Innovation in the pharmaceutical industry has been limited for a long time to the research and development of new active compounds; meanwhile, the structure of the production, dominated by batchwise technologies, has not changed to date. As has already been demonstrated in several other industrial sectors, continuous manufacturing (CM) has many advantages over batch processes. Faster, cheaper, and more flexible production can be developed with a significantly higher level of quality assurance. In the recent years the main regulatory agencies recognized the need for a change in drug production and started to promote continuous technologies and encourage pharmaceutical companies to develop and adapt such processes. As a result, by today extensive research was conducted in the various fields of pharmaceutical technologies from drug substance to drug product manufacturing. Many publications deal with synthetic steps carried out in flow reactors and crystallizations implemented in a continuous manner, and on the formulation side continuous filtration, drying, granulation, and blending have all been studied to a lesser or greater extent. Moreover, besides the modification of these traditional processes to continuous operation, novel, intrinsically continuous technologies are being studied as well. In order to entirely exploit the advantages of CM, the mainly separately developed processes need to be integrated to form end-to-end systems from the raw materials to the final dosage forms. However, even the integration of two technological steps is a challenging task. The development of end-to-end systems requires deep process understanding and a holistic approach toward process development and optimization. The aim of this work is to give insight into the state-of-the-art and new directions in integrated continuous pharmaceutical technologies by critically reviewing the recent literature of the broad field.
Natural hemp fabric reinforced epoxy resin composites were prepared in flame retarded form.Fabrics were treated in three ways: the first method involved the immersion of preheated fabric into cold phosphoric acid solution (allowing penetration into the capillaries of the fibres) and subsequent neutralization, the second way was a reactive modification carried out with an aminosilane-type coupling agent, while the third treatment combined the sol-gel surface coating with the first method. The introduction of P-content into the reinforcing fibres resulted in decreased flammability of not only the hemp fabrics, but also of the flame retardancy of epoxy composites, comprising it changed advantageously. By applying aminetype phosphorus-containing curing agent (TEDAP) in combination with the treated fabrics, V-0 UL-94 rating was achieved. Composites of unexpectedly improved static and dynamic mechanical properties could be prepared only when the simple phosphorous fibre treatment and reactive flame retardancy was combined. . This problem can be solved or moderated by using flame retarded biofibres combined with matrix containing flame retardant additive, by which way the polymer concentration of the matrix and thus its strength can maintained [16,17,18].In this work the idea of flame retarded reinforcement was adapted to epoxy resin composites, by combining it with P-containing crosslinking agent as reactive flame retardant in the matrix.Hemp fabrics were selected for forming flame retarded reinforcement and a P-containing amine [19,20] was applied as curing agent in the FR matrix composites. Materials and methods MaterialsThe epoxy Fabric treatmentTwill woven hemp fabrics (HF) were washed with water to remove dust and impurities and then dried in oven at 70 °C for 12 h. The fibres were treated in three ways in order to render them flame retardant. In the first case, the so-called thermotex procedure [21] was applied.The high-temperature treatment of the fabrics allows better absorption of the treating solution to the capillaries of the fabric. For this purpose, the fabrics were preheated at 120 °C for 2 h, and then immersed in cold 17 mass% phosphoric acid solution for 5 min. The ratio of fabric to phosphoric acid solution was 1 g to 10 ml. As the acid may induce long-term degradation in cellulose fibre structure, it was neutralized by immersing the fabrics in 5% ammonium hydroxide solution. The excess of the treating and neutralizing solutions were removed by pressing the fabrics by a foulard. After treatment, the fabrics were dried in air. The amount of the absorbed phosphorus was determined by the mass increase of the treated fibres and by elemental analysis using energy-dispersive X-ray spectroscopy (see section 2.3.3). The mass increase of the THF fibres was 8 mass%, which means the absorption of 1.7 mass% of P (1.65 mass% by elemental analysis).In the other case, sol-gel treatment of the fabrics was carried out using Geniosil GF-9 aminetype silane. The fabrics were immersed in 10 mass% toluene solution...
Addition of Ammonium Polyphosphate/Polyamide‐6 system is known to provide flame retardancy in many polymers blends via an intumescent process. Particulate fillers (talc and calcium carbonate) are used in large quantities in PP. Combination of fillers in PP can modify the properties of the polymeric matrix. This study investigates the effect of fillers (talc and calcium carbonate) on the fire performance of the Polypropylene/Ammonium polyphosphate/Polyamide‐6 blend. It is shown that the fire performance strongly depends on the nature of the filler used. Talc increases and calcium carbonate decreases in the fire performance of the blend.
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