Four Strategic Pillars
CATALYST DESIGN & SYNTHESIS
Developing the next generation of catalysts
Improved functional materials by design represents the frontier of modern science and technology. Through a combination of state-of-the-art computational methodologies and a broad synthetic skillbase we can assist you to develop and bring to fruition strategies for the rational design of both homogenous and heterogeneous catalysts. Our industry experience also allows us to critically examine the commercial viability of synthetic routes. Our heterogeneous catalysis labs are fully equipped for the preparation of a wide range of catalysts using either conventional ((wet impregnation, incipient wetness, precipitation, adsorption techniques) or unconventional protocols (microwave and nanomaterial synthesis). We also possess a comprehensive range of facilities for drying, calcination, ball milling, sieving, reduction and passivation of catalyst samples. Air sensitive and pyrophoric compunds are routinely handled in our synthesis labs. We also have facilities for the preparation and purification of organic compounds.
Unravel the complex
The application of a broad range of techniques available to us can help unravel the structure and composition of complex mixtures. Our array of analytical techniques enables us to effectively probe a diverse range of samples including carbonaceous deposits on catalysts, waxes, polymers, soluble organometallic compounds and the complex product slates of refinery processes and biomass transformations. Our extensive experience is not only built on laboratory generated samples; we have studied complex mixtures arising directly from commercial production units and even built lab scale rigs to mimic production units to hone the quality and relevance of our outputs
Making the process real
The efficient generation of catalytic data is of paramount importance; the objective is to extract the most information possible without compromising quality. Utilising our world class facilities, we can provide rapid and where necessary parallel screening of numerous catalysts and/or varying reaction conditions as well as long term trials lasting many months. Purpose-built gas and solvent delivery system allow the study the effect of trace additives/poisons down to sub ppm levels. Experimental design and data handling allows both acquisition and analysis of kinetic data leading to detailed models suitable for use at commercial scale. We believe we have everything necessary to efficiently convert data into knowledge and thus accelerate the path to commercialisation
Understand your catalyst, understand your process
We can help you to optimise your process through detailed characterisation of catalysts including under operating conditions. This greater insight into catalyst structure and in operando behaviour can yield step changes in performance. We have built a remarkably comprehensive suite of catalyst characterisation facilities. In addition to standard equipment we have a range of custom designed facilities (built by trusted industry partners) or commercial units that have undergone bespoke modifications. Our in operando capabilities enable investigations of catalysts under process conditions providing insights into the genesis of catalyst structure during activation, operation and deactivation. Excellent local and national networks mean we are uniquely positioned to provide access to extensive, cutting edge characterisation facilities tailored to meet the needs of individual projects.
Comprehensive details of our facilities and expertise are included in another document, available on request
We can offer:
- A truly holistic approach to catalyst characterisation
- In situ and in operando techniques
- Hands on expertise in both theory and practise
- An extensive network of trusted partners as required
We can offer:
- State-of-the-art computational methodologies
- Comprehensive homogeneous and heterogeneous catalyst preparation.
- Kilogram scale preparation of organic compounds for application testing
- Expertise in nanomaterial synthesis
We can offer:
- Homogeneous and heterogeneous catalyst testing with on-line analysis
- High Throughput Experimentation
- Fixed bed, stirred tank and slurry reactors
- Custom built systems for gas and solvent delivery
- Data provision to facilitate scale up
- Identify the right techniques
- Analyse complex mixtures
- Effectively couple techniques to expedite projects
Core Competencies and Areas of Expertise.
- Heterogeneous catalysis: 32-Tube parallel Fixed Bed Reactor unit
- Heterogeneous catalysis: 4-Tube parallel Fixed Bed Reactor unit
- Heterogeneous catalysis: 1 Litre Slurry Reactor
- Heterogeneous catalysis: Multi-purpose fixed bed reactor
- Heterogeneous catalysis: Fixed bed reactor for refinery catalysis
- Homogeneous catalysis: A number if batch autoclaves (various sizes available)
- Temperature Programmed Techniques and Surface Area Measurement
- Static Chemisorption
- BET Surface Area and Pore Size Analyser
- Thermal Analysis Combined DSC/TGA/MS
- Infrared spectroscopy
- Raman Spectroscopy
- Surface spectroscopy
- Powder X-ray diffraction
- High Pressure NMR
Chemical synthesis and Design
- Heterogeneous Catalyst Preparation
- Microwave synthesis
- Ball milling and sieving
- Synthesis and handling of air sensitive materials
- Computational capabilities
- Electrospray Ionisation Mass Spectrometry
- Gas Chromatography
- Shimadzu QP2010 Ultra GCxGC-MS
- 3High Performance Liquid Chromatography (HPLC-UV/RI)
- High Performance Gel Permeation Chromatography (GPC)
- Ametek Mass Flow Indexer (MFI)
- Mettler Toledo DL32 Coulometric Karl Fischer Titrator
If you are interested in any of these techniques or areas and would like to know more please feel free to contact us and we will be happy to speak with you.
32-Tube parallel Fixed Bed Reactor unit
The efficient generation of catalytic data is of paramount importance; the objective is to extract the most information possible without compromising quality. High Throughput Evaluation is an enabling technology that allows for the rapid and parallel evaluation of numerous catalyst formulations and/or varying reactor conditions. The technology relies on the miniaturization of conventional micro-reactors and the application of rapid, automated analysis and data interpretation techniques. Fixed bed reactors (FBR) and in particular multi tube parallel FBR units can provide an efficient way to rapidly screen large numbers of small catalyst samples (mg quantities) in a short timeframe. With years of experience in syngas transformations, a high level of technical understanding (in both experimental design and data handling) and state of the art custom designed fixed bed reactor systems, developed in association with our long term collaborators Integrated Lab Solutions GmbH (ILS) we can help you to efficiently generate knowledge. The main unit has been designed to allow both the quick screening of catalysts and the ability to carry out extended runs (160 days). Due to the design of the unit these modes of operation can be achieved simultaneously using the four independent reaction blocks. The flexibility of the unit also allows a variety of conditions to be accessed including the co-feeding of reaction inhibitors and water. The unit consists of 32 reactor tubes and is split into two independent sections each containing 2×8 reactors. Each of the 4 blocks of 8 reactors has its own Ar, CO, H2 and spare Mass Flow Controllers (MFC). Water (or other liquids) co-feeding is possible via high pressure syringe pumps. Pressure rating 50bar; Temperature rating 470°C; Tube ID=2.4 mm; Typical sample load ~50-200 mg.
4-Tube parallel Fixed Bed Reactor unit
Whilst High throughput methodologies are often used to quickly screen a large number of catalysts using small sample loadings in order to identify promising candidates, further optimisation of the most promising catalysts often requires more flexible operating conditions. This is made possible by the use of our 4-tube FBR unit also from ILS. The flexibility and high accuracy of this unit stems from the fact that each tube operates totally independently, having its own set of mass flow controllers (MFC) and temperature control via a thermocouple inside the catalyst bed. The individual MFCs allow catalysts with different activities to be tested at the same conversions which is often critical for accurate selectivity comparisons. Results obtained on this unit have been used in several patent applications over the years where small differences in activity and/or selectivity provided evidence of novel catalyst properties. Pressure rating 50 bar; Temperature rating 470 °C; Tube ID=6.3 mm; Typical sample load ~400-800 mg.
1 Litre Slurry Reactor
Heterogeneous catalysis can also be conducted in continuous stirred tank reactors, CSTRs: Our laboratory has two 1L slurry reactors. These reactors are custom designed to provide optimal gas, liquid and solid (catalyst) reaction hydrodynamics and allow continuous product removal. Two product knock out pots (hot pot and cold pot) allow for continuous operation for extended periods of time. This is critical for the study of catalyst lifetime and to explore the rate of catalyst deactivation with time online.
Multi-purpose fixed bed reactor
We have a fixed bed reactor supplied by Cambridge Reactor Design suitable for a wide range of applications. It operates at temperatures up to 550 °C and pressures to 20 bar. Gases, liquids or a combination of the two can be used as feeds. A syringe pump enables accurate liquid flow delivery down to very low rates, ca. 10 µL/min, such that small amounts of catalyst can be tested at realistic liquid space velocities. Reaction products are collected in a trap, cooled to sub-ambient temperatures if required, or analysed by on-line GC. In the case of the latter, a heated transfer line, (temperatures up to 120 °C), prevents condensation of moderately volatile species. Computer control facilitates long term experiments where unattended operation is necessary.
Fixed bed reactor for refinery catalysis
We have a purpose-built FBR which is currently configured for the testing of refinery catalysts under industrially relevant conditions. The flexibility of the unit also allows a wide range of other applications. The reactor system has the following specifications:
• Dimension of tubular reactor: ID from 1/4 -3/8 inch for catalyst loading of 0.1 10 g
• Design pressure: 1 60 bar
• Design temperature: up to 550 °C
• Flow rate of gas feed: 0-50 mL/min controlled by Brooks SLA5850C MFC
• Flow rate of liquid or liquefied gas: 0.01 to 10.00 mL/min at a pressure of 0 to 2500 psi delivered by LabAlliance Series I pump
This highly flexible reactor has been successfully used for numerous catalytic evaluations of metal/metal oxides and solid acid catalysts for olefin transformations, alcohol dehydration and CO2/CO hydrogenation reactions under industrial conditions. Equipped with state-of-art safety systems, continuous unattended experiments up to 100 h have been carried out for catalyst life time studies. Detailed on-line and offline product analysis can be used to obtain mass balances for complex multi-phase reactions.
The laboratory is equipped with a purpose-built gas delivery system, including scrubbing trains, capable of supplying ethene, propene, 1-butene, hydrogen, Ar/N2 and vacuum, to each of 7 autoclaves of varying specification. An eighth autoclave is equipped to additionally receive CO2. The MFC system is capable of doping ppm levels of additive/poison gases concomitant with primary feed gas and is routinely used. All the autoclaves are equipped with gas-entraining stirring, internal cooling, electronic temperature and pressure monitoring, and with the exception of the glass units, external fluidised heating-cooling jackets. A purpose-built solvent system, allows 5 solvents to be purified, de-gassed and pumped directly into any vessel, at any pressure. The uptake of substrate gases is monitored via Coriolis flow meters and logged by PC, along with vessel pressure. All autoclaves are coupled directly to gas inlet GC-FID and have liquid phase FID-GC and GC-MS available. We have demonstrated expertise in the acquisition and analysis of kinetic data leading to detailed models suitable for use at commercial scale. All data comes with detailed statistical analysis to determine experimental uncertainty and thus confer confidence in the significance of the data. The equipment is also suited towards toll production for batch sizes up to 1 kg. A number of high pressure 50mL batch autoclaves are also available.
The laboratory is also equipped with: Radleys 6-well (250 mL) parallel reactor, Schlenk lines for catalyst preparation; a GPR-1200 oxygen detector capable of measuring percentage down to ppb levels of oxygen in a range of gas streams; an Ametek 3050-OLV gaseous moisture meter; and a gas detection/alarm system
Temperature Programmed Techniques and Surface Area Measurement
The Micromeritics 2920 is designed to chemically characterise the surface and bulk chemical properties of solid materials. Typical experiments that can be carried out on this instrument include temperature programmed reduction (TPR), temperature programmed oxidation (TPO) and temperature programmed desorption (TPD) as well as pulse chemisorption of gases and liquid vapours and temperature programmed surface reactions (TPSR). We have expertise in using a wide variety of probe molecules such as CO, N2O, NO, CH4, NH3 and CH3OH. The Micromeritics 2950 affords all the capabilities of the 2920 (except the vapour chemisorption) but it can additionally allow experiments to be carried out at high pressure, up to 50 bar. A Balzers Thermostar quadrupole mass spectrometer is connected to both instruments so gaseous products can be monitored as a function of time or sample temperature. Both instruments are connected to a custom designed gas manifold system which allows us to select and feed up to 8 different gases per instrument.
A Micromeritics ASAP 2020 is available for both physisorption and static chemisorption measurements. In the case of chemisorption, isotherms are determined using active gases to obtain quantitative data on parameters such as active metal area, average crystallite size and active metal dispersion. A heated manifold / vapour option allows us to follow changes in physico-chemical properties of supports and catalysts after in-situ treatment with water or hydrocarbon vapours. In addition, a cryostat option enables controlled chemisorption studies at sub ambient temperatures.
BET Surface Area and Pore Size Analyser
A Micromeritics Gemini VI is available for surface area measurements on solid materials. The Gemini can be used to determine BET surface area (Single and Multi-point), Multi-point Langmuir surface area, t-Method micropore volume and area, BJH method, Dubinin, M-P method and Total pore volume.
Thermal Analysis Combined DSC/TGA/MS
A Netzsch STA 449 F1 Jupiter® is used to perform thermal stability, decomposition studies, probe phase transitions, and melting processes. Our STA 449 F1 Jupiter (left) can perform simultaneous Thermogravimetric (TG) Differential Thermal Analysis (DTA)/Differential Scanning Calorimetry (DSC) analyses, with a balance resolution of 0.025 μg over the temperature range 25 – 1550 °C. There is also the capacity to perform Pulse Thermal Analyses (PTA) experiments. The system is equipped with an optional water vapour furnace for conducting experiments under atmospheres of water and with the addition of the custom designed multiple gas manifold, measurements in corrosive gases can be obtained. The STA 449 F1 Jupiter is coupled with a Mass Spectrometer; the QMS 403 Aëolos® quadrupole mass spectrometer (on the left of the picture) is a new compact mass spectrometer with a heated capillary inlet system for routine analysis of gases and, in particular, volatile decomposition products of thermal analysis.
Our Nicolet Avatar 370 FT-IR spectrometer is located in a glove box for the analysis of extremely air sensitive and hygroscopic materials. The Avatar 370 is fitted with KBr optics, giving a low frequency cut-off of around 400 cm-1, and can operate with MCT or DTGS detectors. Samples can be analysed as liquids (solution cell) or solids (KBr discs) in transmission mode. Ancillary modules (DRIFTS and PAS) can be housed in the sample compartment and allow the study of a diverse range of materials. Materials can also be studied under reactive gas atmospheres and at elevated temperatures using custom-built DRIFTS reaction chambers.
Our Thermo Nicolet Nexus FT-IR Spectrometer is fitted with CsI optics providing a broader spectral range (down to 200 cm-1). The Nexus contains two detectors (MCT and DTGS fitted) making it possible to switch quickly between the two if required. Sampling techniques are similar to the Avatar; comparable experiments can be carried out on the two instruments. Additionally, the Nexus can accommodate a customised autoclave, fitted with spectroscopic windows, for the study of solutions at elevated temperature and pressure.
A VERTEX 80v FT-IR spectrometer is coupled to a RAIRS system located in a dry box. The VERTEX 80v has an evacuated optics bench that can eliminate atmospheric moisture absorption for ultimate sensitivity and stability; enabling demanding experiments such as high resolution, ultra fast rapidscan, step-scan, or UV spectral range measurements. The PM RAIRS system (opposite) allows the study of flat surfaces under pressures of highly IR absorbing gases, without the need for complex background subtracted.
Our Bruker ALPHA-P FT-IR spectrometer with Diamond ATR sampling module provides rapid analysis of solids or liquids at ambient temperature and pressure without the need for sample preparation
Our LabRam HR800 Raman microscope has multiple excitation lines (325, 457, 488 or 514 nm) and automated sample stage for mapping in 3 dimensions. Our Raman set-up can be coupled with several custom-built high-pressure reaction chambers, fitted with sapphire windows, for in operando studies. A wide range of gases, including hydrogen and carbon monoxide, can be passed through a bed of material/catalyst at a controlled rate and over a broad temperature range (90‑1200 K). The exit gas stream is coupled to an online GC (or MS) allowing for the determination of structure function relationships in catalysis.
The Kratos Axis Ultra DLD XPS instrument is utilised to investigate the surface elemental composition of solid materials. It also provides information about the chemical state of the surface constituents. The instrument integrates all the latest development in electron optics, including the in-lens charge compensation and the magnetic lens, resulting in an instrument with unsurpassed performance. In addition to the standard monochromatic Al and the achromatic Mg/Al sources, the instrument is uniquely equipped with an Ag Lα monochromated source; advantageous for the removal of Auger contributions but also offers the possibility of analysing of deeper layers (see opposite). The system has an integrated custom Gas Reaction Chamber (RT to 1000 °C; vacuum to 6 bar) for sample preparation
Powder X-ray diffraction
XRD is a powerful technique for characterising the bulk properties of solids such as heterogeneous catalysts. Our PANalytical X’Pert Pro MPD is fitted with a cobalt X-ray tube and a Pixcel detector. Air stable powders can be analysed on a spinner stage. An Anton Paar reaction chamber, XRK900, can be used to follow structural changes under controlled atmospheres, both for activation and under reaction conditions, providing information on bulk phase transformations. Gases are delivered to the in situ chamber at a controlled rate via a series of mass flow controllers. The exit gas stream can be analysed by an on-line GC.
High Pressure NMR
Our high pressure NMR tubes are constructed from single crystal sapphire bodies with precision machined titanium heads. Capable of withstanding pressures of 50 bar at 150 °C the high pressure NMR capability enables speciation of catalyst solutions under reaction conditions of commercial relevance
Chemical synthesis and Design
Heterogeneous Catalyst Preparation
We are fully equipped for the preparation of heterogeneous catalysts using conventional wet impregnation, incipient wetness and precipitation techniques. Following impregnation or precipitation our suite of synthesis facilities enable material calcination/conditioning, ball milling, sieving and reduction. Additional capabilities include the preparation of materials via microwave calcination and separation using centrifugation.
Impregnation: The initial stages of impregnation and controlled drying are performed by rotary evaporation using a series of temperature and pressure controlled Bucchi Rotovapor R‑210 systems. Calcination: The calcination step, involving fixing of the metal precursor to the support by thermal activation, is perfomed via fluidisation in vertical quartz tubes. We have two custom designed facilities comprising both lenton and carbolite tubular furnaces. These units are all housed in vented hoods allowing material calcination/treatment to be carried out using toxic and flammable gases including H2, CO and NO. Several additional tube and chamber furnaces (Carbolite CWF 1100 and Carbolite RHF1500) provide heating capacity up to 1200 °C. Precipitaion: Our Mettler Toledo LabMax automatic lab reactor provides a route to heterogeneous catalysts via precipitation methods. Computer control can be used for developing and optimising bench scale preparations, allowing reaction data to be collected in real time. The LabMax functions as a continuously stirred tank reactor and can be used with a jacketed 0.6 L or 1 L glass vessel. Different stirrer options for the agitator motor (stirrer options include glass anchor/Hastelloy anchor / pitch blade stirrer) are possible, depending on the preparation requirements. Control can be achieved by temperature or pH via separate feed pumps. Microwave Synthesis: Our CEM Discover S-Class microwave reactor can be used to carry out synthesis under pressurized (accommodates 10 mL, 35 mL and 80 mL pressure vials) and atmospheric conditions (accommodates up to 125 mL round-bottom flask). The system can operate up to a maximum temperature of 300 °C with a power output of 300 W. The reactor is equipped with an in situ camera and has automated pressure control. Affording faster reaction times compared to conventional heating methods the reactor has been used in the preparation of metal oxide nanoparticles (synthesis reduced to 30 minutes from 3 days) and the calcination of supported metal precursors (calcination time reduced from 10 hours to 5 minutes). Centrifugation: For the separation of precipitated solids we have a Sigma 2-16P Centrifuge that holds 6 × 50 mL/15 mL tubes in a fixed angle rotor operating up to 7800 rpm and a Minispin Eppendorf micro-centrifuge that holds 12 eppendorfs in a fixed angle rotor with a maximum speed of 13,400 rpm. Both units have digital speed and time control. Ball Milling: A Fritsch planetary ball mill, Pulverisette 6, and a Fritsch vibratory sieve shaker, Analysette 3 Pro, are available for the control of solid particle size. An array of sieves permits separation of solid material into a range of size fractions from 2 μm to 2 mm.
Synthesis and handling of air sensitive materials: Our extensive capabilities for the preparation and handling of air sensitive materials include three MBraun glove boxes (Unilab and Labmaster DP), fitted with freezer compartments for chemical storage, multiple Schlenk lines and a Radleys parallel reaction station. One of our glove boxes is also fitted with a gate valve that is used for the inert atmosphere transfer of solid materials directly to XPS and TEM instruments. For the synthesis of air sensitive materials using solution based chemistry, such as phosphines and organometallic complexes, dry and degassed solvents are generated by two solvent purification systems (MBraun).
Distillation: Our Fisher Technology Spaltröhr HMS 500 AC rig is a fully automated distillation apparatus capable of processing volumes from 50‑500 mL. The operating conditions span from atmospheric pressure down to 1 mbar over the temperature range RT to 400 oC. The unit is fully heat traced to allow distillation of heavy products, which are solids at RT. Fraction collection volumes can be adjusted between 1‑60 mL and collection is fully automated.
Computational capabilities: The wealth of experimental techniques at the St Andrews facility is complemented by state-of-the-art computational methodologies using a compute cluster (9×BL460c G7 blades with 2×6-core i7 CPU’s). We apply a wide spectrum of sophisticated computational techniques including various flavours of DFT, time-dependent DFT, many-body perturbation theory (MPn), methods based on random-phase approximation (RPA), highly correlated coupled cluster methods, like CCSD(T), but also COSMO-RS for the adequate simulation of bulk solvent effects and to predict fluid thermodynamic data. Our expertise in the skilful application of these theoretical methods broadly covers theory-based rational catalyst improvement & design, computational spectroscopic characterisation of reactive intermediates and computational fluid thermodynamics.
Electrospray Ionisation Mass Spectrometry: Our Bruker ElectroSpray Ionisation (ESI) micrOTOF-Q II Mass Spectrometer allows the analysis of a range of diverse samples from single component species requiring high mass accuracy and/or structural identification via MSn (via use of collision cell), through to characterisation of complex mixtures such as commercial production samples. The instrument has a range of 50 20,000 m/z and an accuracy <5 ppm over the entire range. It has a CryoSpray Ionisation (CSI) source for ESI at low temperatures. The ionisation temperature ranges from -100 °C to +350 °C. The instrument is connected to a glove box which allows meaningful analysis of air/moisture sensitive samples. Furthermore, techniques have been developed to allow real-time monitoring of reaction progress by direct feed of reactor contents into the mass spectrometer.
Gas Chromatography: Agilent Technologies, Eight Agilent 7890 refinery gas analysers (3 channel, 2×TCD, 1×FID) are currently in operation for the analysis of complex mixtures of hydrocarbons (olefins, paraffins, oxygenated compounds, etc.). Four further instruments (Agilent 6890); one quadrupole benchtop GCMS and three standard split / split-less injectors with FIDs are standalone instruments mostly fitted with PONA columns, but other columns (e.g. INNOWAX etc.) are also available for different applications. Shimadzu QP2010 Ultra GCxGC-MS, Our Shimadzu Comprehensive GC-MS (GCxGC-MS) System comprising of a combination of fast scanning, high-sensitivity quad GCMS-QP2010Ultra and the Zoex Corporation series of modulators, ZX-1 or ZX-2. The QP2010Ultra quadrupole mass spectrometer is able to scan fast enough to fully characterize 100 ms to 600 ms peaks created by the modulation process. An added capability is the chemical ionization and negative chemical ionization for molecular ion spectral analysis and electrophilic compound selectivity. The spectra generated by quad-MS are easily matched using the standard commercially available libraries.
3 High Performance Liquid Chromatography (HPLC-UV/RI): The Shimadzu Prominence, a fully automated system with high speed injection for large numbers of samples (via a heated auto sampler), consists of a number of modular units; i.e. System Controller CBM-20A, Solvent Delivery Unit LC-20A, Auto-Sampler SIL-20A, Column Oven CTO-20A (20-80oC), UV-VIS detector SPD-20A, Refractive Index Detector RID-10A, On-line Degassing Unit DGU-20A, Low-pressure gradient unit, High Pressure Switching Valves. A fraction collector (FRC-10A) is also fitted which enables accurate fraction collection even when the peak elution time varies, by catching the target component according to variations in the chromatogram. These pure fractions can then be analysed by NMR, IR or MS. LabSolutions software allows for the fast and efficient operation and processing of data
High Performance Gel Permeation Chromatography (GPC): The Shimadzu Prominence GPC/SEC unit operates from the same platform as the HPLC allowing easy transition between operations enabled by high pressure switching valves. Fitted with robust Phenogel™ size exclusion columns (50 500 Å) composed of highly cross-linked polystyrene-divinylbenzene (PSDVB), the system allows for high resolution and tight linear calibration. Columns are temperature stable up to 140 °C which is important for applications involving solutes with limited solubility at ambient temperatures, or where solubility considerations demand the use of viscous solvents such as DMF or DMSO. This temperature stability is particularly useful when analyzing polymers such as polyethylene and polypropylene which require higher temperatures.
Ametek Mass Flow Indexer (MFI): flow rate corresponding to low molecular weight and vice versa. The MFI consists of a small die (2 mm diameter) inserted into an extruder. A weight is applied to the heated extruder containing molten material and a sample of the melt is taken after the desired period of time and is weighed accurately. The MFI is expressed as grams of polymer per 10 minutes of flow time, for the given weight applied . Viscosity of viscous/melted solids can be measured for sample sizes from 0.5 to 10 g between temperatures of 20 °C and 200 °C, using a weight set from 210 g to 21 kg.
Mettler Toledo DL32 Coulometric Karl Fischer Titrator: The Karl Fischer equipment is used to determine water content in the range of 1 ppm – 5 % present in various organic compounds like hydrocarbons/chlorinated hydrocarbons, alcohols/phenols, ketone, ether, esters and bio-oils. The detection limit is approx. 10 mg per sample (equivalent to 1 ppm water for 10 g sample). The repeatability of analysis depends on the size of the sample and the range of water content.