Ageing and stabilization polymers is a major part of materials science. Aging of polymers defined as a set of chemical and physical transformations, leads to the loss of their set the desired properties. The main role in these transformations belong to chemical processes of degradation and crosslinking of macromolecules. Processes decomposition and structuring polymer conjugates include radical...

Hydrophylic fumed silica AR974 was tested as a potential nanofiller for the production of composite isotactic polypropylene filaments/fibers (containing 0.25–2 vol % of nanoparticles) via melt compounding and subsequent hot drawing. The objectives of this study were as follows: (i) to investigate the effects of the composition and the processing conditions on the microstructure and the thermal ...

The effect of nanofilles additives containing copper oxide nanoparticles stabilized by a polymer matrix high-pressure polyethylene obtained the mechanochemical method on features structure and properties metal-containing nanocomposites based isotactic polypropylene was studied using differential thermal (DTA) X-ray phase (XRD) analyzes. improvement strength, deformation rheological parameters, ...

The use of polymer blends and composites based on fossil-based bio-based polymers has become an important environmentally protective alternative for common disposable plastics applications such as packaging, bottles trays. disposal these more degradable products, however, may also harm the environment and, therefore, recycling systems becomes relevant. Recycling involves reprocessing which can ...

in this research, old magazine (omg) recycled fiber and glass fiber (gf) were mixed at different levels of 10%, 20%, 30% and 40% (based on weight) with two levels of 50% and 60% polypropylene (pp) and then the produced composites evaluated compared to those from net polypropylene. on the basis of obtained results from normalization equations in different treatments done, two treatments has been...

polypropylene / polystyrene blends containing montmorillonite (mmt) were prepared using a twin screw extruder followed by fiber spinning. the melt intercalation of pp and ps alloys was carried out in the presence of a compatibilizer such as maleic anhydride-g-polypropylene (mpp). the crystallization morphology, thermal behaviors and mechanical properties of polypropylene/polystyrene (pp/ps) nan...

A range of rheological and morphological techniques, contributed by nine laboratories, are used to characterise the flow behaviour in a model long fiber reinforced thermoplastic system. It is concluded that in capillary rheometry, the pressure drop fluctuations that typifl the flow arise from two mechanisms, that of local fiber fraction inhomogeneity passing through the die, and the instability...

Effects of accelerated and natural weathering on the molecular weight distribution (MWD) and crystallinity of polypropylene (PP) in wood plastic composites (WPC) were investigated. The composites were produced from pine fibers (60%) and PP (40%). Prolonged weathering caused an increase in wood degradation and erosion thereby leaving cracks and ‘‘pits’’ on the surface. Pyrolysis gas chromatograp...

The aim of this study was to compare the results of the surgery of inguinal hernias using flat polypropylene mesh and three-dimensional prolene (PHS) mesh. The study included two groups of 40 male patients, aged 18-50 years, with the diagnosis of inguinal hernia. One group was operated with a flat polypropylene mesh, while the second group was operated with three-dimensional prolene (PHS) mesh....

This study evaluated the influence of the addition of cetrimide and polypropylene glycol to sodium hypochlorite (NaOCl) on its capacity to dissolve pulp tissue. Bovine pulp fragments with standardized weight and volume were immersed for 5, 15 and 30 min in 2 mL of NaOCl and Hypoclean (NaOCl added with cetrimide and polypropylene glycol) solutions at 5.25%, 2.5%, 1%, 0.5% and 0.25% and afterward...