QUALITY CONTROL OF COMPOSITION OF BLACK POLYMERES

ANALYSIS OF NONTRANSPARENT POLYMERS Aim: Industrial Quality Control of polymers Procedure Mixture design Attenuated Total Reflection Derivative spectroscopy Multivariate calibration

Calibration Prediction x y y x

Instrumental (spectral) variables Wavelength Absorbance System Selective a variable (The concentration of an analyte) Wavelength Absorbance X Y

A B C 3-Component mixture The mixture range of a three-component system, is described by a triangular surface X A + X B + X C = 1 (closure)

A B C A B C

A B C 15% 35% 60% 80% 10% 0%

ROI (Region of Interest) Production Target Sample

The Mixture Design

sample PRESSURE IR-beam,OUT IR-beam,IN ZnSe-crystall Attenuated Total Reflection (ATR)

INTENSITY VS WAVENUMBERS

Raw and 2nd derivative Spectra

2nd Derivative Spectra

SAMPLE x (2nd derivatives of spectra) y1y1 y2y2 y3y3 WAVENUMBER PREDICTIVE / SPECTRAL VARIABLES PREDICTED VARIABLES/ CONCENTRATIONS

PREDICTION

LOADINGS COMP. 1

LOADINGS COMP. 2

LOADINGS COMP. 3

LOADINGS COMP. 4

LOADINGS COMP. 5

Attenuated Total Reflectance spectrum 2nd derivative spectrum Concentrations (Mixture space) PREDICTION

By looking at instrumental analysis as a way of numeric characterisation of complex system, the kinds of prediction analysis shown in this lecture can be performed to obtain any kind of property of a system that can be precisely represented by a continuous instrument profile.

CHEMOMETRICS/QUALIMETRICS

RAW MATERIAL (FEED) MANUFACTURING PROCESS PRODUCT QUALITY=f(NIR) CONTROL=f(NIR) QUALITY=f(NIR) PROPERTY(QUALITY) <= NIR RELATIONSHIPS

PROCESS CHEMOMETRICS IDENTIFY CRITICAL STEPS CONTROL? NEW MEASUREMENTS? NEW TOOLS?