Serichim technical approach to new fatting agents Technical and Progress Meeting 22 nd June 2012.
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Transcript of Serichim technical approach to new fatting agents Technical and Progress Meeting 22 nd June 2012.
Serichim technical approach to new fatting agents
Technical and Progress Meeting 22nd June 2012
Application characteristicsof 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
Amino Acid Abundance in Mammal Skin
(Residues/1000)
Progressive abundance
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
Amino Acid Abundance in Mammal Skin
(Residues/1000)
Progressive abundance
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
Amino Acid Abundance in Mammal Skin
(Residues/1000)
Progressive abundance
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
Amino Acid Abundance in Mammal Skin
(Residues/1000)
Progressive abundance
Formula Chemical reactivity
Glu 74 74
COOH
Asp 47 121
COOH
Amino Acid
Abundance in Mammal Skin
(Residues/1000)
Progressive abundance
Formula Chemical reactivity
Met 6 986
tioether
The starting point
• Chlorinated paraffin
• Sulphochlorinated paraffins
• Fatting by physical interactions with hide
• Tanning & Fatting by chemical interactions with collagen reactive groups
Chemical interactions
R S
O
O
Cl + CollagenH R S
O
O
Collagen + ClH
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 managementandamento densità in base alle temperature e ° di clorurazione
0.9
0.95
1
1.05
1.1
1.15
1.2
1.25
1.3
1.35
0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55
° di clorurazione
de
ns
ità
, g
/ml
"@25°C"
"@40°C
"@50°C"
"@60°C"
andamento viscosità in base alle temperature e ° di clorurazione
1
10
100
1000
10000
100000
0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55
° di clorurazione
visc
osi
tà, c
p
"@25°C"
"@40°C"
"@50°C"
"@60°C"
Equations
neclorurazio di gradoc
aparaffinic catena della lunghezza
),(),(ln
lT
clBclA
Tclcl ),(1),(
Viscosity
Density
Mixture equations
2
2
1
1
2211
1
lnlnln
ww
xx
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
R
O
Cl+ CollagenH
R
O
Collagen+ ClH
R
O
OCH3
+ CollagenH
R
O
Collagen+ CH3 OH
OH2
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 co-products is troublesome
R
O
OH
+ S O
Cl
Cl
R
O
Cl
+ ClH + S OO
R
O
OH
+ P
Cl
Cl
Cl R
O
Cl
+ P OH
Cl
Cl
R
O
OH
+ P
Cl
Cl
Cl Cl
Cl
R
O
Cl
+ ClH + P O
Cl
Cl
Cl
Acid chloride plant(to be assembled)
Fatty acidmelter
Chlorinationreactor
Thyonylchloride
SO2/HClto scrubbing
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 chloridesName Formula RN Appearence
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
112-67-4 Pale yellow liquid
203-996-7 (solid in winter)
112-76-5 Pale yellow liquid
204-004-5 (solid in winter)
112-77-6
204-005-0Oleic chloride CH3(CH2)7CH=CH(CH2)7COCl Pale yellow liquid
Isostearic chloride C17H35COCl-
Pale yellow liquid
74918-57-3Pale yellow liquid
Stearic chloride CH3(CH2)16COCl
Palmitic chloride CH3(CH2)14COCl
Isopalmitic chloride C15H31COCl
Lauric chloride CH3(CH2)10COCl Pale yellow liquid
Myristic chloride CH3(CH2)12COCl Pale yellow liquid
Pelargonic chloride CH3(CH2)7COCl Pale yellow liquid
Caprylic chloride CH3(CH2)8COCl Pale yellow liquid
Caproic chloride CH3(CH2)4COCl Pale yellow liquid
Capric chloride CH3(CH2)6COCl 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.