Temperature dependence of the thermal diffusivity in composites of epoxy and polyester resins, loaded with carbonyl iron particles, has been studied using the photopyroelectric technique. Increments of eight and 2.5 times the thermal conductivity of the polymers are obtained, as the volume concentration of microparticles is increased from 0% to 40% for epoxy and from 0% to 20% for polyester matrices, respectively. Additionally, the thermal diffusivity falls systematically as the temperature is increased from 270 to 400 K; the effect is more pronounced for high concentration of microparticles in epoxy composites. The glass transition of the composites is explored by implementing a numerical differentiation algorithm. In order to explain the consequences of the loading of the composites on the thermal conductivity, a modified Lewis-Nielsen model, which includes the presence of crowded regions in the samples, is used to study heat transfer in a wide range of particle concentrations.
MamunyaYPDavydenkoVVPissisPet al.Electrical and thermal conductivity of polymers filled with metal powders. Eur Polym J2002; 38: 1887–1897.
2.
GaoLZhouXDingY. Effective thermal and electrical conductivity of carbon nanotube composites. Chem Phys Lett2007; 434: 297–300.
3.
QingYZhouWLuoFet al.Microwave electromagnetic properties of carbonyl iron particles and Si/C/N nano-powder filled epoxy-silicone coating. Physica B Condens Matt2010; 405: 1181–1184.
4.
QingYZhouWLuoFet al.Epoxy-silicone filled with multi-walled carbon nanotubes and carbonyl iron particles as a microwave absorber. Carbon2010; 48: 4074–4080.
KimuraSKatoTHyodoTet al.Electromagnetic wave absorption properties of carbonyl iron-ferrite/PMMA composites fabricated by hybridization method. J Magnet Magnet Mater2007; 312: 181–186.
7.
LiuLDuanYLiuSet al.Microwave absorption properties of one thin sheet employing carbonyl–iron powder and chlorinated polyethylene. J Magnet Magnet Mater2010; 322: 1736–1740.
8.
JosephNThomas SebastianM. Electromagnetic interference shielding nature of PVDF-carbonyl iron composites. Mater Lett2013; 90: 64–67.
9.
Medina-EsquivelRAZambrano-ArjonaMAMendez-GamboaJAet al.Thermal characterization of composites made up of magnetically aligned carbonyl iron particles in a polyester resin matrix. J Appl Phys2012; 111: 054906–054906.
SalazarA. On the influence of the coupling fluid in photopyroelectric measurements. Rev Sci Instr2003; 74: 825–827.
12.
MarinelliMMercuriFZammitUet al.Photopyroelectric study of specific heat, thermal conductivity, and thermal diffusivity of Cr2O3 at the N’eel transition. Phys Rev B1994; 49: 9523–9532.
13.
ZammitUPaoloniSMercuriFet al.Self consistently calibrated photopyroelectric calorimeter for the high resolution simultaneous absolute measurement of the specific heat and of the thermal conductivity. AIP Adv2012; 2: 012135–012135.
14.
MorikawaJTanJHashimotoT. Study of change in thermal diffusivity of amorphous polymers during glass transition. Polymer1995; 36: 4439–4443.
15.
HutchinsonJMMontserratS. The application of modulated differential scanning calorimetry to the glass transition of polymers. I. a single-parameter theoretical model and its predictions. Thermochimica Acta1996; 286: 263–296.
16.
PhamJQMitchellCABahrJLet al.Glass transition of polymer/single-walled carbon nanotube composite films. J Polym Sci B Polym Phys2003; 41: 3339–3345.
17.
MaxwellJC. A treatise on electricity and magnetism, New York: Dover Publications, 1954.
18.
BruggemanDaG. Berechnung verschiedener physikalischer konstanten von heterogenen substanzen. I. dielektrizittskonstanten und leitfhigkeiten der mischkrper aus isotropen substanzen. Ann Phys1935; 416: 636–664.
19.
DengFZhengQSWangLFet al.Effects of anisotropy, aspect ratio, and nonstraightness of carbon nanotubes on thermal conductivity of carbon nanotube composites. Appl Phys Lett2007; 90: 021914–021914.
20.
PalR. On the Lewis – Nielsen model for thermal/electrical conductivity of composites. Compos A Appl Sci Manuf2008; 39: 718–726.
21.
PalR. New models for thermal conductivity of particulate composites. J Reinf Plast Compos2007; 26: 643–651.
22.
HanZFinaA. Thermal conductivity of carbon nanotubes and their polymer nanocomposites: a review. Progr Polym Sci2011; 36: 914–944.
23.
Vogel CR. Computational methods for inverse problems. Frontiers in Applied Mathematics, Soc for Industrial & Applied Math. Philadelphia: Society for Industrial and Applied Mathematics. ISBN: 978-0-89871-507-1, 2002.
24.
Chartrand R. Numerical differentiation of noisy, nonsmooth data, numerical differentiation of noisy, nonsmooth data. ISRN 2011; 2011.
25.
RudinLIOsherSFatemiE. Nonlinear total variation based noise removal algorithms. Physica D Nonlin Phenom1992; 60: 259–268.
26.
NielsenLE. The thermal and electrical conductivity of two-phase systems. Industr Eng Chem Fund1974; 13: 17–20.
27.
LizundiaEOleagaASalazarAet al.Nano- and microstructural effects on thermal properties of poly (l-lactide)/multi-wall carbon nanotube composites. Polymer2012; 53: 2412–2421.
28.
SalazarAOleagaA. On the piezoelectric contribution to the photopyroelectric signal. Rev Scientific Instr2005; 76: 034901–034901.
29.
MichelsJWidmannRCzaderskiCet al.Glass transition evaluation of commercially available epoxy resins used for civil engineering applications. Compos B Eng2015; 77: 484–493.
30.
LiemHCabanillas-GonzalezJEtchegoinPet al.Glass transition temperatures of polymer thin films monitored by Raman scattering. J Phys Condens Matter2004; 16: 721–721.
31.
LucasJCBorrajoJWilliamsRJJ. Cure of unsaturated polyester resins: 1. Heat of copolymerization and glass transition temperature. Polymer1993; 34: 3216–3219.
32.
HashimotoTMorikawaJKuriharaTet al.Frequency dependent thermal diffusivity of polymers by temperature wave analysis. Thermochimica Acta1997; 304–305: 151–156.
33.
CarslawHSJaegerJJC. Conduction of heat in solids, 2nd ed. Oxford: Clarendon Press, 1986.
34.
SalazarA. On thermal diffusivity. Eur J Phys2003; 24: 351–351.
35.
ZhouSQNiR. Measurement of the specific heat capacity of water-based al2o3 nanofluid. Appl Phys Lett2008; 92: 093123–093123.
36.
BevingtonPRobinsonDK. Data reduction and error analysis for the physical sciences, 3rd ed. New York: McGraw-Hill Higher Education, 2002.
37.
MuellerSLlewellinEWMaderHM. The rheology of suspensions of solid particles. Proc R Soc A2010; 466: 1201–1228.
38.
PabstWGregorovEBertholdC. Particle shape and suspension rheology of short-fiber systems. J Eur Ceramic Soc2006; 26: 149–160.
39.
LewisTBNielsenLE. Viscosity of dispersed and aggregated suspensions of spheres. Trans Soc Rheol1968; 12: 421–443.
40.
MooneyM. The viscosity of a concentrated suspension of spherical particles. J Coll Sci1951; 6: 162–170.
41.
Ordonez-MirandaJYangRAlvarado-GilJJ. A crowding factor model for the thermal conductivity of particulate composites at non-dilute limit. J Appl Phys2013; 114: 064306–064306.
