E.S. Obolonkova

Influence of the properties of the matrix polymer on the strain characteristics of dispersion-filled composites based on polyethylene and crumb rubber

Mechanical properties of highly filled composites based on polyethylene of various grades and crumb based on ethylene-propylene-diene rubber were studied. The influence of the crack resistance of the matrix polymer on the strain properties of rubber-reinforced plastics was considered. A scheme of failure of highly filled composites with the deformable filler was suggested.

Phenomenological Description of the Mechanisms of Deformation and Degradation of Polypropylene Particles during Mechanochemical Modification in the Solid Phase

This work considers the mechanism of deformation and degradation of polypropylene (PP) particles during solid phase mechanochemical modification in an extruder. Electron microscopy was used to investigate the morphological changes to particles of different dimensions (4 hierarchical levels), their internal structure and surface during increases in the duration and intensity of their exposure to mechanochemical impacts in an extruder. We provided a detailed description of the morphology of the original PP in references (refs.. 1–3). Table 1 contains information on the structure of the particles of the original PP.

Influence of Time and Intensity of Solid Phase Mechanochemical Modification on the Morphology of Polypropylene Particles

An investigation of the dynamics of the change to the granulometric structure of polypropylene (PP) when modified in a solid state of aggregation (ref. 1) identified a correlation between the degree of grafting of a comonomer with the degree of plastic deformation of the polymer particles. The plastic deformation of the material is assessed (ref. 1) from the change in the particle dimensions by means of particle size analysis. The objective of this work was to investigate the influence of the intensity and time of mechanochemical modification of PP in a solid state of aggregation on the morphology of the particles and to compare the results of electron microscopy with the results of particle size analysis. The particles were grouped in four different hierarchical levels differentiated by order of magnitude. The levels were as follows: 1 – (0.1–1.0 μm), 2 – (1.0–10 μm), 3 – (10–100 μm) and 4 – (10000 μm). The fourth structural level of the polymer contained particles from all three finer levels (for more details see [refs. 2–4]). Where plastic deformation and the degradation of the material caused a change to the specific surface of the polymer, we evaluated it for materials produced in different conditions. The results obtained were compared with a number of grafted –COOH groups in different material fractions produced in similar conditions (refs. 1, 5).