共查询到20条相似文献,搜索用时 15 毫秒
1.
Kaushik Pal R. Rajasekar Dong Jin Kang Zhen Xiu Zhang Samir K. Pal Chapal K. Das Jin Kuk Kim 《Materials & Design》2010
The effect of fillers on morphology and wear characteristics are studied in butadiene rubber (PBR)/high styrene rubber (HSR)/natural rubber (NR) blends with different types of carbon black. SAF N110 with SRF N774 type of carbon black shows a significant effect on curing studies and mechanical properties by reacting at the interface between PBR, HSR and NR matrix. Blends containing the same carbon blacks show high abrasion resistant properties against Du-Pont abrader, DIN abrader and different mining rock surfaces and also is found to be the toughest rubber against all types of rock. 相似文献
2.
The aim of the present research work is to develop expanded graphite (EG) and isocyanate modified graphite nanoplatelets (i-MG) filled SBR/BR blends, which can substitute natural rubber (NR) in some application areas. The present study investigated the effect of i-MG on the physical, mechanical and thermo-mechanical properties of polybutadiene rubber (BR), styrene butadiene rubber (SBR) and SBR/BR blends in the presence of carbon black (CB). Graphite sheets were modified to enhance its dispersion in the rubber matrices, which resulting in an improvement in the overall physical and mechanical properties of the rubber vulcanizates. Compounds based on 50:50 of BR and SBR with ∼3 wt% nanofillers with CB were fabricated by melt mixing. The morphology of the filled rubber blends was investigated by wide angle X-ray diffraction (WAXD) and high resolution transmission electron microscopic (HR-TEM) analyses. The intercalated and delaminated structures of the nanofiller loaded rubber blends were observed. Scanning electron microscopic (SEM) analysis of the cryo-fractured surfaces of the rubber compounds showed more rough and tortuous pathway of the fractured surfaces compared to the fractured surfaces of the only CB loaded rubber composites. Filled rubber compounds exhibit increase in the ΔS (torque difference) value, reduced scorch and cure time compared to their respective controls. Dynamic mechanical thermal analysis (DMTA) of the filled rubber compounds shows an increase in the storage modulus compared to the controls. Isocyanate modified graphite nanoplatelets (i-MG) containing rubber compounds in the presence of CB showed an increase in the mechanical, dynamic mechanical, hardness, abrasion resistance and thermal properties compared to the alone CB filled rubber vulcanizates. 相似文献
3.
The aim of this work was to develop and characterize styrene butadiene rubber (SBR) composites filled with SBR industrial scraps (SBR-r) devulcanized by microwave. The SBR-r was ground under ambient conditions and subjected to microwave exposure for 1, 2 and 3 min. The composites were developed by the incorporation of 80 phr (parts per hundred of rubber) of the devulcanized SBR-r into the rubber matrix and subsequent revulcanization. The rheometric and physical–mechanical properties (shore A hardness, compression set, tensile and tear strength) were determined. The samples were submitted to two types of accelerated aging processes, in an air oven (thermo-oxidation) and an artificial weathering test in a UV chamber (photo-oxidation). The results were compared with a control sample submitted to the same conditions. For further application in automotive profiles, the set of results indicated that the best performance was achieved by the composite containing SBR-r devulcanized for 2 min in a microwave. For this composite, the changes in the chemical characteristics after aging were evaluated with cross-link density and Attenuated Total Reflectance–Fourier Transform Infrared Spectroscopy (ATR–FTIR) analyses. The results revealed that the aging mechanism was dependent on the presence of SBR-r and on the time of aging. The cross-link density analysis confirmed the occurrence of cross-link scissioning at shorter aging times and the formation of additional cross-linking in the postcure process. The ATR–FTIR results indicated an oxidative process occurring on the surface of the composites for both aging processes. Moreover, artificial weathering presented a more pronounced change in the chemical structure of the samples. 相似文献
4.
In the present study, rice husks filled styrene butadiene rubber (SBR)/linear low density polyethylene (LLDPE) 50/50 blends with a compatibilizer, maleic anhydride (MAH) were prepared using a brabender plasti-corder. Virgin SBR/LLDPE blend was also prepared. The physico-mechanical as well as dielectric properties were investigated. Increasing MAH concentrations in SBR/LLDPE blends resulted in an increase in the tensile strength, elongation at break and hardness. After a certain concentration (2.5 phr), a reduction in these properties was found. On the other hand an increase in the dielectric properties as well as in the mass swell in both toluene and oil with MAH was noticed. After certain concentration of rice husk filler (25 phr) an abrupt increase in permittivity ε′ and dielectric loss ε″ was obtained. These results are supported by the mechanical properties measurements. The scanning electron microscopy (SEM) indicates that the presence of MAH increases the interfacial interaction between SBR/LLDPE blends on one hand and also rice husk filler and the blend on the other hand. 相似文献
5.
A New approach is introduced to incorporate multi-walled carbon nanotubes (MWCNTs) in cementitious materials. The MWCNTs are
dispersed in styrene butadiene rubber (SBR) matrix before mixing the matrix with cement. Surfactants have been successfully
applied to enhance the dispersion and functionalization of MWCNTs in SBR. The significance of using this MWCNTs–SBR nanocomposite
on the mechanical characteristics including compressive and tensile strengths and microstructural features of latex modified
mortar (LMM) were examined. Subsequently, the significance of the functionalized MWCNTs on surface chemistry, microstructure
and thermal stability of SBR were characterized. MWCNTs were found to be a useful additive for enhancing the mechanical response
and thermal stability of SBR. MWCNTs–SBR nanocomposite was observed to be able to bridge micro-cracks in the LMM which helped
enhancing its mechanical properties. The ability of MWCNTs to enhance the mechanical response of SBR polymer matrix might
be attributed to chemical bond that functionalized MWCNTs can establish with the SBR polymer matrix. The enhanced MWCNTs–SBR
nanocomposite gave rise to improved microstructural features of the LMM. Microstructural investigations showed MWCNTs were
well dispersed in and bonded to the SBR matrix. 相似文献
6.
采用固相法制备了玉米淀粉接枝马来酸酐(MAH)和苯乙烯(St)的共聚物Starch-g-MAH-St(SMS)。采用机械共混法制备了接枝改性淀粉/丁苯橡胶(SMS/SBR)复合材料,研究了复合材料的力学性能、热空气老化性能、动态力学性能以及微观形态。结果表明,SMS/SBR复合材料的力学性能优于未改性淀粉/SBR复合材料和纯SBR。当苯乙烯和MAH单体用量都为原淀粉质量的10 %且SMS的用量为20 g/100 g SBR时,SMS/SBR复合材料的力学性能最佳。经100℃ 热空气老化48 h后,复合材料的拉伸强度仍可达10 MPa。与纯 SBR硫化胶相比,SMS/SBR复合材料的玻璃化转变温度(Tg)降低。微观形态分析显示,淀粉经改性后粒子尺寸减小,在SBR 中的分散性得到了改善,与SBR基体的相容性得到了提高。 相似文献
7.
为探究环氧化对白炭黑(SiO2粒子)在溶聚丁苯橡胶(SSBR)基体中分散性的作用,首先,以SSBR和环氧化溶聚丁苯橡胶(ESSBR)为基体,白炭黑为补强填料,分别制备了SiO2/SSBR、SiO2/ESSBR混炼胶和硫化胶;然后,采用FTIR、SEM和其他测试方法研究了材料的结构、形貌、硫化特性、耐磨性能、准静态力学性能和动态力学性能。结果表明:随环氧度从0增大到14.73%,生胶的门尼黏度增大。ESSBR分子链中的环氧基团与SiO2粒子表面的硅羟基反应形成稳定的化学键,抑制SiO2粒子团聚,促进其均匀分散;当环氧度为6.87%时, SiO2粒子在ESSBR中的分散性最好。随环氧度增大, SiO2/ESSBR硫化胶的拉伸强度先增大后减小、耐磨性能先增强后减弱、断裂伸长率降低、100%和300%定伸强度增大、玻璃化转变温度升高、0℃时的损耗因子显著增大、抗湿滑性增强、60℃时的损耗因子略有增加且滚动阻力增大。因此, SSBR硫化胶经环氧化改性后综合性能提高,当其环氧度在6.87%~8.51%范围内时, SiO2/ESSBR硫化胶的综合性能最优。 相似文献
8.
The present research work demonstrated the reinforcing effect of expanded graphite (EG) and modified EG (MEG) with and without carbon black (CB) on the physical, mechanical and thermo-mechanical properties of emulsion polymerized styrene butadiene rubber (SBR) vulcanizates. In separate batches, EG and MEG flakes with and without CB were incorporated into the SBR by melt blending. The microstructures of the nanocomposites were precisely characterized by wide angle X-ray diffraction (WAXD) analysis and high resolution transmission electron microscope (HR-TEM). EG and MEG filled SBR compounds showed improvement in the curing features, mechanical, thermal and dynamic mechanical properties than their respective controls. 相似文献
9.
Ratcheting response of nylon fiber reinforced natural rubber/styrene butadiene rubber composites under uniaxial stress cycles: Experimental studies
下载免费PDF全文
![点击此处可从《Fatigue & Fracture of Engineering Materials & Structures》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. Vahidifar E. Esmizadeh G. Naderi A. Varvani‐Farahani 《Fatigue & Fracture of Engineering Materials & Structures》2018,41(2):348-357
The present study intends to study the ratcheting response of nylon fiber reinforced natural rubber (NR)‐styrene butadiene rubber (SBR) composite samples under asymmetric stress cycles. Uniaxial tests conducted on composite samples have shown how influential the weight fraction of short nylon fibers on the stress‐strain curves/loops under monotonic and cyclic loads is. NR/SBR composite samples with various fiber contents of 0, 10, 20, 30, and 40 per hundred rubber (phr) were tested under asymmetric stress cycles. In these tests, stress‐strain hysteresis loops were progressively shifted over stress cycles resulting in progressive plastic strain accumulation. Over stress cycles, ratcheting strain progressed within the first few cycles with a relatively high rate, and as the number of cycles increased, this rate decayed resulting in a plateau in strain accumulation (shakedown). The ratcheting strain rate and magnitude resulting in shakedown were highly affected by the nylon fiber content. The experimental observations showed that this plateau (shakedown) occurred after a number of cycles in NR/SBR composite samples where the widths of hysteresis loops stayed unchanged. Samples with no fiber and that with 10 phr fiber content possessed high ratcheting rates leading samples to failure after a few stress cycles. Fracture surfaces in these samples were further analyzed through SEM investigation. 相似文献
10.
Kaushik Pal R. Rajasekar Dong Jin Kang Zhen Xiu Zhang Jin Kuk Kim C.K. Das 《Materials & Design》2009,30(10):4035-4042
Epoxidized natural rubber (ENR) and organoclay nanocomposites (Cloisite 20A) were prepared by solution mixing in this study. The obtained nanocomposites were incorporated in natural rubber (NR) and high styrene rubber (HSR) blends in presence of ISAF and SRF types of carbon black as reinforcing fillers. Morphology, curing characteristics, mechanical and thermal properties and wear characteristics of the nanocomposites against standard abrader and different mining rock surfaces were analyzed. The morphology of the ENR/nanoclay showed a highly intercalated structure. The nanocomposites containing SRF N774 type of carbon black has showed increase in cross-link density, maximum torque and cure rate index compared to ISAF N231 type of carbon black. The overall mechanical properties and thermal stability was higher for the nanocomposites containing SRF type of carbon blacks. The compounds containing EC in NR–HSR have higher barrier properties compared to without EC. EC with SRF N774 carbon black has showed minimum compression set value due to the increased formation of effective network chains due to higher reinforcing efficiency of the nanoclay in the rubber matrix. EC with SRF N774 type of carbon black showed high abrasion resistance property against Du-Pont abrader, DIN abrader and rock–rubber experimental study and also it has been found to be the toughest rubber compound against all types of rock under the present study. Concrete has been identified as the major abrader against the blends than other rock types. 相似文献
11.
12.
In order to improve the dispersion of silica in rubber matrix and to avoid volatility and extractability of the antioxidants, antioxidant functionalized silica is synthesized through reaction of precipitated silica and antioxidant coupling agent which is synthesized by (3-glycidyloxypropyl)trimethoxysilane (A-187) and N-phenyl-1,4-phenylenediamine (PPDA). This antioxidant functionalized silica with different antioxidant content is then incorporated into styrene–butadiene rubber (SBR) to study their reinforcement and antioxidation effects. The tensile strength of these composites is much higher than that of neat silica/SBR, and increases with increasing antioxidant content. It is close to that of bis(triethoxysilylpropyl)tetrasulfane (TESPT) modified silica/SBR when the antioxidant content exceeds 3.9% (by weight to silica). Furthermore, SBR filled with antioxidant functionalized silica has greatly improved stability in thermal oxidative ageing and damp heat ageing. 相似文献
13.
N. M. Renukappa Siddaramaiah R. D. Sudhakar Samuel 《Journal of Materials Science: Materials in Electronics》2007,18(6):635-645
Different weight fractions of aluminum (Al) powder viz., 10, 20, 30, 40, 50, 60 and 70 phr were incorporated into styrene
butadiene rubber (SBR) matrix. The Al powder filled and vulcanized SBR composites have been characterized for mechanical properties
such as tensile strength, tensile modulus and surface hardness. A drastical improvement in tensile strength and tensile modulus
with increase in filler content of the composites was noticed. The electrical properties such as dielectric constant, tan
delta and dielectric loss were measured for all the four compositions. The effect of volume fraction (0–70 phr) of conducting
filler, frequency (100 kHz–30 MHz), temperature (25–75°C) and relative humidity on dielectric constant, dielectric loss and
tan delta values of the composites were studied. 相似文献
14.
Silica/reduced graphene oxide (SiO2@rGO) hybrids were fabricated by an electrostatic assembly, and subsequently, SiO2@rGO was incorporated into styrene butadiene rubber (SBR) to fabricate SBR composites. The dispersion status of SiO2@rGO and the filler–rubber interfacial interaction were investigated. Likewise, the amount of constrained region was quantified and the findings suggested that the greater the volume fraction of constrained region has possessed, the stronger the interfacial interaction has had. Moreover, the contribution of constrained region to the performance of composites was quantitatively analyzed by the mechanical analysis and the tube model, and the results showed that it is the effect of constrained region, rather than the contents of SiO2@rGO, which controls the reinforcement of composites. Specifically, the higher the volume fraction of constrained region is, the better the mechanical properties of composites will be. Also, SiO2@rGO can be utilized as novel reinforcing filler for fabricating the green tire materials with high performance. 相似文献
15.
Fei Wang 《Fullerenes, Nanotubes and Carbon Nanostructures》2018,26(1):61-68
This paper presents a simple strategy that utilizes the regulation of curing temperature to control the orientation of the aligned graphene nanosheets (GNSs) in styrene butadiene rubber (SBR). GNSs would settle from the well-dispersed GNSs suspensions with the styrene butadiene latex (SBL) mixture under the field of gravity to form parallel-aligned GNSs composites with enough standing time at a lower curing temperature. The vertical-aligned GNSs composites were formed by the combined effect of gravity and steam inductive force within a higher curing temperature. The detail forming mechanisms were discussed in the investigation. The parallel-aligned GNSs/SBR composites demonstrated anisotropic conductivity between the parallel and the perpendicular directions. Along with parallel direction, a percolation threshold value of the GNSs was 0.13 wt%, and 0.58 S/cm and of electric conductivity was attained when the GNSs content was 3 wt%. Along with vertical direction, it the GNSs showed insulating property. 相似文献
16.
E. BAYRAKTAR N. ISAC K. BESSRI C. BATHIAS 《Fatigue & Fracture of Engineering Materials & Structures》2008,31(2):184-196
Elastomeric matrix composites (EMCs) subjected to static and fluctuating loads basically fail due to the nucleation and growth of defects. Also, high hydrostatic pressure can influence the mechanical behaviour of EMCs. The change in behaviour of EMCs due to the nucleation of cavitations under hydrostatic pressure is studied here to understand the mechanics underlying the damage mechanism. Two types of materials for pancake specimens are used in this study; natural rubber (NR) vulcanized and reinforced by carbon black and synthetic rubber (styrene‐butadiene‐rubber, SBR). In situ observations of uniaxial tension and torsion tests are also presented by using X‐ray computed tomography (CT) (medical scanner) and the results are compared with those from scanning electron microscopy (SEM). 相似文献
17.
N. M. Mathew A. K. Bhowmick B. K. Dhindaw S. K. De 《Journal of Materials Science》1982,17(9):2594-2598
Tensile rupture of natural rubber (NR) and styrene-butadiene rubber (SBR), vulcanized by sulphur and peroxide systems, both with and without fillers, has been studied by scanning electron microscopy (SEM). NR gum fracture surfaces show evidence of straininduced crystallization, which is absent in SBR. The fracture surfaces of filler-reinforced NR and SBR vulcanizates are characterized by their roughness and by the presence of short and curved tear lines. Increase of cross-link density changes the fracture mode. Peroxide-cured SBR undergoes brittle fracture, whereas sulphur-cured SBR shows a smooth surface with a few straight tear lines. 相似文献
18.
This study investigated the effects of core–shell kaolin–metal oxide pigments on the rheological, physico-mechanical and dielectric properties of styrene–butadiene rubber composites. In this way, newly prepared core–shell pigments based on kaolin as the core representing 90% of the whole pigment was covered with different metal oxides (CaO, MgO and CaO⋅MgO) comprising the shell which represents only 10% of the prepared pigments were incorporated with different concentrations in styrene–butadiene (SBR) rubber composites. Studying the different properties of pigmented and unpigmented SBR composites were done. Scanning electron microscopy (SEM) was used to feature out the surface morphology. Addition of the new pigments increased the tensile strength and strain energy, while elastic modulus was decreased. This study revealed that there is a significant effect of the new prepared pigments on SBR properties and the optimum pigment loading was 40 phr for CaO/kaolin, while it was 2.5 phr for MgO/kaolin. The dielectric results also showed that, the values of ε′ (relative permittivity) and ε′′ (dielectric loss) increased with increasing core shell content. Moreover, the samples containing MgO/kaolin and MgO⋅CaO/kaolin showed promising dielectric properties with low relative permittivity and electrical insulating properties. The different measurements showed good agreement in their results. 相似文献
19.
In the present study, the effect of different curing systems including sulfur, dicumyl peroxide, dicumyl peroxide/coagent and radiation/coagent on the mechanical and physico-chemical properties of acrylonitrile butadiene rubber (NBR) was studied. In order to correlate, the effect of curing systems on rubber, the comparison was carried out at comparable value of volume fraction of rubber in swollen gel (Vr) for NBR vulcanizates. Mechanical properties like tensile strength, elongation at break, modulus, Young’s modulus, tearing strength and abrasion loss of vulcanizates have been followed up for comparison. In addition, physico-chemical properties like swelling ratio, soluble fraction, and cross-link density were investigated. On the other hand, the effects of fuel, thermogravimetric analysis, and thermal ageing have been studied. 相似文献
20.
Effect of fillers on natural rubber/high styrene rubber blends with nano silica: Morphology and wear 总被引:1,自引:0,他引:1
Kaushik Pal R. Rajasekar Dong Jin Kang Zhen Xiu Zhang Samir K. Pal Chapal K. Das Jin Kuk Kim 《Materials & Design》2010,31(2):677-686
The blends of high styrene rubber (HSR) and natural rubber (NR) with nano silica were prepared using a blending technique in presence of different types of carbon black. The effect of filler on morphological and wear characteristics was studied. ISAF (Intermediate Super Abrasion Furnace) type of carbon black have showed a significant effect on optimum cure time, cure rate index and mechanical properties by reacting at the interface between HSR and NR matrix. All the samples show only one melting peak on the DSC curve; this is attributed to the same backbone structure of the matrix and the carbon black reinforcement. The samples containing 30 wt.% of HSR with ISAF type of carbon black has shown maximum heat buildup, lower swelling and lower compression set value. Blends containing ISAF type of carbon black with 30 wt.% of HSR showed high abrasion resistant properties against Du-Pont abrader, DIN abrader and different mining rock surfaces and also is found to be the toughest rubber against all types of rock. Coal is main abrader against the rubber under this study. 相似文献