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United States Department of Agriculture

Agricultural Research Service

Title: Measuring Degradation of Individual Components in Multicomponent Biodegradable Plastics by Fourier Transform Infrared Spectrometry

item Gordon, Sherald
item Imam, Syed
item James, Christopher

Submitted to: Polymers and the Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 22, 2000
Publication Date: N/A

Interpretive Summary: Biodegradable plastics are being developed in a number of research laboratories concerned about the persistence and ecological effects of synthetic plastics in the environment worldwide. Agricultural polymers such as starch and cellulose are being investigated as replacements for synthetic petrochemical-based polymers. Combinations of these polymers are blended and incorporated into thermoplastic materials. The materials are then tested to determine physical properties and to measure the rate and extent of component polymer biodegradation over time under environ- mental conditions. A new mathematical method was developed that uses infrared spectra of pure polymers and composite plastics to quantify degradation of the individual polymers after biodegradation.

Technical Abstract: A new chemometric method based on Beer's Law was derived that uses peak ratios from Fourier transform infrared spectra of neat polymers and their composite plastics to quantify degradation of the individual polymers after biodegradation. In a significant advance over traditional chemometric methods, this method does not require sampling of as many or more different composites as the number of polymers in the composite being analyzed. When the neat polymer spectra are known, only two measurements, one before and one after biodegradation, are needed. Another potentially major advance is that the method allows automation of analytical infrared wavelength selection by computer from all possible wavelength combinations. In this paper, the theoretical basis and derivation of the mathematical model is presented and verified for multi-component systems.

Last Modified: 4/22/2015
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