Spectroscopic and Quantitative Chemometric Analysis of the Epoxidised Oil/Amine System

Abstract

The competitiveness between the oxirane functional group and the ester functional group present in a derivative epoxidised oil was studied by monitoring a model system which involved epoxidised oleic oil and aniline (1 : 1). The reaction was carried out under isothermal conditions at 95°C and monitored in situ by near infrared (NIR) spectroscopy. This system is taken as a model of the curing process in the manufacture of epoxy resins from triglycerides and diamines. Conventional spectroscopic analysis and generalised two-dimensional NIR correlation spectroscopy analysis have led to the conclusion that, even though the formation of secondary amines by ring-opening of the oxirane group as a consequence of the nucleophilic attack of the aniline is prior, the formation of amides as a consequence of the ester group reactivity is a competitive reaction. The presence of the two aforementioned reactions is also in accordance with the significant number of factors found when the spectra data matrix was analysed by evolving factor analysis. By applying multivariate curve resolution-alternating least squares to the NIR spectra obtained during the reaction, it has been possible to obtain the concentration and the spectra profiles of each chemical species involved in the reaction. The performance of the model was assessed by two parameters: alternating least squares lack of fit (lof = 1.67 %) and explained variance (R 2 = 99.68%). The recovered spectra of the generated products have the characteristic bands associated with the two postulated reactions.

Two-dimensional correlation spectroscopy in polymer study

“…2DCOS probes with various analytical techniques, such as IR, near-IR (NIR), Raman, X-ray, UV-Vis, THz, NMR spectroscopies, and even chromatography, have been successfully applied in polymer studies. 2DCOS has been extensively used in the IR study of polymers (Kim et al, 2006b ; Huang et al, 2009 ; Unger et al, 2009 , 2011 ; Del Río et al, 2010 ; Huang and Kuo, 2010 ; Jelèić et al, 2010 ; Jia et al, 2010 ; Lee et al, 2010 , 2012 ; Peng et al, 2010 ; Popescu and Vasile, 2010 , 2011 ; Zheng et al, 2010 ; Cheng et al, 2011 ; Jin et al, 2011 ; Kuo and Liu, 2011 ; Musto et al, 2011 ; Wang and Wu, 2011 ; Zhang et al, 2011 ; Ando et al, 2012 ; Qu et al, 2012 ; Su et al, 2012 ; Wu et al, 2012 ; Chai et al, 2013 ; Lai and Wu, 2013 ; Park et al, 2013 ; Shinzawa et al, 2013 ; Wang et al, 2013 , 2014 ; Galizia et al, 2014 ; Hou et al, 2014 ; Noda, 2014c ; Seo et al, 2014 ). Among the applications of 2DCOS in polymer study, temperature is the most used as an applied external perturbation (Kim et al, 2006b ; Unger et al, 2009 , 2011 ; Jia et al, 2010 ; Peng et al, 2010 ; Popescu and Vasile, 2010 ; Tang et al, 2010 ; Zheng et al, 2010 ; Cheng et al, 2011 ; Wang and Wu, 2011 ; Su et al, 2012 ; Wang et al, 2013 , 2014 ; Hoshina et al, 2014 ; Hou et al, 2014 ; Seo et al, 2014 ).…”

“…In the field of polymer study through 2DCOS, IR spectroscopy is the most commonly used analytical probes. The advantages of 2DCOS, such as the enhanced spectral resolution and determination of sequential changes of spectral band intensities, can provide the useful information in characterizing structural changes of polymer obtained as a function of a perturbation, which is not readily observed in the conventional spectroscopy (Kim et al, 2006b ; Huang et al, 2009 ; Unger et al, 2009 , 2011 ; Del Río et al, 2010 ; Huang and Kuo, 2010 ; Jelèić et al, 2010 ; Jia et al, 2010 ; Lee et al, 2010 , 2012 ; Peng et al, 2010 ; Popescu and Vasile, 2010 , 2011 ; Zheng et al, 2010 ; Cheng et al, 2011 ; Jin et al, 2011 ; Kuo and Liu, 2011 ; Wang and Wu, 2011 ; Zhang et al, 2011 ; Ando et al, 2012 ; Qu et al, 2012 ; Su et al, 2012 ; Wu et al, 2012 ; Chai et al, 2013 ; Lai and Wu, 2013 ; Park et al, 2013 ; Shinzawa et al, 2013 ; Wang et al, 2013 , 2014 ; Hou et al, 2014 ; Noda, 2014c ; Seo et al, 2014 ).…”

“…The generalized 2DCOS can elucidate information in spectral variations, e.g., IR (Kim et al, 2006b; Cerdà-Costa et al, 2009; Huang et al, 2009; Unger et al, 2009, 2011; Del Río et al, 2010; Huang and Kuo, 2010; Jelèić et al, 2010; Jia et al, 2010; Lee et al, 2010, 2012; Peng et al, 2010; Popescu and Vasile, 2010, 2011; Zheng et al, 2010; Cheng et al, 2011; Jin et al, 2011; Kuo and Liu, 2011; Musto et al, 2011; Quaroni et al, 2011; Wang and Wu, 2011; Zhang et al, 2011; Ando et al, 2012; Qu et al, 2012; Su et al, 2012; Wu et al, 2012; Chai et al, 2013; Lai and Wu, 2013; Park et al, 2013; Shinzawa et al, 2013; Wang et al, 2013, 2014; Galizia et al, 2014; Hou et al, 2014; Noda, 2014c; Seo et al, 2014), Raman (Radice et al, 2010; Tang et al, 2010; Ma et al, 2011; Ji et al, 2012; Pazderka and Kopecký Jr, 2012; Brewster et al, 2013; Grzeszczuk et al, 2013; Noda, 2014d), terahertz (THz) (Hoshina et al, 2012, 2014), X-ray (Guo et al, 2011), UV-Vis (Hong et al, 2005; Jiang and Wu, 2008; Sikirzhytski et al, 2012; Zhong et al, 2012), NMR (Oh et al, 2009; Li et al, 2013), fluorescence (Hur et al, 2011; Zhang et al, 2013), and even chromatography (Izawa et al, 2001), under various external perturbations, such as thermal, electrical, optical, magnetic, and chemical perturbations (Noda, 1986, 1993; Hong et al, 2005; Kim et al, 2006b; Jiang and Wu, 2008; Cerdà-Costa et al, 2009; Huang et al, 2009; Oh et al, 2009; Unger et al, 2009; Del Río et al, 2010; Huang and Kuo, 2010; Jelèić et al, 2010; Jia et al, 2010; Lee et al, …”

“…The most popularly applied external perturbation in 2DCOS is temperature (Kim et al, 2006b; Unger et al, 2009, 2011; Jia et al, 2010; Peng et al, 2010; Popescu and Vasile, 2010; Tang et al, 2010; Zheng et al, 2010; Cheng et al, 2011; Wang and Wu, 2011; Pazderka and Kopecký Jr, 2012; Chai et al, 2013; Li et al, 2013; Wang et al, 2013, 2014; Hoshina et al, 2014; Hou et al, 2014; Seo et al, 2014). Applications of 2DCOS in investigations of intriguing properties of polymer system measured by different types of analytical probes has been substantially increased (Izawa et al, 2001; Hong et al, 2005; Kim et al, 2006b; Jiang and Wu, 2008; Huang et al, 2009; Oh et al, 2009; Unger et al, 2009, 2011; Del Río et al, 2010; Huang and Kuo, 2010; Jelèić et al, 2010; Jia et al, 2010; Lee et al, 2010, 2012; Peng et al, 2010; Popescu and Vasile, 2010, 2011; Radice et al, 2010; Tang et al, 2010; Zheng et al, 2010; Cheng et al, 2011; Guo et al, 2011; Jin et al, 2011; Kuo and Liu, 2011; Ma et al, 2011; Wang and Wu, 2011; Zhang et al, 2011; Ando et al, 2012; Hoshina et al, 2012, 2014; Qu et al, 2012; Su et al, 2012; Wu et al, 2012; Zhong et al, 2012; Chai et al, 2013; Grzeszczuk et al, 2013; Lai and Wu, 2013; Park et al, 2013; Shinzawa et al, 2013; Wang et al, 2013, 2014; Hou et al, 2014; Noda, 2014c,d; Seo et al, 2014). Generalized 2D correlation spectra has notable advantages: examination of inter- or intra-molecular interactions and determination of the sequential order of events, which is hardly depicted in conventional spectroscopy.…”

Analysing the Temperature Effect on the Competitiveness of the Amine Addition versus the Amidation Reaction in the Epoxidized Oil/Amine System by MCR-ALS of FTIR Data

“…To analyze the temperature effect, the experiment was carried out at 60°C and at 30°C. These values were selected considering that, in a previous work [ 22 ] in which the temperature was 95°C, conversion values higher than 50% were observed from the beginning of the reaction, which does not allow the accurate analysis of the system. In addition, the homopolymerization of the EMO reagent at the two experimental temperatures was also monitored in order to evaluate the extent of this reaction.…”