Transcript Serichim technical approach to new fatting agents

Serichim technical approach
to new fatting agents
Technical and Progress Meeting 22nd June 2012
Application characteristics
of fatting agents
Aims and objectives of fattening
Lubricate the surface of the fibers of collagen and interfibrillar
spaces, replacing the water molecules removed with the
processing and drying, so as to restore the skin to the state of
natural softness and elasticity.
The fattening is crucial to make the leather have the
characteristics required by the wanted product, in terms of tact,
flexibility ...
Structure of collagen
• From the chemical
point of view: a
sequence of various
aminoacids linked
together by peptidic
(amide) bonds.
• From the structural
point of view: fibrous
bundles with spatial
stability due to
hydrogen bonds
How fatting can be obtained
• By making a solid phase mixture between
the collagen fibres and the fatting agent:
physical reversible fattening;
• By reacting collagen moiety with a fatting
agent able to bond with collagen
aminoacids.
How collagen can be functionalised:
no handle groups
Abundance in
Progressive
Amino Acid Mammal Skin
abundance
(Residues/1000)
Formula
Chemical
reactivity
Gly
329
326
inert
Pro
126
452
inert
Ala
109
561
inert
Leu
24
585
inert
Val
22
607
inert
Phe
13
620
inert
Ile
11
631
inert
How collagen can be functionalised:
OH handle groups
Abundance in
Progressive
Amino Acid Mammal Skin
abundance
(Residues/1000)
Formula
Chemical
reactivity
Hyp
95
95
OH
Ser
36
131
OH
Thr
19
150
OH
Hyl
6
156
OH
NH2
Tyr
3
159
OH phenol
How collagen can be functionalised:
nitrogen handle groups
Abundance in
Progressive
Amino Acid Mammal Skin
abundance
(Residues/1000)
Formula
Chemical
reactivity
Lys
29
29
NH2
Hyl
6
35
OH
NH2
His
5
40
imidazole
How collagen can be functionalised:
carboxylic and thioether handle groups
Abundance in
Progressive
Amino Acid Mammal Skin
abundance
(Residues/1000)
Formula
Chemical
reactivity
Glu
74
74
COOH
Asp
47
121
COOH
Amino
Acid
Abundance in
Progressive
Mammal Skin
abundance
(Residues/1000)
Formula
Chemical
reactivity
tioether
Met
6
986
The starting point
• Chlorinated paraffin
• Fatting by physical
interactions with hide
• Sulphochlorinated
paraffins
• Tanning & Fatting by
chemical interactions
with collagen reactive
groups
Chemical interactions
O
R
S
O
Cl
+
H
Collagen
O
R
S
Collagen
+
HCl
O
The reacting functional group of sulphochlorinated paraffins is the
“titrable” chloride group: which is the role of chain chlorine atoms?
Leather compatibility
Physical properties, like viscosity and density
Oxidative and hydrolytic resistance
Leather compatibility
• Mixibility of groups
present in the
(chlorinated) skeleton
with collagen
characteristics
groups.
• Spatial
reconfigurability of
fatting agent
• It should depend on
the nature of groups:
hydrocarbon type or
chlorinated type
• It should also depend
on the “polymeric”
chain lenght
Mixibility index
• There is a property that can be assumed
as mixibility index?
• There are data?
• Until now we were not able to envisage a
suitable test.
Physical properties
• Viscosity and density were assumed as leading
properties.
• Those properties were measured for several
chloroparaffins with different chain length, at
different chlorination degrees and as a function
of temperature.
• A model was developed to calculate viscosity
and density for pure products and mixtures.
• The method was developed for chloroparaffins,
and can be applied to other chlorinated fatty
agents.
Property management
andam ento densità in base alle tem perature e ° di clorurazione
1.35
1.2
"@25°C"
1.15
"@40°C
1.1
"@50°C"
1.05
"@60°C"
1
0.95
0.9
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
° di clorurazione
andam ento viscosità in base alle tem perature e ° di
clorurazione
100000
"@25°C"
10000
"@40°C"
1000
viscosità, cp
densità, g/ml
1.3
1.25
"@50°C"
100
"@60°C"
10
1
0.2
0.25
0.3
0.35
0.4
° di clorurazione
0.45
0.5
0.55
Equations
Viscosity
B(l , c)
ln   A(l , c) 
T
l  lunghezza della catenaparaffinica
c  grado di clorurazione
Density
   (l, c)1   (l, c)T 
Mixture equations
ln  x1 ln 1  x 2 ln 2
1


w1

w2
1  2
Suggestions for future
developments
• There is a general rule for predicting the
viscosity and density values due to the
insertion of a chlorine group in a
methylenic chain, irrespective of the other
functional groups?
Chemical resistance:
some general considerations
• “iso” chains have to be avoided because
of tertiary carbon atom reactivity.
• Chlorinated chains are protected against
oxidation
• Unsaturated hydrocarbon chains should
be absent
Candidate sulphonated chloroparaffin substitutes
from renewable raw materials
•
•
•
•
Saturated fatty acid chlorides
Chlorinated fatty acid chlorides
Fatty methyl esters
Chlorinated fatty methyl esters
O
O
+
R
H
+
Collagen
Cl
R
O
R
HCl
Collagen
O
O
CH3
+
H
+
Collagen
R
H2O
Collagen
H3C
OH
Acid chlorides as substitute
• Reactivity very similar to sulphonated
chloroparaffins.
• Amide bonds and ester bonds are mainly
formed
Acid chloride preparation
• Starting material: fatty acids like palmitic or
stearic acids;
• Chlorinating agents:
– Thionyl chloride
– Phosphorus trichloride
– Phosphorus pentachloride
– Oxalyl chloride
– Phosgene
• Catalyst: dimethylformamide hydrochloride
Main concerns in fatty acid chloride
preparation
• An excess of the
chlorinating agent is
required;
• Big quantities of
wastes are produced;
• Separation of acid
chloride from the
reagents/reaction coproducts is
troublesome
O
+
R
OH
O
Cl
S
Cl
O
Cl P
O
+
OH
Cl
S
O
P
Cl P
OH
Cl
O
Cl
Cl
O
Cl
+
R
Cl
OH
R
O
Cl
+
+
HCl
Cl
O
R
+
R
Cl
Cl
Cl
+
R
Cl
HCl
+
Cl P
Cl
O
Acid chloride plant
(to be assembled)
Thyonyl
chloride
Fatty acid
melter
SO2/HCl
to scrubbing
Chlorination
reactor
Preliminary tests
• Starting material should be acid chlorides
from lab chemical suppliers
• Lab preparations should be limited to
fotochemical chlorination of acid chlorides
Fatty acid chlorides
Name
Formula
Caproic chloride
CH3(CH2)4COCl
Capric chloride
CH3(CH2)6COCl
Pelargonic chloride
CH3(CH2)7COCl
Caprylic chloride
CH3(CH2)8COCl
Lauric chloride
CH3(CH2)10COCl
Myristic chloride
CH3(CH2)12COCl
Palmitic chloride
CH3(CH2)14COCl
Isopalmitic chloride
C15H31COCl
Stearic chloride
CH3(CH2)16COCl
Isostearic chloride
C17H35COCl
Oleic chloride
CH3(CH2)7CH=CH(CH2)7COCl
RN
142-61-0
205-549-1
111-64-8
203-891-6
764-85-2
213-131-2
112-13-0
203-938-0
112-16-3
203-941-7
112-64-1
203-994-6
Appearence
Pale yellow liquid
Pale yellow liquid
Pale yellow liquid
Pale yellow liquid
Pale yellow liquid
Pale yellow liquid
112-67-4
Pale yellow liquid
203-996-7
(solid in winter)
Pale yellow liquid
74918-57-3
112-76-5
Pale yellow liquid
204-004-5
(solid in winter)
Pale yellow liquid
112-77-6
204-005-0
Pale yellow liquid
Photochlorination plant
(operating)
Planned experimental activities
• Preparation of kg samples of chlorinated
methyl esters as request
• Preparation of 50 grams samples of
several chlorinated fatty chlorides for
characterisation
• Preparation of about two kg samples of
selected chlorinated acid chlorides.
Planned computational activities
• Development of a group based correlation
for densities and viscosities of chlorinated
and not chlorinated moieties.