Abstract

Abstract

Increased environmental awareness is driving the continuous search for new eco-friendly materials. Within the category of Wood Plastics Composites (WPC), a new "Green Composite" is proposed, whose matrix is a bio-polyethylene (bioPE) obtained from sugar cane and whose load, with reinforcing properties due to its fibrous structure, is Thyme, as a residue from the distillation of a liquor manufactured in a local company. Load concentrations of 10%, 30% and 50% %w have been studied. Since the polymers are processed in the molten state and the loads influence their visco-elastic behavior, it is necessary to know the rheological behavior of these new compounds, in order to evaluate their processability. The melt polymer viscosity is very sensitive to the temperature and the shear rate at which it is being processed. The Cross-WLF model, based on the experimental results obtained with a capillary rheometer, describes the rheological behavior of the materials, thus enabling the determination of the viscosity of these new bio-compounds under different conditions than those tested. In this way the processability of these new materials can be evaluated.

Abstract

Nowadays asphalts modified with polymers (PMA) are used in a wide range of applications, for example, as waterproofing, pavements and membranes, and are being object of a great amount of publications and patents. The processes of modification of asphalt with polymers are widely used to achieve the use of asphalts for some applications where the use of non-modified asphalt is not suitable due to their high thermal susceptibility, their tendency to oxidize or their high content of saturated and aromatic compounds. In this work, milled rubber has been used as an asphalt modifier for the manufacture of waterproofing covers. The use of milled rubber makes it possible to find a viable outlet for the large quantities of discarded tires that accumulate in the tanks and achieve an ecological benefit. Therefore, the rheological study of new compositions with different percentages of polymer addition have been carried out. As main results, it is observed that the asphalt without polymer (MA) at 30º C behaves practically like a Newtonian liquid, while the PMA samples behave as non-Newtonian fluids. On the other hand, the addition of rubber leads to an increase in two orders of magnitude of the elastic and viscous modulus, as does the complex viscosity. The yield stress is greater in the PMA samples, and both the maximum force and the adhesion work increase. The addition of elastomer increases the viscosity of the product, but further increases its elastic component. In MA, the viscous component is greater than the elastic component whereas in the PMAs this behavior is reversed.

Abstract

Abstract

Abstract

Abstract

The investigation into recycling methodologies for composite materials has emerged as a prominent area of study, encompassing both theoretical research and practical implementation. Within this context, the present study focuses on the mechanical recycling of obsolete epoxy resin pieces reinforced with fiberglass, which are subsequently repurposed as fillers in the production of new profiles through pultrusion technology.

A comprehensive examination of the grinding process, granulometric distribution, and rheological properties of the final system was conducted, with the objective of maximizing the filler content within the resin while optimizing the properties of the manufactured profile. Consequently, a flat profile measuring 10 cm in width was successfully fabricated, which incorporates the recycled filler comprising up to 30 % of the resin’s total weight. This achievement was realized by employing a pultrusion system measuring 25 meters in length, coupled with a heated flat plate mold spanning 80 cm.

Following the fabrication of the profile, an extensive characterization of both its physicochemical properties and mechanical behavior was conducted to investigate the influence of filler on the ultimate product. The outcomes obtained demonstrate compelling evidence that the incorporation of the recovered filler effectively enhances the interlaminar properties of the pultruded composite materials, thereby underscoring the inherent potential of the charge as a reinforcing agent.

Abstract