Juan José Potti revealed a new method for recycling av rubber from car tires.

CRUMB RUBBER MODIFIED BITUMEN. OTHER WAY TO RECYCL CAR TIRES

Abstract

Use of grinded crumb rubber (CR) is a technology which is being used for already 40 years. However, the introduction of European Directives in Spain has generated an important awareness as far as recycling and exploitation of this residue in road construction is concerned. Probisa has a long tradition in this investigation field: studies of bituminous mixes carried out both using the dry and the humid way. Based on its experience, Probisa has developed a wide range of polymer modified bituminous binders exclusively resulting from CR. Besides the intrinsic characteristics of the binder, special attention has been paid to its viscosity to obtain bituminous mixes which can be handled under the same conditions as conventional PMB. In this way, they are coherent with the ecoefficiency objective, aimed at in all recycling processes. The paper also deals with limitations of current empirical test methods when it comes to quantifying characteristics of bituminous binders. As an alternative, a methodology based on functional behaviour tests is proposed.

Read the whole report:

http://congress.cimne.upc.es/rilem04/admin/Files/FilePaper/p330.pdf

The same report in Spanish

http://www.probisa.com/Publicaciones/showfile.aspx?id=1061

MSc thesis from Luleå tekniska universitet (Luleå Univeristy of Technology/Maskinteknik/Polymer Engineering)

Author: Jinxia Li; [2008]

Keywords: Recycled EPDM rubber; Unvulcanized rubber; LDPE; EMA; Reactive compatibilization; Non-reactive compatibilization; Ethylene octene copolymer; Phenolic resins; Tensile properties; Tear strength; Microstructure; Pressing pressure; rubber recycling,

Abstarct: Blends containing recycled EPDM rubber and thermoplastics, EMA and LDPE were studied. Two compatibilization methods, reactive and non-reactive, were evaluated. Ethylene octene copolymer (EXACT 0210) was used as non-reactive compatibilizer. Phenolic resins (SP1045 & HRJ10518) were reactive agents. There existed an optimal composition of compatibilizers which were 25wt% in the case of reactive and non-reactive agents added to 15wt%EMA and 55-60wt% EPDM rubber.

EXACT-compatibilized blends gave high elongation at break while phenolic resin-compatibilized mixtures gave high stiffness in comparison with the chosen reference material. Comparison in compatibilizing capabilities HRJ-10518 and SP-1045 was carried out. The former one had better capabilities than the latter at high compatibilizer content. Talcum was used as anti-agglomeration agent but failed to work properly. Pressing pressure could be minimized without any adverse effect. Non-vulcanized rubber was used to enhance tear strength but its effect was small by assuming that there exists degradation of the interfacial surface at high temperature. SEM analysis revealed homogeneous microstructure in both kinds of compatibilization. EXACT 0210-compatibilized blends showed more plastic deformation of the matrix than reactive blends. Stable connection between phases was also observed.

Tensile strength of the LDPE based blends were a little lower than that of EMA based blends and the hardness was a little higher. Compared to EMA based blends, the elongation at break was much lower while the young's modulus was much higher with LDPE based blends. Compression set of both LDPE and EMA based blends was high compared to the reference materials supplied by Rerub AB, Piteå.

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