Examine the Sadtler infrared library

Identification Of polymer samples Dana Garcia, Arkema Group, King Of Prussia, PA, USA 280059 Abstract Spectroscopy
The identification of polymer samples is a particular challenge.
In general, polymers with a single component are rarely encountered.
In most cases, the formulation of the polymer is complex. The main component is the polymer. The secondary component may be organics (including modifiers, processing AIDS and plasticizers) and inorganic substances (fillers, flame retardants).
The sample ir spectra of Sadtler is an effective identification method.
This article will introduce a practical case analysis
The experiment
The sample of unknown object was obtained by slicing machine. After CHCl3 extraction, the infrared spectrum was obtained by Analect Fourier infrared microscope with a resolution of 4cm1 and a scanning number of 64.
The soluble residue was also measured by infrared microscopy under the same experimental conditions.
After THF dissolution, the insoluble part was separated and measured by potassium bromide pressure plate. The spectral resolution was 4cm-1 and the scanning number was 100.
All Fourier infrared spectra are baselined and converted to satler data format.
All data were normalized by satler software and the Euclidean distance algorithm was used in the retrieval.
For samples with reduced MCT test range, the low end of the retrieval range is set to 800cm-1.
Analysis: the original sample spectra were retrieved in the monomer and polymer spectra database by the Sadtler database, and the results are shown in figure 1.
According to the matching table, the main groups of the samples were divided into PVC, and the matching coefficient (HQI) showed that there were differences between the unknown sample formula and the formula in the spectral database.
Based on the results of preliminary identification, we dissolved the sample in tetrahydrofuran to remove the PVC component.
The spectrum of the insoluble part is shown in FIG. 2, indicating that there is inorganic substance in the sample.
After searching in the spectrum library of inorganic and polymer additives, it was found that the spectrum of the substance matched that of CaCO3.
Subsequently, we compared the spectrum of CHCl3 extractant with that of the library in the matching table.
Through comparative analysis, we came to the following conclusion: very small amount of PVC still exists in the sample.
The extraction spectrum was then retrieved in the monomer, polymer and plasticizer spectral database, and the results are shown in figure 3.
After further identification, the substance was identified as Elvaloy, a copolymer * of vinyl acetate/carbon monoxide/ethylene, used as a PVC modifier.
The matching coefficient is 997, in addition to the baseline differences and the residual factors of PVC, it is also attributed to the differences between the monomer ratio of our substances and the compounds in the spectral library.
Conclusion it can be inferred from the results that the unknown object is a PVC containing CaCO3 and Elvaloy modifier.
Sarterer database can be used to quickly determine the main components of the polymer, and the appropriate extraction solvent can be selected for additive identification.
If there is no database, a lot of manpower needs to be wasted to do the spectrogram comparison, and it is not necessarily guaranteed to be successful.

Edit comment * this place ElvaloyTM comes from "Index of Polymer Trade Names," VCHPublishers, New York, NY.
Users of the bio-rad satler database will find that bio-rad further collects many important physical and commodity attributes.