Infrared Analysis of Butadiene Polymers

Abstract

Whereas older methods for the determination of 1,2-, cis-1,4 and trans-1,4 units in high polymers require pure olefins as calibration substances, this is no longer necessary with the newly developed method which is described in this paper. From 3 different polymer samples 3 dilution series are prepared and the infrared spectra are recorded. The extinction coefficients are extrapolated to c=0 by a modified base line procedure and the resulting operational extinction coefficients are coupled mathematically (determinants) to yield the actual extinction coefficients of the pure isomers. These may be expressed as mole per cent of the isomeric units for the individual polymer samples. The procedure described may also be applied to other chemical mixtures without the need for pure calibration substances.

2H-NMR Imaging of Stress in Strained Elastomers

“…The microstructure of the oligomer molecules was examined by quantitative evaluation of the IR spectrum. 28 This yielded a composition of 7% 1,2-monomer addition, 38% trans-1,4, and 55% cis-1,4 monomer addition, which confirmed earlier investigations. 12 The mechanical characterization of the NR band was performed by stressstrain measurements and evaluation of the data with the phenomenological description by Ogden: 29 A fit of this function to the stress-strain data gave the parameters shown in Table 1.…”

“…An additional M w determination using GPC could not be carried out due to rapid curing of the oligomers on the column. The microstructure of the oligomer molecules was examined by quantitative evaluation of the IR spectrum . This yielded a composition of 7% 1,2-monomer addition, 38% trans-1,4, and 55% cis-1,4 monomer addition, which confirmed earlier investigations .…”