High Pressure DSC Differential Scanning Calorimeter

Transcription

1 High Pressure DSC Differential Scanning Calorimeter

2 Introduction The Differential Scanning Calorimetry (DSC) is the most popular thermal analysis technique to measure endothermic and exothermic transitions as a function of temperature. The instrument is used to characterize polymers, pharmaceuticals, foods/biologicals, organic chemicals and inorganics. Transitions measured include Tg, melting, crystallization, curing, cure kinetics, onset of oxidation and heat capacity. Unsurpassed performance Revolutionary Sensor Design Combined Heat Flux & Power Compensation in one Sensor Unsurpassed sensitivity for detection of melts and weak transitions Benchmark resolution precise separation of close lying events Reliable Automation up to 64 position autosampler Widest temperature range from -150 C to 725 C in one measurement The LINSEIS Differential Scanning Calorimeters (DSC) operates in agreement with national and international standards such as: ASTM D 6186, D 5483, E 1858, E 1782, C 351, D 3417, D 3418, D 3895, D 4565, E 793, E 794, DIN 51004, 51007, 53765, 65467, DIN EN 728, ISO 10837, 11357, LINSEIS DSC 1000 HP This product was developed to provide a High pressure DSC with a broad temperature range ( C) for all common applications. Furthermore emphasis was placed on an extremely stable baseline and high reproducibility. The design allows manual and automatic operation. The conception of the cell guarantees maximum mechanical and chemical resistance. The 120 thermocouple sensor MR12 provides highest resolution and outstanding sensitivity. Application areas Adsorption, desorption Oxidation induction time Vulcanisation Curing Hydration Reaction seperation DSC 1000 High Pressure 2

3 Technology Sensors MR Thermocouples in a row ensure unparalleled resolution. The glass ceramic sensor designs ensure highest resolution and durability. This sensor is perfectly suited for day to day operation in research and quality control. Crucibles HR24 The combined heat flux & power compensation sensor for most demanding application, 240 thermocouples ensure unsurpassed sensitivity and resolution. Even with smallest sample quantities and slow heating rates weak transitions can be detected. Sensors The key part of every DSC is the sensor, so don t make any compromise. Up to now it has been impossible to achieve highest resolution and sensitivity in one sensor. The revolutionary design of the HiperRes Sensor line now enables just that. The 120 or 240 thermocouples deliver the highest resolution on the market. This permits the detection of smallest thermal effects. The glass ceramic sensor structure ensures shortest possible time constants, permitting the separation of overlapping effects over the full temperature range. Unlike competing metal sensors the ceramic design does not oxidize and thus can be used ongoing over the full temperature range without aging effect. 3

4 Technical specifications Software Technical specifications DSC 1000 Temperature range -150 up to 725 C Heating and Cooling Rates Sensor Pressure Ultra high pressure option LN 2 -option Gases 0.01 to 150 C/min Highest Sensitivity Shortest Time Constant heat flux MR 120 or HR bar 300 bar liquid nitrogen cooling option (-150 C) Measurement under static or dynamic conditions Measurement under static or dynamic preassure conditions Software All thermo analytical devices of LINSEIS are PC controlled and the individual software modules exclusively run under Microsoft Windows operating systems. The complete software consists of 3 modules: temperature control, data acquisition and data evaluation. The Linseis 32 bit software encounters all essential features for measurement preparation, execution and evaluation with a DSC run, just like with other thermo analytical experiments. Due to our specialists and application experts LINSEIS was able to develop this easy understandable and highly practical software. Features Temperature Modulated DSC Repetition measurements with minimum parameter input Evaluation of current measurement Curve comparison up to 32 curves Curve subtraction Multi-methods analysis (DSC TG, TMA, DIL, etc.) Zoom function 1. and 2. Derivative Multiple smoothing functions Complex peak evaluation Multipoint calibration for sample temperature Multipoint calibration for change of enthalpy Cp calibration for heat flow Storage and export of evaluations Program capable of text editing Export and import of data ASCII Data export to MS Excel Signal-steered measuring procedures Zoom in function Undo function The following interesting physical properties of materials can be measured: Enthalpy, melting energy Specific heat Glass point Crystallinity Reaction enthalpy Thermal stability Oxidation stability Aging Purity Phase transformation Eutectics Polymorphs Product identification 4

5 Applications Oxidation Induction Time (OIT) Heat Flow [W/g] min 300 psi O min 200 psi O min 100 psi O Time [min] The OIT method is a standardized procedure, providing information about the thermal and oxidative stability of raw materials. Its main application is the investigation of polymers and plastic materials which are undergoing continous aging processes and therefore have to be equipped with various stabilizers according to their oxidation liability. There are two different OIT procedures: Using the dynamic procedure (characteristic: temperature), the sample is heated at a defined heating rate from the beginning in air or oxygen atmosphere. The beginning of an oxidation process will be detected as an exothermic divergence of the baseline which is characterized by a specific temperature. Advantages and Disadvantages of the dynamic procedure are the short expenditure of time as well as the lower sensitivity of the measurement that comes along with it, especially at higher temperatures. The more common, standardized static procedure (characteristic: time) differs in the atmosphere while heating the sample: Here the sample is heated at inert nitrogen atmosphere to a temperature (200 C) beyond the melting point. Afterwards the atmosphere is changed to air or oxygen atmosphere and the isothermal measurement starts. Depending on the substance, after a while an oxidation process can be observed as divergence of the baseline at a specific time. This point marks the so called OIT time. 5

6 Vapor pressure diagramm of water If the vapour pressure of any liquid reaches the value of it s environmental pressure, the substance begins to boil. In case of water this point is usually reached at 100 C at normal atmosphere. By increasing the environmental pressure, the boiling point will change to higher temperatures, too. This effect is different for each substance (due to their individual vapour pressures) and therefore it is often necessary to measure phase diagrams. This can be done with the LINSEIS High Pressure DSC, as shown in the example. The boiling point of water was determined at different pressures, where it appeared as an evaporation peak. These peaks can be plotted to a phase diagram according to the Clausius Clapeyron equation, where the resulting diagram fi ts the literature values in a good way. This procedure can be done with almost every non corrosive liquid. 200 mw Heating rate: 5 C/min Atmosphere: N 2 Crucibles: Al with pierced lids 1.25 bar 5.0 bar 25.0 bar 50.0 bar bar Temperature [ C] 6 Measured: H V = 40.6 KJ/mol Literature: H V = 40.5 KJ/mol 5 In (p/p 0 ) = /T In (p/p 0 ) /T [1/1000K] LINSEIS Application Handbook: Polymer Applications DTA DSC HDSC TG TMA DIL MS/FTIR Coupling 6

7 LINSEIS GmbH Vielitzerstr Selb Germany Tel.: (+49) Fax: (+49) LINSEIS Inc. 109 North Gold Drive Robbinsville, NJ USA Tel.: (+1) Fax: (+1) LINSEIS China Kaige Scientific Park 2653 Hunan Road Shanghai Tel.: (+86) Fax.: (+86) LINSEIS France Bureaux Paris 52 Boulevard Sébastopol Paris Tel.: (+33) Products: DIL, TG, STA, DSC, HDSC, DTA, TMA, MS/FTIR, In-Situ EGA, Laser Flash, Seebeck Effect, Thin Film Analyzer, Hall-Effect Services: Service Lab, Calibration Service