Relationship Among Thermal Ageing Degradation, Dynamic Properties, Cure Systems, and Antioxidants in Natural Rubber Vulcanisates

Pimolsiriphol, Vorapong; Sae‐Oui, Pongdhorn; Sirisinha, Chakrit

doi:10.1080/03602550601152861

Cited by 38 publications

(38 citation statements)

References 19 publications

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“…This is because, as the aging proceeds [29], the molecular weight of the rubber increases and chain molecules are generated, thereby widening the molecular-weight distribution. Thus, the rubber molecules have reduced flexibility [30], which limits the intermolecular slippage and reduces the swelling [31]. In the case of unaged specimens, the initial crosslink density is about 4.5 × 10 −5 mol/cm 3 , and it can be confirmed that the crosslink density increases up to 14.5 × 10 −5 mol/cm 3 as the aging progresses.…”

Section: Swelling-test Resultssupporting

confidence: 52%

Study on the Aging Behavior of Natural Rubber/Butadiene Rubber (NR/BR) Blends Using a Parallel Spring Model

et al. 2018

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Natural rubber/butadiene rubber (NR/BR) blends are widely used in industrial areas for absorbing vibrations and shocks because of their excellent elastic stability. However, when an industrial-equipment surface is exposed to sunlight and oxygen over a long period of time, the rubber hardens. As a result, the tensile properties of the rubber material and the behavior of the strain-energy density function are changed, greatly reducing the performance of the rubber product. However, only a few experimental studies on the aging characteristics of NR/BR blends are available, and it is difficult to find a study that analyzes the organic relationship of the changes in the mechanical (stress-strain curves, strain-energy density, etc.) and chemical (cross-linked structure, crosslink density, etc.) properties. In this study, a swelling test was performed on an aged rubber compound, and the result was substituted into the Flory-Rehner equation to obtain the quantitative crosslink density. The results revealed a linear relationship between the strain-energy density (SED) and the crosslink density (CLD) when the cross-linked structure increase was represented by a parallel spring model. Finally, the relationship between the strain-energy density and the crosslink density was summarized as a formula, and a method for predicting the aging behavior of NR/BR blends using the crosslink density was proposed.

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Section: Swelling-test Resultssupporting

confidence: 52%

Study on the Aging Behavior of Natural Rubber/Butadiene Rubber (NR/BR) Blends Using a Parallel Spring Model

et al. 2018

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“…In the aging process, oxidative crosslinking was slightly greater than degradative chain scission, and the number of crosslinking points between macromolecular networks was increased and the flexibility of molecules was decreased, which limited the intermolecular slip [31,32] and resulted in the slow increase of the crosslinking density of HTPB coating. There existed an exponential function relationship between crosslinking density and aging time, which was also widely used in the analysis of the thermal accelerated aging test [33,34], as shown in Equation (1):…”

Section: Aging Results Of Crosslinking Densitymentioning

confidence: 99%

“…The fitting results are shown in Table 1 and the fitting curve is shown in Figure 3. It can be seen from the fitting results that the correlation coefficient between the fitting results of In the aging process, oxidative crosslinking was slightly greater than degradative chain scission, and the number of crosslinking points between macromolecular networks was increased and the flexibility of molecules was decreased, which limited the intermolecular slip [31,32] and resulted in the slow increase of the crosslinking density of HTPB coating.…”

Section: Aging Results Of Crosslinking Densitymentioning

confidence: 99%

Influence of Thermally-Accelerated Aging on the Dynamic Mechanical Properties of HTPB Coating and Crosslinking Density-Modified Model for the Payne Effect

Zheng

2020

Polymers

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Hydroxyl terminated polybutadiene (HTPB) coating is widely used in a solid rocket motor, but an aging phenomenon exists during long-term storage, which causes irreversible damage to the performance of this HTPB coating. In order to study the effect of aging on the dynamic mechanical properties of the HTPB coating, the thermally-accelerated aging test was carried out. The variation of maximum elongation and crosslinking density with aging time was obtained, and a good linear relationship between maximum elongation and crosslinking density was found by correlation analysis. The changing regularity of dynamic mechanical properties with aging time was analyzed. It was found that with the increase of aging time, T g of HTPB coating increased, T α , tan β and tan α decreased, and the functional relationships between the loss factor parameters and crosslinking density were constructed. The storage modulus and loss modulus of HTPB coating increased with the increase of aging time, and decreased with the increase of pre-strain. The aging enhanced the Payne effect of HTPB coating, while the pre-strain had a weakening effect. In view of the Payne effect of HTPB coating, the crosslinking density was introduced into Kraus model as aging evaluation parameter, and the crosslinking density modified models with and without pre-strain were established. The proposed models can effectively solve the problem that the Kraus model has a poor fitting effect under the condition of small strain (generally less than 1%) and on the loss modulus, which have improved the correlations between the fitting results and the test results.Polymers 2020, 12, 403 2 of 20 of 1 H NMR (nuclear magnetic resonance), and analyzed the influence of the crosslinking density on the macro-mechanical properties.It was found that with the increase of crosslinking density, the hardness and modulus of the material increased linearly, while the elongation at break decreased linearly. Katarzyna et al. [5] found that the existence of crosslinking resulted in the increase of the glass transition temperature T g . Actually, the linear relationship equation between T g and crosslinking density was derived in the study of Fox and Loshaek [6]. Although the linear equation was not completely consistent with some later results [7-9], they also came to the same conclusion that the crosslinking can increase the glass transition temperature of the polymer. In the study of Celina et al. [10], it was found that the crosslinking density of HTPB elastomers increased with the aging time. The mainly aging reaction was oxidation crosslinking, and the change of crosslinking density affected the mechanical properties of the material. Byungwoo et al. [11] also got the same conclusion. The test results demonstrated that the crosslinking density increased with the increase of aging temperature and aging time, and the crosslinking changed with the change of aging condition. The functional relationship between strain energy density and crosslinking density was established.Dynamic mechanical ...

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“…Moreover, high‐tensile properties of ICCF are attributable to the improvement in tensile strength and modulus for the fiber composite compared with NR matrix. The increase in M300 of biocomposites due to improvement in crosslinking density and the incorporation of ICCF into the rubber matrix increased the stiffness of the vulcanizates as it represents the material stiffness …”

Section: Resultsmentioning

confidence: 99%

Fabrication and characterization of natural rubber/Imperata cylindrica cellulose fiber biocomposites

Thulasimani

Subramaniam

Husseinsyah

2015

Asia-Pacific J Chem Eng

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Imperata cylindrica (IC) is one of the most abundantly found agricultural wastes that have been used to produce lignocellulose fiber and nanocellulose. Cellulose fiber from IC leaves has been isolated and characterized using Fourier transform infrared spectroscopy and scanning electron microscope. Biocomposite was prepared using Imperata cylindrica cellulose fiber (ICCF) as reinforcing filler and natural rubber (NR) as the matrix. The NR vulcanizates were cured with conventional vulcanization (CV) and efficient vulcanization (EV) curing system using two roll mills. The effect of ICCF content on curing characteristic, tensile properties, and morphology of ICCF-filled NR vulcanizates was studied. The results indicated that the tensile strength and tensile modulus of EV system were higher compared with CV system. The tensile strength and modulus at 300% increased as the ICCF content increased accompanied by a moderate decrease in elongation at break. The morphology study of biocomposites showed that ICCF were dispersed better in the NR matrix.

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Relationship Among Thermal Ageing Degradation, Dynamic Properties, Cure Systems, and Antioxidants in Natural Rubber Vulcanisates

Cited by 38 publications

References 19 publications

Study on the Aging Behavior of Natural Rubber/Butadiene Rubber (NR/BR) Blends Using a Parallel Spring Model

Study on the Aging Behavior of Natural Rubber/Butadiene Rubber (NR/BR) Blends Using a Parallel Spring Model

Influence of Thermally-Accelerated Aging on the Dynamic Mechanical Properties of HTPB Coating and Crosslinking Density-Modified Model for the Payne Effect

Fabrication and characterization of natural rubber/Imperata cylindrica cellulose fiber biocomposites

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