polypropylene

This study investigates the influence of low­temperature exposure (–18 °C) and ultraviolet (UV) irradiation on the mechanical properties of polymer films used in flexible packaging applications. The research focuses on widely used materials, including glossy and matte polypropylene (PP) and polyethylene terephthalate (PET) films of various thicknesses. Mechanical tensile tests were performed to evaluate the elasticity, tensile strength, and mechanical resistance of the films before and after exposure to cold and UV radiation.

The possibility of obtaining metallized granules of high-tonnage polymers using classical metallization technology was studied. It is shown that this technology is not effective during the metallization of polyethylene and polypropylene. Certain positive points during metallization were achieved only in the case of polyvinyl chloride granules.

In this paper the method of modification of polypropylene planar surfaces and microfibers through covalent grafting of a polyacrylic acid nanolayer by a free radical mechanismis presented.After grafting of the nanolayers, the hydrophobic surface of the polypropylene acquires hydrophilic properties. These changes are confirmed by the alteration of the free surface energy on the planar surfaces and by the increase of retentioned water by the microfibers before and after modification.

The influence of Ni-containing polymer-silicate filler on the technological properties of polypropylene is presented. It was found that the introduction of silicate fillers modified by polyvinyl alcohol change the flow patterns of polypropylene melts, in particular viscosity increases and anomalous viscosity shifts. The change of thermomechanical curves of polypropylene under the action of modified silicate fillers is shown.

 The properties of the filled polymer compositions largely depend on the nature and surface properties of the fillers- basalt fiber. The possibility of modifying the surface of the basalt fiber with commercial polyhexamethyleneguanidinehydrochloride and non-commercial polydiethyleneaminoguanidine - appretes, were demonstrated for the first time.

The interrelation of physico-mechanical and technological characteristics of newly created nanocomposites on the basis of polypropylene (PP)/polyamide (PA-6) mixture with PVP-modified montmorillonite has been investigated. The significant impact of modified polyamide on technological, physical and mechanical properties and heat resistance of polypropylene has been determined. It has been established that the melt flow index of the resulting composites increases by more than 2 times, compared with pure PP.

Low-melting glass has been synthesized in the system PbO-ZnO-B2O3 and Na2O-P2O5-MoO3 and its composition has been developed. The effect of the glass chemical composition on the softening temperature and the change of appearance during the heating have been established. Polypropylene-based composite with different content of glass powder as a filler was obtained. Thermophysical properties of the composites were determined. Introduction of glass powder to the polypropylene composition damaged the material structure homogeneity.

Mixtures based on polypropylene (PP) and polyamide (PA) are of great importance as structural materials, the mixing of which reduces the negative characteristics of the original polymers. Non-polar PP significantly reduces water absorption of the material during mixing with polar high hydrophilic PA. As a result, the effect of moisture on the mechanical and thermal properties of the composites decreases. On the other hand, mixing PP with PA can extend the temperature range of material exploitation at negative temperatures.

The deformation properties of polypropylene modified by highly dispersed magnesium hydrosilicate are researched. It was established that the part of elastic deformation decreases with increasing of silicate filler content and the part of highly elastic and plastic deformation – increases. This fact indicates the formation of physically structured polymer composition material. Досліджено деформаційні властивості поліпропілену, модифікованого високодис- персним магнію гідросилікатом.

The essential effect of the nature and the content of the fine-grained modified polyvinylpyrrolidone magnesium hydrosilicate on the degree of crystallinity and crystallite sizes of polypropylene was established. This effect is caused by the change in the structural formations at the phases interface and by the nature of intermolecular interactions. Fine-grained particles of the modified magnesium hydrosilicate act as the additional centers of crystallization within the polymer composite material.