The impact of modifiers of different origins on the biodegradability of polylactide-based materials was investigated. It was found that incorporating starch and epoxidized soybean oil into the polylactide matrix accelerates the biodegradation of the polymer composite. The effect of starch and epoxidized soybean oil on intermolecular interactions within the system was examined.
The changes in the crystal structure of polyhydroxybutyrate, polylactide, and their blends during biodegradation under the influence of bacteria and fungi were studied using X-ray diffraction analysis. It was found that microorganisms induce structural transformations in polymers, which occur without significant mass loss of the samples. X-ray diffraction analysis revealed that biodegradation is a complex multifactorial process that depends on the nature of the polymer and microorganisms and is characterized by microstructural changes in the film samples.
The peculiarities of the production and structure of combined composites based on polylactide 3D printed matrices and polyurethane resin were investigated. The physical and mechanical properties of the obtained composites were determined depending on the content of modifiers in the polyurethane resin. In particular, an increase in Brinell hardness and impact toughness of products based on 3D matrices filled with modified resin was revealed.
The hydrolytic degradation of polyhydroxyalkanoates, polylactide and their mixtures in vitro in physiological solution and phosphate-salt buffer as well was researched. The hydrolysis intensity of biopolymers was evaluated via the mass loss, change in molecular weight as well as the water absorption applying the methods of infrared spectroscopy and complex thermal analysis. It was determined that films based on the researched biodegradable polymers thermostated in a phosphate-salt buffer have been degrading faster than in physiological solution.
Polylactide composite materials with organic filler-modifier starch, inorganic filler -calcium carbonate and plasticizer - epoxidized soybean oil for 3D printing have been developed. On the basis of the modular deformation method of calculation the elastic-plastic and deformation properties of the developed modified polylactide materials are determined. The change of modulus of deformation, modulus of elasticity, modulus of high elasticity depending on the composition of the composite is revealed.
The regularities of obtaining polylactide film composite materials with simultaneous silver nanoparticles formation were researched. The influence of the nature of polylactide and its structure (amorphous and amorphous-crystalline), of the glycerin plasticizer on the solvent evaporationkinetics was determined. To give polylactide composites fungicidal properties, the silver reduction reaction by the interaction of argentum salts with polyvinylpyrrolidone was applied. A main technological scheme for obtaining films based on polylactide with fungicidal properties is proposed.
Polylactide composite materials with inorganic filler -calcium carbonate which have been modified with epoxidized soybean oil and glycerin have been developed. On the basis of the modular-deformation method of calculation the elastic-plastic properties of the developed polylactide materials and the coefficient of structure are determined. The change of the modulus of deformation, modulus of elasticity, surface hardness, Vicat softening point and thermomechanical characteristics of polylactide composites is revealed.
The most common additive methods of processing polylactide materials are analyzed. Attention is paid to the features of methods of selective laser sintering, stereolithography and modeling by layer surfacing, as well as the advantages and disadvantages of using biodegradable materials, including polylactide. Approaches to the development of composite materials based on polylactide with additives of different nature and their technological and operational characteristics are substantiated.
The technological parameters of the process and the design of the extrusion head for the manufacture of products such as “pipe” of polylactide composite materials by extrusion, its construction elements are calculated. Prototypes of a product made of biodegradable plastic were obtained.
The influence of talc filler, its content, as well as an additional heat treatment and temperature on the regularities of polylactide materials water-absorption has been researched. Based on the obtained data, the water diffusion coefficient in polylactide materials and the activation energy of the diffusion process were determined. It was found that the process of water absorption by the filled and heat-treated materials based on polylactide proceeds slower and requires more activation energy of the process.