Recycling of reticulated polymers

Abstract

There is ever increasing pressure in society not only in the sense of encouraging recycling but in deterring, by means of legislation, the deterioration of the environment with heavy fines in sectors of the economy such as producers of electric batteries and chemicals/packaging, which pollute rivers and streams. Our objective in this project is to develop the industrial procedure for breaking the chemical bonds responsible for the reticulation of plastics or rubbers by the application of high energies, such as microwaves, ultra-sound and others. These techniques are probably the most efficient, clean and economic process for recycling reticulates, since they break down the two-dimensional bonding scheme of the reticulation, without depolymerization of the polymer and permit new reticulation (or vulcanization) with properties equivalent to the original compound. In this case, the recycled material returns as an active commodity. Very efficient for nitrilic rubbers (NBR), neoprene (CR) and polymers which possess polar groups, this method uses doses of microwave energy at a specific frequency and in sufficient quantity for the effective de-reticulation of the polymer. The research developed for each application leads to a process (sonic or microwave) always combined with a concentration of chemical products (processing auxiliaries) with a dosage of around 2 per cent. It is sold at R$ 20.00 per kilo, which represents a cost of R$ 0.40 per kilo of recycled material which, added to the costs of processing, in general R$ 0.50 per kilo, amounts to a total of R$ 0.45 for a material with a virgin resin price of R$ 3.20 per kilo for EVA and which rises above R$ 8.00 for imports such as neoprene and EPM/EPDM. (AU)