fatty Alcohol
Carboxylates
Fatty Alcohol
Category
Specification
INCI Name
Trideceth-7 Carboxylic acid
Appearance
Clear Amber Liquid
Color, Gardner
3 Max
Acid Value
45.0 – 52.0
% Solids
90.0 – 92.0
pH (1 % DI water)
3.0 – 4.0
Solubility (DI water)
Cloudy, translucent
NaCl
1.0 % Max
Betaines
S Amido betaines are prepared by the reaction of sodium
mono chloroacetate with an amido tertiary amine. Sodium
chloride is produced.
Problem
S Make 200 grams of a 35% active Lauramido propylbetaine
Problem
S Next Determine Formula of Reactants
S Lauramidopropyl dimethylamine
S Sodium monochloroacetate
C17H36ON2
C2H2O2Na Cl
Problem
S Determine MW Reactants
S Lauramidopropyl dimethylamine
C12*17 =204
H36 1*36 = 36
O 1*16= 16
N2 2*14=28
C17H36ON2
204+36+28 = 268
 Sodium monochloroacetate
C2*12 = 24
H2 *1= 2
24+2+32+23+36=117
C2H2O2Na Cl
O2*16=32
Na 23*1
Cl 36*1=36
Problem
S Determine Mole Ratio and %
Material
MW MR
Lauryl DMAPA
268 1.0
Sodium monochloroacetate 117 1.0
Total
MCH %
Grams
268
69.6 139.2
117
30.4
60.8
385 100.0
200.0
Problem
S Adjust for water (60% water)
Material
MW MR
Lauryl DMAPA
268 1.0
Sodium monochloroacetate 117 1.0
Total
Material
100 %
Lauryl DMAPA
69.6 * .40
Sodium monochloroacetate 30.4 * .40
Water
Total
MCH %
Grams
268
69.6 139.2
117
30.4
60.8
385 100.0
200.0
40%
27.85
12.15
60.00
Problem
S Adjust for water (60% water)
Material
MW MR
Lauryl DMAPAS
268 1.0
Sodium monochloroacetate 117 1.0
Total
Material
100 %
Lauryl DMAPA
69.6 * .40
Sodium monochloroacetate 30.4 * .40
Water
Total
MCH %
Grams
268
69.6 139.2
117
30.4
60.8
385 100.0
200.0
40%
27.85
12.15
60.00
% NaCl is 4.2% for 40% Active
Amino Propionates
S These products are a type of amphoteric surfactant that are
capable of existing in a cationic, anionic and zwitterionic form
depending upon pH.
S This separates them from betaines, which are amphoteric
surfactants that cannot exist in the anionic form.
S The products are made by the reaction of a primary amine with
two moles of acrylic acid in aqueous solution.
S Additionally, unlike betaines these products do not have salt
produced during the reaction and consequently are salt free.
Amino Propionates
Amino Propionates
Amino Propionates
Amino Propionates
Quats
Quats, or more formally, quaternary compounds are tetra-substituted
ammonium compounds. The generic formula is as follows;
R2
|
1
R -N+-R3
|
R2
M-
R1 is generally alkyl or alkylamido.
R2 most often is methyl, or hydroxy ethyl.
R3 is commonly methyl, ethyl, or benzyl.
The exact nature of the “R” groups dictates performance.
The M is a counter-ion needed for charge balance and is generally either
Cl, or CH3SO4.
Chloride Quat
S Quaternary compounds, or simply quats are cationic
compounds. This class of materials find a wide range of
applications, including conditioning of hair and skin and
germicidal compounds. The reaction is one in which a
tertiary amine is reacted with an organic chlorine containing
compound for example benzyl chloride to produce a quat
liberation inorganic chloride ion.
Chloride Quat
- Balanced Equation:
CH3
|
CH3(CH2)17-N +
|
CH3
CH3
|
+
-> CH3(CH2)17-N -CH2-C6H5 Cl
|
CH3
Cl-CH2-C6H5
Stearyl Dimethyl
Benzyl Chloride
Stearalkonium Chloride
Chloride Quat
S Germicidal Quats include:
S Benzalkonium chloride
S Cetyl trimethylammonium bromide
S Cetylpyridunium chloride
S Cetylpyridinium chloride
S Benzethonium chloride
Sarcosinates
S Sarcosinate surfactants are mild, biodegradable anionic
surfactants derived from fatty acyl chlorides and sarcosine.
S These compounds features lather building and resistance to sebum
delathering in cleaners, polymers, industrial chemicals, petroleum
and lubricant products.
S Sarcosinates are used as a foaming and cleansing agent for
shampoo, shaving foams and foam washes and is soap bars to take
advantage of the excellent lather and skin feel contribution.
Sarcosinates
Sarcosinates
Electrophilic
Substitution
S
Electrophilic Substitution
Electrophilic Substitution
Sulfonation
S SO3,prepared by the burning of sulfur, is reacted with fatty
alcohol giving the fatty sulfate sauer ester, which is
neutralized in a subsequent step water by hydroxide ion,
most commonly with sodium as the counter ion. Potassium
ammonium and even lithium salts have been prepared.
Electrophilic Substitution
Sulfonation
Special Requirements
S SO3 is a very reactive corrosive and noxious material.
Commonly SO3 is made by burning sulfur just prior to
sulfation.
S The use of SO3 in making products is not recommended
since very specialized reactors and handling equipment are
needed.
Electrophilic Substitution
Sulfonation (CSA)
S Chlorosulfonic acid, a liquid, is reacted with fatty alcohol
giving the fatty sulfate sauer ester, and unlike the SO3
version HCl.
S The HCl is removed via vacuum and reacted with water to
make aqueous HCl.
S To the extent the HCl is not removed the product has NaCl
after neutralization.
Electrophilic Substitution
Sulfonation (CSA)
- Balanced Equation:
Step 1 (sulfation)
CH3(CH2)11OH +
Lauryl Alcohol
HSO3Cl
à
CSA
CH3(CH2)11OSO3H + HCl
Lauryl sulfate
(free Acid form)
Hydrochloric
Acid
Step 2 (Neutralization)
CH3(CH2)11OSO3H + NaOH -------à
water
Lauryl Alcohol
Sodium
Free Acid
H ydroxide
ROSO-3 Na+
S odium Lauryl
S ulfate
+ H2O + NaCl
Water
Salt
Special Requirements
S Chlorosulfonic acid (CAS), while easier to handle than SO3
is likewise a very reactive corrosive and noxious material. If
it comes in contact with water it liberates HCl gas. It can
cause a fire in contact with celluosics. The use of CSA in
making products needs to be conducted under very specific
anhydrous conditions, and the resulting HCl gas needs to be
removed and disposed of properly. Consequently, very
specialized reactors and handling equipment are needed.
Cyclo-addition reactions
Round and round we go…
S
Cyclo-addition reactions
S There are a set of rules called the Woodward Hoffmann
Rules
S Essentially they determined that the pathway of concerted
pericyclic reactions were determined by the symmetry
properties of the orbitals that were directly involved.
S Reactions involving
S 4n + 2 electrons will be thermogenically allowed (heat)
S 4n electrons will be photogenically allowed
Diels-Alder Reaction
S This reaction is a reaction involving a Diene (4 electrons)
and a Dienophile (2 electrons)
S All you need is heat!
Diels-Alder Reaction
Diels-Alder Reaction
S What are the starting materials?
1.
2.
2 + 2 clycoaddition
S These types of reactions are photochemically allowed.
S All you need is hν light.
R1
R1
+
R2
R2
Dimer Acid
S Dimer acid describes a reaction mixture that is composed of
a series of substituted cyclohexene-dicarboxylic acids
formed by the Diels-Alder reaction. The reaction requires a
dienophile and a diene. The mixture of products is a
consequence of the various isomers that can occur with the
reaction. Commercially, the product is made using tall oil
fatty acid, derived from pine trees. This material has roughly
the proper stiochometric ratio of diene ( linoleyl) to
dienophile (oleyl).
Dimer Acid
Dimer Acid
Click Chemistry
New and improved…
S
Click Chemistry
S “Click Chemistry” is a concept pioneered by Barry
Sharpless, seeks to define the “ideal” chemical reaction.
S Give High Chemical Yields
S Produce few or no toxic byproducts
S Be stereospecific
S Produce products that are physiologically stable
S Have simple reaction conditions.
http://vimeo.com/46865607
Click Chemistry
S Click chemistry is a reaction involving an azide N3 and a
Alkyene.
Cu(I)
Click Chemistry
O
O
Cl
O
NaN3
N3
OH
N3
O
N
N
N
OH
Ring Opening
Alkoxylation
S Lower molecular weight epoxides (oxiranes) such as ethylene oxide,
propylene oxide and butylene oxide are capable of reacting with
hydroxyl generally under base catalysis, causing a ring opening and
an addition of oxyalkylene group
S Reaction with ethylene oxide adds polyoxyethylene groups, with
propylene oxide adds polyoxypropylene groups and with butylene
oxide adds polyoxybutylene groups.
S All these groups and mixtures thereof bring new solubility properties
to the compounds to which they are added. The resulting compound
likewise contains a hydroxyl group so a variety number of moles of
oxide can be added.
S Lower molecular weight oxiranes are very reactive and the safe and
efficient utilization of these materials require rigorous chemical
engineering, advanced materials handling technology and innovative
catalyst technology
Ring Opening
S Ring opening reaction is a reaction where a ring is open or
broken.
S Ethoxylation
S Propoxylation
S Carboxylation (anhydrides)
Alkoxylation
Ethoxylation
is the reaction of an alcohol with ethylene oxide, producing a
R-O-(CH2CH2O)xH
Propoxylation is the reaction of an alcohol with propylene oxide, producing a
R-O-(CH2CHO)xH
|
CH3
Ring Closing Reactions
S
How about a molecule that has
an Alcohol and acid?
S If a molecule has two reactive groups on it, it can form
cyclics.
S The reactive groups have to be the correct number of
carbons apart.
S 6>5>7
O
4
2
1
O
HO
HO
O
6
3
5
Lactone
+
HOH
Ring Closing Reactions
Ring Closing Reactions
Ring Closing Reactions
Lactams
S Description: The preparation of lactams from ether amine
and butryolactone actually occurs in two distinct steps. The
first is ring opening of the butryolactone by nucleophilic
attack of the carbonyl by the ether amine. The second is ring
closure, making water and a cyclic amid, commonly called a
lactam.
O
HO
H2N
O
S Are molecules that are cyclic amides
NH +
Lactam
HOH
Lactams
Ring Closing Reactions
S Imidazoline
S Description: Amino ethyl ethanol amine (AEEA) is reacted
with a fatty acid to produce an amide with a free amino
group. Subsequently, the ring is closed at high temperature
producing a second mole of water.
Ring Closing Reactions
Note: The first reaction (amid
formation) occurs at about 180oC.
The second occurs as the
temperature is increased to 200oC.
Efficient removal of water is
necessary to obtain a high purity
(90%+) product.
Sorbitan Esters
S Sorbitol, a hexose sugar, is cyclized by dehydration to form the 1:4
sorbitan structure.
S Esterification occurs mainly at the side-chain OH group, but some
occurs at the ring OH's.
S Sorbitan esters are products made the reaction of sorbitol and
fatty acids. Sorbitol is generally provided as a 70% solution in
water. The reaction actually includes three distinct steps. They are
(1) removal of water, (2) cyclization of linear sorbitol to make
sorbitan and (3) esterification of the sorbitan with a fatty acid.
Many modern techniques make the product in one batch running
the first step in the presence of all the raw materials, then cyclizing
and esterifying in tandem
Sorbitan Esters
Sorbitan Esters
Sorbitan Esters
Alkylpolyglucoside
S Description: Alkylpolyglucoside or APGs have been known
for many years. If fact in 1893, the German chemist Emil
Fischer combined fatty alcohols and glucose obtained from
coconut or palm kernel oil and corn for the first time in
1893. However, it took almost one hundred years, to
commercialize these products
Alkylpolyglucoside
- Balanced Equation:
O=C-H
|
H-C-OH
|
HO-C-H
|
H-C-OH
|
HOCH2
à
CH 3(CH2)11OH
O
/
RO-(H)C
|
HO-(H)C
\
\
C(H)-CH2-OH
|
C(H)-OH
+ H 2O
/
C
/ \
OH H
There is actually a complex mixture of products formed during the reaction. The one
above is the most simple
Alkylpolyglucoside
Why is ring closing a problem?
S If a molecule has two reactive groups on it, it can form
1
O
6
O
O
+
4
5
O
O
3
O
-
2
Carbon-Carbon Bond
Formation
How do we form carbon-carbon bonds…
S
Tutomerization
S Tautomers are isomers that interconvert by a chemical
reaction called Tautomerization.
Why is this reaction important?
S Everything we have done so far has dealt with the formation
of Carbon-R bonds, but what about Carbon-Carbon bonds?
S The most common why to do this involves an Enol
S What is a Enol?
-
O
O
R
R
H
Base
Enol
Enol Reactions
Enol reacted with an acid
O
-
O
O
+
OH
R
O
Enol with an Ester
-
O
O
OR1
R
+
R
+ H2O
O
1.
O
1.
1
+
HOR
R
Enol Reactions
Enol with Aldehyde
O
-
O
+
H
O
1.
R
R
+ H2O
Aldol Condensation
Guerbet Reaction
( an Aldol Condensation)
S Under the proper conditions, linear alcohols can be oxidized
to aldehydes, undergo an aldol condensation and produce
Guerbet alcohols. The class of materials has been known for
many years. Guerbet alcohols are regio-specific beta
branched oils that are liquid to very low temperatures. They
are super-fatting agents and are used to make a variety of
esters.
Guerbet Reaction
( an Aldol Condensation)
Guerbet Reaction
( an Aldol Condensation)
Amine Oxidation
Amine Oxides
S An amine oxide, also known as amine-N-oxide and N-oxide, is a
chemical compound that contains the functional group R3N+-O−
(sometimes written as R3N=O or R3N→O).
S In the conventional formula assigned to the amine oxides
R3N→O, the link uniting the nitrogen and oxygen atoms is a
semipolar bond.
S The term amine oxide applies only to oxides of tertiary amines
including nitrogen-containing aromatic compounds like pyridine.
A tertiary amine is reacted with 35% peroxide in aqueous
solution. The product is an amine oxide.
Amine Oxides
Amine Oxides
-Typical Specifications
Appearance
Provides a general indication of heat history and product quality
Amine Oxide Active Measures purity
pH (10% Sol.) Measures pH an important indication of product ionic nature.
Free Peroxide Measures unreacted H2O2 and consequently % reaction.
Free Amine
Measures unreacted amine and consequently % reaction.
Color (APHA) Provides a general indication of heat history and product quality.
Reduction
S Perhaps one of the most important and commonly overlooked
reaction class is a group of related reactions called reduction.
Within the class are several key reaction types,
1.
2.
3.
hydrogenation,
hydrogenolysis and
reduction.
S The commonality is the fact that hydrogen is reacted with various
organic materials in the presence of a catalyst and most often a
solvent.
S As will become clear the choice of organic material, solvent and
catalyst has a profound impact on the product obtained.
Group Specific
(Hydrogenolysis)
Hydrogenolysis
S Hydrogenolysis is a process in which hydrogen, in the
presence of a suitable metal catalyst reacts with an organic
compound breaking it into two molecules that are in low
oxidation state ( for example a ethyl ester to two alcohols).
Group Specific Hydrogenolysis
S This reaction allows for the reduction of the methyl ester
while keeling the vinyl group in tact. The process relies
upon specific catalysts developed to have this specificity.
This reaction is used to make commercial oleyl alcohol and
related materials.
Group Specific Hydrogenolysis
Polymers
S
What are Polymers?
S Polymers are macromolecules
S
Poly = Many
S
-mer = Parts
S Typically Polymers can be:
S Natural
S Synthetic
Brief History
S “Polymer” was first used by Berzelius in 1833.
S In 1839, Charles Goodyear discovered vulcanization, by
combining natural rubber with sulfur and hearting it to 270
“Drop the idea of large molecules.
°C
S
S
Organic molecules with a
The first truly synthetic
polymerweight
used on ahigher
commercial
scale500
molecular
than
was phenol-formaldehyde resin by
“bakelite”.
doBaekeland,
not exist”
-Advice given to Hermann Staudinger
In 1920, Staudinger:
S Polymers are high molecular weight molecules. (Nobel Prize in
1953)
S The Prevailing Theory: Polymers were aggregates of small molecules.
Polymer chemistry
S Polymer chemistry is organic chemistry on a much larger
scale.
S It involves the reaction of molecules or monomers with at
least two reactive sites.
S Free radical chemistry involves double bonds.
S When the molecular weight of polymers is increased, the
mechanical and chemical properties of the polymers will
drastically change.
Nylon 6,6
S Wallace Carothers invented Nylon 6,6.
S 1940 Nylon hit the streets
Nylon Rope Trick
S The polymerization is so quick that when the two materials
come into contact, they instantly form a polymer.
New Terms
S Structural Unit or Monomer Unit: The monomer or the residue
from the monomer.
S Repeat unit: the unit enclosed in the brackets.
S Homo Polymer: Polymer formed by one monomer.
S Hetero polymers or copolymers: Contain more than one atom
type in the bracket unit.
S Degree of Polymerization (DP or Xn): The total number of
structural units in the polymer chain.
S Polydispersity (PDI): Polymer are polydisperse meaning they have
many different polymer chain lengths.
Polymer Nomenclature
S Based on the Monomer:
If “X” is a single word, the name of the polymer is is written
out directly
PolyX
If “X” consists of two or more words, parentheses should be
used.
Poly(vinyl chloride) (PVC) is made by the polymerization of vinyl
chloride
CH2=CHCl
Polymer Nomenclature
S Based on polymer Structure
S The most common method for condensation polymers since
the polymer contains different functional groups than the
monomer.
Common Functional Groups….
Polyesters
Polyamides
Polycarbonate
Polyurethane
Definitions
S Thermoplastic: Polymers that are not cross-linked can melt
and flow, can dissolve.
S Step growth polymers: They are called step growth because
the monomer adds on either chain end. Molecular weight
builds slowly, high molecular weight only at high
conversion.
S Chain Growth Polymers: New monomers add to the chain
end only. Every reaction adds to the molecular weight.
MW Difference Chain and Step
Growth
Chain growth
Molecular Weight
S Since this is polymer chemistry, we will consider a very
realistic, everyday example to explore Molecular weight……
10,000 lbs
1 lbs
Mn
Mn = 2,000
Molecular Weight
Polydispersity (PDI)
S So how can we tell which molecular weight do we use?
S Both Mn & Mw have value, but how do we apply them to a
polymer sample?
S In Polymer science it is common to use the ratio of the
weight average to the number average as a measure of the
breadth of the distribution rather than the moments and this
ratio is called the polydispersity.
Molecular Weight
S First we have to understand a basic principle in polymer
chemistry
S Hydrodynamic volume of a polymer in solution
GPC
S This technique is an INDIRECT method for determining
molecular weight
S It is based off of comparing the Hydrodynamic Volume of
your polymer in solution to the Hydrodynamic Volume of a
series of Polymers of known size and distribution
(Standard).
S The polymer is dispersed into a solvent and passed though a
column, based on the size of the polymer, the elusion time
will be different
GPC
Molecular Weight
GPC
S It is important to note that:
S If you take 3 polystyrene samples of the exact same MW, but have
different polymer structure (branched, linear, comb-like) they can
elute at DIFFERENT TIMES!!!
S Also, if you have have 2 polymers of the exact same MW, one
Polystyrene and the other one PMMA. They can elute at
DIFFERENT TIMES!!!!
S Luckily for us Benoit and co-workers came up with a Universal
Calibration Curve.
S Based on:
S The product of Intrinsic Viscosity & MW was directly proportional to
Hydrodynamic Volume.
GPC
Tm and Tg
S Polymeric materials are characterized by two major types of
transition temperatures- The crystalline melting temperature
(Tm) and the glass transition temperature (Tg)
S Tm : the melting temperature, just like a traditional small
molecule.
S Tg : The temperature at which the amorphous domain of a
polymer take on the characteristic properties of the glassy
state = brittle, stiffness and rigidity.
DSC
DSC
Free Radical Polymerization
S There are several steps involved in the polymerization
process.
S Initiation
S Propagation
S Termination
Polymerization
S Most commonly BPO is used to polymerize Styrene
.
x
2
Polymerization
.
.
S n
+
Chain Growth Polymerization
S This type of polymerization happens by a series of steps,
most commonly a series of reactions.
S Common Ester is formed when an acid is reacted with an
alcohol, but what about a diacid and diol?
O
O
O
R1
HO
O
HO
HOCH2CH2CH2OH
+
H
H
O
R1
OCH2CH2CH2O
n
Common Step Growth
S Polyurethane
S Nylon
Controlled Living
Polymerization
S
Controlled “Living”
polymerization
S There are a few techniques that can produce polymers with
a PDI close to 1.
S Atom Transfer Radical Polymerization (ATRP)
S Reversible Addition-Fragmentation Chain Transfer (RAFT)
S There are some problems with the Controlled living, but
these two are promising for the cosmetic world.
ATRP
O
+ CuCl + Ligand
R1
R1
O
O
O
R1
+ CuCl2 + Ligand
.
.
+
.
R1
O
O
O
Cl
O
.
R1
O
O
)nCl
(
O
O
O
O
O
O
+
O
O
O
R1
O
.
O
O
+ CuCl2 + Ligand
R1
O
O
O
.
R1
O
Cl
+ CuCl + Ligand
O
O
O
O
Synthesis
GPC
Mn = 43,000 g/mol
PDI = 1.13
–
–
RAFT
H3C
CH3
.
C
N
H3C
.
I
I
CH3
S
C
N
+
Z = Ph
Z
S
R = C(CH3)2CN
S
S
.
R
Z
.
R
R
S
Z
S
RAFT
Macromolecules 2008, 41, 8429-8435
Organic Chemistry for
Cosmetic Chemist
Questions?
S
Organic Chemistry for
Cosmetic Chemist
S