A Novel Option for Waste Tire Rubber Reutilization: Refrigerant in Solid-State Cooling Devices
Pith reviewed 2026-05-25 09:45 UTC · model grok-4.3
The pith
Waste tire rubber exhibits giant barocaloric effects that position it as a viable refrigerant for solid-state cooling devices.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
Vulcanized waste tire rubber and its polymer blends with vulcanized natural rubber display giant barocaloric effects, with adiabatic temperature changes and isothermal entropy changes that are comparable to or better than most barocaloric materials reported in the literature, together with faster thermal exchange than vulcanized natural rubber alone.
What carries the argument
Barocaloric effect in vulcanized waste tire rubber, in which applied pressure produces large reversible entropy and temperature shifts that can drive a refrigeration cycle.
Load-bearing premise
The giant barocaloric responses arise from intrinsic properties of the waste tire rubber rather than from measurement artifacts, sample inhomogeneity, or unknown processing history of the discarded tires.
What would settle it
Repeating the pressure-cycle calorimetry on multiple independently sourced waste tire rubber samples and confirming that the giant entropy changes remain consistent after controlled cleaning or homogenization steps.
read the original abstract
Management of discarded tires is a compelling environmental issue worldwide. Although several approaches have been developed to recycle waste tire rubbers, their application in solid-state cooling is still unexplored. Considering the high barocaloric potential verified for elastomers, the use of waste tire rubber (WTR) as refrigerant in solid-state cooling devices is very promising. Here, we investigated the barocaloric effects in WTR and polymer blends made of vulcanized natural rubber (VNR) and WTR, in order to evaluate its feasibility for solid-state cooling technologies. The adiabatic temperature change and the isothermal entropy change reach giant values, as well as the performance parameters, being comparable or even better than most barocaloric materials in literature. Moreover, pure WTR and WTR-based samples also present a faster thermal exchange than VNR, consisting in an additional advantage of using these discarded materials. Thus, the present findings evidence the encouraging perspectives of employing waste rubbers in solid-state cooling based on barocaloric effect, contributing in both the recycling of polymers and the sustainable energy technology field.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript proposes repurposing waste tire rubber (WTR) and WTR-vulcanized natural rubber (VNR) blends as refrigerants in barocaloric solid-state cooling devices. It claims that these materials exhibit giant adiabatic temperature changes and isothermal entropy changes, with performance parameters comparable or superior to most barocaloric materials in the literature, and that pure WTR and WTR-based samples show faster thermal exchange than VNR.
Significance. If the giant barocaloric responses are intrinsic and reproducible, the work would offer a dual benefit of addressing tire waste recycling while providing a low-cost, high-performance material for sustainable cooling. The reported faster thermal exchange would be a practical advantage. No machine-checked proofs, open code, or parameter-free predictions are present.
major comments (2)
- [Abstract] Abstract: the central claim that ΔT_ad and ΔS_iso 'reach giant values' and are 'comparable or even better than most barocaloric materials' is asserted without any numerical values, error bars, pressure ranges, sample masses, or direct literature comparisons, so the data-to-claim link cannot be evaluated.
- [Abstract] Abstract: no information is supplied on sample provenance, vulcanization history, filler variability across discarded tires, or the pressure-cell thermal protocol, leaving the weakest assumption (intrinsic response versus artifacts or processing history) untested and load-bearing for the headline result.
minor comments (1)
- The abstract would be strengthened by inclusion of at least one quantitative benchmark (e.g., peak ΔT_ad at a stated pressure) to allow immediate comparison with existing barocaloric elastomers.
Simulated Author's Rebuttal
We thank the referee for the constructive comments, which help improve the clarity of our manuscript. We respond to each major comment below and will make revisions where appropriate to strengthen the presentation of our results on the barocaloric performance of waste tire rubber.
read point-by-point responses
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Referee: [Abstract] Abstract: the central claim that ΔT_ad and ΔS_iso 'reach giant values' and are 'comparable or even better than most barocaloric materials' is asserted without any numerical values, error bars, pressure ranges, sample masses, or direct literature comparisons, so the data-to-claim link cannot be evaluated.
Authors: We agree that the abstract, constrained by length, does not quote the specific numerical values. The main text and figures report the measured ΔT_ad and ΔS_iso (with error bars), the pressure range applied, approximate sample masses, and direct comparisons to literature barocaloric materials via a table and discussion. In the revised manuscript we will condense the key numerical results and pressure range into the abstract to make the data-to-claim connection explicit without lengthening the abstract excessively. revision: yes
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Referee: [Abstract] Abstract: no information is supplied on sample provenance, vulcanization history, filler variability across discarded tires, or the pressure-cell thermal protocol, leaving the weakest assumption (intrinsic response versus artifacts or processing history) untested and load-bearing for the headline result.
Authors: We will revise the methods and experimental-details sections to include the available information on sample provenance, the vulcanization history of the VNR component, and a more complete description of the pressure-cell thermal protocol. Filler variability is an intrinsic feature of recycled tire rubber; we will add a short discussion of how this variability was sampled and its possible influence on the measured barocaloric response. The consistency of the giant effects across multiple WTR and blend specimens supports an intrinsic origin, but we will explicitly address the distinction from processing artifacts in the revised text. revision: yes
Circularity Check
No circularity: purely experimental measurements with no derivations or fitted predictions
full rationale
The paper reports direct experimental measurements of barocaloric effects (adiabatic temperature change, isothermal entropy change, thermal exchange rates) in waste tire rubber and blends. No equations, models, or first-principles derivations are presented; claims rest on observed data compared to literature values. No self-citations load-bearing on uniqueness theorems, no fitted parameters renamed as predictions, and no ansatz or renaming of known results. The derivation chain is absent, making the work self-contained against external benchmarks.
Axiom & Free-Parameter Ledger
axioms (1)
- standard math Barocaloric effect is defined by the entropy and temperature response to hydrostatic pressure change in elastomers.
discussion (0)
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