A fractographic study on toughening of epoxy resin using ground tyre rubber

Waste tire rubber as low-cost and environmentally-friendly modifier in thermoset polymers - A review

Nowadays, waste tire rubber (WTR) management is a growing and serious problem. Therefore, research works focused on the development of cost-effective and environmentally-friendly methods of WTR recycling are fully justified. Incorporation of WTR into polymer matrices and composite materials attracts much attention, because this approach allows sustainable development of industrially applicable waste tires recycling technologies. Generally, utilization of WTR as a filler for polymer composites noticeably reduces materials costs, while suitable modification/functionalization of WTR may significantly enhance the performance of plastics and rubbers. This work aims to summarize the literature reports related to the thermoset/WTR composites based on various matrices such as: polyurethanes, epoxy and other resins. It particularly focuses on compatibilization strategies in thermosets/WTR systems and their impact on the chemistry and physical interfacial interactions between thermoset matrix and WTR filler phase, what significantly affecting performance properties of prepared materials. Moreover, future trends and limitation related to thermoset/WTR composites development are discussed.

Toughening of Epoxy Resin: The Effect of Water Jet Milling on Worn Tire Rubber Particles

In this work a cycloaliphatic amine-cured epoxy (EP) resin was modified by micron-scale rubber particles (RP). Nominal RP, in sizes of 200 and 600 µm respectively, were produced using worn truck tires and ultra-high-pressure water jet cutting. The RP were dispersed into the EP resin using different mixing techniques (mechanical, magnetic, and ultrasonic stirring) prior to the introduction of the amine hardener. The dispersion of the RP was studied using optical light microscopy. A longer mixing time reduced the mean size of the particles in the EP compounds. Static (tensile and flexural), dynamic (unnotched Charpy impact), and fracture mechanical (fracture toughness and strain-energy release rate) properties were determined. The incorporation of the RP decreased the stiffness and strength values of the modified EPs. In contrast, the irregular and rough surface of the RP resulted in improved toughness. The fracture toughness and strain-energy release rate were enhanced up to 18% owing to the incorporation of 1% by weight (wt%) RP. This was traced to the effects of crack pinning and crack deflection. Considerably higher improvement (i.e., up to 130%) was found for the unnotched Charpy impact energy. This was attributed to multiple cracking associated with RP-bridging prior to final fracture.

Recycled tyre rubber-thermoplastic composites through interface optimisation

Chemical interactions between a coupling agent and raw materials benefited the improvement of compatibility, homogeneity and interfacial adhesion of a rubber–PE composite.

Effects of atmospheric plasma treatment on the interfacial characteristics of ethylene–vinyl acetate/polyurethane composites

The surface characteristics of ethylene-vinyl acetate (EVA) were modified by argon, air, and oxygen plasma at atmospheric pressure. The surface energies of the EVA were evaluated by contact angles according to a sessile-drop method and adhesion energy (G(IC)) was estimated by a 180 degrees peel test with polyurethane (PU). After the plasma treatments, the surface free energies (or specific polar component) of the EVA increased about five times compared to that of virgin EVA. The adhesion between the EVA and the PU is significantly improved by the plasma treatment. Especially, Ar/air/O(2) plasma treatment increases G(IC) of EVA/PU up to about 600% compared to that of the sample using virgin EVA.