1. A tire tread composition comprising:
o natural rubber in an amount ranging from 25 parts per hundred
5 rubber (PHR) to 100 PHR;
o styrene-butadiene rubber (SBR) in an amount ranging from 25
PHR to 75 PHR;
o carbon black in an amount ranging from 45 PHR to 65 PHR;
o functionalized carbon quantum dots (CQDs) in an amount ranging
10 from 0.01 PHR to 1.0 PHR;
o wherein the functionalized CQDs are synthesized from plant-based
leaves and are designed to improve the tensile strength and
hardness of the tire tread.
15 2. The tire tread composition of claim 1, wherein the functionalized CQDs
are prepared by a hydrothermal process involving:
o crushing plant-based leaves into a powder after drying;
o mixing the powder with double distilled water in a Teflon-lined
stainless steel autoclave;
20 o heating the mixture to a temperature of 180°C for a duration of
eight hours;
o cooling the mixture to room temperature;
o centrifuging the obtained liquid to separate the CQDs;
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o freeze-drying the CQDs containing supernatant to obtain a CQDs
powder;
o further grinding the CQDs powder to achieve a fine CQDs powder
having a size ranging from 3nm to 8nm; and
5 o functionalizing the fine CQDs powder with natural rubber
molecules.
3. The tire tread composition of claim 1, further comprising:
o a silane coupling agent in an amount of 5.4 PHR;
10 o benzothiazyl disulfide (MBTS) in an amount of 1.6 PHR;
o naphthenic oil in an amount of 6.0 PHR;
o processing aids including Struktol 40MS, Koresin, and Escorez
1102 in a total amount of 11.0 PHR;
o stearic acid in an amount of 2.1 PHR;
15 o zinc oxide in an amount of 2.8 PHR;
o sulfur in an amount ranging from 0.5 PHR to 2.0 PHR;
o and an accelerator in an amount of 0.7 PHR.
4. A method for manufacturing a tire tread composition, the method
20 comprising the steps of:
o providing natural rubber in an amount ranging from 25 parts per
hundred rubber (PHR) to 100 PHR;
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o providing styrene-butadiene rubber (SBR) in an amount ranging
from 25 PHR to 75 PHR;
o providing carbon black in an amount ranging from 35 PHR to 65
PHR;
5 o providing functionalized carbon quantum dots (CQDs) in an
amount ranging from 0.01 PHR to 1.0 PHR, wherein the
functionalized CQDs are synthesized from plant-based leaves;
o uniformly mixing the natural rubber, SBR, carbon black, and
functionalized CQDs to form a tire tread composition;
10 o further mixing the tire tread composition with additional
compounding ingredients comprising a silane coupling agent,
benzothiazyl disulfide (MBTS), naphthenic oil, processing aids
including Struktol 40MS, Koresin, and Escorez 1102, stearic acid,
zinc oxide, sulfur, and an accelerator;
15 o vulcanizing the mixed tire tread composition to form a tire tread;
o wherein the resulting tire tread exhibits improved rolling resistance
and wet grip properties due to the inclusion of the functionalized
CQDs.
20 5. The method of claim 4, wherein the functionalized CQDs are prepared by:
o crushing plant-based leaves into a powder after drying;
o mixing the powder with double distilled water in a Teflon-lined
stainless steel autoclave;
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o heating the mixture to a temperature of 180°C for a duration of
eight hours;
o cooling the mixture to room temperature;
o centrifuging the obtained liquid to separate the CQDs;
5 o freeze-drying the CQDs containing supernatant to obtain a CQDs
powder;
o further grinding the CQDs powder to achieve a fine CQDs powder;
and
o functionalizing the fine CQDs powder with natural rubber
10 molecules.
6. The method of claim 5, wherein the additional compounding ingredients
are added in the following amounts:
o a silane coupling agent in an amount of 5.4 PHR;
15 o benzothiazyl disulfide (MBTS) in an amount of 1.6 PHR;
o naphthenic oil in an amount of 6.0 PHR;
o processing aids including Struktol 40MS in an amount of 7.0 PHR,
Koresin in an amount of 2.0 PHR, and Escorez 1102 in an amount
of 2.0 PHR;
20 o stearic acid in an amount of 2.1 PHR;
o zinc oxide in an amount of 2.8 PHR;
o sulfur in an amount ranging from 0.5 PHR to 2.0 PHR;
o and an accelerator in an amount of 0.7 PHR.
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7. The method of claim 6, further comprising the step of:
o adding antioxidants to the tire tread composition in an amount
ranging from 0.01 PHR to 2.0 PHR, with a maximum
5 concentration of 1.5 PHR.
8. The method of claim 7, further comprising the step of:
o adding paraffinic wax and microcrystalline wax to the tire tread
composition in a total amount ranging from 0.0 to 3.0 PHR, with
10 approximately 1.0 PHR per wax.
9. The method of claim 8, further comprising the step of:
o adding process oil to the tire tread composition to facilitate
compound mixing and extrusion, in an amount ranging from 0.0 to
15 an effective amount as needed for processing