Addition Of OMMT Research Articles

Organophilized Montmorillonites as Fillers for Silicone Pressure-Sensitive Adhesives.

In the presented work, organophilized montmorillonites (OMMT) with selected quaternary ammonium compounds (QAC) with different chemical structure ((trioctylmethylammonium chloride-A336, dimethyloctadecyl[3-trimethoxysilyl)propyl]ammonium chloride-D, cetyltrimethylammonium bromide-CTAB, 2-methacryloxyethyltrimethylammonium chloride-MOA) were obtained and used as fillers for physically modified silicone pressure-sensitive adhesives (Si-PSA). Before OMMT addition into Si-PSA matrix, they were analyzed via TGA and XRD techniques. Type of chemical structure of QAC affected d-spacing of OMMT. New self-adhesive materials were obtained based on prepared Si-PSA compositions by adding the obtained fillers to the polymer matrix. New tapes exhibit a good level of useful properties as adhesion, cohesion, and tack-the values did not change or slightly decreased; in addition, the tapes with addition of OMMT showed high thermal resistance reaching the measuring limit of the test equipment-to 225 °C.

Preparation and structure-properties of crosslinking organic montmorillonite/polyurethane as solid-solid phase change materials for thermal energy storage

In order to solve the leakage problem of commonly used polyethylene glycol (PEG) phase change material (PCM), PEG reacted with 4′ 4-diphenylmethane diisocyanate (MDI) to prepare the polyurethane-based solid-solid phase change material (PU-SSPCM) by the two-step solvent method, and the influence of organic montmorillonite (OMMT) on the phase transition property and crystallization capacity of PU-SSPCM was first studied. The solid-solid phase change polyurethane materials were successfully prepared when the molar ratio of PEG to MDI was 0.75, and the organic montmorillonite acted as a crosslinking heterogeneous nucleating agent to improve the temperature control capacity, the crystallization ability and the thermal stability of the solid-solid phase change polyurethane material. When the addition of OMMT was 0.5 wt%, the phase change enthalpy of PU-SSPCM increased to 106.8J/g from 95.46J/g, a constant temperature platform appeared for about 300 s during both the heating and cooling process, thus demonstrating excellent temperature control ability. The relative crystallinity increased to 74.8% from 66.5% and the initial thermal weight loss temperature was increased from 348 °C to 368 °C. • Organic montmorillonite acted as a crosslinking heterogeneous nucleating agent. • Organic montmorillonite enhanced the temperature control capacity the system. • The composites possessed excellent crystallization ability and thermal stability.

Electrical and mechanical properties of partially bio‐based PP/PBS blends nanocomposites elaborated by twin‐screw extrusion

AbstractOrganically modified montmorillonite (OMMT, Cloisite 20) was used as reinforcing filler to prepare nanocomposites from a blend of polypropylene (PP) and eco‐friendly degradable polybutylene succinate (PBS). A PP grafted with maleic anhydride was also added as a compatibilizer. Scanning electron microscopy observations indicated that the blend morphology was affected by the presence of OMMT, which acted as a compatibilizer between PP and PBS. Rheological measurements showed a significant increase of the complex viscosity when OMMT was added above a certain amount. X‐ray diffraction indicated an intercalated structure for all nanocomposites. The addition of OMMT improved mechanical properties of neat matrices and blends. The electrical insulation properties were preserved for low concentrations of OMMT, up to 2 wt%. Then, to guarantee good mechanical properties without deteriorating electrical ones, while maintaining a sufficient bio‐based composition, the 70/30 (PP/PBS) blend with clay concentrations of less than 2 wt% appeared to be the most satisfactory nanocomposite for applications in the field of electrical insulation.

Chlorinated butyl rubber/two-step modified montmorillonite nanocomposites: Mechanical and damping properties

Montmorillonite (MMT) was modified by ultrasound and castor oil quaternary ammonium salt intercalation method to prepare a new type of organic montmorillonite (OMMT). The surface structure, particle morphology, interlayer distance, and thermal behavior of the samples obtained were characterized. The modified OMMT was then added to chlorinated butyl rubber (CIIR) by mechanical blending, and a composite material with excellent damping properties was obtained. The mechanical experiment results of CIIR nanocomposites showed that the addition of OMMT improved their tensile strength, hardness, and stress relaxation rate. Compared with pure CIIR, when the content of OMMT was 5 phr (part per hundred of rubber), the tensile strength of the nanocomposite was increased by 677% and the elongation at break was also increased by 105.4%. The enhancement of this performance was mainly due to the dispersion of the nanosheets in CIIR rubber and the chemical interaction between the organoclay and the polymer matrix, which was confirmed by morphology and spectral analysis. OMMT also endowed a positive effect on the damping properties of CIIR nanocomposites. After adding 5 phr of OMMT, the nanocomposite owned the best damping performance, and the damping factor, tanδmax, was 37.9% higher than that of pure CIIR. Therefore, the good damping and mechanical properties of these CIIR nanocomposites provided some novel and promising methods for preparing high-damping rubber in a wide temperature range.

Effects of Nanoclay on Mechanical and Dynamic Mechanical Properties of Bamboo/Kenaf Reinforced Epoxy Hybrid Composites.

Current work aims to study the mechanical and dynamical mechanical properties of non-woven bamboo (B)/woven kenaf (K)/epoxy (E) hybrid composites filled with nanoclay. The nanoclay-filled BK/E hybrid composites were prepared by dispersing 1 wt.% nanoclay (organically-modified montmorillonite (MMT; OMMT), montmorillonite (MMT), and halloysite nanotube (HNT)) with high shear speed homogenizer followed by hand lay-up fabrication technique. The effect of adding nanoclay on the tensile, flexural, and impact properties of the hybrid nanocomposites were studied. Fractography of tensile-fractured sample of hybrid composites was studied by field emission scanning electron microscope. The dynamic mechanical analyzer was used to study the viscoelastic properties of the hybrid nanocomposites. BK/E-OMMT exhibit enhanced mechanical properties compared to the other hybrid nanocomposites, with tensile, flexural, and impact strength values of 55.82 MPa, 105 MPa, and 65.68 J/m, respectively. Statistical analysis and grouping information were performed by one-way ANOVA (analysis of variance) and Tukey method, and it corroborates that the mechanical properties of the nanoclay-filled hybrid nanocomposites are statistically significant. The storage modulus of the hybrid nanocomposites was improved by 98.4%, 41.5%, and 21.7% with the addition of OMMT, MMT, and HNT, respectively. Morphology of the tensile fracture BK/E-OMMT composites shows that lesser voids, microcracks and fibers pull out due to strong fiber–matrix adhesion compared to other hybrid composites. Hence, the OMMT-filled BK/E hybrid nanocomposites can be utilized for load-bearing structure applications, such as floor panels and seatbacks, whereby lightweight and high strength are the main requirements.

Performance of OMMT/SBS on the rheological properties of asphalt binder

Nanoclays have been successfully introduced into the asphalt binder, either separately or into the polymer modified asphalt binder resulting in the improved mechanical and rheological properties of the asphalt binder. The present research study was undertaken to evaluate the influence of organically modified montmorillonite clay (OMMT) in pure asphalt binder and also in styrene butadiene styrene (SBS) modified asphalt binder. The quantity of OMMT and SBS was varied from 2–6 percent by the weight of the base asphalt binder. The addition of OMMT in an appropriate amount can dramatically enhance the compatibility between SBS and base asphalt. It was observed from the results that modified binders exhibited higher Superpave rutting parameter (G*/sinδ) indicating an improvement in the stiffness of the binder. It was also observed that modified binders (OMMT/SBS) does not exhibit phase separation under high temperatures. Thus high temperature stoage stability could be improved by choosing a proper amount of OMMT and forming an exfoliated structure. Thus it can be concluded that OMMT added to the polymer modified binder (SBS) helps in obtaining better physical and rheological properties on a condition that clay scatters into the binder at the nanoscopic level.

Oxygen barrier properties of organic montmorillonite modified polyamide 11/Poly (vinyl alcohol) films

Organic montmorillonite (OMMT) nano‐platelets were exfoliated and well dispersed in fully bio‐based polyamide 11/Poly(vinyl alcohol) (PA11/PVA) blends. Significantly lower oxygen permeation rates (OTR) were detected for the PA1172.5PVA27.5OMMTx films than those of PA11 and PA1172.5PVA27.5 films. An extremely low OTR of 0.218 cm3/m2·day·atm was found for PA1172.5PVA27.5OMMT1 film modified with 1 PHR optimum concentration of well dispersed OMMT nano‐platelets. Similarly, the free volume characteristics evaluated for PA1172.5PVA27.5OMMTx film series reduced to a minimum as the OMMT concentration reached the optimum value. As revealed by dynamic mechanical and differential scanning calorimetric analyses of PA1172.5PVA27.5OMMTx film series, all dynamic glass transition temperature (Tg), melting temperature (Tm) and percentage crystallinity (Wc) values of PA1172.5PVA27.5OMMTx films were noticeably higher than those of PA1172.5PVA27.5 film without addition of OMMT. In fact, Tgs, Tms and Wcs evaluated for PA1172.5PVA27.5OMMTx films increased to a maximum, as their OMMT reached the optimum concentration. The considerably enhanced oxygen barrier resistance found for PA1172.5PVA27.5OMMTx films was ascribed to the considerably reduced free volume characteristics and much longer permeation path caused by impermeably OMMT nano‐platelets well dispersed in PA1172.5PVA27.5OMMTx films.

Fabrication and investigations on BMI/OMMT nanocomposites with superior high-temperature wave-transparent performance

In this work, stearyltrimethylammoium bromide (STAB) was used to modify montmorillonite (MMT). Subsequently, the modified organic montmorillonite (OMMT) was added into 4,4′-Bismaleimidodiphenyl methane (BDM) and 2,2′-Diallylbisphenol A (DBA) copolymerization system to prepare BDM/OMMT wave-transparent nanocomposites with 0–5 wt% OMMT content. It is found that the addition of OMMT improves the microstructure, thermal properties, and wave-transparent properties of BDM composites. At the addition of 2 wt%, the thermal stability of the resin system is the best, and the fracture morphology changes from brittle fracture characteristics to ductile fracture characteristics. Meanwhile, in X-band (8–12 GHz), OMMT-2 wt% with the thickness less than 2 mm or within 8–10 mm has excellent transmittance (> 90%). Moreover, the effect of temperature change on the wave-transparent performance of BDM/OMMT nanocomposites is investigated. From room temperature to 200 °C, the stability of high-temperature transmittance of OMMT-2 wt% is enhanced, and it still has good transmittance (> 90%) within in a wide thickness range at 200 °C. The enhancement of these properties is closely correlated with the interaction interface formed between OMMT and BDM resin matrix. The addition of OMMT can increase the design selection of BDM resin system and expand its application as a wave-transparent material.

Charaterization and Preparation of PA6/EPDM-g-MAH/OMMT Polymer Alloys Nanocomposites

The Polyamide 6 (PA6)/ maleic anhydride grafted ethylene-propylene-diene monomer (EPDM-g-MAH)/organic montmorillonite (OMMT) nanocomposites were successfully prepared by melt extrusion method at different contents of OMMT fillers. The content of OMMT were studied to discuss the mechanical properties, thermal resistance properties and melt-crystal behavior of the nanocomposites. The results were summarized as follows: The PA6/EPDM-g-MAH/OMMT nanocomposites were prepared using melt extrusion method. The influence of the OMMT filler contents on the properties of PA6/EPDM-g-MAH/OMMT nanocomposites were studied. The mechanical properties and thermal resistance properties were improved with the addition of OMMT. The results showed that when the content of OMMT was 3.5wt%, comparing to the pure PA6, the bending strength was improved 31.7%, the notch impact strength was improved by 40.5%, and the heat deflection temperature was improved by 31.1°C. This kind of nanocomposites had good application prospects.

Microwave-Assisted Synthesis of PGS/PCL Nanocomposite Films: Effect of Organo-Modified Montmorillonite

Microwave-assisted synthesis of polyglycerolsebacate (PGS) - polycaprolactone (PCL) with nanoclay composite films were fabricated in this study. PGS produced via microwave irradiation technique was blended withorgano-modified montmorillonite (O-MMT) and PCL, and cast using thermally induced phase separation technique (TIPS) to produce nanocomposite films. The fabricated films underwent different qualitative characterization to identify its morphology, porosity,wettabilityandmechanical strength. FTIR results showed changes in the band peaks signifying the interaction between PCL, O-MMT and PGS. SEM images of the films displayed filamentous and non-uniform pores present on the films, which became more visible upon the addition of O-MMT and PGS.Also, the films showed improved tensile strength and elongation upon addition of PGS, but on an optimum O-MMT amount. Furthermore, the pore size of films increased upon addition of PGS, which confirmed the effect of its hydrophilic in nature. Thiswas correlated to the enhanced wettability of the films produced and the formation of asymmetric surface structure.

Preparation and characterization of carboxylated acrylonitrile butadiene rubber/carboxylated styrene butadiene rubber (XNBR/XSBR) nanocomposites in the presence of dichlorocarbene-modified SBR (DCSBR) compatibilizer and montmorillonite

Rubber nanocomposites based on carboxylated acrylonitrile butadiene rubber and carboxylated styrene butadiene rubber (XNBR/XSBR) with different compositions (100/0, 80/20, 60/40, 40/60, 20/80 and 0/100) and various montmorillonite (OMMT) contents with compatibilizer dichlorocarbene-modified SBR (DCSBR) were prepared. The results of rheometric tests showed that with adding DCSBR compatibilizer and increasing OMMT, the optimum curing time and scorch time decreased. The X-ray diffraction analysis indicated adding DCSBR compatibilizer causes increase in distance between the layers of silicate plates in the rubber phase of nanocomposites compared to OMMT powder. This phenomenon was also confirmed by direct observation of the microstructure by a transmitted electron microscope. The addition of OMMT and DCSBR compatibilizer surprisingly increased the mechanical properties such as elongation at break, tensile modulus, tensile strength and fatigue strength of the XNBR/XSBR (80/20).

Effect of Organic Montmorillonite on Properties of High-viscosity Modified Asphalt

In order to investigate the effect of organic montmorillonite (OMMT) and its content on properties of high-viscosity modified asphalt, a series of laboratory tests were carried out through zero shear viscosity (ZSV) at 60 °C, rutting factor, ductility at 5 °C, and fatigue factor to analyze high-temperature, low-temperature and anti-fatigue properties of high-viscosity modified asphalt with different OMMT contents. The results show that OMMT/high-viscosity modifier (HVM) composite modification can improve obviously high-temperature performance and fatigue resistance of high-viscosity modified asphalt, but the best improvement effect can be achieved only when adding proper amount of OMMT. The addition of a small amount of OMMT has little effect on low-temperature performance of high-viscosity modified asphalt, but when the content of OMMT exceeds 4%, its low-temperature performance will decrease significantly. The addition of OMMT can improve the temperature sensitivity of high-viscosity modified asphalt’s high-temperature performance, but reduces the temperature sensitivity of its fatigue resistance.

Synthesis of allyl ether and benzyl methacrylate functionalized silane monomers for application in acrylate/montmorillonite nanocomposite emulsion

Allyl trimethylsiloxybutyl ether (ATE) and 3-(trimethylsiloxy) benzylmethacrylate (TBM), tow novel silane involving monomers were successfully synthesized. Then, by in situ intercalative emulsion polymerization of styrene (St), butyl acrylate (BA), ATE and TBM, poly (silane-co-styrene-co-butylacrylate)/montmorillonite, P (Si-co-St-co-BA)/OMMT nanocomposite emulsions were prepared. The structures of monomers were clarified by the FT-IR, 1H-NMR, and 13 C-NMR spectroscopic techniques and nanocomposites by FT-IR. The results indicated that addition of OMMT improved the thermal and morphological properties of emulsions and among the samples tested, the modified nanocomposites which were prepared by intercalating 1 wt% OMMT showed the most desirable effect. It was also demonstrated by TEM that OMMT addition causes some clusters or agglomerated particles into the polymer matrix and the most OMMT layers are dispersed homogeneously.

Preparation of Modified Montmorillonite-Plant Fiber Composite Foam Materials.

In the present study, plant fiber foam materials have significant differences in density compared to conventional plastic foam materials. In view of the current problems of fiber foam materials, the montmorillonite (MMT) organically modified by octadecyl-dimethyl-benzyl-ammonium chloride (ODBA) was added to the preparation of composite foam materials by optimizing the existing formula. The properties of organic montmorillonite (OMMT) and the prepared composite foam materials were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), and a standing wave tube sound absorption tester. The results showed that the pore size inside the plant fiber foam materials with the addition of OMMT was more uniform and arranged more closely and orderly. In addition, when the OMMT was added to 0.1 g, the density of the prepared OMMT-bagasse composite foam materials reached its lowest point of 0.079 g/cm3, which was shared with high foam materials.

Preparation and properties of epoxy-terminated butadiene acrylonitrile rubber-intercalating organic montmorillonite nanocomposites

In this work, a series of epoxy-terminated butadiene acrylonitrile copolymer (ETBN) liquid rubber-intercalated organic montmorillonite (OMMT)-filled epoxy nanocomposites were prepared. The dispersion of OMMT was studied by X-ray diffraction analysis and transmission electron microscope analysis. The mechanical strength and damping properties of the resultant nanocomposites were characterized by mechanical tests and dynamic mechanical analysis, respectively. Thermal stabilities of the pure and modified epoxy samples were studied by thermogravimetric analysis. Results revealed that the addition of OMMT and ETBN could improve the damping properties greatly and decrease the glass transition temperature (Tg) of the composites while the high tensile strength of composites was still maintained. Besides, with the addition of the second nano-filler (nano-CaCO3 or nano-SiO2) into the nanocomposites, the tensile strength of the nanocomposites was further enhanced without decreasing the high damping properties.

Effect of Organo-Modified Nanoclay on the Mechanical Properties of Sugar Palm Fiber-reinforced Polyester Composites

The aim of this study was to investigate the effect of nanoclay on the mechanical properties of sugar palm fiber-reinforced polyester composites. Organo-modified nanoclay (OMMT) was dispersed in unsaturated polyester resin at various weight contents from 1% to 5% using a mechanical stirrer. Naturally woven sugar palm fibers were reinforced in the nanoclay-modified resin, which were then hot compressed to form the composites. The effect of the OMMT weight content on the tensile, flexural, and impact properties of the composites were analyzed. The addition of OMMT resulted in a noticeable improvement in all of the investigated properties, until a certain weight percentage. The tensile properties showed the best improvements at a 2% nanoclay content. However, the 4% nanoclay content resulted in the best enhancements to the flexural and impact properties.

Influence of montmorillonite on ageing resistance of styrene–ethylene/butylene–styrene-modified asphalt

Storage-stable styrene–ethylene/butylene–styrene (SEBS)-modified (SM) asphalt was prepared by the addition of 4 mass/% SEBS and 3 mass/% organic montmorillonite (OMMT). The physical and rheological properties of SM and stable SEBS/OMMT-modified (SOSM) asphalts before and after short- or long-term thermal ageing were tested. The rheological tests showed that SOSM asphalt was more susceptible to ageing and became more flexible after ageing. The addition of OMMT restricted the swelling of SEBS in asphalt and led to an obvious susceptibility of SEBS to ageing. The structural characteristics of modified asphalt and OMMT before and after ageing were investigated by using optical microscope, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, thermal analysis, respectively. The microscopic and thermal analysis confirmed the ageing susceptibility of storage-stable SOSM asphalt.

Structural characteristics and biocompatibility of a casein-based nanocomposite for potential biomedical applications

Natural polymers have attracted increasing attention for biomedical applications owing to their biocompatibility. Casein possesses several interesting properties that make it a good candidate for biomedical materials. In this context, a novel casein-based nanocomposite was created by adding organized montmorillonite (OMMT) as a reinforcing material and ethylene glycol diglycidyl ether (EGDE) as a cross-linking agent. Fourier transform infrared spectroscopy indicated that EGDE had reacted with casein to form a network structure. X-ray diffraction and transmission electron microscopy showed a transformation of the OMMT structure from exfoliated to intercalated with an increase in the amount of OMMT. Scanning electron microscopy revealed that the nanocomposite with low OMMT content was characterized as high porosity. The addition of OMMT and EGDE improved the physical properties of the casein composites, resulting in a lower swelling ratio, higher thermal stability, lower biodegradation rate, and stronger mechanical properties compared with neat casein. A cell counting kit-8 assay demonstrated that the prepared nanocomposite films are biocompatible. These observations suggest that the casein nanocomposite is a promising material for biomedical applications.

Influence of synergism caused by organic montmorillonite and nanometer calcium carbonate on mechanical properties and crystallization of polyamide 1010-based composites

This account showed that nanometer-active calcium carbonate (CaCO3) improved polyamide 1010/organic montmorillonite (OMMT) composites and OMMT boosted polyamide 1010/CaCO3. The mechanical performance suggested the composites to be reinforced through adsorption forces present between the nanofillers and the matrix. The synergistic effect of CaCO3 and OMMT increased the yields and shrunk cavities when observed by scanning electron microscopy. The obvious resulting synergism was verified by X-ray scattering techniques after the addition of OMMT. The concentration of CaCO3 did not change lamellar-size or influence the crystal growth. The effect of CaCO3 on melting behavior was found less significant than that exert on crystallization behavior.

Structure and Properties of a cis-1,4-Polybutadiene/Organic Montmorillonite Nanocomposite Prepared via In Situ Polymerization

ABSTRACTCis-1,4-polybutadiene (cis-1,4-PB) is one of the most important synthetic rubbers, having superior performances such as wear resistance, cold resistance and high elasticity. However, its mechanical properties, including low tensile strength, tear resistance and thermal stability, limit its application in comparison to natural rubber and butadiene-styrene rubber that have excellent overall performances. Thus, the reinforcing of cis-1,4-PB is a necessity. The dispersion of clay in rubbers on the nanoscale can improve the mechanical, gas permeability and thermal properties of the resulting composites. In this paper, organic montmorillonite (OMMT) clay was dispersed into the cis-1,4-PB matrix via an in-situ polymerization method and the chemical structure, phase morphology, mechanical properties and thermal stability of the composite were investigated. The properties of the composite were analyzed by such techniques as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). In the in-situ polymerization, a Ni-based catalyst system with the presence of OMMT showed high efficiency and 1,4-selectivity for the polymerization of butadiene. The OMMT could be dispersed in the polymeric matrix on the nanoscale during the polymerization. The interfusion of OMMT had little influence on the thermal stability and the chemical micro-structure of the cis-1,4-PB when the content of cis-1,4 units was more than 95%. The loss tangent of the composite was higher than that of cis-1,4-PB from −110 to −55°C, the temperature range examined, and the mechanical properties of the cis-1,4-PB/OMMT nanocomposite (NC) were improved upon the addition of OMMT.