Analysis of the Chemical Composition of Rigid Polyurethane (PU) Foams
In this study, the chemical composition of rigid polyurethane foams was measured using FTIR microscopy and Diffuse Reflectance Fourier Transform Spectroscopy (DRIFTS) FTIR. Temperature gradients occurring during the processing of rigid polyurethane foams can cause chemical gradients along the horizontal and vertical axes of the foam.
Analysis of Chemical Composition of Rigid Polyurethane (PU) Foams Using FTIR Microscopy and DRIFTS-IR
In this study, the chemical composition of rigid polyurethane foams was measured using FTIR microscopy and Diffuse Reflectance Fourier Transform Spectroscopy (DRIFTS) FTIR. Temperature gradients that develop during the processing of rigid polyurethane foams can cause chemical gradients along the horizontal and vertical axes of the foam.
Unreacted reactants and products arising from side reactions can remain within the pores in a manner that reduces the mechanical strength of the foam.
Results were obtained for an extremely complex and heterogeneous composite.
By studying the chemical composition of the foam's cellular structure, a distinct spectrum of the gas-filled cell nucleus and cell wall was obtained.
FTIR spectroscopy is an ideal tool for studying changes in chemical composition at both bulk and microscopic levels.
Experimental Conditions – Reactants
Raw materials of cast polyurethane foams sold in the market were used (designated as Part A and Part B according to the manufacturer).
Although exact formulation is not available:
- Part A contains diisocyanate,
- Part B contains polyol, water (blowing agent), a catalyst and a surfactant pre-mixed in optimized proportions.
Part A and Part B were added in equal amounts and mixed until the mixture achieved a uniform appearance.
The foam was then allowed to rise and was left standing for five (5) days.
Based on FTIR results, it is understood that the unique bonding function of uretone may be present in the foam, which provides clues regarding the precise formulations of the starting materials.
Chemist Onur Erdebil Service Department Assistant Manager / Spectroscopy / Ant Teknik References Shimadzu Pittcon 2015 Poster No. 2250-4P Analyzing Chemical Composition of Rigid Polyurethane (PU) Foams using FTIR Microscopy and DRIFTS-IRGallery
