Polyolefin Resin Grade Verification via Attenuated Total Reflectance Spectroscopy
ATR-FTIR verifies polyolefin grades by measuring specific infrared absorbance ratios to quantify comonomer content, branching density, and copolymer structure.
Diamond Internal Reflection Element
Meaning
High-durability optical crystal used in attenuated total reflectance spectroscopy to analyze hard or abrasive polymer samples. A diamond internal reflection element resists the high clamping pressures required to achieve intimate contact with rigid thermoplastic parts. This interface ensures the infrared beam penetrates the surface layer without fracturing the crystal.
Contact Optimization
Incomplete contact between a rigid polymer and an optical crystal causes poor spectral intensity. Utilizing a diamond internal reflection element allows the technician to apply significant torque to the sample clamp. This pressure deforms the thermoplastic specimen against the hard surface to eliminate any air gaps.
Because the crystal is exceptionally hard, it does not scratch or crack under these extreme mechanical loads.
Spectral Window
Optical transmission limits restrict the wavelength range of the measurement. While a diamond internal reflection element offers a broad transmission band, it exhibits intrinsic absorption bands between nineteen hundred and twenty-three hundred wavenumbers. This characteristic limits nitrile analysis.
Wear Resistance
Abrasive compounds can damage softer optical materials over time. Minerals and glass fibres in reinforced resins cause rapid wear on zinc selenide and silicon surfaces. A diamond internal reflection element suffers no such degradation during routine testing of heavily filled engineering plastics.
This durability ensures consistent pathlength and intensity across thousands of measurements.