Ground tire rubber (GTR) surface modification using thiol-ene click reaction: Polystyrene grafting to modify a GTR/polystyrene (PS) blend

Abstract

In this work, a thiol-ene click reaction was used to graft polystyrene (PS) chains onto the surface of ethylene propylene diene monomer-based ground tire rubber (GTR). A thiol-terminated PS (11 kg mol−1) was selected, due to its commercial availability, to modify a postconsumer GTR. The resulting PS-grafted GTR (GTR- g-PS) particles were analyzed via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) to detect surface changes on treated samples. An increase in aliphatic and aromatic carbon atoms was observed by FTIR and XPS, while grafted material was observed by SEM on the GTR surface, confirming that grafting took place. Then, composites were prepared from these GTR- g-PS particles and from PS by solution evaporation, at 50 wt%. A significant increase in tensile (20%) and storage moduli (from 80% at 65°C to 510% at 95°C) was observed by dynamic mechanical thermal analysis when compared to composites prepared with untreated GTR. In addition, GTR samples showed improved thermal resistance, as attested by the shift in degradation temperature for 10% mass loss (from 400°C for GTR to 450°C for GTR- g-PS). This increases the possible range of processing temperature and service temperature (applications) for introduction of GTR in other polymer matrices.

Phase morphology, mechanical, and thermal properties of fiber-reinforced thermoplastic elastomer: Effects of blend composition and compatibilization

“…59 The difference between the residuals in air and nitrogen is related to an additional oxidation step of carbon black to CO 2 around 540°C leading to lower value of residuals in air. 60…”

Recycled HDPE/Natural Fiber Composites Modified with Waste Tire Rubber: A Comparison between Injection and Compression Molding

“…The following supporting information can be downloaded at: , Table S1: Decomposition temperatures (T10 and T50) and residues of the samples produced; Figure S1: Weight and derivative curves as a function of temperature for rHDPE, FF, RR, F40, R40, R25F and R25F* in: ( A , C ) air and ( B , D ) nitrogen; Figure S2: Density of the composites. References [ 5 , 17 , 20 , 21 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ] are cited in the supplementary materials.…”

Photoclick Chemistry: A Bright Idea

“…Alternatively, some materials intrinsically display surface functional groups amenable to photoclick modification directly (e.g., the grafting of thiol-terminated polystyrene to ethylene propylene diene monomer rubber via radical thiol−ene photoclick coupling). 343 The 2D geometry of surface functionalization reactions permits extremely thin samples, which diminishes the concern of light attenuation that may be significant for some photoclick reactions in bulk curing applications. For this reason, reactions involving a one photon, one event type mechanism do not suffer as much from this potential drawback that may mitigate their use in other contexts.…”

“…Thiol–ene and thiol–yne reactions are particularly amenable to this surface treatment approach as a small stoichiometric imbalance can be well tolerated for maintenance of bulk material properties while providing ample surface-level functionality for subsequent reaction. Alternatively, some materials intrinsically display surface functional groups amenable to photoclick modification directly (e.g., the grafting of thiol-terminated polystyrene to ethylene propylene diene monomer rubber via radical thiol–ene photoclick coupling) …”