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Technological features of processing linear block-polyurethanes of different morphology
Authors: V.N. Anisimov, V.V. Anisimov
Number of views: 283
We showed the inability to evaluate the properties and the processing conditions of polyurethanes based of their hardness, although such evaluation is usually used in their marking, this approach does not take into account the peculiarities of molecular structure and the nature of the initial components. A scientifically substantiated approach to the creation of materials based on block-polyurethanes (BPU) of different morphology was developed. The effect of rigid phase content was studied. The characteristic points of the rigid blocks content, Рс1 and Рс2, which correspond to the conditions of geometric phase transitions, were determined and the conditions of the formation of geometric phase morphology with optimal parameters (Рс1РсРс2) were found. Thus, there is a noticeable inflection in all of these graphic dependences for the BPU based on oligo(tetramethylene ether) glycol at points with Pc1=30% and Pc2=50% (conditional strength at tension, elasticity modulus, relative elongation at rupture, hardness, softening temperature, and degree of crystallinity). The technological parameters of BPU molding under pressure with optimal phase morphology, including rapid prototyping complexes (3D printers), have been established. The recommended parameters allowed productively affecting the process of molding under pressure and preparing qualitative products from the developed composites with a specified complex of properties (gaskets, friction supports, elastic elements of gearing devices, extruded strands, circular rings, plates, tubes, etc.). In addition, due to recycling, we managed to substantially reduce ecological risk and increase the commercial attractiveness.