Analysis of degradation of PVC pipe using Fourier Transform Infrared Spectroscopy (FTIR)

Efficacy of phthalate plasticizers in p-PVC varies with change in the surrounding, causing failure of PVC components used in various applications. ATR-FTIR, evaluating the presence of carbonyl groups, is used for the structural analysis of p-PVC components before and after heat treatment of samples.

FTIR analysis is used to study the migration and leaching of phthalate plasticizers from p-PVCs. Phthalate plasticizers are frequently used in PVC applications to achieve the intended flexibility and performance of the PVC. Understanding these plasticizers’ efficacy under increased temperature, radiation, electrical field changes, etc., is critical to avoid failure of components, contamination, and reduced performance. An ATR-FTIR is used for the structural analysis of components of p-PVC before and after heat treatment. 

The effects of temperature treatment on the migration of various phthalate plasticizer modified PVC were studied. FTIR provides rapid qualitative analysis of unknown or known compounds utilizing the vast library of available spectra. Spectral matching reveals phthalate plasticizers’ diffusion by identifying and quantifying the carbonyl functional group (C=O) present in these plasticizers (Figure 1) A significant drop in the concentration of this functional group before and after heat treatment of PVC, modified with various phthalate plasticizers, is observed [Fig. 1 (a) & (b)]. This reduction provides evidence that these plasticizers are consumed at higher temperatures.

Chemical migration into the surrounding atmosphere or other components like seals and fixtures due to aging and environmental degradation is a frequent problem in product manufacturing, litigation, and materials research. Infinita Lab’s vast network of materials testing labs and experts enables us to produce reliable, reproducible, and highly sensitive measurements for identifying and quantifying known or unknown chemicals even at low concentrations. 

Reference:

[1] Tüzüm Demir, A.P. and Ulutan, S. (2013), Migration of phthalate and non‐phthalate plasticizers out of plasticized PVC films into air. J. Appl. Polym. Sci., 128: 1948-1961.