Mesoporous silica reinforced polybutadiene rubber hybrid composite

Int J Ind Chem (2016) 7:131–141 DOI 10.1007/s40090-015-0062-8 RESEARCH Mesoporous silica reinforced polybutadiene rubber hybrid composite Madhuchhanda Maiti1 • Ganesh C. Basak1 • Vivek K. Srivastava1 • Raksh Vir Jasra1 Received: 25 May 2015 / Accepted: 7 October 2015 / Published online: 13 April 2016 Ó The Author(s) 2016. This article is published with open access at Springerlink.com Abstract Polybutadiene rubber (BR) hybrid composites reinforced with mesoporous silica (MPS)/nanoclays, silica and MPS/carbon black were prepared. The primary focus of this research was to incorporate the mesoporous silicate (MPS), e.g., mobil composition of matter (MCM-41) as reinforcing filler in the BR matrix. The textural properties of the mesoporous materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy and N2 isothermal adsorption measurements. The quantity of MCM-41 in the BR matrix was first optimized and the similar optimized quantity of different MPS was compared in terms of tensile strength. The composites were characterized by XRD and scanning electron microscopy. The composite containing 10 phr-loaded MCM-41 showed 250 % improvement in tensile strength compared to the matrix devoid of nanomaterial. The effects of co-incorporation of two different kinds of nanomaterials having different nanostructures, e.g., layered montmorillonite and particulate MCM-41 were also studied. MCM-41 enhanced the mechanical strength of BR almost double the value compared to precipitated silica at the same filler loading. The morphological features of the composites were well corroborated with the mechanical properties. Keywords Polybutadiene
MCM-41
Hybrid composite
Mechanical properties & Madhuchhanda Maiti 1 Reliance Technology Group, Vadodara Manufacturing Division, Reliance Industries Ltd., Vadodara, Gujarat 391346, India Introduction Elastomeric nanocomposites based on nano-sized inorganic particles and clusters have been paid more attention due to the interesting nano-sized effects of the particles [1]. Polymer nanocomposite shows unique properties, combining the advantages of the inorganic nanofillers (e.g., rigidity, thermal stability) and the organic polymers (e.g., flexibility, dielectric, ductility and processability) [2]. The nanoparticles will strengthen the matrix more than the conventional fillers due to high surface area-to-volume ratio and other fascinating properties. The mechanical and thermal properties of the composite will be significantly enhanced if there is a homogenous dispersion of the additives in the polymer matrix. This in turn, increases the interfacial adhesion between the polymer matrix and the nanofillers. Therefore, it is crucial and important to incorporate well dispersed nanofillers to the elastomer network to achieve superior physico- mechanical properties. At higher filler loading, the polymer-filler interaction decreases due to the agglomeration of fillers which ultimately reduces the strength of the composite. To increase the interaction between the matrix and the filler, a variety of methods can be applied such as functionalization or modification of the surface using some coupling agents [3]. Synthesis of mesoporous silica gained importance after the discovery of M41S type of molecular sieves by the scientists in the Mobil Oil Corp in 1990 [4]. These materials have perfectly long-range order, highly tunable pore size and good surface characteristics which make them an ideal material for various applications [5–7]. The polymer or reactive groups in the nano-sized pores extending along the channels to the openings will not only enhance the miscibility through the entanglement and inter-diffusion between the matrix and the particulate, but also highly 123 132 Int J Ind Chem (2016) 7:131–141 suppress the aggregation of fillers. Though there are a few reports available in the literature regarding incorporation of the mesoporous silica (MPS) in different plastic matrix namely PP, PE, PANI, Epoxy, polycaprolactone, PMMA, PS [8–14]; the papers which describe the effect of MPSs in elastomers are very scarce [5, 15, 16]. This paper discusses the effect of variable sized mesoporous silica as reinforcing filler in the polybutadiene rubber matrix. To the best of our knowledge, for the first time, we are reporting the effect of MPS on hybrid composites which contain other fillers like nanoclays, silica and carbon black. It is worth to investigate the synergistic effects of these fillers on the mechanical and dynamic mechanical properties of the hybrid composites. Characterization X-ray diffraction (XRD) The mesoporous materials were characterized by X-ray Diffraction and Transmission electron microscopy. X-ray diffraction analysis were recorded with a Philips X’pert MPD system using Cu Ka X-ray radiations (k = 1.54056 Å) in 2h = 0.5° to 10° range in step size of 0.01 and a step time of 10 s. Transmission electron microscopy (TEM) Experimental Transmission electron microscopy images of the mesoporous silica samples were captured with Titan 6300, FEI, USA, operating at a voltage of 300 kV. The samples were dispersed in acetone and then put on a carbon grid. Materials Scanning electron microscopy (SEM) The mesoporous materials, mobil composition of matter No. 41 (MCM-41) and its precursor with template (MCMT, without calcination), Santa Barbara Amorphous-15 (SBA-15) and mesocellular foam (MCF) were prepared inhouse as per the procedure reported in the literature [17– 19]. BR is supplied by Reliance Industries Limited, India and all the other chemicals are of analytical grade and they are used as such without any further purification. Pluronic P123, Cetyltrimethylammonium bromide (CTAB) and tetra methyl benzene (TMB) were purchased from Sigma-Aldrich, India. Sodium silicate, Zinc oxide, stearic acid, N-cyclohexyl-2-benzothiazolesulfenamide (CBS), bis- (c-triethoxysilylpropyl)-tetrasulfide (Si-69), precipitated silica, N-1,3-dimethyl-butyl-n-phenyl-paraphenylenediamines (6PPD), Micro crystalline wax, carbon black (N 330), diphenyl guanidine, naphthenic oil and sulfur were procured from Labort Fine Chemicals Limited, India. Nanoclay (Cloisite 20A, designated as MMT) was obtained from Southern Clay Products, USA. SEM samples were fractured in liquid nitrogen immersion and mounted with carbon tape wrapping. The images were studied with a Nova Nanosem 650, FEI, USA, instrument, operating at 1 and 10 kV for the mesoporous silica and the composite samples, respectively. Surface area measurement The textual parameters such as surface area (BET), pore volume (PV), and pore diameter (dP) of calcined mesoporous silica samples were obtained from nitrogen adsorption data measured at 77.4 K using Micromeritics ASAP 2020 instrument. All the samples were degassed at 200 °C for 3 h prior to nitrogen adsorption. The specific surface area of the samples was calculated using the Brunauer-Emmett-Teller (BET) method in the rela (...truncated)