THERMOMECHANICAL BEHAVIOUR OF INTUMESCENT FIRE RETARDANT COATINGS

Transcription

1 THERMOMECHANICAL BEHAVIOUR OF INTUMESCENT FIRE RETARDANT COATINGS Andreea Daniliuc H. Jeske, D. Kruse, B. Deppe, C. Weichert, R. Marutzky ECC Fire retardant coatings Berlin

2 The FraunhoferGesellschaft in Germany Itzehoe Lübeck Rostock Bremerhaven Hamburg Oldenburg Bremen 60 Institutes More than employees Biggest institution for applied research in Europe Hannover Berlin Potsdam Teltow Braunschweig Magdeburg Cottbus Oberhausen Paderborn Halle Dortmund Schkopau Leipzig Duisburg Kassel Schmallenberg Dresden St. Augustin Erfurt Jena Aachen Freiberg Euskirchen Gießen Chemnitz Wachtberg Ilmenau Darmstadt Würzburg Bayreuth Erlangen Bronnbach St. Ingbert Kaiserslautern Fürth Nürnberg Saarbrücken Karlsruhe Pfinztal Ettlingen Stuttgart Straubing Freising Freiburg Augsburg Garching München Oberpfaffenhofen Kandern Prien Efringen Holzkirchen Kirchen

3 FraunhoferInstitute for Wood Research, WKI Braunschweig Staff At present 93 permanent employees Budget Approx. 9 million (2010)

4 FraunhoferInstitute for Wood Research Technology of Woodbased Panels Material Analysis and Indoor Chemistry Surface Technology Quality Assessment Structural Engineering and Construction

5 Structural Engineering and Construction Head of Department : Dr. Dirk Kruse Buildingphysical investigations Mechanical investigations Fire research Expert surveys External supervision Approvals

6 Fire Damages Person injury Material Damage Model Building Regulation Requirements Structural fire protection Intumescent fire retardant coatings Efficiency Advantages

7 Intumescence Mechanism 1. Softening of the polymeric binder (e.g. PP) 2. Releasing of inorganic acids 3. Carbonization (e.g. of polyalcohols) 4. Gas formation by the propellant (e.g. melamine) 5. Foaming of the mixture 6. Solidification through crosslinking reactions

8 Development of Intumescent Fire Retardant Coatings Since 1970: VANDERSALL introduced compounding of IFRC Composition polymeric binder acid source carbon source blowing agent Criteria polymer latex inorganic acid (salt) Carbonrich organic compounds (polyol) organic amine Most efficient and studied combination till today is: Acid source Carbon source Blowing agent Ammonium polyphosphate Pentaerythritol Melamine

9 Motivation and Objective Tests for new coatings (formulation, application, smallscalelabortests) are work, time and cost intensive Missing of techniques and predictions for efficiency of IFRC!!! The aim is to develop predictions about new alternative products Using different thermal analytical methods: Single compounds (TGAEGA) Compounds in combination (TGA, DSCMicroscopy) Thermomechanical Tests (TMA)

10 Composition of the Reference Intumescent Coating Agents polymeric binder acid source carbon source blowing agent additive/pigments solvents Reference polyvinyl acetate ammonium polyphosphate pentaerythritol melamine titan dioxide xylene/butyl acetate Alternative acid and carbon sources were investigated in the reference formulation

11 Thermal Degradation of the Binder Polyvinyl Acetate Step I: C 72.2 % acetic acid Step II: C 24.3 % PAHs Reactions of IFRC ingredients should occur at ca C

12 Extinktion Thermal Degradation of Polyvinyl Acetate 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0, Wellenzahlen (cm1 ) FTIR gas spectra at peak maximum of GS curve at 345 C acetic acid (red ) and spectra of acetic acid of TGA vapor phase library (purple) L. Costa, M. Avataneo, P. Bracco, V. Brunella: Char formation in polyvinyl polymers I. Polyvinyl acetate. Polymer Degradation and Stability, 77 (2002)

13 Thermal Degradation of Acid Sources Acid sources Ammonium polyphosphate (APP) Ammonium dihydrogenphosphate (ADHP) Diammonium hydrogenphosphate (DAHP) Ammonium Pentaborate Octahydrate Diammonium sulfate T C m w.% Evolved gases NH H 2 O, NH NH 3, H 2 O ,5 NH 3 H 2 O, NH 3 H 2 O (H 2 O) H 2 O SO 2, H 2 O All acid sources are within the temperature specification!

14 Thermal Degradation of Carbon Sources Carbon sources T m Evolved Reactivity C w.% gases 1,1,1trimethylolpropane H 2 O 2.2 (TMP) 1,1, H 2 O 2.5 tris(hydroxymethyl)ethane (TME) 2hydroxymethyl1, H 2 O 2.8 propanediol (HMPD) mesoerythritol (ET) H 2 O 1.6 Pentaerythritol (PER) H 2 O, CH 3 OH, CH 2 O 2.9 Dipentaerythritol (DiPER) H 2 O, CH 3 OH, CH 2 O 2.4 Tripentaerythritol (TriPER) H 2 O, CH 3 OH, CH 2 O 2.2 Sorbitol (ST) H 2 O 1.1

15 TGA and DSCmicroscopy Measurements of Binary Mixtures Determination of chemical and physical interactions between two compounds Chemical Interactions studied through TGA M theo (T): Sum of TGAcurves of single compounds M exp T : TGAcurve of the binary mixture M T = M exp T M theo (T) Physical Interactions studied through DSCmicroscopy

16 ADHP Melamine 350 C 450 C

17 APP Melamine 320 C 400 C

18 TMA Measurements of Coatings Combinations of acid sources and carbon sources in the reference IFRC Polymeric binder, blowing agent and pigments concentrations remained unchanged no. coatings TMA results [µm ± %] no. coatings TMA results [µm ± %] 1 F S0 K F S0 K F S1 K F S1 K F S2 K F S2 K F S3 K0 n.e.* 24 F S3 K4 n.e. 5 F S4 K0 n.e. 25 F S4 K4 n.e. 6 F S0 K F S0 K F S1 K F S1 K F S2 K F S2 K F S3 K1 n.e. 29 F S3 K5 n.e. 10 F S4 K1 n.e. 30 F S4 K5 n.e. 11 F S0 K F S0 K F S1 K F S1 K F S2 K F S2 K F S3 K2 n.e. 34 F S3 K6 n.e. 15 F S4 K2 n.e. 35 F S4 K6 n.e. 16 F S0 K3 n.e. 36 F S0 K F S1 K F S1 K F S2 K F S2 K F S3 K3 n.e. 39 F S3 K7 n.e. 20 F S4 K3 n.e. 40 F S4 K7 n.e. Sx =Acid Source Kx=Carbon Source

19 Expansion [µm] TMA Results Combinations Acid SourceCarbon Source

20 Conclusions and Selection TGA M T positive effects DSC microscopy char residue, physical interactions TMA foam development Combinations APP ADHP DAHP APBO DAS Melamin PER DiPER TriPER ET () ST/TMP/TME/HMPD ()

21 Predictions of New Compounds for IFRC Using Thermoanalytical Methods 1. Thermal degradation of the binder in which temperature region should intumescence happen? 2. Thermal degradation in combination with reactivity of single compounds give information on suitability 3. TGA and DSCmicroscopy measurements of binary mixtures (acid source and blowing agent) give advice of chemical and/or physical interactions 4. TMA measurements show the influence on the expansion of IFRC dependent on the new compound 5. Final scaled up formulations and burning tests can be carried out further

22 THANK YOU FOR YOUR ATTENTION!!!