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Materials and Interfaces
Enhanced mechanical performance and antioxidative efficiency of styrenebutadiene rubber via 4-aminodiphenylamine functionalized mesoporous silica Jing Lin, Dechao Hu, Yuanfang Luo, Bangchao Zhong, Zhixin Jia, Tiwen Xu, and Demin Jia Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.8b00035 • Publication Date (Web): 26 Mar 2018 Downloaded from http://pubs.acs.org on March 26, 2018
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Enhanced mechanical performance and antioxidative efficiency of styrene-butadiene rubber via 4-aminodiphenylamine functionalized mesoporous silica Jing Lin&, Dechao Hu&, Yuanfang Luo, Bangchao Zhong, Zhixin Jia*, Tiwen Xu, Demin Jia Key lab of Guangdong for high property and functional polymer materials, South China University of Technology, 381 Wushan Road, Guangzhou 510640, China *Corresponding author: Tel: +86-020-87114857, E-mail address:
[email protected] &
Jing Lin and Dechao Hu contributed equally to this work.
Abstract: We reported a newly prepared functionalized nano particles (RT@MS) using mesporous silica with antioxidant intermediate 4-aminodiphenylamine (RT) via the linkage of KH-560. RT@MS was used as nano filler to fabricate SBR composites. Under the condition of equal antioxidant and filler components, functionalized mesoporous silica can greatly enhance the mechanical properties of SBR owing to the uniform dispersion and strong interfacial interaction between SBR and RT@MS. Besides, the anti-aging behavior of SBR/RT@MS composites was systematically evaluated by thermal oxidation exothermic enthalpies and oxidation induction time before and after solvent exaction. The results indicated that RT@MS showed much better thermal and oxidative stabilities and longer service life than the most commonly used antioxidant N-isopropyl-N'-phenyl-4-phenylenediamin in SBR due to the improved migration resistance of immobilized RT.
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Keywords: nano particles; surface treatments; particle-reinforced composites; antioxidative behavior. 1. Introduction Nanoparticles are playing a pivotal role in a wide range of fields, such as medicine, biotechnology, polymer, optoelectronic devices, sensors and catalysis1-5. And their application areas are acutely dependent on the size, shape, structure and surface activity of nanoparticles. Mesoporous silica is a kind of nanoparticles with unique mesoporous structure and high surface area, which has been established as a promising nanocarrier and attracted widespread attention for their promising biomedical applications, especially in drug delivery systems6, 7. Styrene butadiene rubber (SBR) is widely used in applied polymer industry owing to its numerous outstanding properties such as excellent processability and abrasion resistance. However, because of the unsaturated molecular structure, SBR is vulnerable to heat and oxygen aging, which severely deteriorates the mechanical properties and service life of rubber products8, 9. Some commercial antioxidants can make a difference to some extent, but there are also some defects restricting their application, for instance, low antioxidative efficiency, easy volatility and migration10, 11
. Preparing novel antioxidants by grafting the low molecular weight antioxidants on
the surface of inorganic filler has been considered as an effective method to achieve improved antioxidative effect12-14. Besides, it has been found that rubber antioxidants modified inorganic filler can realize uniformly dispersion and enhanced interfacial bonding in rubber matrix15. In our previous work, 4-aminodiphenylamine(RT)
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modified halloysite nanotubes/silica hybrid has achieved synergistic enhancement of interfacial interaction and antioxidative behavior in styrene butadiene rubber16. However, to the best of our knowledge, there has been no report about the construction of antioxidant functionalized mesoporous silica and no report about its impact on the reinforcement and anti-aging for rubber composites. Considering the unique mesoporous structure of mesoporous silica, the antioxidant functionalized mesoporous silica may offer superior improvements for the ultimate mechanical performance and antioxidative effect of rubber composites. In this paper, mesoporous silica was firstly introduced as nanocarrier to prepare a novel kind of functionalized nano particles (RT@MS), which was characterized by FTIR, XPS and TGA. Then it was applied in SBR matrix to systematically investigate the effects of RT@MS on the filler dispersion, interfacial bonding, mechanical performances and anti-aging behavior of SBR nanocomposites. 2. Experimental 2.1. Materials SBR (1502) was supplied by Guangzhou Institute of Rubber Products, China. Stearic acid (SA), zinc oxide (ZnO), accelerator N-cyclohexyl-2-benzothiazolesulfenamide (CZ), antioxidant intermediate 4-aminodiphenylamine (RT), antioxidant N-isopropyl-N'-phenyl-4-phenylenediamin (4010NA), insoluble sulfur and (3-glycidoxypropyl)trimethoxysilane (KH-560) were industrial grade products. Tetraethylorthosilicate (TEOS), hexadecyl trimethyl ammonium bromide (CTAB), ammonium hydroxide (NH3·H2O) and absolute ethanol
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were analytically pure and commercially available. 2.2. Fabrication of functionalized mesoporous silica Mesoporous silica (MS) was prepared through sol-gel process from the hydrolysis and condensation of TEOS. The synthetic procedure of the functionalized mesoporous silica is shown in Figure 1 CTAB (0.35g) and NH3·H2O (3.0g) was dissolved in 140 mL water at 80°C for 0.5h. Then 3.0g of TEOS was added and stirred for another 2 h. The obtained products were washed with ethanol for several times and calcined for 3 h at 700oC in a muffle furnace to remove the template CTAB. 8.0 g of mesoporous silica and 2.4 g of KH560 were mechanical mixed in absolute ethanol for 12 h at 90 oC to obtain the modified mesoporous silica (m-MS). Finally, 4.0 g of RT was dissolved in absolute ethanol and reacted with modified mesoporous silica for 12 h at 90 oC to obtain functionalized mesoporous silica (RT@MS).
Figure 1. Synthetic route of the functionalized mesoporous silica nanoparticles. 2.3. Preparation of SBR composites The fundamental compositions of SBR compounds used here were listed as follows: SBR, 100phr; filler (MS, m-MS, RT@MS), 30phr; ZnO, 5.0phr; SA, 2.0phr; CZ, 2.0phr; sulfur, 1.6phr. The antioxidant contents of different composites were fixed 4
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at 2phr. It is worth noting that the content of RT in SBR/RT@MS composites was consist of extra added part and the grafted RT in RT@MS (according to the residue measured by TGA). SBR was compounded with above ingredients on two-roll mill at room temperature and then heating cured at 160 oC for the optimum cure time. 2.4. Characterizations TEM was performed on a JEOL2100. FTIR was conducted on a Bruker Vector 70 FTIR spectrometer with KBr thin pellets in 4000 cm-1 to 400 cm-1. Thermogravimetric analysis (TGA) was performed on a Netzsch TG209F1 under flowing nitrogen atmosphere at a rate of 20 oC /min from 30oC to 750oC. X-ray photoelectron spectroscopy (XPS) was recorded on a Kratos Axis Ultra (DLD) with a monochromated Al Ka (1486.6 eV) source. The m-MS and RT@MS for FTIR, XPS and TGA tests were sufficiently extracted with absolute ethanol for 72 h to remove un-reacted silane coupling agent and antioxidant. Scanning electron microscopy (SEM) images were acquired on LEO1530. Samples for SEM observations were fractured in liquid nitrogen and then sputter-coated with a thin layer of platinum. Dynamic mechanical analysis (DMA) was performed on a NETZSCH 242C instrument with a dynamic strain of 0.5% and frequency of 5Hz. The samples were heated from -100 oC to 100 oC at a heating rate of 3oC/min. Tensile tests were determined with UCAN UT-2060 testing machine following ASTMD 412. The Mooney-Rivlin equation was used to estimate the filler-rubber interfacial interaction 17,18. And the Mooney-Rivlin plots of the reduced stress (σ*) versus the reciprocal of the extension ratio (λ) can be obtained by following equation:
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σ∗ = ⁄
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(1)
The σ is the nominal tensile stress, and the extension ratio λ= L/L0 is the ratio of deformed and undeformed length19, 20. The thermal behaviors of SBR/MS composites in the glass transition region (Tg) were conducted on a NETZSCH DSC 204 F1. The samples were heated from -80°C to 30°C at a rate of 10°C/min under flowing nitrogen atmosphere. Then, the thermal parameters such as heat capacity step (∆Cpn) and the weight fraction of immobilized polymer layer (χim) were calculated by: ∆C pn = ∆C p (1 − w )
(2)
χ im = (∆ C p 0 − ∆ C pn ) ∆ C p 0
(3)
Where w is the weight fraction of filler in rubber compounds, ∆Cp and ∆Cp0 are the heat capacity jump in the glass transition district of filled and unfilled polymer composites, respectively21, 22. The thermal oxidation test of SBR/MS composites was performed under flowing oxygen atmosphere by a NETZSCH DSC 204 F1 at different heating rates. The OIT test of SBR composites before and after extracted for 7days with ethanol was determined on DSC NETZSCH 204 F1. First, the samples were heated from 30oC to 180 oC with a heating rate of 20oC/min under flowing nitrogen and then isothermal for 5min. Subsequently, the gas was changed as oxygen flow, and the OIT curves were recorded until the exothermic peak appeared.
3. Results and Discussion 3.1. Characterization of RT@MS
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Figure 2 illustrates the FTIR spectra of MS, m-MS and RT@MS. Compared with the spectrum of MS, several new characteristic peaks for m-MS at 2858cm-1and 2943cm-1 attributing to -CH2 stretching vibration were appeared. As for RT@MS, there are two absorption peaks at 1497 and 1519 cm-1 ascribed to benzene ring in the spectrum, indicating the existence of RT molecule in RT@MS. Owing to RT and KH560 have been sufficiently extracted with absolute ethanol, it can be deduced that RT was successfully immobilized on the surface of mesoporous silica through chemical bonding.
Figure 2. FTIR spectra of MS, m-MS and RT@MS. XPS was used to provide more accurate information for chemical character of the sample. The XPS spectra of m-MS and RT@MS in N1s are shown in Figure 3. In m-MS, there are no certain signs about N1s. However, the peak of N1s in RT@MS is split into two similar peaks, which are assigned to the characteristic of C-N (396.3 eV) and N-H (398eV), respectively23. Therefore, the results of XPS further demonstrate that the RT is chemically immobilized on the surface of MS via the linkage of KH560.
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Figure 3. XPS spectra of m-MS and RT@MS in the N1s region. TGA curves of MS, m-MS and RT@MS are shown in Figure 4. Owing to the existence of RT and silane coupling agent, RT@MS exhibits lower initial decomposition temperature than the pristine MS and m-MS. Based on the mass losses of m-MS and RT@MS, the grafted antioxidant content onto the surface of mesoporous silica nano particle is about 3.7 wt%.
Figure 4. TGA curves of MS, m-MS and RT@MS. 3.2. Analysis of the immobilized polymer layer The change of heat capacity is generally related to polymer molecular 8
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morphology at the glass transition24. The DSC curves of SBR and SBR composites in the glass transition region were measured, and the corresponding values of ∆Cpn and χim are depicted in Figure 5. It can be seen that the value of heat capacity step of unfilled SBR is higher than that of SBR composites. It is because rubber chains are unrestricted without the influence of filler particles, giving a greater contribution to glass transition. However, on a condition of the same content of filler, higher value of heat capacity step of SBR/RT@MS composites is responsible for the thick immobilized polymer layer approaching RT@MS. Due to the polar reduction of filler particles modified by RT, the improved compatibility between SBR and RT@MS makes more rubber chains tangled on the surface of RT@MS, which makes it difficult for rubber segment to relax in glass transition district. Moreover, thick immobilized polymer layer approaching RT@MS also demonstrates strong interfacial interaction between SBR and RT@MS is formed.
Figure 5. DSC curves of the glass transition district of unfilled SBR and filled SBR composites. 3.3. Morphologies of SBR composites SEM images of SBR composites in Figure 6 show the morphology of MS and 9
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RT@MS in the SBR matrix. From Figure 6a, MS as large agglomerates is unevenly dispersed in SBR matrix owing to the hydrogen bonding formed by the abundant surface hydroxyl groups. After being functionalized with antioxidant molecules, the surface hydroxyl groups were sufficiently consumed, leading to a large increase of hydrophobic surface of the RT@MS. Therefore, the RT@MS is evenly dispersed in SBR matrix as illustrated in Figure 6c. Furthermore, the image of SBR/RT@MS composites at high magnification indicates most RT@MS are nearly imbed in SBR matrix, which provides reliable evidence for a significantly improved interfacial bonding between RT@MS and SBR matrix.
Figure 6. SEM images of SBR composites: (a, b) SBR/MS; (c, d) SBR/RT@MS. 3.4. Dynamical mechanical analysis of SBR composites It is well known that loss factor (Tan δ) in the glass transition district is associated with the elastic segment mobility of polymer25. As seen from Figure 7a, the glass transition temperature of SBR/RT@MS composites, usually interpreted as the peak of Tan δ curves, is greatly increased, indicating the formation of stronger interfacial interaction between SBR and RT@MS. Significantly, the maximum value 10
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of Tan δ for SBR/RT@MS composites is markedly higher than that of SBR/MS composites, which might be explained by the proposal schematic diagram of dispersion of MS and RT@MS in SBR matrix as depicted in Figure 7b and 7c. Some rubber fractions are caught in MS as aggregates and could not anticipate in relaxation of rubber chains as shown in Figure 7b, leading to largely decreasing of loss factor for SBR/MS composites. In contrast, RT@MS is uniformly dispersed in SBR and few rubber fractions are trapped, more rubber chains are contributing to loss factor. Simultaneously, the value of loss factor at 0 oC and 60 oC are generally used to estimate the wet traction and rolling resistance, respectively. As shown in inset (in Figure 7a), it is found the loss factor at 0 oC and at 60 oC for SBR/RT@MS composites is increased to 0.220 and decreased to 0.100, comparing 0.172 and 0.128 for SBR/MS composites, which demonstrates SBR/RT@MS composites have outstanding wet kid resistance and less rolling resistance, and RT@MS has promising application of green tire.
Figure 7. Loss factor Tan δ (a) as a function of temperature for SBR composites; proposal schematic diagram of dispersion of MS (b) and RT@MS (c) in SBR.
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3.5. Mechanical performances of SBR composites The stress-strain behavior can directly reflect the mechanical performances of polymer composites. As illustrated in the inset in Figure 8, the stress of SBR/RT@MS composites more sharply increases with the increase of strain and give a superior mechanical property than other composites, which can be explained by the results of Mooney-Rivlin plots of unfilled SBR and filled SBR composites. As illustrated in Figure 8, σ* of unfilled SBR changes a little, while σ* of filled SBR increases at high λ. Finite rubber chains extensibility between nearby nanoparticles is major responsible for the increased σ* for the filled elastic network26. It is observed all abrupt upturns of σ* appear in SBR/MS composites, even, the abrupt upturn of SBR/RT@MS composites is seen at lower strain. It is ascribed to the good filler dispersion and strong interfacial interaction in SBR/RT@MS composites, resulting in the occurrence of rubber chains orientation bridging nearby nanoparticles at the relatively small deformation.
Figure 8. Mooney-Rivlin plots and stress-strain curves of the unfilled SBR and filled SBR composites. 12
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It has been confirmed that the amount of stretched straight rubber chains formed between neighbouring nanoparticles when applying stretch is directly related to the strength of rubber composites27. From forgoing results, it is concluded that strong interfacial interaction in SBR/RT@MS composites endows the surface of RT@MS with thick immobilized polymer layer, more rubber chains are stretched straightly between neighbouring RT@MS during stretching. Obviously, the stress loaded on SBR/RT@MS composites is transferred from the stretched straight rubber chains to the RT@MS and more energy is dissipated. In turn, less stretched straight rubber chains are subject to the stress for SBR/MS composites, leading the stress could not be dissipated between SBR and MS. Above results demonstrate functionalized mesoporous silica can significantly improve the mechanical performances of SBR composites. 3.6. Antioxidative behavior of SBR composites Figure 9a and 9b show the DSC curves of SBR/RT@MS composites under flowing oxygen and the relationship of peak temperature (Tmax) versus heating rate of SBR composites, respectively. The DSC curves of SBR/m-MS/4010NA not given here show a similar tendency. From Figure 9a, it can be found that there is an obvious exothermic peak for each DSC curve due to the oxidation of double bond for rubber chains. Here, the thermal oxidative stability of rubber composites can be reflected by the value of Tmax28. Compared with SBR/m-MS/4010NA composites with equal antioxidant and filler component, SBR/RT@MS composites give much higher values of Tmax at any heating rates, indicating that RT@MS can endow SBR with better
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thermal oxidation resistance than antioxidant 4010NA. Several reasons can be introduced to explain the outstanding antioxidative efficiency of RT@MS. First, compared with free antioxidant 4010NA, chemical immobilized RT on the surface of mesoporous silica can effectively restrict its migration and volatilization at elevated temperature. Second, the sufficiently functionalized modification reduces the polar of RT, which can significantly reduce agglomeration of RT. Furthermore, the strengthening interfacial interaction and uniform dispersion of RT@MS in rubber matrix also give a positive contribution to the favorable antioxidative performance of SBR/RT@MS composites.
Figure 9. DSC curves of SBR/RT@MS at different scanning rate(a) and corresponding Tmax versus heating rate of SBR composites(b). The migration of antioxidant is closely linked with the service life of rubber composite, and the difference of oxidation induction time (OIT) before and after solvent extraction is usually used to reflect the migration of antioxidant. Figure 10a illustrates the OIT curves of SBR composites before and after solvent extraction for 7 days. The OIT value of SBR/m-MS/4010NA is 117.6 min before extraction, and that of SBR/RT@MS is greatly improved to 137.5 min, which indicates immobilized 14
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antioxidant has a great antioxidative efficiency in SBR than low molecular weight antioxidant 4010NA. After extraction for 7 days, the OIT values of SBR composites are all decreased. Notably, the reduction of OIT value for SBR/RT@MS is less than that of SBR/m-HS/4010NA composites as illustrated in Figure 10b, demonstrating that RT@MS has excellent anti-migration property.
Figure 10. The OIT curves(a) of and OIT value(b) of SBR composites before and after extraction for 7 days. 4. Conclusions In this paper, mesoporous silica (MS) was firstly used as nanocarrier to fabricate novel functionalized nano filler (RT@MS). FTIR, TGA and XPS measurement confirmed that 4-aminodiphenylamine (RT) has been successfully immobilized on the surface of mesoporous silica. Also, strong interfacial bonding between RT@MS and SBR endowed SBR/RT@MS composites with superior mechanical properties. Besides, the results of differential scanning calorimeter analysis showed improved antioxidative efficiency and anti-migration property of RT@MS in the SBR composites than the most commonly used antioxidant N-isopropyl-N'-phenyl-4-phenylenediamin due to lower migration of immobilized RT. 15
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Therefore, the development of RT@MS is expected to provide superior reinforcement and anti-aging effect in rubber nanocomposites, and may be a valuable inspiration for the preparation of other functionalized nanoparticles. Acknowledgements The authors are grateful for the financial support from the National Natural Science Foundation of China (51703063, 51573051), the 973 Program (Grant No. 2015CB654700 (2015654703)), Special Funds for Applied Science and Technology Research and Development of Guangdong Province (2015B020237004, 2015B020235010), Fundamental Research Funds for the Central Universities (2017BQ033) and China Postdoctoral Science Foundation (2017M612658). References (1) Ling, D. Surface ligands in synthesis, modification and assembly of nanoparticles for biomedical applications. Nanomed. Nanotechnol. 2016, 12, 461. (2) Giljohann, D. A.; Seferos, D. S.; Daniel, W. L.; Massich, M. D.; Patel, P. C.; Mirkin, C. A. Gold Nanoparticles for Biology and Medicine. Angew. Chem. Internat. Edit. 2010, 49, 3280-3294. (3) Manjula, P.; Boppella, R.; Manorama, S. V. A Facile and Green Approach for the Controlled Synthesis of Porous SnO2 Nanospheres: Application as an Efficient Photocatalyst and an Excellent Gas Sensing Material. ACS Appl. Mater. Inter. 2012, 4, 6252-6260. (4) Liu, M.; Peng, Q.; Luo, B.; Zhou, C. The improvement of mechanical performance and water-response of carboxylated SBR by chitin nanocrystals. Eur. Polym. J. 2015, 68, 190-206. (5) Wang, X.; Wang, L.; Su, Q.; Zheng, J. Use of unmodified SiO 2 as nanofiller to improve mechanical properties of polymer-based nanocomposites. Compos. Sci. Technol. 2013, 89, 52-60. (6) Tang, F.; Li, L.; Chen, D. Mesoporous Silica Nanoparticles: Synthesis, Biocompatibility and Drug Delivery. Adv. Mater. 2012, 24, 1504-1534. (7) Liang, Y.; Mai, W.; Huang, J.; Huang, Z.; Fu, R.; Zhang, M.; Wu, D.; Matyjaszewski, K. Novel hollow and yolk-shell structured periodic mesoporous polymer nanoparticles. Chem. Commun. 2016, 52, 2489-2492. (8) Zhong, B.; Shi, Q.; Jia, Z.; Luo, Y.; Chen, Y.; Jia, D. Preparation of silica-supported 2-mercaptobenzimidazole and its antioxidative behavior in 16
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styrene-butadiene rubber. Polym. Degrad. Stab. 2014, 110, 260-267. (9) Abdelwahab, N. A.; El-Nashar, D. E.; El-Ghaffar, M. A. A. Polyfuran, polythiophene and their blend as novel antioxidants for styrene- butadiene rubber vulcanizates. Mater. Design 2011, 32, 238-245. (10) Wei, H.; Guo, L.; Zheng, J.; Huang, G.; Li, G. Effect of Nanosilica-Based Immobile Antioxidant on thermal oxidative degradation of SBR. Rsc Adv. 2015, 5, 62788-62796. (11) Fu, Y.; Zhao, D.; Yao, P.; Wang, W.; Zhang, L.; Lvov, Y. Highly Aging-Resistant Elastomers Doped with Antioxidant-Loaded Clay Nanotubes. ACS Appl. Mater. Inter. 2015, 7. (12) Gao, X.; Hu, G.; Qian, Z.; Ding, Y.; Zhang, S.; Wang, D.; Yang, M. Immobilization of antioxidant on nanosilica and the antioxidative behavior in low density polyethylene. Polymer 2007, 48, 7309-7315. (13) Pan, Q.; Wang, B.; Chen, Z.; Zhao, J. Reinforcement and antioxidation effects of antioxidant functionalized silica in styrene–butadiene rubber. Mater. Design 2013, 50, 558-565. (14) Guo, L.; Lei, H.; Zheng, J.; Huang, G.; Li, G. Synthesis of Nanosilica-Based Immobile Antioxidant and Its Antioxidative Efficiency in SBR Composites. Polym. Compos. 2013, 34, 1856-1862. (15) Hu, D.; Jia, Z.; Zhong, B.; Chen, Y.; Luo, Y.; Jia, D. A facile and green preparation of nanosilica-supported antioxidant and its reinforcement and antioxidation effect on styrene-butadiene rubber. Int. J. Polym. Anal. Ch. 2016, 21, 185-197. (16) Lin, J.; Luo, Y.; Zhong, B.; Hu, D.; Jia, Z.; Jia, D. Enhanced interfacial interaction and antioxidative behavior of novel halloysite nanotubes/silica hybrid supported antioxidant in styrene-butadiene rubber. Appl Surf Sci.2018, 441, 798-806. (17) Tang, Z.; Huang, J.; Wu, X.; Guo, B.; Zhang, L.; Liu, F. Interface engineering toward promoting silanization by ionic liquid for high-performance rubber/silica composites. Ind Eng Chem Res. 2015, 54, 10747-10756. (18) Zhong, B.; Dong, H.; Lin, J.; Jia, Z.; Luo, Y.; Jia, D.; Liu, F. Preparation of halloysite nanotubes–silica hybrid supported vulcanization accelerator for enhancing interfacial and mechanical strength of rubber composites. Ind Eng Chem Res. 2017, 56, 9135-9142. (19) Lu, L.; Zhai, Y.; Zhang, Y.; Ong, C.; Guo, S. Reinforcement of hydrogenated carboxylated nitrile–butadiene rubber by multi-walled carbon nanotubes. Appl. Surf. Sci. 2008, 255, 2162-2166. (20) Shergold, O. A.; Fleck, N. A.; Radford, D. The uniaxial stress versus strain response of pig skin and silicone rubber at low and high strain rates. Int. J. Impact Eng. 2006, 32, 1384-1402. (21) Rooj, S.; Das, A.; Stöckelhuber, K. W.; Wang, D.-Y.; Galiatsatos, V.; Heinrich, G. Understanding the reinforcing behavior of expanded clay particles in natural rubber compounds. Soft Matter 2013, 9, 3798. (22) And, Y. I., Ishida, H. A Study of Morphology and Intercalation Kinetics of Polystyrene-Organoclay Nanocomposites. Macromolecules 2005, 15, 6513-6519. 17
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(23) Point, S.; Minea, T.; Bouchet-Fabre, B.; Granier, A.; Turban, G. XPS and NEXAFS characterisation of plasma deposited vertically aligned N-doped MWCNT. Diam. Relat. Mater. 2005, 14, 891-895. (24) Ediger, M. D.; Forrest, J. A. Dynamics near Free Surfaces and the Glass Transition in Thin Polymer Films: A View to the Future. Macromolecules 2014, 47, 471-478. (25) Huda, M. S.; Drzal, L. T.; Mohanty, A. K.; Misra, M. Effect of fiber surface-treatments on the properties of laminated biocomposites from poly(lactic acid) (PLA) and kenaf fibers. Compos. Sci. Technol. 2008, 68, 424-432. (26) Bokobza L, E. B. A Theoretical and Experimental Study of Filler Effect on Stress-Deformation-Segmental Orientation Relations for Poly(dimethylsiloxane) Networks. Macromolecules 2000, 23, 8858-8864. (27) Wang, Z.; Liu, J.; Wu, S.; Wang, W.; Zhang, L. Novel percolation phenomena and mechanism of strengthening elastomers by nanofillers. Phys. Chem. Chem. Phys. 2010, 12, 3014-3030. (28) Zhong, B.; Jia, Z.; Shi, Q.; Yang, C.; Luo, Y.; Jia, D. Characterization of effects of thermal-oxidative aging on styrene-butadiene rubber/silica composites with vitamin C-lanthanum complex. Int. J. Polym Anal Ch. 2016, 21, 1-10.
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