Analytical Method
The thermal degradation of polymer samples in an inert atmosphere allows for the direct chemical identification of synthetic and natural fibres. In this specialized procedure, pyrolysis gas chromatography uses rapid heating to break down non-volatile textile samples into smaller, volatile fragments without the need for complex solvent extraction. These fragments are then separated in a gas chromatography column and detected by mass spectrometry.
This technique is highly effective for identifying synthetic microfibres, elastomeric blends, and complex fabric finishes.
Thermal Decomposition
Controlled thermal breaking occurs at temperatures ranging from five hundred to eight hundred degrees Celsius. At these high temperatures, the pyrolysis gas chromatography system systematically cleaves the polymer chains of the textile sample, producing a highly characteristic mixture of monomeric and oligomeric fragments. The resulting pyrogram, or chromatogram of pyrolysis products, behaves like a fingerprint of the original polymer.
This fingerprint allows for the rapid identification of specific nylon grades, polyester types, or acrylic polymers.
Fibre Identification
Multicomponent fabric analysis is simplified because different polymer types yield distinct degradation products during the run. For example, polyurethane coatings yield specific diisocyanates, while acrylic fibers yield acrylonitrile monomers, allowing for the simultaneous detection of both components in a single test.
Instrumental Accuracy
Sample preparation is minimal since the solid fibre or coating is placed directly into the sample holder. This direct analysis eliminates the risk of sample contamination and reduces laboratory time during large-scale quality audits.
