Cimtec itri pvc eva tin-ldh nanocomposites interflam 2010

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Cimtec itri pvc eva tin-ldh nanocomposites interflam 2010

  1. 1. New PVC and EVA nanocomposites based on LDH’s and novel hybrid tin-LDH nanoparticles
  2. 2. 2 Why nanotechnology?Why nanotechnology? Different nanoparticles, different effectsDifferent nanoparticles, different effects Spherical particles Lamellar structure Tubular structure Silica, alumina, ceria, zinc oxide, … Montmorillonite Hydrotalcite Flame retardant Stabilizer Carbon nanotubes and nanofibers Scratch and abrasion resistance, UV filtering Electrical conductivity
  3. 3. 3 Nanoparticles and flameNanoparticles and flame retardancyretardancy MONTMORILLONITE HYDROTALCITE Cationic clay: negative charges of layers balanced by the presence of cations in the interlamellar gallery Anionic clay: positive charges of layers balanced by the presence of anions in the interlamellar gallery Mg(OH)6 4- Al(OH)6 3- H2O CO3 2-
  4. 4. 4 Nanoparticles and flameNanoparticles and flame retardancyretardancy Why nanofiller as flame retardant?Why nanofiller as flame retardant? • Higher specific surface area • Lower quantity needed with respect to traditional particles • Possibility of surface modification to promote the affinity with different polymers • Improvement of mechanical properties • Barrier effect of lamellas on oxygen diffusion
  5. 5. 5 CimtecLabCimtecLab  R&D Laboratory in AREA Science Park (Trieste)  R&D Laboratory in Soleto (Lecce) Two R&D laboratoriesTwo R&D laboratories
  6. 6. 6 CimtecLabCimtecLab Main R&D activitiesMain R&D activities  design and development of high-performance thermosetting and thermoplastic nanocomposites (low gases permeability, resistance to cryogenic conditions, halogen-free fire retardant materials, etc.)  development of novel polymeric materials from by-products of natural origin  study of surface treatments combining sol-gel formulations and plasma treatments  synthesis of nanoparticles with various techniques (sol-gel, ionic exchange, etc.)
  7. 7. 7 Synthesis and modification of LDHSynthesis and modification of LDH  Know-how and expertize of CimtecLab  Co-precipitation route preferred  Other routes under development Synthesis routesSynthesis routes Organic modification of LDHOrganic modification of LDH  Needed to increase the compatibility between the nanofiller and the polymer  Ion exchange reactions used 0 200 400 600 800 1000 1200 1400 0 5 10 15 20 25 30 2Theta Intensity d=7.54A d=3.82A 0 500 1000 1500 2000 2500 3000 3500 0 5 10 15 20 25 30 2Theta Intensity d=26,32A d=13,98A d=9,58A
  8. 8. 8 LDH nanocompositesLDH nanocomposites OM-LDH nanocomposites: high degree of intercalation/exfoliation Morphological analysis: TEMMorphological analysis: TEM 500 nm 100 nm44.000x 110.000x Intercalated tactoids + exfoliated lamellas Experimental resultsExperimental results  Intercalated/exfoliated LDH nanocomposites obtained thanks to suitable organic modification  Synergy between LDH and phosphorous-based additives
  9. 9. 9 ITRIITRI • R & D organisation based in St Albans, UK • Primarily funded by world’s major tin producers • Over 75 year history in tin research – tin metal, its alloys & chemicals • Specific expertise in inorganic flame retardants & smoke suppressants • ITRI’s Fireproof Laboratory offers wide range of fire tests, polymer processing & chemical / analytical services to industry
  10. 10. 10 Current research interestsCurrent research interests  Coated fillers & nano-particulate additives  Low smoke - zero halogen formulations  Nanoclays (cationic & anionic) & nano-composites  Natural fibres – flame retardancy, thermal stability, bonding in composites…  Fireproof - small scale polymer compounding & testing
  11. 11. 11 Zinc stannateZinc stannate Zinc Hydroxystannate (ZHS)Zinc Hydroxystannate (ZHS) ZnSn(OH)6 ca. 40% tin by weight Suitable for use in polymer processing at temperatures below 200°C Zinc Stannate (ZS)Zinc Stannate (ZS) ZnSnO3 ca. 50% tin by weight Suitable for use in all polymer systems
  12. 12. 12 Technical benefitsTechnical benefits  Very low toxicity – safe & easy to handle  Combined flame retardancy & smoke suppression  Action in condensed & vapour phases  Lower heat release rates  Non - pigmenting & low opacity  Synergy with other flame retardants (halogenated FR’s, inorganic fillers, nanoclays)
  13. 13. 13 Coated fillersCoated fillers  ITRI developed processes for coating ZHS and ZS on to low cost inorganic fillers US patent 6,150,447 European Patent 833,862  Use of coated fillers allows significant reduction in overall filler loading  Better polymer processing  Improved physical & mechanical properties
  14. 14. 14 Coated fillers - typesCoated fillers - types Coatings Fillers Zinc hydroxystannate (ZHS) Alumina trihydrate (ATH) Zinc stannate (ZS) Magnesium hydroxide (MH) Tin(IV) oxide Calcium carbonate Tin(IV) phosphate ‘Ultracarb’ Tin(IV) borate Titanium dioxide Typical coating levels from 2.5 – 10% w/w on filler Silica Anhydrous alumina Zinc borate Sodium bentonite Nanoclays
  15. 15. 15 The HYBRID projectThe HYBRID project Why this project?Why this project? Main object: to deliver a series of novel fire – retardant additives, each individual product tailored to meet specific end application requirements Three different ways to obtain the nanoparticles:  Intercalation of tin organic species between LDH lamellas  Deposition of tin species on to the LDH particles  Partial replacement of Mg/Al ions with Sn ions in the LDH lattice
  16. 16. 16 The HYBRID projectThe HYBRID project Why this project?Why this project? Characteristics of novel additives:  inorganic tin – layered double hydroxide synergistic systems  flame retardant and smoke suppressant  non toxic
  17. 17. 17 The HYBRID projectThe HYBRID project Why this project?Why this project? Second object: to enhance the fire – retardant functionality of cardanol, a natural derived by-product of the food industry, and create a new plasticizer to replace phthalate plasticizers Cardanol is an oily alkyl –phenolic product (having up to 3 unsaturations in the flanking alkyl chain) obtained by vacuum distillation of “cashew nut shell liquid” (CNSL) OH R Cardanol
  18. 18. 18 The HYBRID projectThe HYBRID project Why this project?Why this project?  Increase of environmental concerns  Increase of regulatory activity in relation to certain types of FR  No toxicity (for example, replacement of heavy metal oxides)  Need of halogen – free additives  Need of replacing phthalate plasticizers
  19. 19. 19 The HYBRID projectThe HYBRID project Project tasksProject tasks 1. Synthesis and characterization of LDH including modification with ionic tin species 2. Synthesis of synergistic tin – LDH FR additive powders including use of nano- coating techniques 3. Development of novel plasticizer and additive dispersion 4. Compounding and characterization of polymeric nano-composites 5. Laboratory – scale fire test 6. Production and evaluation by industry tests of prototype cables
  20. 20. 20 Experimental ResultsExperimental Results
  21. 21. 21 LDH synthesisLDH synthesis 2 different methods NaOH/Na2CO3 METHOD: • Precipitation of metal salts in a medium of NaOH/Na2CO3 UREA METHOD: • Urea is the precipitation medium for metal salts • During urea hydrolysis formation of carbonate and hydroxide ions Incorporation of Sn4++ ions
  22. 22. 22 LDH synthesisLDH synthesis TestTest  ICP analysis  Scanning electron microscopy  XRD analysis  BET surface area  Malvern particle sizing (wet and dry)
  23. 23. 23 LDH synthesis – Urea methodLDH synthesis – Urea method Experiment number Mg/Al/Sn atomic ratio determined from Icp analysis Mg/(Al+Sn) atomic ratio Particle size- dry (d0.5, µm) Particle size- wet (d0.5, µm) BET surface area (m2 /g) UREA1 1.1:1:0 1.10 5.0 6.39 31.3 UREA2 1:1:0.12 1.12 3.7 17.7 84.1 UREA3 0.24:1.0:0.46 0.16 86.6 21.64 230.8 UREA4 1.0:1.0:1.0 0.5 144.2 16.5 208.9 UREA5 1.0:1.0:0 1 271.0 - 69.0 UREA6 0.34:1.0:1.0 0.17 200.0 - 221.0 Tin precipitate 0:0:1 0 - - 205.3
  24. 24. 24 LDH synthesis – Urea methodLDH synthesis – Urea method XRD analysisXRD analysis
  25. 25. 25 LDH synthesis – Urea methodLDH synthesis – Urea method Hexagonal platelet structure of the hydrotalcite, which corresponds to the particle size results obtained on the Malvern of 5 microns SEM: UREA1SEM: UREA1
  26. 26. 26 LDH synthesis – Urea methodLDH synthesis – Urea method XRD analysisXRD analysis
  27. 27. 27 LDH synthesis – Urea methodLDH synthesis – Urea method Hexagonal platelet can be seen, corresponding to the measured particle size of 3.7 microns. However there is some agglomeration and particles do not seem as ordered as in UREA1 SEM: UREA2SEM: UREA2
  28. 28. 28 LDH synthesis – Urea methodLDH synthesis – Urea method XRD analysisXRD analysis
  29. 29. 29 LDH synthesis – Urea methodLDH synthesis – Urea method No platelet could be seen on the SEM, probably because the MG:Al stoichiometric ratio for this experiment is 0.24:1. There are no characteristic hydrotalcite peaks shown on the XRD spectra SEM: UREA3SEM: UREA3
  30. 30. 30 LDH synthesis – Urea methodLDH synthesis – Urea method XRD analysisXRD analysis
  31. 31. 31 LDH synthesis – Urea methodLDH synthesis – Urea method No platelet can be seen on the SEM. Only agglomerated particles of tin oxide. The XRD spectrum indicates that LDH’s are present. SEM: UREA4SEM: UREA4
  32. 32. 32 LDH synthesis – Urea methodLDH synthesis – Urea method XRD analysisXRD analysis Recorded on the precipitate formed when the metal salts were pre-mixed prior to addition of the urea
  33. 33. 33 LDH synthesis – Urea methodLDH synthesis – Urea method ICP analysisICP analysis The Mg:Al atomic ratio is around 1:1 in the final product In the cases of UREA 3 and 6, the ratio Mg:Al is 0.24:1.0 and 0.34:1.0; LDH lattice was not formed. This result is supported by XRD spectra which show no characteristic peaks of LDH BET surface area determinationsBET surface area determinations BET surface area highest when Mg/Al+Sn is low BET surface area highest when tin content is high
  34. 34. 34 LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod Experiment number Mg/Al/Sn atomic ratio determined from Icp analysis Mg/(Al+Sn) atomic ratio Particle size- dry (d0.5, µm) Particle size- wet (d0.5, µm) BET surface area (m2 /g) NA1 3.0:0.98:0.0 3.06 88.0 20.86 85.1 NA2 3.0:0.85:0.13 3.02 113.1 27.86 90.9 NA3 3.0:0.79:0.19 3.06 42.3 29.8 15.1 NA4 3.0:0.68:0.39 2.80 64.0 32.7 8.05 NA5 3.0:0.48:0.49 3.09 244.0 19.8 6.1 NA6 3.0:0.0:0.98 3.07 190.7 46.4 29.4
  35. 35. 35 XRD analysisXRD analysis LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod
  36. 36. 36 SEM: NA1SEM: NA1 LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod No platelet could be seen on the SEM. XRD shows the characteristic spectrum of LDH Platelet are too small to be seen under the SEM
  37. 37. 37 XRD analysisXRD analysis LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod
  38. 38. 38 SEM: NA2SEM: NA2 LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod No platelet can be seen on the SEM, only agglomerated particles XRD suggest that platelets are present
  39. 39. 39 XRD analysisXRD analysis LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod
  40. 40. 40 SEM: NA3SEM: NA3 LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod Agglomerated particles are visible Hydrotalcite and magnesium hydroxy stannate phases should be both present according to the XRD spectrum
  41. 41. 41 XRD analysisXRD analysis LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod
  42. 42. 42 SEM: NA4SEM: NA4 LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod Agglomerated particles are visible Hydrotalcite and magnesium hydroxy stannate phases should be both present according to the XRD spectrum
  43. 43. 43 XRD analysisXRD analysis LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod
  44. 44. 44 SEM: NA5SEM: NA5 LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod Agglomerated particles are visible Hydrotalcite and magnesium hydroxy stannate phases should be both present according to the XRD spectrum The level of LDH is very low
  45. 45. 45 XRD analysisXRD analysis LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod
  46. 46. 46 SEM: NA6SEM: NA6 LDH synthesis – NaOH/NaLDH synthesis – NaOH/Na22COCO33 methodmethod Agglomerated of magnesium hydroxy stannate
  47. 47. 47 ConclusionsConclusions • Urea method is an effective method to produce well ordered hexagonal hydrotalcite, but is not compatible with incorporation of Sn into the system • The ratio Mg/Al is not controllable using urea • With NaOH/Na2CO3 method the concentrations are much greater than those used in the Urea method, the XRD spectra are similar but the size is smaller than 5 microns • The “optimum” experiment which forms the highest yield of LDH with the highest amountof Sn is NA3. It is interesting to evaluate if Sn can be maximised The next phase of the project is to determine the fire retardant benefits of LDH with incorporated tin compared with those of a standard LDH
  48. 48. Thank you for your attentionThank you for your attention

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