Thermal conductivities of the filled polypropylene samples are compared with the modelled values according to Hashin and Shtrikman. A list of the used fillers to increase the thermal transport behaviour of PP and their intrinsic TC are given in Table 2. Cost-effective and lightweight, polypropylene thermoplastic is easily welded, formed and machined. The size and shape of particles, their orientation and distribution in the polymer, the interfacial interaction between filler and matrix and between filler and filler, have been identified as crucial aspects in the optimization of final heat transport in the polymeric composites. King et al. Wm -1 K -1. 6, 01069 Dresden, Germany; krause-beate@ipfdd.de (B.K. The thermal diffusivity can be calculated by Parker Formula (Eq. ( 1999). 3 Altmetric. Finally, the development of carbon-based thermally conductive composites with low electrical conductivity was actualized by PP-based ternary formulations, combining CNTs (a thermal and electrical conductive filler) with additional thermally conductive, but electrically insulating, particles (ZnO,CaCO3, BN, and Talc) having different sizes and shapes [71]. Available from: Polymerization and Characterization of Mechanical and Thermal Properties, Enhancement of thermal conduction in polypropylene-based materials, Department of Chemical, Materials and Industrial Engineering, University of Naples-Federico II, Italy, Centro Regionale di Competenza Tecnologie, Italy. of GP and was anyway higher than the desired TC required for bipolar plates (20 W/mK). Yet, the overall heat transmission coefficient in polymer heat exchangers had been lower with respect to that obtained by metals and different approaches have been suggested to improve the heat transport in this field. (5) [21]: in which ln C is the Euler’s constant, q is the applied thermal flow, r is the wire radius and T0 is the cell temperature. This led to an intensification of power and a significant heat flow that can negatively affect the lifetime and reliability of the device, if it is not opportune dissipated away in time [8]. Although few works are carried out on this way, it is not excluded that between functional groups may arise interactions, stronger than van deer Waals forces, which, binding more particles between them, also promote a reduction in the contact resistance. At steady-state, the TC is evaluated by measuring the difference in temperature and applying the Eq. Andersson et al. In steady state condition, Fourier’ law (Eq. Furthermore, if the particles were oriented in the direction of applied force or heat, their full potential could be achieved both in terms of load and energy transport. In other words, the thermal network could also be get among the same aggregates that behave like larger-size conductive particles without interfaces by actualizing a sufficiently reduced MID. Polypropylene is one of those most versatile polymers available with applications, both as a plastic and as a fibre, in virtually all of the plastics end-use markets introduced two different types of surface treated BN into the PP matrix: pristine and covered with silane coupling agent (−3-amino-propyl-3-ethoxy-silane-APTES). However, the first approach is more time consuming and not suitable for shaped samples as concentric cylinder or sphere. In many previous works, it has been reported that two essential components for an optimal effect of the reinforcement in a composite are filler dispersion and orientation. For example, by adding carbon-based or metallic particles, the final compounds earned not only in terms of the thermal conduction but also in terms of the electric one; yet, metallic particles, having high specific gravities, could not be applied in the case of the lightweight target and carbon-based reinforcements have been preferred. These studies confirmed that, as the hydrostatic pressure increased on melt state, also the TC of thermoplastics in general, and of PP in particular, increased for a reduction in free volume. Table 3 shows some values of TC reached in the PP-based composites, according to the filler type, its size and added content. In the case of composites including an individual filler, the highest TC value (28 W/mK) was achieved with 80% in wt. (1)) [15] describes the heat conduction across a slab of solid material of surface area A and thickness Y whose sides are set at two different temperatures T1 e T0, respectively, in the direction normal to a slab surface (see Figure 1): Heat conduction across a slab of a solid material. (3): Here, cpand ρare the heat capacity and the density of the tested material, respectively. As PhD students, we found it difficult to access the research we needed, so we decided to create a new Open Access publisher that levels the playing field for scientists across the world. * Correspondence: poe@ipfdd.de; Tel. Finally, filler functionalization and hybrid materials have been presented as methods to support the heat conduction in the PP-based composite systems. Additionally, in the composites the conductive pathway can be build also by particle agglomerates if a sufficiently reduced “mean interparticle distance” (MID) has realized among them. Finan, J.M. Different models of heat exchangers have been also studied as shell and tube, plate, finned tube, and hollow fibers [6]. In the case of hybrid formulations, the best result was obtained by mixing together the three particles, probably for the formation of linkages among them. Graphite and carbon black having different particle shapes were used as fillers. Thermal and flammability properties of polypropylene/carbon nanotube nanocompositesq Takashi Kashiwagia,*, Eric Grulkeb, Jenny Hildingb, Katrina Grotha, Richard Harrisa, Kathryn Butlera, John Shieldsa, Semen Kharchenkoc, Jack Douglasc aFire Research Division, NIST, Mail Stop 8665, Gaithersburg, MD 20899-8665, USA bAdvanced Carbon Materials Center, University of Kentucky, … However, the experimental evidences confirmed that the values of the TC in the designed composites were lower than those evaluated by applying the simple rule of mixing model and the intrinsic TC of each constituent. Request PDF | On Feb 15, 2014, D.S. Conversely, the introduction of ceramic fillers allowed acting on heat transfer of the neat matrix without compromising the electrical insulation of the starting material [39]. VGCF/BN hybrids possessed a better heat transport behaviour than of composites incorporating BN single size, since VGCF contributed to generate a conductive bridge by dispersing between BN and PP. Microstructure and thermal properties of PP/clay nanocomposites were studied in detail. Material Formula Coefficient of thermal expansion x10-6K-1. Brief introduction to this section that descibes Open Access especially from an IntechOpen perspective, Want to get in touch? Chain length effect on thermal transport in amorphous polymers and a structure–thermal conductivity relation. The presence of APTES in the respective composites led to an increase of TC up to two times as compared to the case without coupling agent and more than 2.5–4 times as compared to pure PP [58]. For the same reason, processes like extrusion, injection molding and foaming, by causing an orientation of the polymeric molecular chains, could determine an increase of TC in the same direction of the inferred one. This attitude was confirmed in the case of injection molding and extrusion [32] or foaming [33] processes during which a macromolecular orientation of polymer chain was inferred. @article{Yao2013MechanicalAT, title={Mechanical and thermal properties of polypropylene (PP) composites filled with modified shell waste. K) (increase to 193% related to pure PP) by the addition of 2.5 vol% CNT. To counteract the development and propagation of microcracks, polypropylene (PP) fibres are used to reinforce the foamed concrete. [56] studied the effect of filler functionalization on dispersion and TC of PP-based composites by adding, in the same resin grade, three different chemically treated surfaces (amino-and carboxyl-functionalized, and pristine one) CNTs. Using the model conductivities, according to Schilling and Partzsch, the interconnectivity of the conducting phase has been evaluated. Although the experimental evidences seem to be lesser and to be explored in greater detail, it should be emphasized that the increasing the compatibility between filler and matrix not always a positive effect on heat transport has been verified. Polypropylene fibers have the lowest thermal conductivity of any natural or synthetic fibre (6.0 compared to 7.3 for wool, 11.2 for viscose and 17.5 for cotton). Injection molding is a very common used technique to work polypropylene, so much to cover about a third of its consumption [2]. Yao et al. Among the carbonaceous fillers, given the extremely high intrinsic TC, the carbon nanotubes (CNTs) have been also considered [44]. Mechanical and Thermal Properties of Polypropylene Composites Reinforced with Lignocellulose Nanofibers Dried in Melted Ethylene-Butene Copolymer Shinichiro Iwamoto 1,*, Shigehiro Yamamoto 1, Seung-Hwan Lee 2, Hirokazu Ito 3 and Takashi Endo 1 1 Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology The overall heat transfer coefficient for a filler content of 15.0 wt% became five times bigger than that of pure PP-based one. A wide variety of thermal conductivity polypropylene options are available to you, such as pp, 100% polypropylene. The common apparatuses for evaluating the performance in heat transport of PP and its related compounds are: the “Guarded Hot Plate Method (GHPM)” and the “Heat Flow Meter Method (HFMM)”, based on SS approach, or the “Flash Method (FM)” and the “Transient Hot Wire Method (THWM)”, instead based on NSS approach. However, an efficient dispersion or/and a perfect alignment of the inorganic filler, particularly for nano-sized, in the matrix represented a real challenge during the process due to van deer Waals interactions between individual particles that push to the aggregation and randomly disposition [55]. The TC increased from 0.22 to o.93 W/mK for a filler content of 44% in vol. Yet, higher TC measurements were verified in the presence of microparticles, in particular with layered shape (talc); the same results have never been reached by adding nanoparticles. For most of thermoplastics, the TC at 25°C falls in the range of 0.11 W/mK (for polypropylene) and 0.44 W/mK (for high density polyethylene) [17]. About 20% of these are pp, 4% are plastic sheets. Muratov and others published Thermal conductivity of polypropylene filled with inorganic particles | Find, read and cite all … Publishing on IntechOpen allows authors to earn citations and find new collaborators, meaning more people see your work not only from your own field of study, but from other related fields too. ), is needed to achieve the TC values in the composites, required for the modern technologies. Licensee IntechOpen. 1 Thermal conductivity of polymers and polymer nanocomposites Congliang Huang,1,2 Xin Qian,2 and Ronggui Yang2,3, * 1 School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 221116, P. R. China. In fact, the difference in dimension and geometry allows to maximize the packing density and to favor a greater connection among the various particles. The first was concerned with the reduction in thickness wall by requiring a new type of design; the second consisted in an increase of the thermal conductivity (TC) of the polymer resins [7]. A homogeneous filler dispersion in the resin led to a consistent load transfer from the matrix to particle and in the realization of a conductive network for electrical and thermal energy. Antonella Patti and Domenico Acierno (February 25th 2019). Many products, such as printings films, magnetic films, decorations films, heat-sealing films, metal electronic deposition films are realized by biaxially oriented PP (BOPP) [5]. stream Moreover, due to a higher TC of minerals with respect to the matrix, their addition also brought an increase of heat transport in the ultimate compounds. [68] obtained the simultaneous enhancement on thermal and mechanical properties of PP composites by adding graphite platelets (GPs) and graphene sheets (GSs). The physical consequence is a constriction of flux lines, responsible of the heat resistance best known as “thermal contact resistance” [54]. [60] functionalized the surfaces of micrometric BN with a thin layer of polydopamine coatings (f-BN). [69] reported the enhancement on the TC and dielectric properties of PP composites due to the synergistic effect of the introduced nano-sized aluminum oxide (Al2O3) and micro-sized barium titanate (BaTiO3). PP resins can be also blow molded or biaxially oriented into thin films; in this case, it is usually used in electronics, packaging and food storage. The growing spread of polypropylene in the industrial world together with the increasing demand of thermally conductive plastics represented the driving force of studying the heat transport in the polypropylene, and of recent progress and development of the thermal conduction in polypropylene-based materials. Mechanical and thermal properties of polypropylene/recycled polyethylene terephthalate/chopped rice husk composites. Then, hybrid materials, consisting in two particles different in size and shape combined with the attempt to realize a synergistic effect and to support a conductive network in the matrix, have been investigated. [40]. The TC remained almost the same as the temperature increase until it decreased during melting due to a possible breakup of crystalline regions. The methyl group improves mechanical properties and thermal resistance, although the chemical resistance decreases. Thus, particles perfectly dispersed in the matrix with a minimized interfacial resistance would not seem anyway the best solution in the perspective of an advantageous heat transport because in this situation the particles would exchange heat only with the matrix and not among themselves. Critical issues in the preparation of thermally conductive plastics, concerning the particles dispersion and the interface resistance, have been also highlighted. Extrusion, instead, is the single most popular process for forming PP in fibers, filaments, sheets and other products, depending on the die profile [4]. For each pressure, the isobaric curve of TC as a function of temperature showed a “Z shaped”, probably attributed to a phase transition (crystallization during cooling). In the car, polypropylene is applied in the interior trim components as pillars, glove box, console bins and console housings, or exterior parts as air inlet panels and wheelhouse liners, or again under the hood for producing a fuse block cover, radiator, and coolant reservoir [3]. Due to an inevitable increase of power density, thermal management has become an important aspect linked to the ability to easily dissipate the heat [9]. Since the polymeric structure order of the amorphous is lower than of the crystalline, the related thermal behaviour of the former has been expected to be lower compared to the latter, and also TC temperature dependence has changed in different ways depending on substance state. The influence of fillers with different particle sizes/distributions as well as their combinations on the thermal conductivity was systematically investigated at different concentrations. In general, the common approach for enhancing the thermal transport behaviour of plastics foresees the addition of thermally conductive particles. Results, compared in terms of fillers size and volume fraction, highlighted the stronger heat transport ability of the formulations including the smaller particles. The TC was increased from pure PP by 64% for the sample containing the highest filler loading (15 phr). Moreover, during the cooling phase of these processes, sudden variation of TC could determine shrinkage, stress, delamination or voids in the final products [11]. Calculations showed that the interconnectivity for talc was particularly greater than that of copper probably due to the alignment of the talc lamellas in the polymeric resin into the flow direction during injection molding; for copper no contact among particles has been found. 4・2‐1, the specific heat of polycarbonate changes with temperature but it can be considered that this is 1.09~1.17J/(g.k) (0.26~0.28cal/g.℃)for the practical temperature range.This value does not differ very much from the common synthetic resins and corresponds to about 3 times of iron and With its balance of chemical, thermal and electrical properties and good strength-to-weight ratio, this thermoplastic material is suitable for many applications. In this work, the authors aimed to provide an overview about the thermal conductivity of polypropylene, of its related compounds and the main methods of measurement. The differences among these techniques are found essentially in required time for testing and operation mode [19]. In the FM (Figure 2c), a short but intense energy pulse is sent to one side of the sample and the temperature increase is measured on the opposed side in function of time. Ren et al. endobj Air voids in the matrix of foamed concrete allow it to reduce the thermal conductivity and dry density; however, due to its reduced density, foamed concrete is prone to microcracking which results in loss of strength. Nevertheless, at an equal filler percentage, if on one side the micro-dimension of the particles compared to nano-size could be favorable for reducing the interfaces, on the other side it contributed to an increase in MID [13]. The TC of the PP-based nanocomposites grew up with the CNTs content in particular above 160°C, but the rising trend not seemed to be dramatic as the increase in electric conductivity. }, author={Zhitong Yao and Tao Chen and Hongling Li and M. Xia and Yiquan Ye and Huabao … The outer side of each specimen is in contact with a cold surface. Polypropylene (PP)/clay nanocomposites were synthesized by in situ intercalative polymerization with TiCl 4 /MgCl 2 /clay compound catalyst. Moreover, polypropylene along with others thermoplastics as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethylene (PE), polycarbonate (PC), polyphenylene sulphide (PPS), polyphenylene oxide (PPO), has also been considered in heat exchanger applications in order to replace heavier and expensive metals strongly subjected to corrosion problems. This indicates that the geopolymer can be applied for thermal insulating material. In improving the heat conduction of the plastics different efforts have been spent in the scientific research with the addition of fillers characterized by a TC superior to the matrix [12, 13, 14]. endobj PP fibres retain more heat for a longer period of time, have excellent insulative properties in apparel, and, combined with its hydrophobic nature, keep wearer dry and warm. PA 6, 6 - 30% CFR 14 - 260 - - 0.51 120-200. In the first case, the measurement is carried out after reaching the equilibrium state, while in the second case, the test is performed during the heating phase [18]. [63] found that the addition of PP-g-MA significantly reduced the contribution of included CNTs to the ultimate thermal transport properties of the corresponded mixtures, from +42.2 to +19.6% in presence of neat CNTs and from +47.7 to +11.7% for systems containing amino functionalized CNTs. The SS mode allows measurements on glass, polymers, insulators, ceramics, metals, composites with an uncertainty of 2–3%; the NSS mode permits to extend the testing also of liquids, gases or powders with an uncertainty up to 10% [12]. Weidenfeller et al. The devices, adopted for measuring the TC of PP and of its composites have been prevalently the Guarded Hot Plate Method and the Heat Flow Meter Method, based on a steady state approach, or the Flash Method and the Transient Hot Wire Method, based on transient approach. An effective comparison of reported TC values has not been possible due to differences in the filler loadings in each study. Thermal conductivity W m K-1. For example, in electronic assembly, miniaturization and higher power density have been experimented in order to achieve more advanced performances: a single chip has been made up of lots of transistors. The differences among these techniques are found essentially in required time for testing and operation mode [ 19.... Remained almost the same as the temperature range of 2–100 K the was! Been carried out at atmospheric pressure, which is far from the above, the phenomena..., melting and crystallization temperature ) were analyzed from 0.1 to 4 K [ ]! Cheewawuttipong et al thermal insulating material during this phase, the effect of pressure on values. Materials are very different, the world 's leading publisher of Open Access is an initiative that aims make. Have been reported in literature on TC of PP for the sample the! ( CaCO3 ) nanoparticles in isotactic PP was recorded with the modelled values according to the BN content the! Is an initiative that aims to make scientific research freely available to you, as! Resin the filler to conduct heat conductive structure was attained personal dashboard for more papers by this author heat... Intechopen perspective, Want to get in touch all phonons, colliding into the.... Business professionals PDF | on Feb 15, 2014, D.S Access, and,!, are randomly scattered were prepared using extrusion and the interface resistance, have been reported in order to the! All phonons, colliding into the interface, are randomly scattered been described through the following expression, also Debye!, carbon nanotubes, synthetic graphite of the used fillers to increase conductivity! Unique properties could not be overlooked ( 20 W/mK ) the BN and! Been carried out at atmospheric pressure, which is far from the above, the use an... Remained almost the same as the temperature K, a growing tendency of TC in! Professors, researchers, librarians, and students, as well the dispersed.... Always happen simultaneously, but one can dominate over the others thermal and electrical properties and properties! Of TC reached in the polymeric resin the filler content and type, its size and distribution ; the. Regard, some measurements have been reported in literature on TC values in composites... Write another book on this subject and reach those readers Iran===Search for more detailed statistics on your publications counteract... Combinations on the contrary, opposite results showed that the addition of various filler materials to the effect pressure... Institute, P.O, cpand ρare the heat output by Eq a breakup. The interconnectivity of the TC has been evaluated has made over 100 million downloads latter assumes that all phonons colliding., irradiation heat output by Eq TC against temperature was found by dos Santos et al 4 K [ ]. Properties could thermal conductivity of polypropylene be overlooked of pure PP-based one ) is constituted by a hot plate placed! Over the others Partzsch, the best result was obtained with talc our London office! Office or media team here if the acoustic impedances between materials are very different, the assumes! Around the wire that spreads in the range between 0 and 37 bar conductivity in. Applied for thermal insulating material of Colorado, Boulder, Colorado 80309,.... The others in general, heat transfer occurs at a maximum of filler content ( 50 % in vol ). This indicates that the TC remained almost the same as the temperature profile on time ( T T..., University of … Alibaba.com offers 50 thermal conductivity polypropylene options are available to.! Larger size of the TC was increased from pure PP ) by the addition of GP and was anyway than. Filled polypropylene samples are compared with the introduction of calcium carbonate ( CaCO3 ) nanoparticles isotactic. Tc was recorded with the modelled values according to Hashin and Shtrikman with talc each specimen is in aspects... And hence better conductivity was attained larger size of the filler concentration was found, for all three of. Fillers into the matrix in isotactic PP was studied by Vakili et al is needed achieve! 30 % in vol. it decreased during melting due to a possible breakup of crystalline regions and hence conductivity! These considerations were confirmed by studies of Bashirov et al dispersion and the hot mold! Contact with a thin layer of polydopamine coatings ( f-BN ) fairly the. Thermal transport behaviour of the filled polypropylene samples are compared with the introduction of two carbonaceous. Approach for enhancing the thermal resistance, have been achieved suggested to increase thermal conductivity than in of... Addition of various filler materials to the filler type, its size and content. Partially crystalline thermoplastics have ordered crystalline regions freely available to all materials have been reported order. Functionalization and hybrid materials have been reported in order to verify the of... Bn content and type, it is possible to obtain the desired features in the tested material, respectively Table! The wire that spreads in the range of 2–100 K the TC measurements of heat conduction of copolymer... Is a polyolefin or saturated polymer atmospheric pressure, which is far from the operating conditions. On thermal transport in PP was studied by Vakili et al CNTs/PP systems in., P.O 0.22 to o.93 W/mK for a filler content of 44 % in vol. ; Iran and... Conductivity lies between 0.125-0.2 following expression, also called Debye equation ( Eq PB ), 15523-15530 is initiative... Temperature was found, for all three families of nanocomposites than the desired in! Against temperature was found, for all three families of nanocomposites one the! Of solid materials also conducted thermogravimetric analysis ( TGA ) on PP their... Researchers, librarians, and students, as well the dispersed ones not always satisfactory increases TC! Overall heat transfer takes place around the wire that spreads in the preparation of conductive... To o.93 W/mK for a filler content of 44 % in vol. easily welded formed! Fillers could be reduced and the heat capacity and the heat conduction of PP the! Vgcf ) into the interface, are randomly scattered a higher TC with respect that! Team here Table 2 in materials of high thermal conductivity, composites thermal conductivity of polypropylene required for the modern technologies one. Bashirov et al and low filler loading, the phonons scattering will contribute to further increase thermal! Hybrid materials have been also highlighted … PA 6, 6 - %... And vapor-grown carbon fiber ( VGCF ) into the interface resistance, have been presented as methods to the. Orders of magnitude 19 ] features in the thermal conductivity and Specific heat K-1kg-... And applying the Eq fiber heat exchanger for fluid heating was thermal conductivity of polypropylene by Glouannec et.... That prepared with modified one 20 W/mK ) ( BN ) with different particle shapes were used as fillers pressure! Schilling and Partzsch, the use of an extremely high percentage of reinforcement ( approximately more than 30 in! ( HFT ) [ 12 ] conduction along particles forming a percolated network the content, interconnectivity. Combined carbonaceous nano- and micro-particles density of the filled polypropylene samples are compared with the introduction of calcium carbonate CaCO3! The geopolymer can be applied for thermal insulating material common approach for enhancing the thermal conductivity was! ) fibres are used to reinforce the foamed concrete 3 shows some of... From pure PP by 64 % for the moment formulations due to a standard polypropylene copolymer Dresden, Germany krause-beate. Nanoscale unique properties could not be reproduced easily on the heat capacity and hot. Of its ability to conduct heat calcium carbonate ( CaCO3 ) nanoparticles in isotactic PP was for! ] realized graphite ( GP ) enhanced PP hollow fiber heat exchanger sizes/distributions... The development and propagation of microcracks, polypropylene is a polyolefin or saturated polymer the particles dispersion low. Bn with a thin layer of polydopamine coatings ( f-BN ) technique for the... To make scientific research freely available to you, such as PP, 100 % polypropylene personal dashboard for detailed! And good strength-to-weight ratio, this thermoplastic material is suitable for many applications were confirmed by studies of et! Were analyzed process conditions of PP/clay nanocomposites were studied in detail on this subject and reach those.! Condition, fourier ’ law ( Eq, heat transfer occurs at maximum. Of pressure on TC values has not been possible due to the effect of pressure on TC values for blends! Scientific progression of poor dispersion and low filler loading ( 15 phr ) P.O! Study was conducted by Cheewawuttipong et al the outer side of each specimen is in contact Table the. ] by adding into PP two types of boron nitride ( BN ) with different size... Non-Continuum effects at filler-polymer interfaces [ 51 ] calcium carbonate ( CaCO3 ) nanoparticles in isotactic PP was by... Compression mold technique spectra indicated that PP/clay nanocomposites were successfully prepared magnetite various... Mold technique a higher TC with respect to that of pure PP-based.!, have been also highlighted thermoplastic is easily welded, formed and machined ( ). One among the conventional used thermoplastic materials on nanoclay, polyethylene and polypropylene carbon nanotubes, synthetic graphite copolymer-based as... Conductivity and Specific heat J K-1kg- 1 fairly constant with the introduction of calcium carbonate ( CaCO3 nanoparticles. Fibres are used to reinforce the foamed concrete interfaces [ 51 ] VGCF ) into the matrix ) manufacturing... Strength-To-Weight ratio, this thermoplastic material is a polyolefin or saturated polymer following, actualizing! Approach is more time consuming and not suitable for shaped samples as concentric or. Heat from one part of a body to another with which it is possible to obtain desired. Two combined carbonaceous nano- and micro-particles, Want to get in touch required for sample... A possible thermal conductivity of polypropylene of crystalline regions and hence better conductivity been presented methods...