Effect of polyethylene glycol on the properties of styrene‐butadiene rubber/organoclay nanocomposites filled with silica and carbon black

Polyethyene glycol (PEG) is widely used as a dispersing agent and can also be used to prevent the adsorption of ingredients on the surface of silica. From the XRD results, PEG that was used as the dispersing agent on the SBR/organoclay compound filled with silica and carbon black (CB) was intercalated between the organoclay layer. Additionally, the interactions with the PEG differed depending on whether 3‐aminopropyltriethoxysilane (APTES) or N,N‐dimethyldodecylamine (DDA) were used as clay modifiers. When PEG was added, the T_g of the SBR/silica/APTES‐MMT compound increased through the formation of hydrogen bonds between the ether linkages of PEG and the hydroxyl groups of APTES. For the SBR/silica/DDA‐MMT compound with PEG, slippage occurred between the silicate, and DDA because of the alkyl chain of DDA. The SBR/silica/APTES‐MMT/CB compound with PEG exhibited the highest T_g value and the highest bound rubber content, with high modulus values at 100 and 300%. The SBR/silica/DDA‐MMT/CB compound had the best properties in terms of the wet skid resistance and the rolling resistance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Novel fabrication of disorderly exfoliated sodium montmorillonite in a styrene–butadiene rubber matrix

Using industrial technologies, we prepared a sodium montmorillonite (Na‐MMT) slurry and an irradiated styrene–butadiene rubber (SBR) latex, and then spray dried them to produce a novel, ultrafine fully vulcanized powder SBR (UFPSBR)/Na‐MMT nanocompound powder in which the nanoscale UFPSBR particles and exfoliated Na‐MMT were isolated and stuck together. When the UFPSBR/Na‐MMT nanocompound powder was mixed with crude SBR, the exfoliated Na‐MMT was disorderly dispersed in the SBR matrix because of the carrier nature of the UFPSBR particle, which is compatible with SBR and disperses easily in the SBR matrix, and the SBR/UFPSBR/Na‐MMT ternary nanocomposite was prepared. When compared with SBR/Na‐MMT binary composites, the SBR/UFPSBR/Na‐MMT ternary nanocomposite has a shorter vulcanization time, higher strength, and better flame retardancy because of the good dispersion of exfoliated Na‐MMT in the SBR matrix with a Na‐MMT loading range of 4 phr. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2013     

Technological and processing properties of natural rubber layered silicate‐nanocomposites by melt intercalation process

Natural rubber nanocomposites were produced by melt‐mixing of natural rubber with organically modified silicates. For comparison, a pristine‐layered silicate and a nonlayered version [English Indian clay (EIC)] were also included in the study. The layered silicate used was sodium bentonite (BNT) and organoclays used were octadecylamine‐ modified montmorillonite (MMT‐ODA) and methyltallow bis‐2‐hydroxyethyl ammonium‐modified montmorillonite (MMT‐ TMDA). Accelerated sulfur system was used for the vulcanization of the nanocomposites. The dispersion of these silicates was studied by X‐ray diffraction and transmission electron microscopy. The organoclay‐incorporated composites exhibited faster curing and improved mechanical properties. The improvement in the mechanical properties of the composites followed the order MMT‐ODA > MMT‐TMDA > EIC > BNT. The property improvement was attributed to the intercalation/exfoliation of the organically modified silicates because of their high initial interlayer distance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2537–2543, 2006     

Preparation and characterization of poly(styrene‐co‐butadiene) and polybutadiene rubber/clay nanocomposites

Poly(styrene‐co‐butadiene) rubber (SBR) and polybutadiene rubber (BR)/clay nanocomposites have been prepared. The effects of the incorporation of inorganically and organically modified clays on the vulcanization reactions of SBR and BR were analysed by rheometry and differential scanning calorimetry. A reduction in scorch time (t_s1) and optimum time (t₉₅) was observed for both the rubbers when organoclay was added and this was attributed to the amine groups of the organic modifier. However, t_s1 and t₉₅ were further increased as the clay content was increased. A reduction in torque value was obtained for the organoclay nanocomposites, indicating a lower number of crosslinks formed. The organoclays favoured the vulcanization process although the vulcanizing effect was reduced with increasing clay content. The tensile strength and elongation of SBR were improved significantly with organoclay. The improvement of the tensile properties of BR with organoclay was less noticeable than inorganic‐modified clay. Nevertheless, these mechanical properties were enhanced with addition of clay. The mechanical properties of the nanocomposites were dependent on filler size and dispersion, and also compatibility between fillers and the rubber matrix. Copyright © 2004 Society of Chemical Industry     

Combining In‐Situ Organic Modification of Montmorillonite and the Latex Compounding Method to Prepare High‐Performance Rubber‐Montmorillonite Nanocomposites

Summary: To improve the interfacial interaction in MMT‐SBR nanocomposites, one type of UOAC was introduced to in‐situ modified MMT before latex compounding with SBR. The influence of the UOAC/MMT ratio on the structure and properties of MMT/SBR nanocomposites were carefully studied by XRD, TEM, and mechanical testing. It was found that through the in‐situ organic modification, a rubber‐intercalated structure of MMT was obtained in the nanocomposites, and the amount of rubber‐intercalated structure strongly depended on the UOAC/MMT ratio. The tensile strength of MMT‐SBR nanocomposites was enhanced dramatically from 4 to 18 MPa by in‐situ organic modification of MMT.

Stress‐strain diagram of SBR/clay nanocomposites.     

Grafting hydroxy‐terminated polybutadiene onto nanosilica surface for styrene butadiene rubber compounds

Hydroxy teminated polybutadiene (HTPB) was grafted onto the surface of nanosilica particles via toluene di‐isocyanate (TDI) bridging to reduce filler–filler interactions and improve dispersion of nanosilica in rubber. Also, this prepolymer as modifier contains double bonds which participate in sulfur curing of styrene butadiene rubber (SBR) matrix to enhance filler/polymer interaction and reinforcement effects of silica. The reactions were characterized by titration and Fourier transforms infrared spectroscopy. Thermogravimetric analysis was utilized to evaluate the weight percentage of grafted TDI and HTPB. About 60% of the hydroxyl sites of silica were reacted with excess TDI in the first reaction. In the second reaction, HTPB as desired reactive coating was grafted on the functionalized nanosilica to constitute about 24 wt % of the final modified silica. The sedimentation experiments showed good suspension stability for the modified nanosilica in the organic media. Scanning electron microscopy revealed nanoscale dispersion of modified silica aggregates in the SBR matrix at concentration of about 14 phr. Also, vulcanization characteristics and mechanical properties of compounds demonstrated that HTPB grafting improved dispersion of nanosilica as well as its interaction to the rubber matrix as an efficient reinforcement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparing Exfoliated MMT/Polymer Nanocomposites by Combined Latex Compounding and Spray‐Drying

A facile and easily industrialized approach for preparing highly dispersed MMT/polymer nanocomposites is developed by combining the latex compounding method and a spray‐drying process. Clay particles are successfully delaminated into layers, and layer re‐stacking is effectively prevented. HR‐TEM and XRD results confirm that MMT layers achieve exfoliated or nearly exfoliated dispersion in both MMT/styrene‐butadiene rubber and MMT/PS nanocomposites. Compared with melt‐blended MMT/SBR composites, MMT/SBR nanocomposites prepared by this new strategy exhibit extremely high dynamic modulus.

     

High‐performance hydrogenated nitrile butadiene rubber composites by in situ interfacial design of nanoclays

Considering industrial requests, it has become a hot issue to prepare advanced rubber composites with high strength and great toughness. Despite enhanced strength and stiffness, rubber composites suffer markedly reduced extensibility and toughness. Herein, a novel interfacial strategy is proposed to fabricate amine‐modified montmorillonite (MMT)/hydrogenated nitrile butadiene rubber composites by designing in situ ionic bond interfaces. The well‐distributed interfaces, which are composed of protonated amine groups on the MMT surfaces and electronegative methacrylic acid (MA), were constructed by adding a slurry with a small amount of MMT and MA to rubber. After the vulcanization, self‐polymerization of MA developed nanoparticles and grafting structures onto rubber chains to bond MMT by strong ion attractions. Although the crosslinking degree of rubber was reduced, the dispersion of MMT and its interfacial interactions with rubber were improved remarkably, as demonstrated by morphology observations, dynamic mechanical analysis and infrared spectra. As a result, the strength, modulus, elongation, toughness and gas barrier properties of the rubber composites were simultaneously strikingly improved relative to composites without MA modifiers. We believe that this work provides a promising methodology of fabricating high‐performance rubber composites. © 2019 Society of Chemical Industry     

Studies on preparation and properties of vinyltriethoxysilane‐grafted styrene‐butadiene rubber

Graft polymerization of vinyltriethoxysilane (VTES) onto styrene‐butadiene rubber (SBR) was carried out in latex using benzoic peroxide (BPO) as an initiator. The concentration of VTES effecting on vulcanization characteristics, mechanical properties and thermal properties of VTES‐grafted SBR (SBR‐g‐VTES) were investigated. The grafting of VTES onto SBR and its pre‐crosslinking were confirmed by attenuated total teflectance‐Fourier transform infrared reflectance and proton nuclear magnetic resonance. The mechanism of graft polymerization was studied. The results revealed that the minimum torque, optimum cure time, tensile strength, thermal decomposition temperature, and glass transition temperature (T_g) all increased with the increasing concentration of VTES. But the grafting efficiency of VTES, rate of vulcanization, and elongation at break of the SBR‐g‐VTES decreased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Rectorite powder modified by butadiene‐styrene‐vinyl pyridine rubber: Structure and its dispersion in styrene‐butadiene rubber

Rectorite (REC) powders modified by butadiene‐styrene‐vinyl pyridine rubber (VPR) were prepared by spray drying, designated as REC‐VPRs. X‐ray diffraction (XRD), Scanning electron microscope (SEM), and transmission electron microscopy (TEM) analyses showed that in the REC‐VPRs, VPR did not intercalate into the intergallery of layers. However, compared with REC, the layers of REC‐VPRs had more wrinkles and piled loosely. To strengthen the interfacial interaction between VPR and REC, a REC‐VPR was treated by volatilized hydrochloric acid, resulting in the formation of ion bonds between REC and VPR, according to Fourier transform infrared spectra measurements. XRD analyses revealed that the intercalated structure emerged in acid treated REC‐VPR filled styrene‐butadiene rubber (SBR). However, the better dispersion was observed for the SBR composite filled with REC‐VPR without acid treatment, indicating that a proper interfacial interaction between REC and VPR is the key to improve the dispersion of REC layers in SBR. Acid treatment did not improve the tensile and tear strengths of the SBR composite filled with REC‐VPR. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013     

Preparation and characterization of elastomer‐based nanocomposite gels using an unique latex blending technique

Nanocomposite (NC) gels based on natural rubber (NR) and styrene butadiene rubber (SBR) were prepared by using a unique latex blending technique. These NC gels were prepared by first blending the water swollen unmodified montmorillonite clay (Na⁺‐MMT) suspension into the respective latices followed by prevulcanization to generate crosslinked nanogels. Use of water assisted fully delaminated Na⁺‐MMT suspension resulted in predominantly exfoliated morphology in the NC gels, as revealed by X‐ray diffraction study and transmission electron microscopy. Addition of Na⁺‐MMT significantly improved various physical, mechanical and thermal properties of these NC gels. For example, 6 phr of Na⁺‐MMT loaded NR based NC gels registered 54% and 200% increase in tensile strength and Young's modulus, respectively, compared to the unfilled NR gels. SBR based NC gels also showed similar level of improvement in mechanical properties. Mechanical properties of NC gels prepared using this route were also compared with the NC gels prepared by co‐coagulation and conventional curing technique and found to be superior. In the case of dynamic mechanical properties, NC gels showed higher glass transition temperatures along with a concomitant increase in storage moduli, compared to the unfilled gels. These Na⁺‐MMT reinforced NC gels also exhibited markedly improved thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

The effect of organic modifier‐12‐aminolauric acid on morphology and thermal properties of polylactide nanocomposites

A novel organically modified montmorillonite (OMMT) based on a bifunctional organic modifier‐12‐aminolauric acid (ALA) was synthesized. Polylactide (PLA) nanocomposites with this new and traditional OMMT were prepared by solution casting method. The effects of the organic modifiers on structure, morphology and thermal properties of PLA nanocomposites have been investigated using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The results indicate that ALA has distinct effects on the dispersion of MMT platelets into the PLA matrix, where partial exfoliated as well as intercalated structures have been obtained, when compared with ordinary modifier, cetyltrimethyl ammonium bromide (CTAB). TGA data verifies that PLA nanocomposites with ALA‐MMT organoclay display enhanced thermal stability. The optimal clay loading of ALA‐MMT occurs at 3%wt, leading to the best compromise between clay dispersion and thermal properties. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Poly(4‐methyl‐1‐pentene)/clay nanocomposites: effect of organically modified layered silicates

The preparation and properties of poly(4‐methyl‐1‐pentene) (PMP)/clay nanocomposites are reported. Melt intercalation of PMP is carried out with organoclays of different cation/charge exchange capacities and modifiers to facilitate intercalation of the polymer into the silicate layers. The effect of modifiers on the structure and properties of PMP/clay nanocomposites is explored. XRD patterns confirm the intercalation of polymer in the layered silicates as evidenced by the increase in the inter‐layer spacing which is dependent on the type of modifier used. Dynamic mechanical analysis shows increments in the storage modulus over the temperature range studied for all of the three clays, but the extent depends on the type of clay modifier used. The coefficient of thermal expansion is lower for all of the nanocomposites, as compared to the pristine polymer, indicating improved dimensional stability Copyright © 2003 Society of Chemical Industry     

Styrene butadiene rubber/clay nanocomposites for tire tread application

Homogeneous and stable dispersion of layered silicates in their rubber nanocomposite is a matter of interest as it can significantly affect the material properties. Herein we propose a facile and easily industrialised approach for preparing highly dispersed montmorillonite (MMT)/rubber nanocomposites by the latex compounding method. Furthermore, an efficient way of enhancing the interlayer spaces of organically modified MMT (f-MMT) with alkyl-ammonium chains while mixing the styrene butadiene rubber (SBR) is reported. The f-MMT embedded SBR matrix shows a remarkable improvement of the modulus and tensile strength even in the low loading rate, which is ascribed to the well dispersion of the f-MMT enhancing interfacial interaction with the rubber matrix. Furthermore, we manufactured the practical pneumatic tire using f-MMT/SBR nanocomposite with outstanding wear resistance, grip performance and low-rolling resistance for the green tire application, opening up enormous opportunities to prepare high-performance rubber composites for future engineering applications.     

Effect of silane coupling agent on the structure and mechanical properties of nano‐dispersed clay filled styrene butadiene rubber

In rubber nanocomposites containing inorganic clay, the reinforcement effect has always been relatively insignificant due to the poor interfacial interaction between the rubber matrix and clay fillers. In this work, the silane coupling agent bis[3‐(triethoxysilyl)propyl]tetrasulfide (Si‐69) was employed through mechanically blending with styrene butadiene rubber (SBR)/clay (100/30) nanocompound that was prepared by combined latex compounding and spray‐drying technique, to serve as the molecular bridge between SBR matrix and clay filler and strengthen the interfacial interaction. TEM and XRD characterization indicated that Si‐69 significantly improved the dispersion of the silicate layers in the SBR matrix. The RPA analysis and the mechanical property study of the SBR/clay nanocomposites revealed that the filler network interaction was weakened while the filler–rubber interaction was strengthened upon the addition of Si‐69. POLYM. COMPOS., 37:890–896, 2016. © 2014 Society of Plastics Engineers     

Effect of low molecular weight polybutadiene as processing aid on properties of silica‐filled styrene–butadiene rubber compounds

Because silica has strong filler–filler interactions, a silica‐filled rubber compound shows a poor filler dispersion compared to a carbon black‐filled one. Improvement of the filler dispersion in silica‐filled styrene–butadiene rubber (SBR) compounds was studied using low molecular weight polybutadiene (liquid PBD) with the high content of 1,2‐unit. By adding the liquid PBD to the silica‐filled SBR compound, the filler dispersion and flow property are improved. The cure time and cure rate become faster as the 1,2‐unit content of the liquid PBD increases for the compounds containing the liquid PBD. The crosslink density increases linearly with increase in the 1,2‐unit content of the liquid PBD. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3135–3140, 2003     

Compatibility improvement of poly(lactic acid)/thermoplastic polyurethane blends with 3‐aminopropyl triethoxysilane

Poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) blends were prepared via a melt‐blending process with or without the addition of a 3‐aminopropyl triethoxysilane (APTES) compatibilizer at different dosages. The addition of the compatibilizer showed improved compatibility between TPU and PLA; this led to an enhanced dispersion of TPU within the PLA matrix. With the addition of 1‐phr APTES, the crystallization behavior did not vary much, but this exacerbated the formation of a second melting temperature for PLA at higher temperature. However, the addition of 5‐phr APTES into the PLA/TPU blends depressed the crystallization temperature and resulted in a melting temperature depression phenomena with the disappearance of the second melting peak because of the lubricated effect of low‐molecular‐weight species of APTES. The addition of a low dosage of APTES improved the impact strength further from 29.2 ± 1.4 to 40.7 ± 2.7 J/m but with a limited improvement in the tensile properties; this indicated that a higher dispersion of the dispersed phase did not always improve all of the mechanical properties because of the low‐molecular‐weight nature of the compatibilizer used. The physical properties of the added modifier needed to be considered as well. A low dosage of APTES (1 phr) also increased the viscosity because of the improved interaction between TPU and PLA at all of the investigated shear rate regions, but a higher dosage of compatibilizer induced another plasticizing effect to reduce the viscosity. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42322.     

Properties of silica‐filled styrene‐butadiene rubber compounds containing acrylonitrile‐butadiene rubber: The influence of the acrylonitrile‐butadiene rubber type

Because silica has strong filler‐filler interactions and adsorbs polar materials, a silica‐filled rubber compound exhibits poor dispersion of the filler and poor cure characteristics in comparison with those of a carbon black‐filled rubber compound. Acrylonitrile‐butadiene rubber (NBR) improves filler dispersion in silica‐filled styrene‐butadiene rubber (SBR) compounds. The influence of the NBR type on the properties of silica‐filled SBR compounds containing NBR was studied with NBRs of various acrylonitrile contents. The composition of the bound rubber was different from that of the compounded rubber. The NBR content of the bound rubber was higher than that of the compounded rubber; this became clearer for NBR with a higher acrylonitrile content. The Mooney scorch time and cure rate became faster as the acrylonitrile content in NBR increased. The modulus increased with an increase in the acrylonitrile content of NBR because the crosslink density increased. The experimental results could be explained by interactions of the nitrile group of NBR with silica. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 385–393, 2002     

Improvement of properties of silica‐filled styrene–butadiene rubber compounds using acrylonitrile–butadiene rubber

Since silica has strong filler–filler interactions and adsorbs polar materials, a silica‐filled rubber compound has a poor dispersion of the filler and poor cure characteristics. Improvement of the properties of silica‐filled styrene–butadiene rubber (SBR) compounds was studied using acrylonitrile–butadiene rubber (NBR). Viscosities and bound rubber contents of the compounds became lower by adding NBR to the compound. Cure characteristics of the compounds were improved by adding NBR. Physical properties such as modulus, tensile strength, heat buildup, abrasion, and crack resistance were also improved by adding NBR. Both wet traction and rolling resistance of the vulcanizates containing NBR were better than were those of the vulcanizate without NBR. The NBR effects in the silica‐filled SBR compounds were compared with the carbon black‐filled compounds. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1127–1133, 2001     

Preparation,characterization, and application of NR/SBR/Organoclay nanocomposites in the tire industry

The natural rubber/styrene butadiene rubber/organoclay (NR/SBR/organoclay) nanocomposites were successfully prepared with different types of organoclay by direct compounding. The optimal type of organoclay was selected by the mechanical properties characterization of the NR/SBR/organoclay composites. The series of NR/SBR/organoclay (the optimal organoclay) nanocomposites were prepared with various organoclay contents loading from 1.0 to 7.0 parts per hundreds of rubber (phr). The nearly completely exfoliated organoclay nanocomposites with uniform dispersion were confirmed by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The results of mechanical properties measurement showed that the tensile strength, tensile modulus, and tear strength were improved significantly when the organoclay content was less than 5.0 phr. The tensile strength and the tear strength of the nanocomposite with only 3.0 phr organoclay were improved by 92.8% and 63.4%, respectively. It showed organoclay has excellent reinforcement effect with low content. The reduction of the score and cure times of the composites indicated that the organoclay acted as accelerator in the process of vulcanization. The incorporation of a small amount of organoclay greatly improved the swelling behavior and thermal stability, which was attributed to the good barrier properties of the dispersed organoclay layers. The outstanding performance of co‐reinforcement system with organoclay in the tire formulation showed that the organoclay had a good application prospect in the tire industry, especially for the improvement of abrasion resistance and the reduction of production cost. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011