FROM NANOPARTICLES TO ADVANCED MACRO APPLICATIONS

1. FROM NANOPARTICLES TO ADVANCED MACRO APPLICATIONS The 4th International Conference on NANOTECHNOLOGY FOR THE PLASTICS & RUBBER INDUSTRIES February 2, 2009 Shenkar College of Engineering & Design

2. NANO - POSS ENHANCED POLYMER ADHESIVES Dr. Ana Dotan Prof. Hanna Dodiuk Plastics Engineering Shenkar

3. Nano enhancement – How? • The small nano particles presents an enormous surface area • The potential of using nano fillers for enhancement of adhesive properties is promising provided • agglomeration is avoided • good interfacial bonding is obtained

4. Nano structuring methodology Functionalization of the nano particles surface leads to chemical reactions in reactive polymer systems (thermosetting) The large surface area of nano particles (hundreds of m2/gr.) leads to interaction with polymer molecules in the nano level Nano Structured Adhesives & Composites

5. Objectives Study the effects of • POSS functionalities • nano structure of adhesives • macro properties of adhesives

6. Polyhedral oligomericsilsesquioxanes • The name silsesquioxane comes from the “sesqui”, which means one and a half • General formula: (RSiO1.5)n - 1.5 oxygens for each silicon • The suffix “ane” represents a hydrocarbon group, R. • The term polyhedral indicates the cage or polyhedron nature of the (RSiO1.5)n core. http://matdl.org/matdlwiki/index.php?title=softmatter:POSS

7. POSS POSS chemical composition is a hybrid, intermediate (RSiO1.5) between that of silica (SiO2) and silicone (R2SiO). POSS molecules can be thought of as the smallest particles of silica possible.

8. Structure of silsesquioxane

9. Dimensions and functionality

10. non reactive end groups • partial • functionalization • many reactive • end groups :

11. POSS Functionalities 3-(Aminoethyl)amino)propyl-Heptaisobutylsubstituted 2-(3,4-Epoxycyclohexyl)ethyl)-Heptisobutyl substituted Octaphenyl substituted Glycidoxypropyldimethylsilyloxy- Heptacyclopentyl substituted isocyanatopropyldimethylsilyloxy – Heptacyclopentyl substituted

12. POSS nanocomposites • The incorporation of POSS cage structure into polymeric networks often results in dramatic improvements in polymer properties • increase in use temperature • oxidation resistance • surface hardening • improved mechanical properties • reductions in flammability and heat evolution

13. Dispersionnanostructure of POSS in polymermatrix POSS agregates Top row: Electronenergyfiltered (EF) compositionalimages of C and Si. Bottomrow: combinedSi+C elemental map, Si/C elemental map, and a conventional non-EF brightfieldimage. POSS molecules are Si richcomparedtothepolymermatrixwhichis C richcomparedto POSS molecules. http://www7430.nrlssc.navy.mil/facilities/emf/nanocomp.htm

14. Epoxy-POSS nanocomposites

15. Epoxy adhesives

16. Methodology • Nano structuring of epoxy adhesives by a variety of functionalized POSS particles • Effect on bulk & adhesion properties

17. Experimental • Analysis methods • Dynamic Mechanical Analysis (DMA) • Lap shear strength: ASTM D-1002. Aluminum adherends + unsealed chromic acid anodization • Peel strength: ASTM D-1876. Aluminum adherends+ unsealed chromic acid anodization

18. Results

19. Tg of POSS/Low temp. EPOXY Tg(°c) Tg increases in the range of 2-5 Wt.% of POSS

20. Tg of POSS/Med. temp. EPOXY Tg increases in the range of 0.5-1 Wt.% of POSS

21. Tg of POSS/High temp. EPOXY Tg increases in the range of 2-3 Wt.% of POSS

22. EFFECT OF POSS ON STORAGE MODULUS at 25 oC Low temp. Epoxy Highest effect at low concentration of reactive POSS

23. The Effect of POSS on Storage Modulus at 25oC Med. temp. Epoxy Highest effect at low concentration of POSS

24. The Effect of POSS on Storage Modulus at 25oC High temp. Epoxy Highest effect at low concentration of POSS

25. Low temp. EPOXY/POSS ADHESIVES Shear and Peel Strengths * Weight concentration at maximum Tg

26. High temp. epoxy/POSSPeel Strength Best results for amino, glycidoxy& epoxy POSS

27. High temp. epoxy/POSSShear Strength Best results for 3% Amino POSS No significant increase in SS

28. Polyurethane-POSS nanocomposites

29. POLYURETHANE ADHESIVES • Materials • Trifunctional polypropylene polyether polyol (Desmophen 1380 BT, Bayer, Germany) • Linear polypropylene ether polyol (Desmophen 1110 BD, Bayer, Germany) • A mixture of diphenylmethane-4,4’-diisocyanate (MDI) with isomers and higher functional homologues (Desmodur VK 10, Bayer, Germany)

30. EXPERIMENTAL • Analysis methods • Differential Scanning Calorimetry (DSC) • Dynamic Mechanical Analysis (DMA) • Lap shear strength: ASTM D-1002 • Peel strength: ASTM D-1876

31. Glass Transition Temperature of PUR - POSS

32. The effect of 1, 3 and 5 wt% POSS-octaphenyl on storage modulus

33. The effect of 1, 3 and 5 wt% POSS-glycidoxypropyl on storage modulus

34. Adhesive Properties: Shear Strength

35. Adhesive Properties: Peel Strength

36. CONCLUSIONS • The type of the functional groups (reactive/non reactive) of the POSS nano particles, is the dominant factor in the formation of the molecular network and resultant properties • Optimal concentration exists for each functional derivative of POSS for Tg increase of adhesives systems • Optimal concentration exists for each functional derivative of POSS for toughening of adhesives systems • Only small amounts (< 5%) are needed to cause significant improvements, due to the large surface area of nano particles • Excess amounts results in plasticization effect

37. Acknowledgements TehilaEfrat – Shenkar, UML Irena Belinsky - IPRC THANK YOU FOR THE ATTENTION