Rheological characterization of polyethylene/polyester recycled tire fibers/ground tire rubber composites

Abstract

The rheological behavior of polyester recycled tire fibers (RTF) mixed with ground tire rubber and linear low density polyethylene (LLDPE) with and without styrene–ethylene–butylene–styrene grafted maleic anhydride (SEBS‐g‐MA) as a compatibilizer was investigated in the melt (small amplitude oscillatory shear) and solid (dynamic mechanical analysis) states. In particular, the effect of RTF content (10, 25, and 50 wt %), extrusion screw speed (110, 180, and 250 rpm), and temperature profiles (extrusion and injection molding) was studied. In general, it was found that the rheological properties in the melt state (modulus and viscosity) of the uncompatibilized samples increased with RTF content, but higher values were obtained when SEBS‐g‐MA was added due to better interfacial coupling. Although similar results were obtained in the solid state, it was shown that melt rheology can better explain the variations as the measurements are more sensitive to the interface quality since the matrix contribution is less important. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46563.

The effect of polyester recycled tire fibers mixed with ground tire rubber on polyethylene composites. Part II

“…This trend can be related to poor interfacial adhesion of the binary blends (polar and nonpolar materials). 5 Also, the compatibilized blends produced even lower mechanical properties than the uncompatibilized samples. This behavior is associated to the low rigidity of the rubbery structure of SEBS-g-MA, 5,9,15 as well as the presence of GTR.…”

“…5 Also, the compatibilized blends produced even lower mechanical properties than the uncompatibilized samples. This behavior is associated to the low rigidity of the rubbery structure of SEBS-g-MA, 5,9,15 as well as the presence of GTR. 16 As seen in Figure 1, better compatibility between LLDPE and GTR with the addition of SEBS-g-MA leads to better stress transfer from the matrix to the rubber particles leading to lower overall rigidity of the compounds.…”

“…Furthermore, a substantial decrease in the elongation at break occurred when the RTF reached its highest content (50%) resulting in a 97% (uncompatibilized) and 94% (compatibilized) decrease when compared to neat LLDPE. This can be related to two different phenomena: limited interfacial adhesion between RTF and LLDPE even in the presence of the compatibilizer, 5 and limited chain mobility of GTR particles due to their cross-linked nature. Nevertheless, the rubbery structure of the compatibilizer led to higher tensile strain at break overall.…”

“…But due to compatibility limitations, a “compatibilizer” having a similar structure with the polyolefin and PET as well as GTR must be added. 5 To date, some work can be found on synthetic fibers reinforced composites 6 and natural fibers reinforced polyolefin/GTR blends. 7,8 For example, Ferreira et al 6 worked on waste polyamide (W-PA) from scrap tires to reinforce waste PET (W-PET) (25/75 wt%).…”

“…In the first part of this study, a complete characterization of the RTF and its compounds with linear low-density polyethylene (LLDPE) was presented using different processing conditions. 5 From the samples produced, a morphological analysis was performed to get a clear picture of the final materials structure (particle size and dispersion). Here, an analysis is made on the effect of RTF content (mixed with GTR particles) on the physical and mechanical properties of these samples.…”