Addition Of Organo-montmorillonite Research Articles

Preparation and flame retardant properties of organic montmorillonite synergistic intumescent flame retardant polypropylene

Ammonium polyphosphate (APP) and aluminium diethylphosphonate (ADP) were mixed according to the mass ratio of 4:1, compounded with dipentaerythritol (DPER) to construct a novel intumescent flame retardant (IFR), and organo-montmorillonite (OMMT) as a synergistic flame retardant, then melt blended to prepare intumescent flame retardant polypropylene (PP) composites. The flame retardancy, thermal stability, and mechanical properties of flame retardant polypropylene composites were examined using the limiting oxygen index (LOI), vertical combustion test, thermogravimetric analysis, and cone calorimetry test. The results showed that the LOI value of the flame retardant composite PP3 reached 31.3%, UL-94 reached V-0 level, the peak heat release rate (pHRR) and the total heat release (THR) decreased by 87.8% and 33.7%, respectively, compared with the original sample of PP, and the break elongation increased by 216.4% compared with that of the sample PP1 without the addition of OMMT. The findings demonstrated that adding OMMT to IFR in the right dosage can have a positive synergistic flame retardant impact.

Preparation and characterization of PET/SEBS incorporated with organomontmorillonite

This study is focused on the characterization of polyethylene terephthalate (PET)/Styrene-Ethylene-Butylene-Styrene (SEBS)/Organomontmorillonite (OMMT) blends. SEBS-g-MA is used as compatibilizer and SEBS is the impact modifier at 30 %wt. The compounds were blended by twin-screw extruder and molded for test specimen by injection molding. The effect of OMMT types (Cloisite15A and Cloisite30B) and contents (1 and 3 %w/w) on properties of PET blends with SEBS and SEBS-g-MA were investigated. The PET composites incorporated with Cloisite15A had higher impact strength and %elongation at break whereas lower tensile strength than the one with Cloisite30B. Comparing with PET/SEBS/SEBS-g-MA blends, adding OMMT into PET/SEBS/SEBS-g-MA would increase thermal property. However, it had no significant changes with higher OMMT. %Crystallinity of PET would be increased with OMMT contents. PET/SEBS/SEBS-g-MA had lower %LOI but higher burning rate compared with PET. However, the addition of OMMT could improve flame retardant properties of PET blends. Addition of Cloisite15A and Cloisite30B into PET/SEBS/SEBS-g-MA increased %LOI. From UL 94 tests, polymer composites could be classified in HB class. The burning rate of polymer composites was decreased with increasing OMMT due to decomposition of OMMT act as a barrier to inhibit combustion.

Analysis on the Influence of O-MMT in the Properties and Bacterial Count of PVDF Nanocomposite Membrane

Polymer nanocomposites have become an exciting field of research and have attracted interest in both academia and industry. In this study, the addition of Organo-Montmorillonite (O-MMT),an ideal polymer filler due to its non-toxicity, large availability, well-known intercalation/exfoliation chemistry, and reactivity in Poly (vinylidene fluoride) (PVDF) membrane, a widely used polymer in separation fields owing to its remarkable mechanical, thermal, and chemical properties produced via non-solvent induced phased separation is observed. Presence of both polymers were confirmed using Fourier transform infrared spectroscopy (FTIR). These membranes were subjected to Scanning Electron Microscopy (SEM) which revealed addition of the filler reduced the porosity and further increasing O-MMT’s concentration led to a relatively smoother membrane. Influence of O-MMT in the porosity made no uniform trend however reduction in pore sizes was observed. Membranes were able to elongate at an average of 80% of its original length however tensile strength of the membranes all showed brittleness behavior of the films. Sterility Bacterial count also revealed that there are no infiltration colonies in the membranes. Analysis of the study further showed other factors that needs to be accounted since they were observed to highly affect the structure and properties of the membranes.

Synthesis of polymer hybrid latex poly(methyl methacrylate-co-butyl acrylate) with organo montmorillonite via miniemulsion polymerization method for barrier paper

Hybrid polymer latex based on combination of organic-inorganic materials, poly(methyl methacrylate-co-butyl acrylate) (PMMBA) and organo-montmorillonite (OMMT) were synthesized via miniemulsion polymerization technique. Modification of montmorillonite (MMT) through the incorporation of myristyltrimethylammonium bromide (MTAB) into the clay’s interlayer spaces were investigated by Small-Angle X-ray Scattering (SAXS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). Barrier property and thermal stability of polymer latex film sample were investigated through its Water Vapor Transmission Rate (WVTR) and Thermogravimetric Analysis (TGA). The results indicated that addition of OMMT as filler in PMMBA increased the barrier property and thermal stability of the latex film. Addition of 8.0% (wt) OMMT increased the barrier property and thermal stability. Miniemusion polymerization process with higher addition (>8.0 wt%) of OMMT resulting in high latex viscosity, particle size, and high amount of coagulum. The utilization of this hybrid polymer could benefits paper and board industries to produce high quality barrier paper for food packaging.

Organomontmorillonite-modified soybean oil-based polyurethane/epoxy resin interpenetrating polymer networks (IPNs)

In this work, in order to investigate the reinforcement effects of organomontmorillonite (OMMT) in soybean oil-based polyurethane (PU)/epoxy (EP) interpenetrating polymer networks (IPNs), a series of OMMT-modified PU/EP IPNs were prepared. The impacts of OMMT on the structure, morphology, glass transition, damping properties, thermal stability, and mechanical properties of the PU/EP IPNs were characterized by X-ray diffraction, scanning electronic microscope, dynamic mechanical analysis, thermogravimetry analysis, and tensile test. Results reveal that the addition of OMMT increases the glass transition temperature of the PU/EP IPNs. However, the damping properties of the PU/EP IPNs are lowered with the incorporation of OMMT. The addition of OMMT heightens the thermal stability of the PU/EP IPNs. Tensile tests show that the addition of OMMT significantly increases the tensile strength and tensile modulus of the PU/EP IPNs. With 4 and 6 % loading of OMMT, the tensile strength and tensile modulus increase 64 and 391 %, respectively.

Preparation of Poly(phenylene oxide)/Polyamide-6 Nanocomposites with High Tensile Strength and Excellent Impact Performance

Organo-montmorillonite (OMMT) was introduced into SEBS-g-MA toughened poly(phenylene oxide)/polyamide-6 (PPO/PA6) blends simply by melt extrusion. The effects of OMMT on morphology, rheology, and mechanical behaviors of toughened PPO/PA6 nanocomposites were studied by scanning electron microscope, transmission electron microscope, capillary rheometer and mechanical tests. The addition of OMMT could decrease the size of dispersed PPO domains in PA6 matrix and melt viscosity of the toughened PPO/PA6 nanocomposites. Besides, exfoliated OMMT also brought significant improvement of tensile properties and heat deflection temperature (HDT), simultaneously. For nanocomposites with exfoliated OMMT, OMMT induced more core–shell toughening particles with the optimized size, and thus, elastomer-OMMT synergistic toughening was achieved in the PPO/PA6 nanocomposites. Consequently, PPO/PA6 nanocomposites with high tensile strength, excellent impact performance, improved HDT, and good processability were obtained.

Joint Effect of Compatibilizer and Organo-Montmorillonite on Compatibilization of Polyamide-6/Poly(phenylene oxide) Blend: Morphology and Properties

Compatibilizer (styrene–maleic anhydride copolymer, SMA) and organo-montmorillonite (OMMT) were introduced into immiscible polyamide-6 (PA6)/ poly(phenylene oxide) (PPO) blend to obtain quaternary nanocomposites simply by melt extrusion. OMMT tactoids formed in PA6/PPO/OMMT ternary blend would become smaller or disappear with the addition of SMA. Besides, viscosity of SMA compatibilized PA6/PPO blend decreased a lot with the addition of OMMT. Based on these results, a mechanism for joint effect of SMA and OMMT in compatibilizing PA6 and PPO was proposed. We further studied water absorption and tensile properties of the nanocomposites, which were in consistent with the proposed mechanism.

Properties of Poly(Lactic Acid)/ Organo-Montmorillonite Nanocomposites Prepared by Solution Intercalation

Poly(lactic acid)/organo-montmorillonite (PLA/OMMT) nanocomposite films were prepared through solution intercalation using dichloromethane as solvent. X-ray diffraction indicated that organo-montmorillonite (OMMT) was well intercalated and the interlayer spacing d increased by 0.94–1.47 nm. Transmission Electron Microscopy showed that a majority of OMMT was fully exfoliated and uniformly dispersed in the PLA matrix at low filler loading, whereas more intercalated tactoids and aggregates of OMMT existed at high loading. The crystallinity of PLA was hardly changed with the addition of OMMT. Additionally, CO2 permeability and water vapor transmission rate of the composite films were reduced with increasing content of OMMT. At 5 wt% OMMT loading, CO2 permeability and water vapor transmission rate were reduced by 75.8% and 23.9%, respectively. The tensile strength (TS) and Young's modulus of the PLA/OMMT nanocomposites were first enhanced, and then decreased with increasing content of OMMT. Compared with pure PLA, a 83.8% increase in the Young's modulus and a 76.0% improvement in TS were obtained with the addition of 3 wt% OMMT.

Biodegradability studies of poly(butylene succinate)/organo-montmorillonite nanocomposites under controlled compost soil conditions: Effects of clay loading and compatibiliser

Biodegradable nanocomposites were prepared from poly(butylene succinate) (PBS) and organo-montmorillonite (OMMT), in the presence of maleic anhydride-grafted PBS (PBS-g-MA) as compatibiliser. The effects of OMMT loading and PBS-g-MA on the biodegradability of PBS nanocomposites were investigated. Soil burial testing was carried out for 180 days in natural organic humus compost soil under controlled conditions. It is noted that the weight loss of nanocomposites was lower than that of neat PBS, due to the enhanced barrier properties after addition of OMMT. However, the addition of PBS-g-MA increased the weight loss of nanocomposite. The mechanical properties of PBS nanocomposites were significantly reduced after the soil burial. Biodegradation of the material was further confirmed by the decreased molecular weight through gel permeation chromatography (GPC), and changes in the chemical structure as verified by Fourier transform infrared (FTIR) spectroscopy. This was supported by the degraded surface of PBS and the nanocomposites observed under scanning electron microscopy (SEM). The effects of biodegradation on the thermal properties were studied through the differential scanning calorimetry (DSC). In addition, the biodegradation rate of the materials was determined by measuring the carbon dioxide (CO2) evolution. The degraded samples were recovered and PBS-degrading bacteria were found to be present in the exposed samples.

Poly(ethylene-co-vinyl acetate-co-carbon monoxide)/Layered Silicate Nanocomposites: Preparation, Characterization and Properties

For the first time, nanocomposites have been synthesized from ethylene-vinyl acetate-carbon monoxide terpolymer (EVACO) by adding 1, 3 and 5 wt% of organo-montmorillonite (O-MMT) by solution blending. By highresolution transmission electron microscopy (HRTEM), EVACO has been found to crystallize in nano-dimensions. Wide angle X-ray diffraction (WAXRD) reveals the predominance of intercalated morphology in these nanocomposites, while TEM micrographs reveal the co-existence of exfoliated and intercalated morphologies for these hybrids at all levels of clay loading. O-MMT hinders crystallization of EVACO, and due to this, optical transparency is not affected even at 5% O-MMT loading in these nanocomposites. By incorporation of 5% O-MMT, tensile strength of EVACO increases by 660%; while elongation at break decreases by 500%. Addition of O-MMT significantly reduces the thermal stability of these nanocomposites.

Microwave‐assisted preparation of polylactide/organomontmorillonite nanocomposites via in situ polymerization

AbstractMicrowave technology was introduced to assist the synthesis of polylactide (PLA)/organomontmorillonite (OMMT) nanocomposites in bulk by the in situ ring‐opening polymerization of D,L‐lactide. Factors that influenced the polymerizing effects, such as the microwave power, irradiation time, and dosages of the catalyst and OMMT, were studied in terms of tensile strength. The polymerization time was decreased dramatically to 10 min under 90 W of microwave irradiation, and the mechanical and thermal properties of the PLA/OMMT nanocomposites were significantly improved. The composite with the highest mechanical properties was obtained when the dosages of the OMMT and the catalyst were 1.0 and 0.6 wt % of the lactide, respectively. The initial decomposition temperature of the PLA/OMMT(1.0 wt % OMMT) nanocomposite was heightened 11.5°C compared with that of pure PLA. The results of scanning electron microscopy confirmed an improvement in the toughness with the addition of OMMT. The transmission electron microscopy and X‐ray diffraction results indicate that an exfoliated and intercalated nanocomposite was successfully prepared. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Effect of Mixing Sequences on the Flexural and Morphological Properties of Epoxy/ Organo-Montmorillonite Nanocomposites

The epoxy nanocomposites were prepared by addition of Organo-montmorillonite (OMMT) varied from 0 to 10 wt%. In-situ polymerization method was used to prepare epoxy/OMMT nanocomposites by three different mixing sequence methods. Method 1 was performed by mixing OMMT with cycloaliphatic amine (curing agent) first, followed by addition of diglycidyl ether-bisphenol A (DGEBA). Method 2 was carried out by mixing the DGEBA with OMMT first, followed by addition of curing agent. In method 3, the DGEBA and curing agent were mixed first, followed by the addition of OMMT. The objective of the research is to study the effects of mixing sequences on the flexural properties and morphology of epoxy/OMMT nanocomposites. The flexural and morphological properties of epoxy/ OMMT nanocomposites were studied by flexural tests, Field Emission Scanning Electron Microscopy, and X-ray Diffraction (XRD). The flexural modulus of epoxy was improved significantly by the incorporation of OMMT. This is attributed to the reinforcement and exfoliation/intercalation of the OMMT. The flexural modulus and strength of epoxy/OMMT nanocomposites prepared by method 3 was relatively higher than that of the composites prepared by method 1 and 2. The XRD results showed the formation of exfoliated structure in the epoxy/OMMT nanocomposites. Sequence of mixing influenced the dispersion and intercalation/exfoliation of the OMMT in the epoxy matrix. Appropriate mixing sequence should be selected in order to achieve better exfoliation of OMMT and higher flexural modulus and strength of the epoxy nanaocomposites.

Cyclic extrusion of poly(butylene terephthalate)/organo‐montmorillonite nanocomposites: Thermal and mechanical retention properties

AbstractPoly(butylene terephthalate) (PBT) containing 3 wt % of organo‐montmorillonite (OMMT) was prepared using twin screw extrusion followed by injection molding. The effects of thermal cycles (two times extrusion followed by injection molding) were studied on both PBT and PBT/OMMT nanocomposites. The samples were characterized by using tensile tests, flexural tests, field‐emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), and dynamic mechanical thermal analysis (DMTA). The intercalation of the OMMT silicate layers in the PBT was confirmed using XRD. Both tensile and flexural modulus of PBT was improved by addition of OMMT. DSC results revealed that OMMT improved the crystallinity of PBT. The percentage retention in tensile and flexural properties of PBT/OMMT(E2) intercalated nanocomposites (i.e. two times extrusion followed by injection molding) is more than 96%. The melting temperature, crystallization temperature, and degree of crystallinity of PBT/OMMT(E2) is comparable with PBT/OMMT(E1) (i.e. one time extrusion followed by injection molding). This indicates that PBT/OMMT intercalated nanocomposites exhibit good retention‐ability in mechanical and thermal properties after subjecting to two times twin‐screw extrusion followed by injection molding. From the TGA results, it was observed that the thermal stability (e.g. Tonset) of PBT was reduced by the addition of OMMT. However, the addition of OMMT assists in the char formation of PBT. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Flexural, Morphological and Thermal Properties of Poly(Lactic Acid)/ Organo-Montmorillonite Nanocomposites

Poly(lactic acid) (PLA)/organo-montmorillonite (OMMT) nanocomposites were prepared by using solution intercalation and melt intercalation methods. For solution intercalation method, toluene was used as solvent. For melt intercalation method, PLA/OMMT composites were prepared by using single-screw extruder. The flexural properties of PLA/OMMT composites have been studied by using three point bending tests. Comparisons between the flexural properties of PLA/OMMT nanocomposites prepared by both methods have been carried out. The microstructures of the PLA/OMMT nanocomposites were assessed by Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction (XRD) analysis. The thermal properties of PLA/OMMT nanocomposites have been characterized by using Differential Scanning Calorimeter (DSC). The flexural modulus of PLA/OMMT nanocomposites prepared by both solution intercalation and melt intercalation methods increased significantly by the addition of OMMT. For both methods, it was found that the optimum flexural properties of the PLA nanocomposites was achieved at 1 wt.% OMMT loading. The dispersion of OMMT in the PLA prepared by solution intercalation is better than that of melt intercalation method. This is attributed to the ease of intercalation of PLA chain into the OMMT layered silicate during the solution intercalation process. XRD results revealed that intercalation of OMMT layered silicate occurred in the PLA matrix.

Studies on crystallization behaviors and crystal morphology of polyamide 66/clay nanocomposites

AbstractX‐ray diffraction methods, DSC thermal analysis, and polarized light microscopy (PLM) were used to investigate the structural changes of nylon 66/clay nanocomposites. PA 66/clay nanocomposites were prepared by the method of melt intercalation. The results indicate that the addition of the intercalated organo‐montmorillonite (OMMT) can induce generation of the β‐form crystal of PA 66 and substantially affect the arrangement of molecules in the α‐form crystal, although the crystallinity scarcely changes. Also, the DSC results indicate that the addition of OMMT in the PA 66 matrix leads to increases of crystallization temperatures and the full width at half maximum (FWHM) of the exothermic peaks. Moreover, the viscosity factor is the main influence on FWHM of the exothermic peaks of PA 66/clay nanocomposites. The results of nonisothermal crystallization kinetics show that OMMT has the effect of heterogeneous nucleation and leads to the decrease of the size of the spherocrystal. The heterogeneous nucleation effects of OMMTs influence the mechanism of crystallization and the growth mode of PA 66 crystals. PLM photographs verify that the size of spherocrystal is decreased and visually confirm the theory of crystallization kinetics. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 756–763, 2005

Nonisothermal crystallization kinetics of polypropylene/montmorillonite nanocomposites

AbstractThe nonisothermal crystallization kinetics of poly(propylene) (PP) and poly(propylene)/organic‐montmorillonite (PP/Mont) nanocomposite were investigated by differential scanning calorimetry (DSC) with various cooling rates. The Avrami analysis modified by previous research was used to describe the nonisothermal crystallization process of PP and PP/Mont nanocomposite very well. The values of half‐time and Zc showed that the crystallization rate increased with increasing cooling rates for both PP and PP/Mont nanocomposite, but the crystallization rate of PP/Mont nanocomposite was faster than that of PP at a given cooling rate. The activation energies were estimated by the Kissinger method, and the values were 189.4 and 155.7 kJ/mol for PP and PP/Mont nanocomposite, respectively. PP/Mont nanocomposite could be easily fabricated as original PP, although the addition of organomontmorillonite might accelerate the overall nonisothermal crystallization process. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 408–414, 2002; DOI 10.1002/polb.10101