No abstract

No abstract

Free radical bulk terpolymerizations of conjugated linoleic acid (CLA), styrene (Sty), and butyl acrylate (BA) were performed at 80 °C. Terpolymers were characterized for composition, conversion, molecular weight, and glass transition temperature. A pseudokinetic model was developed for the prediction of terpolymer composition and validated with experimental data. One impurity commonly found in CLA, oleic acid, was shown to influence the reaction kinetics significantly. The ability of oleic acid to trap electrons results in the formation of oligomeric species at the beginning of the reaction; after the oleic acid is consumed, the reaction kinetics proceed normally.

The copolymerization of styrene/butyl acrylate in a miniemulsion was monitored inline with an attenuated total reflectance/Fourier transform infrared (ATR-FTIR) probe. ATR-FTIR spectroscopy was used to track the concentration of the monomers, thereby providing conversion and polymer composition data. Offline gravimetry and 1 H-NMR spectroscopy were used to provide a comparison with the ATR-FTIR data. Because of inconsistent results with a univariate method, a multivariate or partial least squares calibration method using the full spectra of the reactions was selected and gave excellent results. No statistically significant differences were found between the offline and ATR-FTIR spectroscopy data coupled with multivariate statistics, and this confirmed that ATR-FTIR spectroscopy is a reliable tool for monitoring the conversion and polymer composition in miniemulsion polymerizations.

Free radical bulk and emulsion co‐ and terpolymerizations of conjugated linoleic acid (CLA) with styrene (Sty) and butyl acrylate (BA) were performed at 80 °C. The polymerizations were monitored using an attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopic probe. Bulk polymerizations were monitored off‐line while emulsion polymerizations were monitored in‐line. Absorbance peaks related to the monomers and polymer were tracked to provide conversion and polymer composition data using a multivariate calibration method. Off‐line measurements using gravimetry and 1H‐NMR spectroscopy were compared to the ATR‐FTIR data and no significant differences were detected between the measurement methods. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43574.