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Made available in DSpace on 2021-06-25T11:10:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Here we present the study of supercapacitors based on molybdenum disulfide and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (MoS2/PEDOT:PSS) composite electrodes deposited by spray-coating. To produce the MoS2/PEDOT:PSS composite ink, dispersions of hydrothermally synthesized MoS2 and PEDOT:PSS were mixed in different weight proportions. Electrodes containing only PEDOT:PSS and MoS2 were also fabricated for comparison. The composite films were deposited by transferring the as-prepared inks to an airbrush coupled to a modified 3D printer base with in-line displacement. The films were characterized in terms of the scanning electron microscope (SEM), Raman spectroscopy, and sheet resistance. The electrochemical properties of supercapacitors were evaluated by cyclic voltammetry (CV), galvanostatic charge/discharges (GCD) techniques, impedance spectroscopy (IS), and their correlated parameters. The maximum specific capacitance of the MoS2-based supercapacitor was estimated to be 145.9 F g−1 at 1 mV s−1, while the 3:1 MoS2/PEDOT:PSS weight ratio supercapacitor exhibited a specific capacitance of 131.1 F g−1. Despite the slightly lower CSP, the 3:1 device provided a better overall performance, with a remarkably higher energy density of 11.2 Wh kg−1 and a maximum power density of 1020 W kg−1. It also displayed better long-term cycle stability, retaining 92% of its initial capacitance after 1000 CV cycles (against 54% of MoS2 devices). In summary, we demonstrated the study and production of a high-performance supercapacitor with spray-deposited MoS2/PEDOT:PSS composite electrodes, in which the production can be easily scalable for mass production and practical applications. School of Technology and Sciences São Paulo State University (UNESP) School of Technology and Sciences São Paulo State University (UNESP) FAPESP: 2018/02604-4

Made available in DSpace on 2020-12-12T01:42:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-01 Successful manufacture of a simple, low cost sprayed Schottky diode compatible with printed electronics using reduced graphene oxide (rGO) as a semi-transparent top electrode and zinc oxide (ZnO) as active layer has been reported in this paper. The rGO was synthesized using modified Hummers’ method and deposited by spray coating. The transmittance analyses of rGO films shows 62.3% transparency for ultraviolet (UV) light and by the Van der Pauw method shows sheet resistance of 19 kΩ/□. The rGO electrode provides an alternative to expensive metallic electrodes such as Au, Pt, Pd and Ag which are not ecofriendly. Furthermore, rGO performs Schottky contact with sprayed zinc oxide film resulting in a diode with the sequence of deposited layers Al/ZnO/rGO and low turn-on voltage that has current–voltage characteristics whose rectifying behavior is affected by the incidence of UV light resulting in a possibility to use that diode as photodetector for this kind of radiation. Departamento de Física Faculdade de Ciências e Tecnologia UNESP Departamento de Física Universidade Federal de Juiz de Fora Departamento de Física Faculdade de Ciências e Tecnologia UNESP

Made available in DSpace on 2020-12-12T02:43:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-01 Universidade Estadual Paulista Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Aluminum-oxide (Al2O3) is a low cost, easily processable and high dielectric constant insulating material that is particularly appropriate for use as the dielectric layer of thin-film transistors (TFTs). Growth of aluminum-oxide layers from anodization of metallic aluminum films is greatly advantageous when compared to sophisticated processes such as atomic layer deposition (ALD) or deposition methods that demand relatively high temperatures (above 300 °C) such as aqueous combustion or spray-pyrolysis. However, the electrical properties of the transistors are highly dependent on the presence of defects and localized states at the semiconductor/dielectric interface, which are strongly affected by the manufacturing parameters of the anodized dielectric layer. To determine how several fabrication parameters influence the device performance without performing all possible combination of factors, we used a reduced factorial analysis based on a Plackett-Burman design of experiments (DOE). The choice of this DOE permits the use of only 12 experimental runs of combinations of factors (instead of all 256 possibilities) to obtain the optimized device performance. The ranking of the factors by the effect on device responses such as the TFT mobility is possible by applying analysis of variance (ANOVA) to the obtained results. School of Technology and Sciences São Paulo State University-UNESP Scholl of Electronic Engineering Bangor University Institute of Geosciences and Exact Sciences São Paulo State University-UNESP School of Technology and Sciences São Paulo State University-UNESP Institute of Geosciences and Exact Sciences São Paulo State University-UNESP FAPESP: 14/13904-8 FAPESP: 16/03484-7 FAPESP: 19/01671-2 FAPESP: 19/05620-3 FAPESP: 19/08019-9

Made available in DSpace on 2018-12-11T17:36:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-05-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Abstract: We report a process for performing the middle electrode for a vertical field effect transistor (VOFET) by the evaporation of a tin (Sn) layer. Bare aluminum oxide (Al2O3), obtained by anodization, and Al2O3 covered with a polymethylmethacrylate (PMMA) layer were used as the gate dielectric. We measured the electrical resistance of Sn while the evaporation was carried out to find the best condition to prepare the middle electrode, that is, good lateral conduction associated with openings that give permeability to the electric field in a vertical direction. This process showed that 55 nm Sn thick is suitable for use in a VOFET, being easier to achieve optimal thickness when the Sn is evaporated onto PMMA than onto bare Al2O3. The addition of a PMMA layer on the Al2O3 surface modifies the morphology of the Sn layer, resulting in a lowering of the threshold voltage. The values of threshold voltage and electric field, VTH = − 8 V and ETH = 354.5 MV/m respectively, were calculated using an Al2O3 film 20 nm thick covered with a 14 nm PMMA layer as gate dielectric, while for bare Al2O3 these values were VTH = − 10 V and ETH = 500 MV/m. Graphical Abstract: [Figure not available: see fulltext.]. School of Technology and Applied Sciences São Paulo State University (UNESP) School of Technology and Applied Sciences São Paulo State University (UNESP) FAPESP: 2013/26973-5 FAPESP: 2014/13015-9

Made available in DSpace on 2022-04-29T08:32:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-15 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Instituto Nacional de Ciência e Tecnologia em Eletrônica Orgânica Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) is a promisor p-type solution-processable molecular semiconductor whose electrical properties are highly dependent on its morphology. Unfortunately, there is a great difficulty in controlling the TIPS-pentacene crystallization because it is extremely affected by many factors, as the deposition method, the solvent type, and others. Here, we studied thin-films of TIPS-pentacene blending with poly(3-hexylthiophene-2,5-diyl) (P3HT:TP blend) in different ratios, aiming to improve TIPS-pentacene morphology. The surface of each film was very dependent on the deposition method and the blend morphology exhibited a high variation with the ratio. The different crystallinities achieved lead to dramatic changes in the charge carrier transport properties throughout the film. The impedance spectroscopy indicated that the small addition of P3HT in the TIPS-pentacene greatly improves its conductivity, however, the TIPS-pentacene forms crystallite agglomerates that did not percolate, prevailing the P3HT conductivities. São Paulo State University – UNESP Faculty of Science and Technology (FCT) Physics Department São Paulo State University – UNESP Faculty of Science and Technology (FCT) Physics Department CAPES: 001 FAPESP: 2020/12282-4

Made available in DSpace on 2019-10-06T17:13:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-30 Zinc acetate dihydrate solution was deposited onto glass and a thin layer of aluminum (10 nm), by spray pyrolysis at 450 °C, growing zinc oxide (ZnO) thin films. The ZnO formation occurs differently on aluminum due to the diffusion process forming AZO at the Al/ZnO interface. The films deposited onto the aluminum showed transmittance above 95%, associated with sheet resistance less than 40 Ω/sq. The high transmittance value with low sheet resistance is crucial for a good transparent electrode. Raman spectroscopy showed a higher degree of doping for films with thin layers of ZnO, and that the diffusion process is high at the Al/ZnO interface. The performance of the transparent electrode was evaluated through the characterization of the Schottky diode (Al:ZnO/ZnO/Au). The factor of ideality (n), resistance in series (Rs), and height of the barrier (ϕB) presented values of 3.79, 1022.6 Ω, and 0.97 eV, respectively. These results demonstrate the simple production of a transparent electrode by the in situ diffusion process using the spray pyrolysis technique. School of Technology and Applied Sciences São Paulo State University (UNESP) School of Technology and Applied Sciences São Paulo State University (UNESP)

The present study reports a two-level multivariate analysis to optimize the production of anodized aluminum oxide (Al2O3) dielectric films for zinc oxide thin-film transistors (TFTs). Fourteen perf...

Made available in DSpace on 2018-12-11T17:02:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-06-01 Poly(3-hexylthiophene):6,13-bis(triisopropylsilylethynyl)-pentacene (P3HT:TP) blends with a ratio of 1:1 (wt/wt) were deposited via spin coating on anodized oxide (Al2O3). A phase separation of the compounds was observed, resulting in the formation of crystalline aggregates of TP molecules that segregate vertically on the surface. The form of segregation depends on the oxide surface treatment used. Spectroscopy analysis shows a higher molecular order of P3HT in the blend than for neat film and that TP molecules are also distributed in the polymeric matrix. Regarding the OFET characteristics, charge carrier mobilities of 1.2 × 10- 3 cm2 V- 1 s- 1 and 2.0 × 10- 3 cm2 V- 1 s- 1 were obtained from devices for untreated and (hexamethyldisilazane) HMDS-treated Al2O3 gate dielectric, respectively. These results confirm that P3HT:TP blends have good potential as an active layer in organic field effect transistors (OFETs). Faculdade de Ciências e Tecnologia UNESP - Univ Estadual Paulista Departamento de Física Faculdade de Ciências e Tecnologia UNESP - Univ Estadual Paulista Departamento de Física

Zinc oxide (ZnO) thin film transistors are well suited to UV sensing application because they absorb predominantly in the UV region due to the wide bandgap (Eg = 3.37 eV) and possess a large exciton binding energy (60 meV) with high radiation hardness. When operated as a transistor, many device performance parameters alter such as threshold Voltage, on-off current and channel mobility. As a result, it is to distinguish between changes in electrical performance induced by UV light and environmental effects that add noise to the sensor performance. In this work, the UV response of zinc oxide thin film transistors (ZnO TFTs) is examined using Taguchi Design of Experiment (DOE) method. By using this multivariate analysis approach, it is possible to reduce the number of calibration tests required for the sensor to accurately assess UV irradiation It is observed that different input conditions (UV power, exposure time, temperature, bias conditions) affect different TFT performance parameters more or less significantly. From the perspective of UV sensing, ON current in the saturation region appears to be the best performance parameter in a ZnO TFT for examining differences in UV exposure.

Made available in DSpace on 2018-12-11T17:35:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-04-01 The production of low cost sensors to monitor environment in some industrial sectors is a current need. In aviculture centers, for example, the concentration of ammonia gas is related to humidity, and it is necessary to control it to avoid contamination. With this need in mind, this paper presents the preparation and characterization of a low cost humidity sensor based on poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) and polyaniline fully printed onto paper by a commercial HP printer. Using electrochemical impedance spectroscopy, an equivalent circuit containing resistive and capacitive parameters was proposed. The resistive parameter R1 is related to values of ambient humidity. The R1 values showed a sensitive response of 200% when relative humidity changes 80%, taking 10 min to reach saturation point. Moreover, the device showed good stability when humidity remained constant. These results indicate that the proposed device is suitable for applying as a humidity sensor that costs less than 1 Euro cent. School of Technology and Sciences São Paulo State University (UNESP) School of Technology and Sciences São Paulo State University (UNESP)

Made available in DSpace on 2015-10-22T07:18:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-01. Added 1 bitstream(s) on 2015-10-22T09:46:00Z : No. of bitstreams: 1 WOS000347696500011.pdf: 661717 bytes, checksum: 8be94e4a0664ccdb5e47a823a7e099ca (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) INEO (Brazil) The effects of humidity on the electrical properties of thermal inkjet-printed copper tetrasulfonated phthalocyanine (CuTsPc) films onto paper substrates are reported. DC electrical measurements revealed that sample resistance decreases from 10(12) Omega in moderate vacuum to approximately 10(7) Omega at highly water-saturated atmosphere. This behavior is attributed to the creation of water pathways on the cellulose fibers that allow ionic species such as impurities, protons (H+), and dissociated Na+ ions from the CuTsPc molecules, to flow. The contribution of the CuTsPc molecules and their dissociated Na+ ions on the sample resistance was elucidated analyzing the electrical response of bare and printed paper substrates. An increase of relative humidity levels (RH) from 10 % to 40-45 % revealed an increase of current of four orders of magnitude for printed samples, whereas less than one order of magnitude was registered for bare paper substrates. Electrical measurements as a function of temperature have shown that moisture can inhibit the semiconducting properties of CuTsPc. Thermal gravimetric studies revealed that approximately 11 % of mass accounting to the presence of water is released above 70 A degrees C, the same temperature in which the sample recovers its dry-state semiconducting behavior. The semiconducting properties of CuTsPc can also be observed upon white light illumination, whereas the charge carrier extraction is governed by the RH level. These results point out the important role of humidity on the electrical properties of paper-based organic, electronic, and optoelectronic devices. Universidade Estadual Paulista (UNESP), Faculdade de Ciências e Tecnologia, BR-19060900 Presidente Prudente, SP, Brasil Instituto Federal de Educação, Ciência e Tecnologia de Santa Catarina (IFSC), BR-89245000 Araquari, SC, Brasil Universidade Estadual Paulista (UNESP), Faculdade de Ciências e Tecnologia, BR-19060900 Presidente Prudente, SP, Brasil

Made available in DSpace on 2015-11-03T15:29:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-01. Added 1 bitstream(s) on 2015-11-04T10:16:12Z : No. of bitstreams: 1 S1516-14392014000600014.pdf: 3036693 bytes, checksum: 9c10b6735a0dbb7c9618b86666398c6d (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) INEO (Brazil) Thermal inkjet-printing of copper tetrasulfonated phthalocyanine (CuTsPc) films containing polyvinyl alcohol (PVA) plasticizer were used to fabricate flexible metal-insulator-semiconductor (MIS) capacitors using anodic aluminum oxide (Al2O3) as the insulating layer. The Al2O3 layer and printed CuTsPc+PVA films were characterized individually and in a MIS structure by electrical impedance spectroscopy. Capacitance-frequency and capacitance-voltage measurements revealed distinct contributions from CuTsPc and PVA on the device electrical response. From these measurements the semiconductor charge carrier mobility, mu, of 1.22x10(-4) cm(2) V-1 s(-1) and the doping density, N A, of 3.1x10(16) cm(-3) were calculated. It was observed a low-frequency electrical response, which was attributed to diffusional processes within the printed film arising from Na+ ions dissociated from the CuTsPc molecule. A simple equivalent circuit model was proposed to take this effect into account. Finally, the results shown here demonstrate the possibility to produce flexible organic electronic devices exploiting the semiconducting properties of water-soluble CuTsPc molecules using low-cost commercial printers. Sao Paulo State Univ UNESP, Fac Sci &Technol, Dept Phys Chem &Biol, Presidente Prudente, SP, Brazil Fed Inst Educ Sci &Technol Santa Catarina IFC, Araquari, SC, Brazil Sao Paulo State Univ UNESP, Fac Sci &Technol, Dept Phys Chem &Biol, Presidente Prudente, SP, Brazil

The development of organic devices requires the fabrication of thin films, and inkjet printing has been shown to be a suitable method to reach this goal. This work describes the printing process and characterisation of polyaniline (PANI) printed on bond and photographic papers using a desktop inkjet thermal printer. To enable printing, a solution composed by PANI, n-methyl-2-pyrrolidone, ethylene glycol, alcohol and water must be prepared. PANI is printed on bond and photographic paper and then doping of PANI is performed by hydrochloric acid vapour exposure. Micro-Raman spectroscopy showed that PANI printed on paper keeps its basic characteristics. The results from electrical measurements showed that the surface resistivity of the printed PANI samples decreases by increasing the printing number, i.e. the number of layers that were deposited, and depends slightly on the paper type. A stretched semicircle followed by a linear upward tail, attributed to Warburg impedance combined with other intrinsic mechanisms of PANI on porous media, are always present on the Cole–Cole plots obtained for doped-PANI on bond paper. It was shown that these parameters significantly change with the relative humidity, opening the possibility to apply PANI/paper-based devices as humidity sensors.

The thermal degradation behaviour of rubber from six new Hevea brasiliensis clones (IAC 40, 56, 300, 301, 302 and 303) from Sao Paulo State, Brazil was studied by thermogravimetry using the Flynn–Wall–Ozawa approach to assess the kinetic parameters (reaction order, activation energy and pre-exponential factor) of the decomposition process. This study indicated that the thermal behaviour is a complex multiple step process, which depends on the type of rubber Hevea clones studied. The rubber from these clones can be classified, following the order of decreasing thermal stability, as IAC 303 > 302 > 56 > 40 > 300 > 301.

Thermoplastic starch/natural rubber polymer blends were prepared using directly natural latex and cornstarch. The blends were prepared in an intensive batch mixer at 150 °C, with natural rubber content varying from 2.5 to 20%. The blends were characterised by mechanical analysis (stress-strain) and by scanning electron microscopy. The results revealed a reduction in the modulus and in tensile strength, becoming the blends less brittle than thermoplastic starch alone. Phase separation was observed in some compositions and was dependent on rubber and on plasticiser content (glycerol). Increasing plasticiser content made possible the addition of higher amounts of rubber. The addition of rubber was, however, limited by phase separation the appearance of which depended on the glycerol content. Scanning electron microscopy showed a good dispersion of the natural rubber in the continuos phase of thermoplastic starch matrix.

The dielectric strength of films made from poly(ethylene terephthalate) (PET) coated with a thin layer of polyaniline (PANI) was studied. The PANI layer was deposited on the PET films by the `in situ' chemical polymerization method. The PANI layer of the PANI/PET films was undoped in NH4OH 0.1 M solution and re-doped with aqueous HCl solution under different pH values varying from 1 to 10. Electric breakdown measurements were performed by applying a voltage ramp and the results showed a dependence of the dielectric strength on the pH of the doping solution due to the changes in the electrical conductivity of the PANI layer. The dielectric strength of PET/PANI films treated under higher pH conditions showed an electric strength about 30% larger than the PET films, since it leads to a non-conductive PANI layer.

This paper is aimed at addressing the differences observed in film properties when poly(vinylidene fluoride-trifluorethylene) P(VDF-TrFE) films are fabricated using distinct methods. Samples were obtained either from casting a solution or by compression molding from a molten phase and characterized by differential scanning calorimetry (DSC). It is shown that the main differences between melt-solidified and cast films arise from the thermal treatment inherent in the former samples.

The development of polymeric blends to be used as matrices for bone regeneration is a hot topic nowadays. In this article we report on the blends composed by corn starch and poly(vinylidene fluoride), PVDF, or poly(vinylidene fluoride-trifluoroethylene), P(VDF-TrFE), to obtain biocompatible materials. Blends were produced by compressing/annealing and chemically/structurally characterized by micro-Raman scattering and Fourier transform infrared (FTIR) absorption spectroscopies, dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM), besides in vivo study to evaluate the tissue response. Vibrational spectroscopy reveals no chemical interaction between the polymers and starch, absence of material degradation due to compressing/annealing process or organism implantation, and maintenance of α and ferroelectric crystalline phases of PVDF and P(VDF-TrFE), respectively. As a consequence of absence of interaction between polymers and starch, it was possible to identify by SEM each material, with starch acting as filler. Elastic modulus (E') obtained from DMA measurement, independent of the material proportion used in blends, reaches values close to those of cancellous bone. Finally, the in vivo study in animals shows that the blends, regardless of the composition, were tolerated by cancellous bone.

Made available in DSpace on 2018-12-11T17:30:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-06-01 Water-gated organic transistors have been successfully exploited as potentiometric transducers in a variety of sensing applications. The device response does not depend exclusively on the intrinsic properties of the active materials, as the substrate and the device interfaces play a central role. It is therefore important to fine-tune the choice of materials and layout in order to optimize the final device performance. Here, polyethylene naphthalate (PEN) has been chosen as the reference substrate to fabricate and test flexible transistors as bioelectronic transducers in liquid. PEN is a biocompatible substrate that fulfills the requirements for both bio-applications and micro-fabrication technology. Three different semiconducting or conducting polymer thin films employing pentacene, poly(3-hexylthiophene) or poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonate) were compared in terms of transconductance, potentiometric sensitivity and response time. The different results allow us to identify material properties crucial for the optimization of organic transistor-based transducers operating in water. Dipartimento di Scienze della Vita Università di Modena and Reggio Emilia (UNIMORE), Via Campi 103 Programa de Pós-graduação em Ciência e Tecnologia de Materiais (POSMAT) Universidade Estadual Paulista (UNESP) Istituto per Lo Studio Dei Materiali Nanostrutturati (ISMN) Consiglio Nazionale Delle Ricerche (CNR), Via Gobetti n.101 Departamento de Física Química e Matemática (DFQM) Universidade Federal de São Carlos (UFSCar) ST Microelectronics Analog and MEMS Group (AMG), Str. Primosole 50 ST Microelectronics Analog and MEMS Group (AMG), Via Remo de Feo 1 Faculdade de Ciências e Tecnologia (FCT) Universidade Estadual Paulista (UNESP) Laboratório Nacional de Nanotecnologia (LNNano) Centro Nacional de Pesquisa em Energia e Materiais (CNPEM) Institut de Ciéncia de Materials de Barcelona (ICMAB) Consejo Superior de Investigaciones Cientifica (CSIC) University of Cambridge Electrical Engineering Division, 9 JJ Thomson Avenue Programa de Pós-graduação em Ciência e Tecnologia de Materiais (POSMAT) Universidade Estadual Paulista (UNESP) Faculdade de Ciências e Tecnologia (FCT) Universidade Estadual Paulista (UNESP)

The authors present DSC studies where heating and cooling rates and also thermal treatments were varied systematically. The results for 60/40 P(VDFTrFE) are presented in this paper which confirm the importance of thermal history and also show that samples with various configurations in terms of ferroelectric phases can be obtained in a somewhat controlled way via thermal treatment.

Surface potential measurements are presented for corona charged P(VDF-TrFE) (polyvinylidene fluoride and trifluorethylene) samples in a constant-current corona triode. The surface potential curves display three distinct regions, characteristic of ferroelectric polymers. The results are interpreted by neglecting the intrinsic conductivity and assuming a dynamics for the electrical polarization which is usually employed in switching measurements of ferroelectric materials, but which is adapted for the constant corona charging condition. >

Thermal degradation behavior of rubber from four rubber clones (RRIM 600, PB 235, GT1 and IAN 873) of the Hevea brasiliensis species was studied by thermogravimetry (TG) using Ozawa's approach to assess the kinetic parameters of the decomposition process. These parameters indicated that the thermal behavior of natural rubber depends on the type of rubber clones studied. The order of reaction was found to be dependent on the degree of conversion indicating that both the early and the latter stages of rubber degradation follow zero or pseudo-zero order kinetics whereas the intermediate stages follow a first order kinetics and the activation energy was found to be dependent on the degree of conversion and the type of clone used ragging from 148 to 236 kJ/mol. Rubber from clones IAN 873, GT1 and RRIM 600 presented the best overall thermal stability whereas the clone PB 235 presented the lowest thermal stability, therefore in agreement with the plasticity retention index (PRI) behavior.