1. Serichim technical approach to new fatting agents Technical and Progress Meeting 22 nd June 2012

2. 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...

3. 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

4. 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.

5. How collagen can be functionalised: no handle groups

6. How collagen can be functionalised: OH handle groups

7. How collagen can be functionalised: nitrogen handle groups

8. How collagen can be functionalised: carboxylic and thioether handle groups

9. The starting point Chlorinated paraffin Sulphochlorinated paraffins Fatting by physical interactions with hide Tanning & Fatting by chemical interactions with collagen reactive groups

10. Chemical interactions 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

11. 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

12. 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.

13. 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.

14. Property management

15. Equations Viscosity Density

16. Mixture equations

17. 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?

18. 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

19. Candidate sulphonated chloroparaffin substitutes from renewable raw materials Saturated fatty acid chlorides Chlorinated fatty acid chlorides Fatty methyl esters Chlorinated fatty methyl esters

20. Acid chlorides as substitute Reactivity very similar to sulphonated chloroparaffins. Amide bonds and ester bonds are mainly formed

21. 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

22. 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

23. Acid chloride plant (to be assembled)

24. Preliminary tests Starting material should be acid chlorides from lab chemical suppliers Lab preparations should be limited to fotochemical chlorination of acid chlorides

25. Fatty acid chlorides

26. Photochlorination plant (operating)

27. 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.

28. Planned computational activities Development of a group based correlation for densities and viscosities of chlorinated and not chlorinated moieties.