Determinação do teor de ENB em EPDM (elastômero puro) por FT-IR de transmissão, por meio de banda relativa

Abstract

ResumoFoi desenvolvida uma metodologia para a determinação do teor de 5-etilideno 2-norboneno (ENB) em amostras de borracha (elastômero puro), à base do copolímero de etileno-propileno-dieno (EPDM), por espectroscopia no infravermelho com transformada de Fourier (FT-IR) de transmissão, sendo as amostras analisadas, após pirólise controlada e em bico de Bunsen. Embora ambas as técnicas tenham apresentado boa precisão, a realizada por pirólise em bico de Bunsen, com uso de banda e concentração relativa, mostrou-se mais adequada à determinação e ao uso em cálculos complementares de teores de ET e P. Palavras-chave: EPDM, ENB, FT-IR, transmissão, pirólise, quantificação. AbstractA methodology was developed for determining the 5-ethylidene-2-norbornene (ENB) content in unvulcanized (pure elastomer) ethylene-propylene-diene (EPDM) elastomer, by transmission Fourier Transform infrared spectroscopy (FT-IR), after pyrolysis with and without temperature (T) control. Although both techniques have shown good accuracy, the pyrolysis without T control technique, with relative bands and concentrations, was more suitable for the ENB content determination and for the complementary calculations of ET and P.

Methodologies for Characterization of Aerospace Polymers/Energetic Materials - a Short Review

“…Transmission/pyrolysis was suitable for analyzing all types of EPDM (neat, raw and vulcanized elastomer), suggesting to be useful for similar formulations. Damazio et al (2015) 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.…”

“…The topics are organized by methodologies, including also the IR or FT-IR techniques couplings with thin layer chromatography (TLC/IR) (Dutra 1996;Damazio 2015;Damazio et al 2014Damazio et al , 2015 and thermogravimetric analysis (TG/FT-IR) (Sanches 2015;Sanches et al 2014Sanches et al , 2015.…”

Evaluation of Techniques for Determination of Hydroxyl Value in Materials for Different Industrial Applications

“…MIR and NIRA calibration curves were developed, relating the band A 3500 and A 7000 , respectively, to the IOH of each polyester sample. MIR and NIRA data calibration curves represent the median (μ or X) (Hórak and Vítek 1978;Mello et al 2018) of five values (Takahashi et al 1996;Damazio 2015) of A 3500 and A 7000 bands' intensity, respectively.…”

Quantification by FT-IR (UATR/NIRA) of NBR/SBR blends

“…The data of all FT-IR/MIR and NIR methodologies, for each sample, represent the median of 5 values of analytical bands intensity chosen, being that the mean standard deviations (Equations 1 and 2) and the relative error (RD) (Equation 3) were calculated by non-parametric treatment in agreement with Hórak [29] and with the methodology adopted successfully in group quantitative studies for rubber and other materials [17,28,30] .ˆn…”

“…The RD of the measurements for each analyzed sample, given in %, was determined by Equation 3, where μ is the median value of A. The median of the relative errors represents the error of the methodology [17,28,30] .…”