Thermal Analysis,Microcalorimetry and Combined Techniques for the Study of Pharmaceuticals

Modern thermal analysis, microcalorimetry and new emerging combined techniques which deliver calorimetric, microscopic and spectroscopic data offer a powerful analytical battery for the study of pharmaceuticals. These techniques are very useful in all steps of development of new drug products as well as methods for quality control in production. The characterization of raw materials enables to understand the relationships between polymorphs, solvates and hydrates and to choose the proper development of new drug products with very small amount of material in a very short time. Information on stability, purity is valuable for new entities as well as for marketed drug substances from different suppliers. Excipients which vary from single organic or inorganic entity to complexes matrixes or polymers need to be characterized and properly controlled. The thermodynamic phase-diagrams are the basis of the studies of drug-excipients interactions. They are very useful for the development of new delivery systems. A great number of new formulations need proper knowledge of the behaviour of the glass transition temperature of the components. Semi-liquid systems, interactions in aqueous media are also successfully studied by these techniques. This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermal Stability and Properties of New NPS-Fertilisers

New NPS-fertilisers are investigated using TG-DTA systems and other techniques to determine their thermal stability and properties. The main component is ammonium sulphate by-product from clean-up technologies. Acidic reaction of ammonium sulphate (AS) is compensated by adding treated or untreated phosphates. Some samples are additionally mechanochemically activated. Tribochemical effects are confirmed. Distribution and conversion of harmful impurities are also studied. The results clearly show that the histories of components, additional treatment and the initial content of impurities affect the thermal properties of the new fertilisers. The mass component's ratio influences the thermal fertiliser's stability and their solubility. It is shown that the by-product from electron beam technology is the most suitable component, because of high-activity. The results obtained confirmed that TG and DTA techniques could be successfully used for products quality control. Most of the simultaneous TG, DTG and DTA curves may have a practical application for future studies and comparative analysis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Material Analysis of Steel Corrosion Products in Water Coolants of Thermal and Nuclear Power Plants

The poor informativity of conventional elemental analysis in the industrial control of equipment corrosion at thermal and nuclear power plants was discussed. A set of methods was proposed for the material analysis of steel corrosion products. The set includes spectrophotometry for determining the chemical composition of hydroxo complexes in aqueous solutions and various versions of Mossbauer spectroscopy for identifying and determining corrosion products in the solid phase of suspensions, loose deposits, and corrosion films on steel surfaces.     

Thermal analysis and X-ray diffraction of untreated coffee’s husk ash reject and its potential use in ceramics

The agro and industrial activities are actually responsible for the production of large amounts of solid wastes in Brazil. The use of industrial wastes as alternative raw materials into ceramic products has been widely developed. The typical materials used in the ceramic formulations present a large diversification of chemical compositions, what allow the incorporation of different types of waste materials in the ceramic mixture. Brazil produces a massive amount of coffee and the lack of adequate landfill areas available to dispose the coffee’s husk ash reject material are causing an ambiental problem for the agro-industry. This work describes research carried out on the thermal characterization and X-ray diffraction of coffee’s husk ash reject and its possible use in the ceramic industry.     

Contribution of Radiation Technology to Environmental Protection

The direct and indirect contributions of radiation technology to environmental protection are summarized. The indirect contribution consists in a considerably decreased or, in some cases, completely abandoned use of harmful substances (such as volatile organic solvents) in radiation-chemical processes, utilization of spent materials and products (in particular, butyl rubber), etc. The direct contribution includes the direct use of ionizing radiation for the purification and disinfection of polluted natural and drinking water, municipal and industrial wastewater, other liquid wastes, gas systems (for example, flue gases from thermal power stations), sewage sludge, and solid wastes (infected medical wastes, polluted soil, etc.); pest control (by radiation sterilization of male insects); etc. The corresponding examples based on recent studies are cited.     

Filtration combustion of solid fuel in countercurrent reactors

The works studying filtration combustion of solid fuels in the countercurrent mode are reviewed. The phenomenon of superadiabatic overheating is described. The data of experimental and theoretical studies and some results of the development of technological processes of production of thermal or electric energy from substandard raw materials and extraction of valuable components (for example, rare metals) from unconventional sources (industrial wastes, poor ores, burrows, etc.) are presented. The processes of safe treatment of problematic wastes are considered.     

Model-based equipment-design for plant-based extraction processes – considering botanic and thermodynamic aspects

The growing demand for plant-based products in the food, cosmetics and pharmaceutical industry leads to the need for a systematic process and equipment-design for the potentially applicable extraction techniques. Therefore, in this article, the classification of plant-based raw materials according to their characteristics is discussed. Furthermore, physicochemical modelling via distributed plug flow approach is applied and its possible fields of application are examined. Here, especially the extraction of water from the plant-based raw material as well as the entailed effects on the equilibrium and the mass transport kinetics are concerned. In addition to that, an evaluation method for the examined and generally available equipment through spider diagram is proposed. The relation to the initially argued botanic systems is discussed in particular. The extraction of vanillin from vanilla beans serves as exemplary system for this.     

Determination of the pseudocomponents and kinetic analysis of selected combustible solid wastes pyrolysis based on Weibull model

The application of thermal analysis to meat products, like all materials, is governed by energy transfer, from which invaluable information on thermodynamics of processes is obtained. Various meat systems have been analyzed with different success ratios. Proteins in meat formed the key area of interest due to their effect on product quality, shelf life, functionality and also their ability to interact with other components. Initially success rates were low owing to lack of sensitivity, results with complex curves, complications in interpretation and a large number of factors affecting the biological system. Later with developments in instrumentation and computer models for better resolution and reproducibility, wider horizons could be covered with easy solutions to complex results. Though thermal analysis has been used exhaustively in meat, research in this area has become stagnant and new areas are being left untouched. This review emphasizes the importance of thermal analysis in the meat industry and also the need to use more advanced equipment for better understanding of the biological changes occurring in muscle during processing and storage.     

Online monitoring of thermoset post-curing by dynamic mechanical thermal analysis DMTA

Thermosetting moulding compounds are synthetic materials which can be easily formed in the molten state and achieve high temperature stability due to a cross-linking process which takes place during manufacture. To ensure thermal and mechanical properties, post-curing of moulded phenolic resin components is necessary for high quality applications. In the industrial practice, post-curing time–temperature-programs are heuristically acquired. In this paper, dynamical mechanical thermal analysis is employed to determine optimal post-curing conditions for injection moulded parts from phenolic resin.     

Thermochemical characterization of chicken litter and peat as a source for energy recovery

The shortage of raw materials and the environmental problems due to pollution require development of new green technologies utilizing some wastes and transforming them to secondary raw materials. The aim of this work is to study the properties of poultry waste to propose possibilities to minimizing the released emissions and avoiding the risk for human health and the environment. At the same time, two types of low grade peats with different origin are studied as components for the production of soil conditioners. During the studies, we applied the inductively coupled plasma (ICP) and chemical analysis, powder X-ray diffraction, thermal analysis, IR spectroscopy, and scanning electron microscopy for determining the composition, crystal phase, the shape and size of particles, and thermal stability of the investigated samples. The chemical and the phase compositions of the studied samples confirmed that the content of nutrient compounds and of the carbon substances is suitable as an effective secondary raw material for soil conditioners. It is found that the poultry wastes and peat samples have a similar phase and chemical composition and contain an organic mass in the form of carbon components with amorphous, fibrous, and skeleton-like structure, suitable to be combined with other nutrient-containing compounds. During the thermal treatment, the carbon compounds are oxidized releasing heat. Based on that the materials under study are considered as environmentally friendly fuels, releasing relatively low emissions.     

Thermochemical investigations of natural phosphate with ammonium sulfate additive

Summary The free energy of the acidic ammonium sulfate is a good precondition its use as an additive or reagent for decomposition of natural phosphates on the way to obtain NPS or NPKS complex fertilizers. During our previous studies it was confirmed that as a result of thermo-mechanical treatment new solid phases are formed as a result of the phosphates decomposition. The aim of this study is to find out appropriate conditions for thermal treatment of Tunisia phosphorite with ammonium sulfate where the content of P₂O₅ soluble forms has its maximum. The process was investigated under dynamic thermal conditions. Structure and phase transformations of the mixtures to intermediate and final solid products are confirmed by different techniques. X-ray powder diffraction, infrared spectroscopy and electron microscopy have been applied successfully and relationship found between phase structure and thermal treatment applied. As a result of the complex studies optimal temperatures are determined. The solid products under optimal conditions contain phosphorous in soluble forms available for plants in the soil. As a final it is concluded that the final products could be used as complex mineral fertilizers.     

混合价黑色氧化铕的制备及其性质初步研究

用含肼甲酸铕在Ｎ２气氛中热分解的方法制得了混合价黑色氧化铕粉末。对它的有关物理化学性质进行了初步研究,得到了相应的结论。     

What Does the Chemical Industry Expect from Physical and Industrial Chemistry?

Process innovation—the systematic optimization of raw materials, energy consumption and product yields—is a constant challenge for those operating plants producing vital basic and intermediate chemicals. The production processes, rather than the products themselves, exhibit life cycles and determine the profitability of downstream manufacturing. The ongoing task of interdisciplinary teams of experts is not just to develop new process routes, but, more commonly, to improve individual process steps. The impulse for this innovation arises from changes in the price and availability of raw materials, economic and environmental considerations and, last but not least, scientific and technological progress. This paper illustrates the opportunities available using examples which have already been put into practice as well as problems not yet resolved. Questions such as the use of alternative feedstocks and the switch to catalytic processes arc addressed and used to suggest novel ideals for basic research. Worthwhile projects are identified in the area of industrial oxidation, both catalytic and non-catalytic. A highly developed, systematic, computer-based method for optimizing the integration of energy flows within a plant is presented and novel measurement techniques for efficient production control and product quality are. discussed. The successful realization of such concepts requires the ability and the willingness to think in terms of new approaches to problem solving, making this an important objective for university education geared to future needs.     

Thermal characterization of dried extract of medicinal plant by DSC and analytical techniques

The increased search for herbal products has generated an increasing interest in improving the quality control of dried extracts by pharmaceutical industry since these are raw materials of great importance by their quality and versatility. This work aimed at the application of various analytical techniques (thermal analysis, X-ray diffraction, scanning electron microscopy, and infrared Fourier transform spectroscopy) in the characterization of dried extracts of two plants from the Brazilian semiarid region with medicinal properties. The DSC curves for the dried extracts of Ximenia americana L. and Schinopsis brasiliensis Engl. showed that thermal processes occur between 33.50 and 118.58 °C and between 39.17 and 126.14 °C. The X-ray powder diffraction revealed high degree of amorphization, but the dried extract of X. americana L. showed some diffraction peaks of high intensity. The IR spectra showed high variety of metabolites in the extracts dried. Through this study it was possible to verify the feasibility of applying these techniques in the characterization of raw materials from medicinal plants for use in the herbal medicines production.     

Degradation issues of polymer materials used in railway field

Polymer materials used in railway field are degraded by environmental factors such as thermal, oxidative, photolytic, hydrolytic, and mechanical. The expected service life of the polymer materials used in railway field is approximately 20 years that is relatively long period for the polymer material; therefore, respective degradation factors should be well considered. Some of the degradation conditions indicate similar mechanism. The oxidative reaction was seen in every degradation conditions under air atmosphere. The hydrolytic reaction was mainly observed in chemical and biological degradations. The degradation behavior of the polymer material was analyzed by various methods. FTIR, thermal analysis (TG, DSC), and molecular weight determination were mainly applied for its purpose. However, the degradation mechanism of practical products made of polymer material was insufficiently studied and the exchange criteria of the products depended on the visual inspection without the suitable degradation analysis not only in the railway field but also in other commercial and industrial fields. In addition, most of the methods to analyze degradation of polymer material are performed on the standard specimen forms. For the installed product, some kinds of damage are generated through the sample collection process; therefore, the damaged products have to be exchanged for brand new ones or repaired totally to be used for more period. Moreover, it is hard to suspend the railway service for the degradation analysis of polymer products. From these backgrounds, the prospect of degradation analysis related to polymer materials used in railway field was proposed.     

Use of sub-ambient DSC to complement conventional DSC and TG

Several drug substances or excipients are hygroscopic. The uptake or loss of water of such substances is generally difficult to control during processing or storage of drug products. DSC instruments with sub-ambient temperature equipment allow the determination of the amount of freezable water by measuring the corresponding melting enthalpy.The determination of freezable water adds valuable information complementary to TG analysis for understanding the processing and storage of raw materials and drug products. Several substances were tested as is, without treatment, after storage at 92% r.h. and after equilibration with water. The results of these experiments showed that it was possible to demonstrate defined hydrate formation, to determine the upper level of binding of water in amorphous substances and to confirm reversible hydrate formations demonstrated by temperature resolved X-ray diffraction.     

Acid and thermal treatments of lateritic bauxites

H₂SO₄ and HCl processes accompanied by thermal treatments at different stages are described for the industrial extraction of alumina from lateritic clay minerals, especially from kaolinite, an important component of lateritic bauxites. The effects of calcination at high temperatures on the pretreatments of the raw lateritic materials, as well as on the thermal transformations of the products (salts) resulting from the acid treatments of lateritic bauxites are analyzed. Beside energetic considerations, separation methods of Al from Fe and from other lateritic-metallic components are emphasized in the extraction and purification processes. The mechanism of a controlled HCl-extracting treatment performed on iron-bearing kaolinite is described, as well as its characterization by IR and DTA ad hoc methods, enabling to distinguish between Al and Fe in the structure of lateritic kaolinite. The location and quantification of Al in the structure of lateritic goethite is also considered. This revised version was published online in August 2006 with corrections to the Cover Date.     

Comparative Studies on Thermal Decompositions of Dinitropyrazole-Based Energetic Materials

Dinitropyrazole is an important structure for the design and synthesis of energetic materials. In this work, we reported the first comparative thermal studies of two representative dinitropyrazole-based energetic materials, 4-amino-3,5-dinitropyrazole (LLM-116) and its novel trimer derivative (LLM-226). Both the experimental and theoretical results proved the active aromatic N-H moiety would cause incredible variations in the physicochemical characteristics of the obtained energetic materials. Thermal behaviors and kinetic studies of the two related dinitropyrazole-based energetic structures showed that impressive thermal stabilization could be achieved after the trimerization, but also would result in a less concentrated heat-release process. Detailed analysis of condensed-phase systems and the gaseous products during the thermal decomposition processes, and simulation studies based on ReaxFF force field, indicated that the ring opening of LLM-116 was triggered by hydrogen transfer of the active aromatic N-H moiety. In contrast, the initial decomposition of LLM-226 was caused by the rupture of carbon-nitrogen bonds at the diazo moiety.     

How safe are NIR-library search systems? Information-theoretical and practical aspects

In chemical and pharmaceutical industries NIR-spectrometric methods are used in quality control laboratories to verify the identity of products and raw materials. However many analytical chemists are not sure how to estimate or even discuss the reliability and security of such systems. In this paper a simple information theoretical concept is applied to describe the uncertainty and other statistical properties of spectrometric and qualitative analytical methods in general.     

Industrial development and applications of plant oils and their biobased oleochemicals

In the concepts for new products, performance, product safety, and product economy criteria are equally important. They are taken into account already when the raw materials base for a new industrial product development is defined. Here, renewable resources gain-again after the earlier “green trend” in the 1980s—increasing attention as an alternative raw materials source compared to fossil feedstock. The industrial use of carbohydrates, proteins, and plant oils aligns perfectly with the principles of Responsible Care and is an important part of green chemistry and sustainability in general. Since the 1950s, oleochemistry has grown to a major research and technology area in several institutions and industries. A large variety of products based on fats and oils have been developed since then for different uses, such as specialties for polymer applications, biodiesel, surfactants, emollients for home and personal-care industries, pesticides and biodegradable mineral oil replacements for lubricants. However, at present it seems that the use of renewable resources, especially plant oils, has to compete more and more with the increasing demand for bioenergy, which could cause an unbalanced supply and demand in the future or even a threat for the increasing demand for food in certain areas of the world.