MSS Chemilume CL400

 

DIN 51835-1   Oxidation stability of oils   DIN

DIN 51835-2   Oxidation stability of lubricating greases   DIN

 

The fundamental cause for the decomposition of most organic material is oxidation reaction. Oxidation in the presence of oxygen happens under common environmental condition whilst treatment and application. For example under higher temperatures and influence of UV-radiation. Oxidation mostly leads to a negative alteration of the material properties.
Therefore the oxidation stability is one of the essential problems during treatment as well as during long term usage of polymeric materials. As consequence the labeling of the oxidation stability of material is one of the essential targets of test technique.
The decomposition of polymeric material can be caused by different factors like mechanical deformation, heat, UV-light, ionizing radiation and others. In general the fact is accepted, that all these factors initiate a reaction with oxygen within the polymers, which is the main cause for the decomposition. The circumstance that the oxygen reaction of polymers was accompanied by small light emissions (Chemiluminescence) encouraged the development of a new CL-sensitive technique, which turned out to be easier and supply information, that were not available by the conventional measuring methods (Oven tests, Infrared-Spectrometry (IR), Oxygen Absorption and Differential-Scanning-Calometry (DSC)).
 
Innovative application of modern technique accelerates the material testing.

Chemiluminescence and Oxidation

Most organic material is decomposited by autocatalytic oxidation that is initiated by influence of heat during treatment (e.g. during extrusion) resp. during intended use or by influence of UV-radiation. During oxidation hydro peroxides are generated which emit light during decomposition. This light is detected and a measure for the grade of oxidation.
 

The Chemiluminescence Signal

To test the oxidation stability the probe is heated in an inert atmosphere and then exposed to pure oxygen. The oxidation increases to an autocatalytic stationary state. The induction period and the velocity constant for this stationary state are a measure for the materials oxidation resistance. With the CL it is often possible to differentiate signals between probes where other methods like determination of Oxygen-Induction Time (OIT) by Differential Scanning Calorimetry (DSC) or the oxygen absorption fail.
 

ChemiLume-Software

By means of the powerful, menu-driven software setting of test parameters, instrument control, data acquisition, graphical charts and quantitative data analysis is easy.

Versatile Test Possibilities

By isotherm tests in oxygen the thermal oxidation stability can be analyzed. By means of linear temperature rise in nitrogen an already existing material oxidation can be analyzed.

Thermal Stability of Petroleum Products

Chemiluminescence requires a material amount of only some milligrams as pellets, flakes, powder or liquid probes. During formulation of natural and synthetic engine oil, which in some extends contained anti-oxidants, differences in induction periods and oxidation rate constants were found. The rating of these materials was done by a lifespan, defined as the ratio of induction period (dimensionless) and oxidation rate constant.
Mineral oil had the lowest, purged oil with vitamin E the highest oxidation stability.
 

Chemiluminescence for Stability Tests

The Chemiluminescence can be used for the evaluation of thermal and photo oxidative stability of untreated and stabilized polymers, the effectiveness of additives and the impact of treatment- or operating-temperatures, storage conditions as well as influences of weather.
It is also used for organic material like food, drugs and biological material.
 

Testing with Light Speed

Polypropylene for commercial dishwashers was stabilized by different additives and concentrations. By means of Chemiluminescence an evaluation of stability was possible in the same rank and dimension as with oven aging tests, but within a fraction of the time. In contrast to subjective evaluations with the oven aging test a quantitative analysis of the material stability was possible.
Chemiluminescence tests allow a fast evaluation which materials are best applicable for certain applications. Stability tests on polymers are done in oxygen at temperatures that are 20 to 50° C below the treatment temperature or during melting-index-test used temperatures. In the test cells precise temperatures between room temperature and 250° C can be set. A cell conditioning at 300° C minimizes the use of cleaning agens.
With the MSS Chemilume CL 400 the scientist for polymers, additives and organic material has a powerful analytic tool available. It is robust, reliable and user friendly within the daily control of product quality are material selection.

Testing with the CL 400

Das Gerät MSS Chemilume CL 400 hat 4 Prüfzellen mit unabhängiger Einstellung von Temperatur, Gasstrom, Prüfzeit und Photomultiplier-Verstärkung. Parallelproben können gleichzeitig unter identischer oder unter verschiedenen Bedingungen geprüft werden, beispielsweise zwecks Untersuchung der Probenhomogenität oder der kinetischen Daten. Unterschiedliche Proben können unter identischen Bedingungen zur Untersuchung von Unterschieden in der Materialstabilität geprüft werden.

Das mitgelieferte Softwarepaket liefert detaillierte Daten bezüglich des CL-Signals und ermöglicht außerdem eine nachfolgende quantitative und qualitative Analyse der CL-Kurve.

MSS Chemilume Standard Equipment

- Probe carriar made of 99,5% pur Aluminum
- Photon counter-Photomultiplier
- Gas flow control
- Maximum test temperature 250° C
- Standard PC with Intel/AMD-Processor
- Windows2000 and WindowsXP-supported software
- Data acquisition
- Probe forceps

MSS Chemilume Specifications
Need for colled water	0,2 l/min.
Water pressure	70 kPa
Temperature range	16 - 21° C
Maximum test temperature	250° C
Need for gas	Oxygen and Nitrogen
Gas flow	25 or 50 ml/min. /cell
Optical sensitivity	Approx. 2 Counts /sec.
Dimensions:
Widths/ Heights / Depths	52cm / 31cm / 51cm
Weight	38 kg
Electrical Specifications:	115- 230V A/C, 360 Watt (max.)

MSS Chemilume Accessories

Circular Cooler

Supplies water cooled to constant temperature to cool th photomultiplier.
100/200/230V A/C, 50Hz or 120V A/C, 60Hz.

Precision Pressure Controller

Second stage, 70-175 kPa for O2 as well as N2.

Photomultiplier-Calibration Kit

Contains lioght standard, neutral grey filter and calibration holder.
Will be provided free of charge on loan.

Temperature-Calibration Kit

Contains a NIST-standard traced temperature calibration device and thermo element.

Oil Test Kit

Contains pot made 99,5% pure aluminum and cover glasses for volatile, liquid probes.