Due to the current environmental situation, biopolymers are replacing the usual synthetic polymers, and special attention is being paid to poly-3-hydroxybutyrate (PHB), which is a biodegradable polymer of natural origin. In this paper, the rate of biodegradation of films and fibers based on PHB was compared. The influence of exposure to soil on the structure and properties of materials was evaluated using methods of mechanical analysis, the DSC method and FTIR spectroscopy. The results showed rapid decomposition of the fibrous material and also showed how the surface of the material affects the rate of biodegradation and the mechanical properties of the material. It was found that maximum strength decreased by 91% in the fibrous material and by 49% in the film. Additionally, the DSC method showed that the crystallinity of the fiber after exposure to the soil decreased. It was established that the rate of degradation is influenced by different factors, including the surface area of the material and its susceptibility to soil microorganisms. The results obtained are of great importance for planning the structure of features in the manufacture of biopolymer consumer products in areas such as medicine, packaging, filters, protective layers and coatings, etc. Therefore, an understanding of the biodegradation mechanisms of PHB could lead to the development of effective medical devices, packaging materials and different objects with a short working lifespan.
Recently, environmental problems caused by the overproduction and consumption of synthetic polymer materials led to an urgent need to develop efficient methods for processing plastics. The accumulation of polymer waste for their subsequent incineration does not solve the problem due to the limited areas of landfills for waste storage. In addition, the incineration of polymer waste can cause toxic air pollution, which, in turn, does not contribute to an improvement in the environmental situation. Recycling plastics, although a more environmentally friendly waste disposal method, requires significant labor and energy costs and can be performed a limited number of times. Thus, the most promising solution to this problem is the creation of biodegradable polymers capable of degradation with the formation of simpler chemical structures (water, carbon dioxide, biomass, etc.), which are easily included in the metabolic processes of natural biological systems. The article provides an overview of the main trends in the creation of biodegradable composites for the needs of agriculture. Also, the article proposes a new composition based on polyethylene with natural rubber that surpasses existing biodegradable materials in a number of physical and mechanical characteristics and has the ability to complete biodegradation in 60 months. It is shown that the studies carried out to date indicate that these composites are highly promising for the creation of biodegradable packaging materials with good performance characteristics. Thus, it was concluded that further research on composites based on polyethylene and natural rubber is important.
Nowadays, the development and research of nonwoven medical fibrous materials based on biopolymers is an area of a great practical interest. One of the most promising methods for producing nonwoven materials with a highly developed surface is electrospinning (ES). In this article, the possibility of efficient sterilization of ultrathin fibers based on polyhydroxybutyrate (PHB) by ozone treatment was considered. The purpose of this work was to select the most optimal morphology of nonwoven materials for medical purposes and to establish the correlation between the supramolecular structure and the physical properties of fibrous materials while under the influence of an ozone sterilization process.
The effect of the hemin (Hmi) on the structure and properties of nanocomposite electrospun materials based on poly-3-hydroxybutyrate (PHB) is discussed in the article. The additive significantly affected the morphology of fibers allowed to produce more elastic material and provided high antimicrobial activity. The article considers also the impact of the hemin on the biocompatibility of the nonwoven material based on PHB and the prospects for wound healing.
Ultrathin electrospun fibers of pristine biopolyesters, poly(3-hydroxybutyrate) (PHB) and polylactic acid (PLA), as well as their blends, have been obtained and then explored after exposure to hydrolytic (phosphate buffer) and oxidative (ozone) media. All the fibers were obtained from a co-solvent, chloroform, by solution-mode electrospinning. The structure, morphology, and segmental dynamic behavior of the fibers have been determined by optical microscopy, SEM, ESR, and others. The isotherms of water absorption have been obtained and the deviation from linearity (the Henry low) was analyzed by the simplified model. For PHB-PLA fibers, the loss weight increments as the reaction on hydrolysis are symbate to water absorption capacity. It was shown that the ozonolysis of blend fibrils has a two-stage character which is typical for O3 consumption, namely, the pendant group’s oxidation and the autodegradation of polymer molecules with chain rupturing. The first stage of ozonolysis has a quasi-zero-order reaction. A subsequent second reaction stage comprising the back-bone destruction has a reaction order that differs from the zero order. The fibrous blend PLA/PHB ratio affects the rate of hydrolysis and ozonolysis so that the fibers with prevalent content of PLA display poor resistance to degradation in aqueous and gaseous media.
The development of new porous polymeric materials with nanoscale pore dimensions and controlled morphology presents a challenging problem of modern materials and membrane science, which should be based on scientifically justified approaches with the emphasis on ecological issues. This work offers a facile and sustainable strategy allowing preparation of porous nanostructured materials based on ultra-high-molecular-weight polyethylene (UHMWPE) via the mechanism of environmental intercrystallite crazing and their detailed characterization by diverse physicochemical methods, including SEM, TEM, AFM, liquid and gas permeability, DSC, etc. The resultant porous UHMWPE materials are characterized by high porosity (up to ~45%), pore interconnectivity, nanoscale pore dimensions (below 10 nm), high water vapor permeability [1700 g/(m2 × day)] and high gas permeability (the Gurley number ~300 s), selectivity, and good mechanical properties. The applied benefits of the advanced UHMWPE mesoporous materials as efficient membranes, breathable, waterproof, and insulating materials, light-weight materials with reduced density, gas capture and storage systems, porous substrates and scaffolds are discussed.