The main challenge of modern polymer science is to search for ways of further development of polymer civilization, which obviously includes living organisms on the Earth, without harmful consequences for civilization and the planet in its entirety. The review considers approaches to handle the problem of environmental accumulation of plastic waste. Promising trends in the development of polymer technologies, which can significantly reduce the amount of waste produced, are highlighted. Separate Sections address original methods of additive manufacturing technologies, such as the extrusion printing technique to produce multilayer films, 3D printing by using high-temperature polyimide materials, new functional siloxane oligomers and hydrogels for medical uses. Much attention is paid to the development and applications of biodegradable materials in medicine, packaging industry and agriculture. An analysis of the European strategy for plastics and plastic disposal demonstrates that it has a number of limitations due to high energy requirements and changes in Earth's carbon balance. The modern approach to plastic waste management free from these shortcomings is briefly outlined. Bibliography — 1233 references.
It is demonstrated that the tensile drawing of high-density polyethylene (HDPE) films in the presence of physically active media via the mechanism of delocalized crazing results in the development of an open-porous structure in the polymer. Depending on tensile strain, overall volume porosity can reach ∼55%. Here, the parameters of the porous structure (pore and fibril diameters) are in the nanometer range. It is also demonstrated that the nanoporous structure with a highly developed surface formed via delocalized crazing is thermodynamically unstable and the related relaxation processes result in the reduction or complete elimination of porosity. Efficient ways of stabilization and preservation of open porosity and parameters of the porous structure of deformed samples of polyethylene are related to complete removal of the liquid medium from the polymer samples and annealing. This approach makes it possible to obtain open-porous materials based on polyolefins with stable characteristics, which is of a significant practical interest.
30 April 2019 in ACS Applied Materials & Interfaces