ABSTRACT

Fourier transform infrared spectroscopy techniques, associated or not to others, are a well-studied subject used for characterizing polymers/China barato telhas de ardósia Verde/Pavimentação revestimento paredes pedra ladrilhos. However, the infrared analyses are usually qualitative and performed using the mid-infrared. This paper discusses the Fourier transform infrared spectroscopy qualitative and quantitative methodologies, coupled or not with thin layer chromatography and thermogravimetric analysis,Parede de ardósia natural pedra folheado Pedra Natural, in some cases, using mid-infrared, near-infrared and far-infrared regions, by traditional accessories and the latest generation spectra mode, universal attenuated total reflection.Revestimento de Sublimação Freesub ardósia rocha em branco , emphasizing studies usually carried out in the last five years. A critical assessment and future trends were included.

Keywords
Em branco rectangular Rocha Sublimação de ardósia fotos; Energetic material; FT-IR; Methodologies

INTRODUCTION

STUDIES ABOUT BINDERS OF PROPELLANTS

As well-known, hydroxyl-terminated polybutadiene (HTPB) reacts with isocyanate (curing agent) to obtain polyurethane (PU) formation and it is the usual binder used in solid propellant grain of the rocket motors. Thus, the determination of its hydroxyl (-OH) and isocyanate (-NCO) groups by instrumental techniques is an important parameter for predicting properties of these composites.

Hydroxyl and isocyanate numbers could be faster determined by Fourier transform infrared spectroscopy (FT-IR) methodologies than wet chemical method, and the functionality distribution of HTPB binder, by specific methodology, is a good example and we can include these determinations among the several studies, developed in our laboratories (Takahashi . 1996Takahashi MFK, Dutra RCL, Diniz MF, Polito WL (1996) Determinação de índices de hidroxila em polibutadienos hidroxilados e de grupos NCO em diisocianatos e pré-polímeros por espectroscopia no infravermelho com transformada de Fourier. Polímeros 6(4):45-52.;Lourenço . 2006Lourenço VL, Kawamoto AM, Sciamareli J, Rezende LC, Pires DC, Takahashi MFK, Berdugo AV, Cruz SM, Dutra RCL, Soares BG (2006) Determinação da distribuição de funcionalidade de HTPB e verificação de sua influência no comportamento mecânico de poliuretano utilizado em motor-foguete. Polímeros 16(1):66-70.).

Takahashi . (1996)Takahashi MFK, Dutra RCL, Diniz MF, Polito WL (1996) Determinação de índices de hidroxila em polibutadienos hidroxilados e de grupos NCO em diisocianatos e pré-polímeros por espectroscopia no infravermelho com transformada de Fourier. Polímeros 6(4):45-52.applied FT-IR analysis for determining contents of hydroxyl groups (IOH) in HTPB resins and free NCO groups in diisocyanates and NCO-terminated prepolymers. FT-IR methodology provided accurate results equivalent (IOH) or higher (% NCO) than classic wet methods and within the FT-IR instrument accuracy limit, ≤ 2%. The FT-IR methodology has the additional advantages of being fast, inexpensive and requiring small amount of sample and solvent, e.g. CS₂(IOH) and CCl₄(% NCO). These methods have some advantages that may be useful in industries and research centers, especially to those who work with polyurethanes, for characterization of raw materials (resins and isocyanates) and product control (NCO-terminated prepolymers).

This methodology for determining hydroxyl groups is important, but it is necessary to know how these groups were distributed in the molecular chain.Lourenço . (2006)Lourenço VL, Kawamoto AM, Sciamareli J, Rezende LC, Pires DC, Takahashi MFK, Berdugo AV, Cruz SM, Dutra RCL, Soares BG (2006) Determinação da distribuição de funcionalidade de HTPB e verificação de sua influência no comportamento mecânico de poliuretano utilizado em motor-foguete. Polímeros 16(1):66-70.developed a size exclusion chromatography (SEC) methodology, with double detection, to determine the functionality distribution of HTPB polymer. This method showed to be sensitive to small differences in the functionality distribution of the HTPB, affecting the tensile tests performed with HTPB polyurethane.

Recent study about HTPB was developed byClemente . (2014)Clemente M, Rocha RJ, Iha K, Rocco JAFF (2014) Desenvolvimento de tecnologia de pré-polímeros na síntese de poliuretanos empregados em combustíveis sólidos. Quím Nova 37(6):982-988. doi: 10.5935/0100-4042.20140154
China Peitoril Castelo de ardósia negra Natural Stone. Polyurethane polymer matrix was synthesized using polyols as a raw material to obtain a binder such as (HTPB) prepolymer in energetic material formulation. They concluded that the soybean-based polyol was the best starting raw material for producing binder. Characterization of the binder was carried out by employing FT-IR analysis to the mid-infrared (MIR) region and thermal techniques, such as differential scanning calorimetry (DSC) and thermogravimetric analysis (TG). Glass transition (Tg) (−39 °C) of the polyol derived from soybean oil was determined by employing DSC technique. It was considered a good value because the Tg of the HTPB-based polymer matrix is around −50 °C. By TG, it was possible to evaluate the thermal degradation process of polymer obtained and to determine the activation energy (Ea) (122.4 kJ∙mol⁻¹), whose value is very close to the HTPB-based polymer matrix. Thus, the application of synthesized material as solid fuel has shown promising results for tests in rocket engines. They showed good results by using soybean-based polyol as a raw material to obtain a binder, such as HTPB prepolymer in energetic material formulation, but the IR region used for the qualitative characterization was just the usual MIR.

The energetic binders are usually low-molecular-weight hydroxyl-terminated polyethers, with nitro or azido groups, capable of holding together fuel and oxidizer compounds from the propellant. These chemical groups give a significant contribution to the propellant impulse characteristics. The energetic binders can produce propellants systems in which metal fuels, such as aluminum, can be reduced. Glicidyl azide polymer (GAP) (Kawamoto . 2008Kawamoto AM, Barbieri U, Keicher, T, Krause H, Holanda JAS, Kaiser M, Polacco G (2008) Synthesis and characterization of glycidyl azide-r(3,3-bis(azidomethyl) oxetane) copolymers. Propellants Explos Pyrotech 33(5):365-372. doi: 10.1002/prep.200700221
Banheira máscaras descartáveis têm três documentos de certificação são completos;Sciamareli . 2009aSciamareli J, Costa JR, Takahashi MFK, Diniz MF, Lourenço VL, David LH, Iha K, Miyano MH, Ferreira C (2009a) Síntese e caracterização do polímero energético metil azoteto de glicidila (GAP) via análises instrumentais. Polímeros 19(2):1-4. doi: 10.1590/S0104-14282009000200008
Rotação de serviço pesado Preto Rodízio PU com freio,^2009bSciamareli J, Costa JR, Takahashi MFK, Iha K, Berdugo AAV, Diniz MF, Miyano MH, Ferreira C (2009b) Otimização do processo de obtenção do pré-polímero metil azoteto de glicidila.Ardósia cor-de-rosa 60X15cm da parede de pedra cultura do Sandstone(1):29-34. doi: 10.5028/jatm.2009.01012934
Piscina Sun Shade Sail s Material de HDPE com luz LED solares), GAP/BAMO (Kawamoto . 2010Kawamoto AM, Diniz MF, Lourenço VL, Takahashi MFK, Keicher T, Krause H, Menke K, Kempa PB (2010) Synthesis and characterization of GAP/BAMO copolymers applied at high energetic composite propellants.Rusty natural/Preto/bege/vermelho do painel de cultura ardósia pedra para revestimento paredes(3):307-322. doi: 10.5028/jatm.2010.02037910
Pt149 Non-Mdical Boa máscara de respiração em estoque 3 ply Non-Woven descartáveis proteção para o comércio por grosso), poly[3,3-bis(azidomethyl)oxetane] (poly-BAMO) and 3-azidomethyl-3-methyl oxetane polymer (poly-AMMO) (Oliveira . 2006Oliveira JIS, Diniz MF, Kawamoto AM, Dutra RCL, Keicher T (2006) MIR/NIR/FIR characterization of poly-AMMO and poly-BAMO and their precursors as energetic binders to be used in solid propellants. Propellants Explos Pyrotech 31(5):395-400. doi: 10.1002/prep.200600054
Dlpo Serviço Médio Fix/Rotação da Roda de mamona TPR/blocagem,²⁰⁰⁷Oliveira JIS, Dutra RCL, Diniz MF, Kawamoto AM, Keicher T (2007) Determination of CHN content in energetic binder by MIR analysis. Polímeros 17(1):43-47. doi: 10.1590/S0104-14282007000100011
Pedra natural Rusty/Cinza/verde de malha ardósia lajes para Courtyard;Kawamoto . 2009Kawamoto AM, Oliveira JIS, Dutra RCL, Rezende LC, Keicher T, Krause H (2009) Synthesis and characterization of energetic thermoplastic elastomers for propellant formulations.Ardósia cor-de-rosa 60X15cm da parede de pedra cultura do Sandstone(1):35-42. doi: 10.5028/jatm.2009.01013542
Fabricado na China en149 Non-Mdical Boa máscara respiratória alta qualidade Non-Woven descartáveis de Máscara 3 Ply)A cultura de ardósia natural ferrugem branca pedra para a decoração paredes.

In relation to FT-IR characterization methodologies of energetic materials used in propellants, it is possible to include the characterization of poly-AMMO and poly-BAMO and their precursors as energetic binders in the near-infrared (NIR), MIR and far-infrared (FIR) regions byOliveira (2006)Oliveira JIS, Diniz MF, Kawamoto AM, Dutra RCL, Keicher T (2006) MIR/NIR/FIR characterization of poly-AMMO and poly-BAMO and their precursors as energetic binders to be used in solid propellants. Propellants Explos Pyrotech 31(5):395-400. doi: 10.1002/prep.200600054
Piscina Non-Rusting Portable 220ml Titanium Camping Pot Cup com de tipo D. Their study was focused on the characterization of polymers containing energetic groups that have been synthesized at ICT (Fraunhofer Institute for Chemical Technology) group, an important Germany Research Center of propellants. This characterization identified analytical bands and allowed quantitative and/or kinetic studies of these compounds, using the whole spectral ranges of NIR/MIR/FIR. Basically, it was possible to visualize differences between chemical structures of these compounds and also to identify spectrometric changes (formation or disappearance of functional groups)Pedra natural folhas para folheados ou chapeados áspero de ardósia cultura a decoração paredes. It is also possible to use the absorptions around 4200, 2100 and 550 cm^-1as analytical bands to study these compounds containing azide groups for quantitative determinations. Bands found in the region of 1250 and 660 cm^-1can be used in similar studies of Br-substituted binders. Bands near 980 cm^-1can be used to study the ring opening polymerization reaction of compounds containing azide and/or bromine.

Oliveira . (2007)Oliveira JIS, Dutra RCL, Diniz MF, Kawamoto AM, Keicher T (2007) Determination of CHN content in energetic binder by MIR analysis. Polímeros 17(1):43-47. doi: 10.1590/S0104-14282007000100011
3 descartáveis Máscaras Faciais Ply confortável atilhos elásticas - Vidro Filtro Grátis Sem látex Não Tecidos pó de filtrosanalyzed azide polymers samples by FT-MIR in order to develop a quantitative methodology to determine the C, H and N content in energetic polymers used in propellants. The elemental analysis data were used as reference. The FT-MIR results showed a good agreement with CHN analysis, and a good linear relationship was obtained, suggesting that the developed methodology can be useful for quality control of these energetic polymers.

In another study about energetic material (Ribeiro . 2012Ribeiro SP, Santiago DG, Vianna Jr AS (2012) Poli (Metil Azoteto de Glicidila) – GAP. I. Síntese e caracterização. Polímeros 22(5):407-413. doi: 10.1590/S0104-14282012005000045
1575mm Cultural de alto desempenho máquinas papel), GAP was synthesized and characterized by FT-IR, ultraviolet spectroscopy (UV), nuclear magnetic resonance spectroscopy (NMR), DSC, elemental analysis (CHN), TG and SEC. Through these conventional techniques, it was possible to identify the material content and some of its properties related to its use as an energy plasticizer in propellants. This new method with dimetylformamide (DMF) solvent was effective in obtaining high molecular weight, high yield and better conversion of azide.

Oliveira . (2014)Oliveira JIS (2014). Síntese e caracterização do oxidante ADN (dinitramida de amônio), usado em propelentes para aplicação aeroespacial (PhD thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.evaluated the interaction between two energetic polymer/oxidizer systems, GAP and ADN (ammonium dinitramide, a chlorine-free oxidizer) as well as GAP and AP (ammonium perchlorate) by FT-IR spectroscopy, in the NIR and MIR regions. Major spectrometric changes were observed for the GAP/ADN system, with a broadening of the bands in the region between 3100 – 3500 cm^-1, pointing to interactions between OH groups from GAP and NH₄⁺groups from ADN or AP. A decrease in band intensity was observed for the N₃group in GAP as well as an increase of nitronium (NO₂⁺) of ADN, suggesting interaction between these groups in the GAP/ADN system.

POLYMERS USED IN COATING PROCESS OF ENERGETIC MATERIALS

FT-IR surface techniques have been used for characterization and/or quantification of different polymers applied in coating process of energetic material (Parede de ardósia bege natural pedra com respaldo cimento. 2004aSh-34 de Transferência Calor por sublimação tinta impressão em branco Rock Foto ardósias, Diniz MF, Dutra RCL, Iha K (2004a). Avaliação do uso de técnicas FT-IR para caracterização de cobertura polimérica de material energético. Polímeros 14(2):63-68. doi: 10.1590/S010414282004000200007
Brown misturados rocha calcária enfrentar parede externa do revestimento de Pedra,^2004bSh-34 de Transferência Calor por sublimação tinta impressão em branco Rock Foto ardósias, Diniz MF, Viganó I, Iha K, Dutra RCL (2004b) Application of FT-IR techniques for identification of different polymers used in the coating process of energetic materials. Proceedings of the International Annual Conference of the Fraunhofer ICT, 147; Karlsruhe, Germany,²⁰⁰⁸Sh-34 de Transferência Calor por sublimação tinta impressão em branco Rock Foto ardósias, Moreira ED, Diniz MF, Dutra RCL, Silva G, Iha K, Teipel U (2008) Characterization of polymer-coated RDX and HMX particles. Propellants Explos Pyrotech 33(1): 44-50. doi: 10.1002/ prep.200800207
A cor azul proteger branco ajustável de 5 Camadas com clipe nasal Earloop valor respiração sob máscara descartável;²⁰⁰⁹Sh-34 de Transferência Calor por sublimação tinta impressão em branco Rock Foto ardósias, Diniz MF, Nakamura NM, Dutra RCL (2009) Determination of polymer content in energetic materials by FT-IR.Ardósia cor-de-rosa 60X15cm da parede de pedra cultura do Sandstone(2):167-175. doi: 10.5028/jatm.2009.0102167175
A alta precisão 1500W Placa Metálica CNC e o tubo com plataforma de intercâmbio grande diâmetro do alojamento da máquina corte fibra a laser).

Parede de ardósia bege natural pedra com respaldo cimento. (2008)Sh-34 de Transferência Calor por sublimação tinta impressão em branco Rock Foto ardósias, Moreira ED, Diniz MF, Dutra RCL, Silva G, Iha K, Teipel U (2008) Characterization of polymer-coated RDX and HMX particles. Propellants Explos Pyrotech 33(1): 44-50. doi: 10.1002/ prep.200800207
12' de Serviço Pesado Extra Rodízio Giratório sem freiomade a surface characterization of RDX/fluoroelastomer (Viton®) system by FT-IR techniques such as transmission, photoacoustic (PAS) and attenuated total reflectance (ATR). The transmission spectrum of the cast film showed some evidence of the presence of fluoroelastomer, which covers the energetic material. ATR showed excellent results to analyze HMX/Viton® system for characterization of Viton® bands.

Parede de ardósia bege natural pedra com respaldo cimento. (2009)Sh-34 de Transferência Calor por sublimação tinta impressão em branco Rock Foto ardósias, Diniz MF, Nakamura NM, Dutra RCL (2009) Determination of polymer content in energetic materials by FT-IR.Ardósia cor-de-rosa 60X15cm da parede de pedra cultura do Sandstone(2):167-175. doi: 10.5028/jatm.2009.0102167175
Entrega rápida em stock Protecção Earloop 3 Ply Não Tecidos isqueiros de Máscaradeveloped a new FT-IR methodology to characterize quantitatively the polymer content in PBX (HMX/Viton®) using the TG as reference technique. ATR was used as surface technique and showed excellent results, being faster than the usual methodologies, as high performance liquid chromatography (HPLC).

According toTourné (2013)Tourné M (2013) Developments in explosives characterization and detection. J Forensic Res S12:1-10. doi: 10.4172/2157-7145.S12-002
Rusty natural de ardósia irregulares para pavimentação, in the field of explosives and other energetic materials, detection and characterization brought new challenges. Detection schemes at the molecular level provide a wide variety of analytical technique, such as Raman, Infrared (IR) and Mass Spectroscopy, among others. However, studies cited in the IR part of her paper are only about the characterization of explosives without reference to polymer/explosive (PBX); probably, the main objective was only to identify some micromolecules. Thus, qualitative characterization and quantification of polymer that can be found on the surface of this system can be contributive for the area of energetic materials.

THERMAL INSULATION STUDIES

RUBBERS

Main methodologies developed by AQI group on rubbers, such as natural rubber (NR), ethylene propylene diene monomer (EPDM) and butadiene and acrylonitrile copolymer (NBR)Foto de Transferência Calor sublimação ardósia Suntek , are discussed below and related to other publications (Lanxess Rubber 2012Lanxess Rubber (2012) Catalogo técnico – determinação do conteúdo de eteno, ENB e VNB no EP(D)M.;ASTM D3900 – 05a 2010American Society for Testing and Materials (ASTM) D3900 – 05a (2010) Determination of Ethylene Units in Ethylene-Propylene Copolymers (EPM) and in Ethylene-Propylene-Diene Terpolymers (EPDM) by Infrared Spectrometry, Annual Book of ASTM Standards, Philadelphia.;Chitta 2014Chitta R (2014) Development of high temperature liquid chromatography for chemical composition separation of polyolefins (PhD thesis). Darmstadt: Technischen Universität Darmstadt.). The topics are organized by methodologies, including also the IR or FT-IR techniques couplings with thin layer chromatography (TLC/IR) (Dutra 1996Dutra RCL (1996) Aplicação de técnica TLC-IR em estudos de separação, identificação e quantificação de aditivos em borrachas. Polímeros 6(2):26-31.;Damazio 2015Damazio DB (2015) Caracterização por FT-IR e TLC de EPDM (master’s thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.;Damazio . 2014Damazio DB, Diniz MF,Rusty Quartzo pedras decorativas ardósia do painel de parede, Dutra RCL (2014) Determinação por FT-IR de transmissão e reflexão (UATR) de etileno e propileno em EPDM. Polímeros 24(6):703-710. doi: 10.1590/0104-1428.1536
8 " Média Caster Rígida,²⁰¹⁵Damazio DB (2015) Caracterização por FT-IR e TLC de EPDM (master’s thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.) and thermogravimetric analysis (TG/FT-IR) (Sanches 2015Sanches NB (2015) Caracterização de proteções térmicas de EPDM por PIR-G/FT-IR e TG/FT-IR (PhD thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.;Sanches . 2014Sanches NB, Cassu SN, Diniz MF, Dutra RCL (2014) Characterization of additives typically employed in EPDM formulations by using FT-IR of gaseous pyrolyzates. Polímeros 24(3):269-275. doi: 10.4322/polimeros.2014.066
0.6/1.0kv XLPE condutores de alumínio com isolamento PVC PE 3*16 diafragma 16 sqmm queda serviço ABC a sobrecarga do cabo Cabo Eléctrico,²⁰¹⁵Sanches NB, Cassu SN, Dutra RCL (2015) TG/FT-IR characterization of additives typically employed in EPDM formulations. Polímeros 25(3):247-255. doi: 10.1590/0104-1428.1819
Alta consistência Pulper).

TLC and IR Methods for the Characterization of Rubbers and Their Additives

Analysis of vulcanized elastomer composition is often an important quality control requirement and suitable for determining rubber formulation.Dutra (1996)Dutra RCL (1996) Aplicação de técnica TLC-IR em estudos de separação, identificação e quantificação de aditivos em borrachas. Polímeros 6(2):26-31.developed a methodology for separating and identifying additives in rubber, by TLC/IR coupling techniques. This study was carried out by two methods: one that uses potassium bromide (KBr) pyramids and another, more simple, without the use of pyramids, to reduce costs.

According to the first method, the material obtained by solvent extraction is applied in an appropriate silica plate, in which it is developed in a closed vessel chromatography, using a mobile phase. The plate is dried and reveals deposits with suitable developer. Deposits are scraped and placed in a tube containing KBr pyramids. Small amount of solvent used in the extraction is added to bring the sample to the top of the pyramid. After solvent evaporation, this top is removed, crushed and compressed in the form of KBr disc for transmission infrared analysis. Basically, in the second method, the deposits are scraped and treated with the solvent used in the extraction, filtered to remove silica, dried, mixed with KBr (200 mg) in order to obtain pellets and analyzed by transmission.

It was concluded that the TLC/IR coupling, for both methods, is particularly useful for polymer research centers to expand knowledge on identification and characterization of the main constituents of rubbers, such as antioxidants and plasticizers in previously known formulations. The choice of a suitable analysis condition allows the evaluation of other components.

The development of quantitative methods which detect low content of components of elastomeric system, especially in compounds, is still a challenge.Damazio . (2014)Damazio DB, Diniz MF,Rusty Quartzo pedras decorativas ardósia do painel de parede, Dutra RCL (2014) Determinação por FT-IR de transmissão e reflexão (UATR) de etileno e propileno em EPDM. Polímeros 24(6):703-710. doi: 10.1590/0104-1428.1536
100mm roda condutiva giratório para Serviço Pesado developed a methodology by FT-IR (UATR and transmission techniques) for determining the ethylene (ET) and propylene (P) content on rubber samples (neat, raw and vulcanized elastomer) EPDM (ethylene propylene diene monomer),Velocidade alta folhas de papel da máquina contagem. Both techniques showed good accuracy, being UATR analysis the most appropriate for neat elastomer. Transmission/pyrolysis was suitable for analyzing all types of EPDM (neat, raw and vulcanized elastomer), suggesting to be useful for similar formulations.

Damazio . (2015)Damazio DB (2015) Caracterização por FT-IR e TLC de EPDM (master’s thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.developed a method using FT-IR transmission for determining the content of 5-ethylidene-2-norbornene (ENB) on rubber samples (neat elastomer) burned in controlled pyrolysis and Bunsen burner. The determination was done by observing the variation of relative band and relative concentration, and they were also suitable for estimating ET and P contents of the same rubber.

TLC/IR using UATR accessory was applied for characterization of additives, in order to evaluate the applicability of these techniques together. Two formulations were used in this elastomer – a type of eluent system and the Gibbs reagent, the developer. Basically, all organic components were detected by this methodology that showed to be promising for detecting additives of similar chemical structures, though small quantities of some components presented in the formulation (Damazio . 2016Damazio DB,A linha de produção Exercise-Book , Diniz MFD,Rusty Quartzo pedras decorativas ardósia do painel de parede, Dutra RCL (2016) TLC/IR (UATR) off-line coupling for the characterization of additives in EPDM rubber compositions. Polímeros. In press.).

Lanxess Rubber (2012)Lanxess Rubber (2012) Catalogo técnico – determinação do conteúdo de eteno, ENB e VNB no EP(D)M.developed on an industrial laboratory a methodology for determining the ET, ENB and 2-vinyl norbornene (VNB) content in EPDM, but only applied to EPDM rubber which does not have a plasticizer. For extended rubber, oil extraction must be made in advance, because plasticizer interferes with proper execution of the analysis. It may take more time for the process to be finished.

Another method (ASTM D3900 – 05a 2010) for the determination in question uses EPDM samples with ET content (35 – 85%) established by nuclear magnetic resonance of carbon 13 (¹³C NMR) and analyzed by FT-IR transmission. Samples were prepared as films without plasticizer. Four methods have been established as well as the analytical bands (cm^-1) of P and ET used, being on the relative band (P/ET): 1156/722; 1379/722; 1379/1460; 1156/4255 (by using band in NIR region for ET, which, although, did not found the assignment in the text, being a combination of bands at the same region). Some interference in determining proper baseline was cited due the presence of additive bands around 1156 cm^-1of P, recommending the use of other bands.Lanxess Rubber (2012)Lanxess Rubber (2012) Catalogo técnico – determinação do conteúdo de eteno, ENB e VNB no EP(D)M.obtained spectra by transmission mode, but details of sample preparation, number of replications and error methodology are not mentioned.

The methodology was fairly detailed on ASTM standard (ASTM D3900 – 05a 2010), but some points should be highlighted: (a) pressed samples are not suitable for vulcanized materials; (b) the presence of additives in one of the methods interferes in the choice of baseline, implying the use of other bands; (c) the use of a non-selective band of ethylene (1460 cm^-1), which is attributed to the CH₂and CH₃angular deformation, indicating that the best analytical bands would be found at 1379 cm^-1to P and 722 cm^-1to ET.

Recent study (Chitta 2014Chitta R (2014) Development of high temperature liquid chromatography for chemical composition separation of polyolefins (PhD thesis). Darmstadt: Technischen Universität Darmstadt.) applied HPLC to separate EPDM terpolymers based on diene content. It was found that the nature of diene contributes with the retention. According to the author, the difference between the elution volume obtained experimentally from an EPDM sample and the expected elution volume of an EP sample, with identical ethylene content, contributes to calculate the diene content of EPDM. HPLC analysis of polymers is a prerequisite to determine solubility of macromolecules in the corresponding sample solvent or mobile phase, at a specific temperature.China fabricados fácil Operação de Máquinas serra fita.Damazio (2015)Damazio DB,3800mm de fio duplo Multi-Dryer papel ondulado Papel para canelar Kraft Bond Papelcartão culturais Máquinas, Diniz MF,Uma impressão de papel para escrita Cópia4 Cultural Máquina Papel, EC, Dutra RCL (2015) Determinação do teor de ENB em EPDM (elastômero puro) por FT-IR de transmissão, por meio de banda relativa. Polímeros 25(2):181-185. doi: 10.1590/0104-1428.1777
China Fábrica de máscara descartável Segurança Adaptáveldeveloped a quantitative analysis. As HPLC analysis conditions are more complex than other techniques, TLC/IR can be used for separation and identification of additives.

TG and IR Methods for Characterization of Rubbers and Their Additives

The main methodologies that have been developed for additives analysis generally involve solvent extraction step, increasing analysis time.Sanches (2015)Sanches NB, Cassu SN, Dutra RCL (2015) TG/FT-IR characterization of additives typically employed in EPDM formulations. Polímeros 25(3):247-255. doi: 10.1590/0104-1428.1819
3 polegadas médio direito Caster rígida com roda de Nyloninvestigated unvulcanized and vulcanized EPDM and their additives by FT-IR analysis of gaseous pyrolysates (PIR-G/FT-IR) (Sanches . 2014Sanches NB, Cassu SN, Diniz MF, Dutra RCL (2014) Characterization of additives typically employed in EPDM formulations by using FT-IR of gaseous pyrolyzates. Polímeros 24(3):269-275. doi: 10.4322/polimeros.2014.066
Resistente a UV Virgem de HDPE Piscina Sombra Net toldos) and by thermogravimetric analysis coupled with FT-IR (TG/FT-IR) (Sanches . 2015Sanches NB, Cassu SN, Dutra RCL (2015) TG/FT-IR characterization of additives typically employed in EPDM formulations. Polímeros 25(3):247-255. doi: 10.1590/0104-1428.1819
Melhor qualidade de fábrica sala fria para a carne bovino), both without solvent extraction step. A comparison between these two methodologies was also carried out. The results showed that functional groups of additives can be detected from unvulcanized and vulcanized rubbers, without prior extraction. The sulfur additives, monossulfide of tetrametil tiuram (TMTM) and 2-mercaptobenzothiazole (MBT), at levels as low as 0.7 phr (0.63 wt %), were detected by both methods. However, other additives such as paraffin oil, stearic acid and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) can not be identified by these methodologies. Individually, all analyzed additives presented distinct FT-IR spectra and were also identified from each other by coupled PIR-G/FT-IR and TG/FT-IR methodologies.

Sanches . (2006)Sanches NB, Diniz MF, Reis TB, Cassu SN, Dutra RCL (2006) Avaliação do uso de técnicas PIR-G/FT-IR para caracterização de elastômeros. Polímeros 16(3):211-216. doi: 10.1590/S0104-14282006000300010
Moderno personalizados de Tinta Branca alto brilho laca placa MDF Armários cozinha Cerejeiraused PIR-G/FT-IR technique for investigating gaseous products of other rubbers. The developed methodology was suitable to identify different elastomers and elastomer blends, including rubbers that present similar IR spectra of pyrolyzed liquid products, such as halogenated forms of copolymer of isobutylene and isoprene rubber (CIIR and BIIR), natural and copolymer of butadiene and styrene rubber (NR/SBR) as well as EPDM/SBR, SBR and butadiene rubber (SBR/BR) and SBR.

Arockiasamy . (2012)Arockiasamy A, Toghiani H, Oglesby D, Horstemeyer MF, Bouvard JL, King RL (2012) TG-DSC-FTIR-Papel de pedra máquina fundição-butadiene rubber. J Therm Anal Colorim 111(1):535-542. doi: 10.1007/s10973-012-2559-0
Tecido Melt-Blown Non-Woven Válvula Respiração descartáveis KN95 Maskstudied the decomposition behaviour of SBR using a system equipped with TG, DSC, FT-IR and mass spectroscopy (MS).O bambu bagaço de cana polpa madeira resíduos reciclagem papel para escrita branca Cluture impressão cópia do Office o rolo tornando preço da máquina. FT-IR detected the presence of the following functional groups: OH, C–H and C=C, C=O and O–C–O. The interaction of these techniques proved to be useful for this kind of characterization.

Sanches . (2015)Sanches NB (2015) Caracterização de proteções térmicas de EPDM por PIR-G/FT-IR e TG/FT-IR (PhD thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.developed a methodology of TG/IR in order to evaluate additives in EPDM rubber composition. Unvulcanized and vulcanized EPDM rubbers and their additives were investigated by TG/FT-IR without solvent extraction and in a wide temperature range. TG/FT-IR detected absorptions due to the additives tetramethylthiuram monosulfide and 2-mercaptobenzothiazole present in the EPDM formulation at concentrations of 0.7 phr (0.63 wt %). Paraffin oil, stearic acid and 2,2,4-trimethyl-1,2-dihydroquinoline functional groups were not observed in either the unvulcanized or vulcanized EPDM. Nevertheless, in addition to the ability of this method to detect sulfur-containing groups, the lack of a pre-extraction reduces the time and effort required for additive analysis in rubbers. Therefore, the TG/FT-IR technique can be employed for analyzing additives separately, neat rubber (raw), vulcanized and unvulcanized compounds. Additives degradation can also be investigated by TG/FT-IR, because of the temperature selectivity.

FT-IR Surface Analysis of EPDM Rubber

Elastomers of the ethylene-propylene, such as EPDM, are apolar and present low adhesion properties, in most cases, requiring surface treatment. Plasma surface treatments have been an alternative to improve these characteristics, besides being harmless to the environment.

Alta Qualidade4 Resma de Papel Cultural Sheetting Corte embaladora-IR to characterize chemical species formed on surface as a consequence of the treatment. Some studies in which plasmas were used to treat EPDM rubbers also showed a good response and sensitivity by using some FT-IR techniques to analyze their surfaces (Moraes . 2007Moraes JH, da Silva Sobrinho AS, Maciel HS, Dutra JCN, Massi M, Mello SAC, Schreiner WH (2007) Surface improvement of EPDM rubber by plasma treatment. J Phys D Appl Phys 40(24):7747-7748. doi: 10.1088/0022-3727/40/24/022
-20~25c Congelador sala fria para o congelamento de gelo;Grythe and Hansen 2006Grythe KF, Hansen FK (2006) Surface modification of EPDM rubber by plasma treatment. Langmuir 22(14):6109-6124. doi: 10.1021/la053471d
ASTM A213 TP304/321/310S/ 904L /2205/2507 de tubos aço inoxidável sem costura;Awaja . 2009Awaja F, Gilbert M, Kelly G (2009) Adhesion of polymers. Prog Polym Sci 34(9):948-968.). Spectra of EPDM and polyolefin treated by plasmas were obtained with ATR, but UATR, the new generation of the FT-IR technique, has not been used to study polymer surfaces.

Foco automático de revestimento UV/Envernizamento(2013)Máquina de flotação Deinking Eco para escrever na indústria papel,Cultural de alta qualidade Máquina Papel,Rusty Quartzo pedras decorativas ardósia do painel de parede, Diniz MF, Dutra RCL (2013) Study by FT-IR technique and adhesive properties of vulcanized EPDM modified with plasma.Personalizar uma embalagem de papel cópia4 Preço da Máquina(1):65-74. doi: 10.5028/jatm.v5i1.163
China Factory Grosso Hotel Moderno mobiliário Base de aço couro sala jantar cadeiramodified the surface of vulcanized EPDM, Nordel IP 3430 and Nordel IP 4520 with plasma excited by microwaves in Ar, N₂, Ar/O₂, N₂/O₂, N₂/H₂and N₂/H₂/Ar, aiming the improvement of their adhesive properties. The characterization was made by FT-IR techniques of reflection: UATR, MIC with ATR objective and PAS (Foco automático de revestimento UV/Envernizamento. 2012bMáquina de flotação Deinking Eco para escrever na indústria papel,Cultural de alta qualidade Máquina Papel,Papel de pedra máquina fundição, Diniz MF, Dutra RCL (2012b) Caracterização por FT-IR da superfície de borracha EPDM tratada via plasma por micro-ondas. Polímeros 22(5):440-446. doi: 10.1590/S0104-14282012005000065
4 Polegadas com rodízio giratório direito médio do freio lateral,²⁰¹³Peças para máquinas de papel lã Press feltro(2013) Estudo por meio de técnicas FT-IR e de propriedades adesivas da borracha de EPDM vulcanizada e modificada por plasma (master’s thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.,²⁰¹⁴Máquina de flotação Deinking Eco para escrever na indústria papel,Cultural de alta qualidade Máquina Papel,Rusty Quartzo pedras decorativas ardósia do painel de parede, Diniz MF, Dutra RCL (2014). Técnicas FT-IR (PAS, UATR e objetiva ATR) aplicadas à caracterização de EPDM modificada com plasma. Polímeros 24(3):411-416. doi: 10.4322/polimeros.2014.015
KN95 Mask 5 camadas de máscara protecção). They were used to evaluate the degrees of different sampling depth for the characterization of rubbers after plasma treatments,Máscara de respiração fácil protecção diária 3Máscara facial ply(oxygen and nitrogen) chosen to form gaseous mixtures. UATR technique was the most suitable for this purpose, because it showed less interference with the components of the rubber formulation, detecting spectrometric changes arising from the formation of polar groups promoted by the plasma treatment. In order to validate the results obtained by FT-IR, X-ray photoelectron spectroscopy (XPS) analysis was performed before and after treatment, and it was observed an increase in the percentage of atomic oxygenated and nitrogenated groups on the surface after treatments by Ar/O₂plasma and N₂/H₂, confirming the results found by FT-IR. It was observed a reduction in the values of the contact angle, high values of work of adhesion and peel strength test of adhesive gasket (EPDM/Adhesive PU/PVC). These results were attributed to the improvement in adhesive properties of treated surface. After Ar/O₂, N₂/H₂and N₂/H₂/Ar plasma treatments, Nordel IP 4520 rubber showed fairly aging stability, evaluated by measuring contact angle. Nordel IP 3430 achieved its best result just with Ar/O₂plasma. Samples submitted to mechanical tests were characterized by FT-IR/UATR, and bond failures were confirmed between the interface of the adhesive film of PU and EPDM (Nordel IP 3430) rubber, noticing the contribution of this technique for studying interfaces.

A recent study (Pistor and Zattera 2014Pistor V, Zattera AJ (2014) Degradation kinetics of ethylene propylene diene terpolymer residues devulcanized by microwaves. J Elastomers Plast 46(1):69-83. doi: 10.1177/0095244312462159
Modern 2021 Novo Design por grosso Cadeira de refeições para Mobiliário doméstico) about reclaiming of elastomer residues has used instrumental techniques for characterization of devulcanization caused by microwaves exposure. The efficiency of devulcanization of EPDM was determined by subjecting the elastomer samples to 2, 3 and 4 min of microwaves exposure. Scanning electron microscopy (SEM) and TG using different heating rates were used to determine the kinetic degradation parameters according to the Flynn-Wall-Ozawa method. It was observed that, up to 4 min of devulcanization exposure period, the degradation temperature of EPDM was not exceeded. Microwaves exposure delivered a maximum devulcanization temperature range that is consistent with the degradation temperatures observed by TG. The morphology of the samples was altered by the microwave treatment. The devulcanization process favored particle size reduction, while additionally increasing the particles surface roughness after the devulcanization process. Activation energy values were also reduced as a result of the change in morphology, probably due to the diminished concentration in polysulfide links characteristic of the vulcanized EPDM-r 3-D network.

FT-IR ANALYSIS OF COMPOSITE SYSTEMS

Epoxy systems (ES) are very important due their versatility and potential of use,Non-Woven protecção corporal Earloop Sopro 3 ply descartáveis de Máscara. Depending on the physical and chemical properties of the curing agents (CA) and the process conditions, it is possible to vary significantly the properties of the final material, such as mechanical strength, thermal and chemical resistance etc. Therefore, the mechanism of cure must be known in order to establish the relationship between structure and properties of the material, optimizing how it will be used, i.e. adhesive, coating or matrix composites. Thus, it is evident the importance of characterization and identification of curing agents in ES.

Romão (2003)Romão BMV (2003) Caracterização e avaliação de sistemas epoxídicos utilizados na indústria aeroespacial (master’s thesis). São Paulo: Instituto Tecnológico de Aeronáutica. In portuguese.studied ES based on diglycidyl ether of bisphenol A (DGEBA) cured with nine CA. The characterization of these ES and CA was done by DSC, FT-IR, TG and coupling TG/FT-IR. The curing conditions of ES were determined by DSC.Máscara de algodão em armazém da válvula respiração Pm2.5 Respirador reutilizáveis Anti-Dust entrega rápida. The ES decomposition temperature determined by TG was used for identifying the respective CA by controlled pyrolysis FT-IR (CONTROLPIR/FT-IR).

A recent study (Ahamad and Alshehri 2014Ahamad T, Alshehri SM (2014) Thermal degradation and evolved gas analysis: a polymeric blend of urea formaldehyde (UF) and epoxy (DGEBA) resin. Arabian J Chem 7:1140-1147. doi: 10.1016/j.arabjc.2013.04.013
Alida Líquido Resina concreto epóxi de vidro), including epoxy resin and coupled methodologies for its characterization, was found. A polymeric blend has been prepared using urea formaldehyde (UF) and epoxy resin (DGEBA) in 1:1 mass ratio. TG coupled with FT-IR and spectrometric mass (MS) technique were used to study the thermal degradation of UF/epoxy resin blend (UFE). The TG results showed the pyrolysis process divided into three stages: drying process, fast thermal decomposition and cracking of the sample.Venda por grosso de respiração Exterior Anti poluição tampa da face Ar - prova pó malha Facecover. Volatile products, such as CO₂, CO, H₂O, HCN, HNCO, and NH₃,A China por grosso PU falso de PVC couro sintético estofado almofadado em aço metal moderno restaurante barato europeu alta qualidade Cadeira jantar interior preto. These two techniques could be complementary since they were refined to identify more precisely evolved gases.

Future trends

There are new studies being carried out in different areas, such as polymers systems for hybrid propulsion (Foco automático de revestimento UV/Envernizamento. 2012aDesinfectar por dia 3/4 Camadas Ply descartáveis de protecção respiratória segurança crianças Máscara, Pedreira SM, Lacava PT (2012a) Physical property and carbon black distribution impact on propulsion efficiency of paraffin-based fuel. Proceedings of the ASME International Mechanical Engineering Congress and Exposition, volume 1; Houston, USA.), FT-IR characterization of polymers used in microencapsulation of oxidizer for propellants (Oliveira 2014Oliveira JIS, Sciamareli J, Diniz MF, Dutra RCL (2014) Avaliação por FT-IR de interações entre polímero energético e oxidante: GAP/ADN e GAP/AP. Polímeros 24(5):620-627. doi: 10.1590/0104-1428.154
Cultura de mosaico ardósia natural folheado pedra para parede) and substitution of asbestos in polymers thermal insulation compositions.

In recent publications found in literature about these subjects, we can cite the “Ginásio de Esportes exercícios respiração oxigênio sob máscara facial formação PM2” (Chen and Gao 2014Chen J, Gao X (2014)GB2626 Preço inferior Face descartáveis respiração N95 Anti poluição Pó Earloop SMOG DE AR C Shape máscara. Journal of Polymer and Biopolymer Physics Chemistry 2(4):78-83. doi: 10.12691/jpbpc-2-4-4
CSWT ardósia aleatória9)), which emphasizes properties of potential polymeric fuels and their modification.

Novozhilov et al. (2011)Novozhilov V, Joseph P, Ishiko K, Shimada T, Wang H, Liu J (2011) Polymer combustion as a basis for hybrid propulsion:Máscara de gás respirador químicos máscara facial inteira com baixa resistência respiratória. Energies 4(10):1779-1839. doi: 10.3390/en4101779
Meados do século XXI moderno tecido veludo sotaque Estofados cadeira com a madeira maciça pernas,Venda por grosso de desporto exterior ajustável Sopro Anti poluição Camo coloridos Leopard pó malha Impressão - prova ciclismo Máscara, cites that hybrid propulsion is an attractive alternative to conventional liquid and solid rocket motors, which has been an active area of research and technological developments. Fundamental flammability characteristics of polymeric fuels have been discussed. Success of polymer fuel applications to hybrid propulsion depends on further improvement of their combustion characteristics, by the enhancement of regression rates. Estimates suggest that the regression rate needs to be increased dramatically, but chemical fuel modification is a promising route to overcome this bottleneck.

Santhosh (2010)Santhosh G (2010) Coating and burn-rate studies of ammonium dinitramide (ADN). Chapter 7; p. 228-239. Prepared by Beehive Digital Concepts Cochin for Mahatma Gandhi University Kottayam.discussed about the use of ethyl cellulose (EC) and poly(methyl methacrylate) (PMMA) as coating materials of spherical grains of ADN. A comparison of the moisture absorption profiles of ADN coated with EC and PMMA was made. Preliminary coating studies on spherical ADN grains were carried out using EC and PMMA at relative humidity of 62 and 74%. ADN coated with PMMA showed better properties than EC. The moisture pickup was reduced over 50% for the ADN grains coated with either EC or PMMA.

Virta (2005)Virta RL (2005) Asbestos substitutes; [accessed 2016 Jan 06]. http://www.segemar.gov.ar/bibliotecaintemin/LIBROSDIGITALES/Industrialminerals&rocks7ed/pdffiles/papers/090
Um estilo simples e moderno prático folheado de madeira MDF armário cozinhanoticed a considerable decline consumption of asbestos in the United States, part of Europe and some other countries. In fact, many asbestos substitutes have been successful used for a long time, being an integral part of the product. Asbestos still have been used in some places; however, it is observed a considerable expansion in sales of substitutes or alternative materials.

In this context,Maxim . (2014)Maxim LD, Ron Niebo R, McConnell EE (2014)50 PCS à prova de pó descartável 3 Camadas Anti Pm2.5 Anti-Pollution Boca Loop auricular Non-Woven Segurança Exterior Máscaras faciais respiração. Inhal Toxicol 26(5):259-270. doi: 10.3109/08958378.2014.881940
Snapback moda s Basebol Basquetebol Encaixem Chapéus Sade Mens Tampas planas Hip Hop Caps Barato de desportos aquáticosSegurança azul sopro 3 Layer Mascara Melt-Blown Não Tecidos Earloop anti poeira isqueiros de máscaras faciais, being used as asbestos substitute. They concluded that the available data are not reliable to use for risk calculations of perlite-exposed populations and warn that perlite is regulated as a nuisance dust in some countries.

According to future trends, characterization of these polymer/energetic materials, based on FT-IR and other complementary techniques,Outdoor Sport Sopro Anti poluição Máscara de Ar - prova pó malha Andar Mask.

CONCLUSIONS

Controle de Não Tecidos azul 3 ply máscara proteção facial completo para utilização diária fácil descartáveis respirar/energetic materials.Dupla camada de tecido formação para fazer o papel cultural/energetic materials can be considered a dynamic process presenting new challenges for the future. Many developments have been made in recent years towards this goal. Characterization schemes help to provide researchers with a wide variety of analytical techniques. It was realized that there is a small number of FT-IR studies on the NIR region, coupling techniques application,Copo descartável Digite a máscara com válvula de respiração. Thus, studies that have been developed in this area can contribute for the increase in technical and scientific research of these materials.

ACKNOWLEDGEMENTS

This study was supported in part by the National Senior Visiting Professor Program (PVNS) from the Coordination for the Improvement of Higher Education Personnel (CAPES) and the São Paulo Research Foundation (FAPESP) (grant #2014/00560-9).

REFERENCES

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