SEC-Py-GC/MS Analysis of High Molecular Weight Polymer Additives
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Solution Overview
Problem
Conventional methods for analyzing high molecular weight additives in polymer resins, such as chromatography, MALDI-TOF MS, and NMR spectroscopy, face challenges in obtaining accurate qualitative and quantitative information due to the large molecular weight and macromolecular structure of these additives, particularly requiring excessive solvents and manpower, and yielding poor accuracy for small amounts or mixtures.
Innovation Solution
The method employs size exclusion chromatography (SEC) to separate fractions of polymer resin samples containing high molecular weight additives with piperidine or morpholine moieties, followed by pyrolysis in a pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) to decompose these additives into lower molecular weight compounds, allowing for the detection of fragment peaks and subsequent qualitative and quantitative analysis based on the sum of these peaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional chromatography methods are used to analyze high molecular weight additives, then the analysis process requires excessive solvents and time, but the measurement precision and accuracy remain poor
Solution Approach 1:
The patent changes the fundamental parameter of molecular weight detection by using MALDI-TOF MS, which can directly detect high molecular weight additives without requiring time-consuming solvent extraction and chromatographic separation processes
Solution Approach 2:
The patent replaces the mechanical chromatographic separation system with a direct mass spectrometry detection system that can analyze high molecular weight additives without physical separation, thereby reducing time and solvent requirements
2Measurement precision
If MALDI-TOF MS or NMR spectroscopy is used to obtain composition information of high molecular weight additives, then qualitative information can be obtained, but quantitative accuracy is poor for small amounts or mixtures
Solution Approach 1:
The patent segments the complex analysis into a simplified single-step MALDI-TOF MS measurement that can handle both qualitative and quantitative analysis, avoiding the need for multiple complex experiments
Solution Approach 2:
The patent makes the MALDI-TOF MS system universal by demonstrating its ability to perform both qualitative structural identification and quantitative content measurement in a single analysis, eliminating the need for separate specialized experiments
3Loss of information
If solvent extraction and chromatography are used to separate high molecular weight additives, then some separation can be achieved, but the large molecular weight and macromolecular structure prevent easy obtaining of composition information
Solution Approach 1:
The patent uses MALDI-TOF MS as an intermediary detection method that can directly interact with high molecular weight additives without requiring prior chromatographic separation, thereby avoiding information loss during the separation process
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables effective qualitative and quantitative analysis of high molecular weight additives by converting them into detectable low molecular weight compounds, providing accurate structural identification and content measurement, overcoming the limitations of traditional methods.
Implementation Method 1
separating a fraction of a polymer resin sample corresponding to a high molecular weight additive
Implementation Method 2
pyrolizing the fraction in a pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) to decompose the fraction into compounds having relative low molecular weight
Implementation Method 3
detecting fragment peaks derived from the piperidine or the morpholine moiety to obtain qualitative information of the high molecular weight additive
Data Source
AI summary
A method for securing qualitative and quantitative information of a high molecular weight additive in a polymer resin sample is disclosed herein. In some embodiments, the method includes separating a fraction of a polymer resin sample using size exclusion chromatography (SEC), wherein the fraction corresponding to a high molecular weight additive, pyrolyzing the fraction in a pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) to obtain a mass spectrum of the pyrolyzed fraction; identifying a structure of the high molecular weight additive by comparing m/z values for fragment peaks in the mass spectrum to m/z values for fragment peaks in a mass spectrum of a standard, and determining the amount of the high molecular weight additive in the polymer resin sample, relative to the total weight of the polymer resin sample by comparing a sum of areas of the fragment peaks to a calibration line of the standard.