Reclaiming of waste guayule natural rubber vulcanizate—reclaim rubber for green tire applications: An approach for sustainable development

Abstract

This article illustrates the reclaiming of guayule natural rubber (GNR) vulcanizate by bis[3-(triethoxysilyl)propyl] tetrasulfide (TESPT), and as-grown reclaim rubber facilitates the silica dispersion in GNR product application without adding any coupling agent. This article deals with the performance evaluation of silica-filled revulcanizates with promising application in green tire. The extent of reclaiming was monitored through the measurement of sol content, cross-link density, Mooney viscosity, and degree of reclaiming. The differential scanning calorimetry study was carried out to evaluate the fraction of immobilized polymer chains and its dependence on cross-link density of the vulcanizates. The Fourier transform infrared study and also sulfur analysis independently indicate the attachment of the fragmented TESPT with the polymer chain and cross-link bonds. The study of mechanical properties clearly shows that in revulcanized GNR, the optimum property is achieved when reclaiming time is set for 40 min. The effect of reclaiming time on dynamic mechanical behavior such as storage modulus and loss tangent was studied. The scanning electron microscopy studies show the coherency and homogeneity of silica-filled revulcanize rubber with reclaiming time.

From Devulcanization of Ground Tire Rubber by Microwaves to Revulcanization: A Revulcanization Kinetic Approach Using a Simple Prediction Model

“…To have useful properties, devulcanized rubber must be vulcanized again, i.e., be revulcanized. In recent literature, several articles analyzing the revulcanization of devulcanized rubbers are found but many in the form of blends ,− or composites containing reinforcement agents such as silica. ,, Formela et al analyzed the influence of different vulcanization system types on the revulcanization behavior of thermomechanical devulcanized ground tire rubber (GTR). The results showed that the revulcanization system used, i.e., the type of accelerator, strongly influenced the revulcanization behavior, which consequently resulted in different static and dynamic mechanical properties.…”

Thermoplastic elastomers based on recycled high-density polyethylene/ground tire rubber/ethylene vinyl acetate: Effect of ground tire rubber regeneration on morphological and mechanical properties

“…The shear forces might cause unselective scission of the rubber main chains and the reduction of the performance of RR particles. 39 The crosslink density of NR particles decreased from 7.2×10 À4 mol/cm 3 to 6.1×10 À4 mol/cm 3 (RR 1 ) and 5.5×10 À4 mol/cm 3 (RR 2 ) after rubber regeneration. The immobilized fraction of rubber chains decreased with decreasing crosslink density of RR because of the vulcanized network is partially broken-up which increased the chain mobility and flexibility of the polymer, while lower chain restriction leads to low rigidity and modulus after regeneration.…”

Efficient thermo-oxidative reclamation of green tire rubber and silanized-silica/rubber interface characterization

“…The chemical structure of the r-SSs obtained by thermo-oxidative reclamation under different temperatures were characterized and compared with pure silica, as shown in Figure 2. All the r-SSs exhibits C-H stretching vibration of -CH2groups in the rubber backbone at 2916 and 2850 cm -1 , CH2-bending vibration at 1450 cm -1 , -CH3 bending vibration at 1374 cm -1 , and Si-O stretching of Si-alkoxy compound at 1070 and 950 cm -1 which is defined as TESPT characteristic peaks by Chorai et al 14 The broad peak at 3442 cm -1 corresponds to -OH stretching of Si-OH in silica.…”