The Department of Paints and Organic Coatings, Institute of Chemistry and Technology of Macromolecular Materials, Faculty of Chemical Technology of the University of Pardubice, is a renowned institution in its field of science and technology. It is equipped with instrumentation for experimental work enabling preparation of starting materials for paints –binders, pigments, corrosion inhibitors and oxypolymerization reaction catalysis. In addition to the application of standardized procedures, homemade analytical and synthesis procedures are also used. The student have available a specialized laboratory in which they familiarize themselves with both basic and advanced problems and synthesis procedures, with methods of analytical determination used in macromolecular chemistry, and in the technology of macromolecular materials and methods for the evaluation of fibres, synthetic resins and polymeric materials. The effect of catalysis on the binder drying process by the oxypolymerization mechanism is investigated by infrared and Raman spectroscopy, by measuring the surface hardness of the films during drying, by the method of needle travel over the drying film, by surface gloss measurement, by measuring the test body indentation depth in the films, and by other methods. Viscosity and rheology measurements on solutions of macromolecular resins, paints, pigmented aqueous suspensions and other systems are made by using various viscometer types. The minimum film-formation temperature (MFT) is measured as an important parameter of water-based polymeric dispersions. The drying of the experimental films is evaluated via their surface hardness (pendulum hardness tester after Perzos and König), drying time determination by evaluating the indentation trace or other procedures standardized for paints.
Objective determination of the colour of solutions and solid or powdered substrates is based on sample transmission and remission measurements providing the film surface colour parameters. The “colour” of the binders, liquid samples and paint fractions can also be assessed visually by using the iodine scale. Binders and resins used in the paint industry are evaluated with respect to their properties, including the non-volatile fraction, softening point and many specific parameters, such as the iodine number, acid value and hydroxyl value. The Department is also equipped with gas autopycnometers for solid materials density measurement.
The surface properties of various substrates, polymers and inorganic and organic pigment powders are examined by scanning electron microscopy: the Department is equipped with an EDX (Inca, Oxford) scanning electron microscope enabling also element analysis. An optical microscope is also available for examining the properties of material surfaces; image analysis is performed in the VIS region. The AFM technique is used to investigate the properties of surfaces of polymeric films and materials.
For the preparation of the paints the students have available dissolvers and pearl mills, high-speed stirrers for both low-viscosity and high-viscosity suspensions and an ultrasonic disperser. Grindometers serve conventional assessment of the results of the milling and dispersing operation (grinding fineness). Other polymeric film parameters include dry film thickness (DFT) and wet film thickness (WFT), the paint film gloss is described by its gloss number. The Department has available equipment for paint and coat parameter evaluation. The physico-mechanical properties of the films are evaluated with respect to the conventional paint industry parameters by using mechanical resistance tests; the adhesion and cohesion components of paint coats are assessed through the adhesion test or the cross-cut test. Test substrates are used to determine mechanical properties of the films by tests such as the cupping test, bending test and impact test; wear resistance is measured as well. The properties of the paints and the starting materials are evaluated by standardized procedures as well as by procedures developed by the Department.
Scientist at the Department develop anticorrosion paint formulations. New anticorrosion pigments and corrosion inhibitors are prepared. High-temperatures furnaces (tube furnace up to 1400°C for syntheses in inert atmospheres and high-temperatures furnaces up to 1200°C and 1600°C in air) are used for the synthesis of the pigments.
Standardized corrosion tests in test chambers filled with simulated corrosion atmospheres are used to evaluate the efficiency of the materials developed. The chambers include a salt chamber (NSS, CASS, AASS salt tests), a chamber with steam and SO2 (Kesternich test), and a chamber with controlled moisture condensation and with general moisture condensation. Weather resistance tests, tests of resistance to UV radiation and simulated solar radiation are performed in QUV panels. The Xenotest is available. Tests in controlled humidity/temperature climatic conditions (conditioning chamber) are carried out. Baths after Machu and Schiffman are also employed for the tests. Specific corrosion attack forms such as filiform corrosion and flash corrosion can also be examined. A potentiostat is used for electrochemical evaluation of the anticorrosion coating properties and anticorrosion pigment efficiency.
Paint preparation
- For conventional paints: dissolver, attritor
- For nanometre-size paints: Netzsch grinding mills providing dispersed product particle sizes in the micrometre and nanometre regions
- For small paint amounts: ultrasonic disperser
- For preparation of the starting materials: electric furnaces (conventional chamber and tube furnaces in air and in inert atmospheres), Fritzsch Pulverisette planetary ball mill
Evaluation of the properties of binders and additives in the liquid form
- Determination of the minimum film-forming temperatures of water-based dispersion binders
- Investigation and evaluation of binders and their drying: Nicolet FT-IR spectrometer
- Dry weight determination: thermo-balance, conventional dryers up to 300°C, Memmert vacuum dryer
- Flow cups for paint flow time measurements and paint binder quality assessment (Ford viscosity cup, BYK cups as per DIN standards)
- Grindometers for pigmented paint and pigmented paste grinding fineness measurement
- Ubbelohde viscometers, Höppler viscometer, Haake rotational viscometer
- Determination of the rheological properties of binders and pigment suspensions: Haake RT 10 rheoviscometer
- Crude paint binder colour assessment on the iodine scale
Evaluation of samples of clear and pigmented films, binders, polymeric films, paints and layers, physico-optical paint properties
- Gloss measurements on a BYK Gardner gloss meter
- Colour measurements on a Chromspec spectrophotometer
- Film surface hardness measurements on a Perzos and König pendulum
- Binder drying time measurement by using a BYK needle travel instrument
Evaluation of the physical and morphological properties of paints and pigments
- AFM microscopy
- SEM
Evaluation of the mechanical properties of paint films
- Adhesion strength measurement with a pneumatic adhesion tester and a hydraulic adhesion tester
- Measurements of film resistance to cupping, impact, bending and indentation (Buchholz indentation test as per ISO 2815).
Evaluation of the anticorrosion properties of paints and their chemical and UV resistance
- Electrochemistry
- Climatic chambers (salt mist, UV, Xenotest, condensation chamber, SO2 chamber)
