Distinction of Polyethylene and Polypropylene by Infrared Spectrum

User Benefits

- The ATR method using the IRSpirit-TX enables easy qualitative analysis of resins. - Polyethylene and polypropylene can be differentiated based on their infrared spectra. - It is also possible to differentiate structural differences between low density and high density polyethylene from differences in their absorption peaks.

Introduction

Synthetic resins generally refer to polymers produced by polymerizing monomers made from a petroleum feedstock. Among the synthetic polymers, hydrocarbon resins are resins that consist mainly of carbon (C) and hydrogen (H). Although various types are known, polyethylene (PE) and polypropylene (PP) are representative hydrocarbon resins. PE and PP can be differentiated based on the infrared spectra acquired by a Fourier transform infrared spectrophotometer (FTIR). Furthermore, if the structures of the same PE differ slightly, those differences also appear in the acquired infrared spectra. Hence, it is possible to differentiate resins with different structures and properties, even in the same PE by distinguishing those differences. This Application News article introduces an example in which the representative hydrocarbon resins PE and PP were measured using an FTIR, and explains the differences in their infrared spectra arising from structural differences in the resins.

June 14, 2024 GMT