MMT Content Research Articles

Noise-reduction coatings based on interfacial hydrogen bonding between hindered phenol/epoxy microspheres and waterborne polyurethane

Waterborne damping materials have the advantages of reducing noise pollution and air pollution. Hybridization with hindered phenol is an effective method to improve damping properties of polymer materials, but this method is limited by the insolubility of hindered phenol. Therefore, it is still an issue to use hindered phenol for improving the damping properties of waterborne polymer materials. In this paper, diglycidylether of bisphenol A (DGEBA) and 3,9-bia [1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]-undecane (AO-80) were used to prepare hindered phenol/epoxy microspheres by direct curing in emulsion containing montmorillonite (MMT). The accumulation of hindered phenol on microsphere surface led to the interfacial hydrogen bonding between microspheres and waterborne polyurethane (WPU), while noise-reduction coatings were prepared by direct compounding. The existence and variation of hydrogen bonds in the materials were investigated. Scanning Electron Microscopy (SEM) and Optical Microscope Analysis (OM) test shows that the particle size of microspheres was directly proportional to AO-80 content and inversely proportional to MMT content. Fourier Transform Infrared Spectrum (FTIR) test proves that the number of interfacial hydrogen bonds between WPU and microspheres was directly proportional to the content of AO-80 on the surface of microspheres and inversely proportional to the particle size of microspheres. The optimal formulation of microspheres is that the ratio of epoxy, AO-80 and MMT is 10: 7: 5 (EAM 1075), and the particle size of microspheres is 20–30 μm. When the ratio of WPU to EAM1075 was 10: 5, according to Dynamic Mechanical Thermal Analysis (DMTA) test, the overall damping capacity of the composite material is improved, its loss factor increased from 0.15 to 0.45 at room temperature, and the damping temperature range of the material was also broadened. Through acoustic resistance test and noise reduction test, the noise reduction effect of the composite coating reached 30 dB.

Structural and electrochemical properties of montmorillonite-poly(ethylene oxide) intercalated nanocomposites for lithium-ion batteries

Poly(ethylene oxide) has been intercalated inside the interlayer galleries of montmorillonite clay and the electrochemical properties of the nanocomposite have been investigated. Interlayer spacing and clay gallery width increase with increasing MMT concentration confirming intercalation of PEO into MMT as observed from XRD results. The fraction of free anions as calculated from FTIR, increases with increasing clay content and remains constant beyond 7.5 wt. % of clay content. Ionic conductivity of the order of 10−4 Scm−1 has been obtained in the case of MMT based electrolytes. The initial increase of conductivity with increasing MMT content can be attributed to the increase fraction of free ions which eventually increases ionic conductivity. After 7.5 wt. % of MMT loading ionic conductivity decreases due to the high viscosity of MMT. Interfacial stability results show that passivation takes place very slowly in MMT based electrolytes. Dielectric properties show that at high frequency relaxation takes place due to the segmental motion of polymer chains and it proves the hopping of ions.

Enhanced hybrid hydrogel based on wheat husk lignin-rich nanocellulose for effective dye removal.

Polyvinyl alcohol (PVA) hydrogels were enhanced mechanically through the addition of lignin-rich nanocellulose (LCN), soluble ash (SA) and montmorillonite (MMT) for dye removal. The hybrid hydrogels reinforced with 33.3wt% of LCN had a 163.0% increase in storage modulus as compared to the PVA/0LCN-33.3SM hydrogel. LCN can be added to the PVA hydrogel to alter its rheological properties. Additionally, hybrid hydrogels were highly efficient in removing methylene blue from wastewater, which was attributed to the synergistic effects of the PVA matrix supporting embedded LCN, MMT, and SA. The adsorption time (0-90min) showed that the hydrogels containing MMT and SA had high removal efficiency, and the adsorption of methylene blue (MB) by PVA/20LCN-13.3SM was greater than 95.7% at 30°C. It was found that MB efficiency decreased with a high MMT and SA content. Our study provided a new method for the fabrication of polymers-based eco-friendly, low-cost and robust physical hydrogels for the MB removal.

Influence of Surface-Modified Montmorillonite Clays on the Properties of Elastomeric Thin Layer Nanocomposites

In recent years, polyurethane nanocomposites have attracted more attention due to the massive demand for materials with increasingly exceptional mechanical, optical, electrical, and thermal properties. As nanofillers have a high surface area, the interaction between the nanofiller and the polymer matrix is an essential issue for these materials. The main aim of this study is to validate the impact of the montmorillonite nanofiller (MMT) surface structure on the properties of polyurethane thin-film nanocomposites. Despite the interest in polyurethane-montmorillonite clay nanocomposites, only a few studies have explored the impact of montmorillonite surface modification on polyurethane's material properties. For this reason, four types of polyurethane nanocomposites with up to 3% content of MMT were manufactured using the prepolymer method. The impact of montmorillonites on nanocomposites properties was tested by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), contact angle measurement, X-ray diffraction (XRD), and optical coherence tomography (OCT). The results showed that chemical and physical interactions between the polymer matrix and functional groups on the montmorillonite surface have a considerable impact on the final properties of the materials. It was noticed that the addition of MMT changed the thermal decomposition process, increased T2% by at least 14 °C, changed the hydrophilicity of the materials, and increased the glass transition temperature. These findings have underlined the importance of montmorillonite surface structure and interactions between nanocomposite phases for the final properties of nanocomposites.

Metal organic framework/clay composite for micro-dispersive solid-phase extraction of sulfonamides and penicillins in milk, and synthetic urine solution coupling with HPLC/DAD detection

In this study, composite as a copper-containing metal–organic framework with montmorillonite (MMT) clay was synthesized and applied as an adsorbent for micro-dispersive solid-phase extraction (µ-dSPE) of sulfonamides (SAs) and penicillins (PENs). The synthesized composites including different content of MMT were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, Brunauer-Emmett–Teller surface area, and thermogravimetric analysis. The determination of antibiotics was performed by high-performance liquid chromatography/diode array detection (HPLC/DAD) using C18 column as stationary phase, 0.1 % trifluoroacetic acid in water, and acetonitrile as mobile phase in gradient mode and detection at 270 nm for SAs and 230 nm for PENs. The as-synthesized composites were examined for their adsorption ability towards target antibiotics. The optimized parameter conditions were 10 mg of adsorbent, 5 mL of sample solution at pH 4, 10 min stirring by vortex, 1 mL of acetonitrile:methanol (1:1) as eluent solvent, and 5 min as elution time. Under optimized conditions, the proposed method presented good linearity from 0.5 to 400 µg/L for SAs and from 1 to 400 µg/L for PENs with coefficients of determination (r2) ≥ 0.9947, low limit of detections from 0.10 to 0.15 µg/L for SAs and 0.30 to 1.50 µg/L for PENs, acceptable repeatabilities less than 3.26 % for both groups and good recoveries from 82.3 % to 116.4 % with relative standard deviations less than 3.9 % for both groups in the spiked milk samples and synthetic urine solution. The developed µ-dSPE method following HPLC/DAD has been successfully applied to the determination of SAs and PENs milk samples and synthetic urine solutions.

Properties of pectin-based films from white-fleshed pitaya (Hylocereus undatus) peel waste as affected by montmorillonite

In this study, pectin was prepared from white-fleshed pitaya (Hylocereus undatus) peel waste to develop a novel biodegradable film, and the reinforcement effect of montmorillonite (MMT) on the films was investigated. The presence of MMT could lower the moisture sensitivity, which was reflected in the lowered moisture uptake capacity and water vapor permeability. The incorporation of MMT into the white-fleshed pitaya (Hylocereus undatus) peel pectin (WPPP) film improved the light-barrier property of WPPP films with the transmittance of ultraviolet and visible light reduced. The WPPP/MMT composite film might have a more compact structure and lower chain mobility, resulting in the improved tensile strength and decreased elongation at break when the content of MMT was 1–5 wt%. In addition, WPPP/MMT composite films demonstrated a higher thermal stability compared with the plain WPPP films. It was found that approximately 90% of the WPPP and WPPP/MMT films were degraded on the 15th days, suggesting their great biodegradability. The present study might demonstrate that pitaya peel waste pectin could become a novel film-forming polymer for edible or packaging films, and the incorporation of MMT was effective in improving the overall performance of films, as reflected by the enhanced tensile strength, thermal stability, and barrier properties to water vapor and ultraviolet as well as visible light, which might assist in the sustainable valorization of pitaya by-products.

Percolation Network Formation in Nylon 6/Montmorillonite Nanocomposites: A Critical Structural Insight and the Impact on Solidification Process and Mechanical Behavior.

The incorporation of montmorillonite (MMT) into Nylon 6 can endow advantages like improved mechanical strength and thermal stability, making Nylon 6/MMT a possible ideal alternative for Nylon 66. However, the relationship between the microstructure and physical properties of nylon 6/MMT nanocomposites is unclear so far due to the complicated system, including the highly asymmetric geometry of the exfoliated MMT layer and the complicated interaction between MMT layers and entangled nylon 6 chains. Herein, we focus on two processes, namely the impact of MMT on the solidification procedure during molding and the toughness–brittleness transition during the tensile stretch, in order to elucidate the structure–property relationship of nylon 6/MMT composites. We firstly studied the solidification process of nylon 6/MMT with bending height experiments. The results showed that the solidification process occurs prior to the crystallization of nylon 6, indicating that a physical crosslinked network rather than a crystalline structure is the reason for the solidification process. Furthermore, the solidification speed has a step change at around 2 wt% MMT content, indicating that the MMT percolation network is related to the transition. We further studied the influence of MMT inclusion on the mechanical properties, and found the tensile strain at break showed a similar step change at around 2 wt% MMT content, which further confirms the existence of an MMT percolation network above 2 wt% MMT content. It was generally believed that the main effect of MMT on nylon 6 is the nanofiller enforcement; we found that the percolation effect of the highly asymmetric 2-D nanofiller plays a central role in influencing the mechanical properties and solidification behavior during molding.

Prediction of compressive creep behaviors of expansive soil exposed to freeze-thaw cycle using a disturbed state concept-based model

Expansive soils are discovered along the high-speed railways in typical cold regions of northeastern China. The long-term safety of slopes with expansive soil along the high-speed railways requires a detailed characterization of the time-dependent performances of expansive soils. In this study, X-ray diffraction, thermal analyses, and triaxial compressive creep tests are performed to explore the effect of freeze-thaw (F-T) cycle and montmorillonite (MMT) content on the creep characteristics of expansive soils collected along the high-speed railways near the stations of Binxi, Jiamusi, and Yanji. The results reveal that an accelerating creep stage in the creep process is observed for soil samples with higher MMT contents. For the expansive soils with higher MMT contents, the creep strain rates in the last creep stage show that there exists a threshold for creep-induced sample failure. The F-T cycle considerably affects the creep deformation of expansive soil and results in a creep failure of expansive soils. An accelerated creep stage is more likely to occur under the action of lower confining pressure. Additionally, by utilizing field investigation and microstructure analysis, the creep failure mechanism of the expansive soil slope after F-T cycle is preliminarily discussed. Finally, a suitable creep model for expansive soils subjected to F-T cycles is proposed based on the disturbed state concept to predict the primary and steady creep stages. The experimental results exhibit good agreement with the predicted values, confirming the validity of the proposed model. This work can provide reliable experimental data for the creep theory of expansive soil subjected to the F-T cycle.

Development of Composite Thin-Film Nanofiltration Membranes Based on Polyethersulfone for Water Purification

The development of thin-film composite membranes has gained more importance as they exhibit higher permeability, higher solute rejection and improved antifouling behavior. The incorporation of hydrophilic nanomaterials within the composite thin film has reported to effectively increase the hydrophilicity and improve the membrane performance. In this study novel thin-film composite nanofiltration membranes were prepared by interfacial polymerization of trimesoyl chloride, polyvinylpyrolidone (PVP) and montmorillonite (MMT) composite on the porous polyethersulfone membrane. The effect of preparation parameters was studied as; reaction time, PVP concentration and MMT content. The properties of the prepared composite thin-film membranes were analyzed in terms of their chemical structure, surface morphological features, pure water contact angle, zeta potential, pure water permeation flux (PWP) and solutes rejection. The prepared composite thin-film membranes showed smoother surfaces, different surfaces functionality and amphoteric surfaces with points of zero charge at pH 7–7.5. The PWP was found to increase with increasing MMT content up to 0.10 wt%. The rejection of crystal violet dye (CV) was studied using the prepared membranes. The membrane with 0.5% PVP, 0.10% MMT and 6 min reaction time showed PWP of 18.1 L/m2 h bar and CV rejection of 80.01%. The rejection of Na2SO4 and MgCl2 increased with increasing MMT content and reached 96% and 35.4%, respectively. The steady state flux was decreased by 5% with increasing MMT content from 0.10 to 0.12 wt% indicating improved antifouling behavior with MMT.

Transparent montmorillonite/cellulose nanofibril nanocomposite films: the influence of exfoliation degree and interfacial interaction

To obtain high performance of nanocomposite films made of cellulose nanofibrils (CNFs) and montmorillonites (MMTs), highly ordered nanostructures and abundant interfacial interactions are of extreme importance, especially for CNF film with high MMT content. Here, we tend to unveil the influence of exfoliation degree of MMTs and their interfacial interactions with CNFs on the properties of ensuing nanocomposite films. Monolayer MMTs (ML-MMTs) prefer to form highly ordered nanostructure during water evaporation induced self-assembly. The obtained nanocomposite film with 30 wt% ML-MMTs exhibits a tensile strength of 132 MPa, a total light transmittance of 90.2% (550 nm), and water vapor transmission rate (WVTR) of 41.5 g mm/m2 day, better than the film made of original MMTs (O-MMTs) and CNFs (30 MPa strength, 60% transparency, and 78.7 g mm/m2 day WVTR). Moreover, the physical properties (153 MPa strength and 20.9 g mm/m2 day WVTR) of nanocomposite film can be further enhanced by constructing ionic interactions between the ML-MMT and CNF using 0.5 wt% cationic polyethylenimine (PEI). However, as the amount of PEI continues to increase, its performance will be deteriorated dramatically because of the disordered orientation of ML-MMTs. This work could provide an insight into the fabrication of high performance MMT/CNF nanocomposite film for advanced applications.Graphical abstract

Dimer acid polyamide/montmorillonite bio-based film for the challenge of air cushions

The increasing use of air cushions in transport packaging brings increased environmental damage due to discarded packaging. A possible solution is to replace petroleum-based polymers with dimer acid polyamide. This work studied the qualities of dimer acid polyamide films with montmorillonite (MMT) addition. The layer structure of MMT and the heterogeneous nucleation effect augment the crystal content of the γ-crystal phase. The oxygen permeability and thermal stability of the film improve as the MMT content is increased, while optical properties decline. The mechanical properties of the film are also affected. Finite-element analysis was used to assess how long air cushions made from dimer acid polyamide/MMT film can last. The results show that dimer acid polyamide/MMT film can fully meet the requirements of air cushions for short-term transportation.

Feasibility of applying pAAm/CA/MMT hydrogels AS slow release fertilizers

AbstractBackgroundDue to population growth, new technologies are needed for the production of fertilizers that can assist in increasing agricultural yields, while at the same time reducing environmental impacts. This article describes the synthesis, characterization, and behavior of a new series of hydrogels composed of polyacrylamide (pAAm), cellulose acetate (CA), and montmorillonite (MMT), suitable for the controlled release of fertilizers. The synergistic effects of the components were evaluated in sorption and desorption studies of a nitrogen fertilizer.ResultsFour hydrogels were obtained: A, B, C, and D, with 0%, 5%, 10%, and 20% of MMT, respectively, in all cases with 10% of CA. The nitrogen contents of hydrogels A‐D were 21.9%, 26.7%, 29.4%, and 25.2%, respectively. Hydrogel C absorbed the greatest amount of solution. Increase of the MMT content from 5% to 10% (w/w) led to swelling increases of 45%, 60%, 27%, and 20.7% at pH 5.0, 6.0, 7.0, and 9.0, respectively. Soil water retention assays showed that the soil containing the synthesized hydrogels retained up to 39% more water, compared to soil without hydrogel, with release during up to 30 days. The hydrogels presented low recovery percentages for applied nitrogen (around 42% lower than for the treatment with urea alone), demonstrating the effectiveness of the materials in reducing losses of nitrogen by leaching. The release of urea in the soil from hydrogel C (pAAm/10% MMT/10% CA) was gradual (25%, 75%, and 89% at 5, 20, and 30 days), indicative of slow release behavior.ConclusionsThe presence of montmorillonite in the hydrogel caused the system to release the nutrient in a more controlled manner than obtained with the pure hydrogel. Hydrogel C, containing 10% montmorillonite and 10% cellulose acetate, showed excellent rates of swelling and nitrogen release in soil. The total nutrient values showed that this new material is potentially viable for application in agriculture.

Study on Clove Oil Microcapsule with Montmorillonite /Polyurethane Hybrid Wall

The microcapsules with inorganic/organic composites as capsule wall were prepared to optimize the performance of microcapsules. The MMT stabilized Pickering emulsion was used as template in the interfacial polymerization. TDI and EDA were polymerized at the oil-water interface to form MMT/PU composite as the capsule wall to encapsulate clove oil. Under the process condition of the dosage ratio of clove oil to TDI 5:1, the content of MMT 2%, and the reaction temperature 70 °C, the embedding rate of microcapsule could reach 92.31%. The average volume diameter of microcapsules was 49.4 μm. The microcapsules were regular and basically spherical shape, smooth surface and high elasticity. TGA showed that the thermal stability of essential oil was improved. The retention rates of clove oil in microcapsules after 40 days storage at 4 °C and 25 °C were more than 80%, indicating that clove oil microcapsules were relatively stable. The relative content of eugenol, the main component in clove oil decreased after storage, while the relative content of secondary components increased.

Thermal, structural, and rheological modifications in recycled polyethylene terephthalate for a sustainable alternative source for additive manufacturing

AbstractThis work reports the thermal, rheological, and crystallographic structural behavior of recycled polyethylene terephthalate (rPET) derived from bottle waste. The intent is to optimize it to an upcoming source for additive manufacturing by modulating its behavior using a chain extender triphenyl phosphite (TPP), nanofiller montmorillonite (MMT K‐10), and catalyst antimony trioxide (Sb2O3). FT‐IR (Fourier Transform Infrared) analysis showed an increase in absorbance due to the Sb2O3. The thermal analysis of the rPET using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) ascertains a 10°C decrease in Tg with a substantial increase in the degradation onset of 7°C due to MMT content. The melt flow index (MFI) study showed an increase with a similar range in intrinsic viscosity and weight average molecular weight (Mw) due to the additives. The percentage crystallinity, interlayer distance, and average crystallite size are determined and analyzed by X‐ray diffraction (XRD) and DSC curves. The results are within the comparative range of both tests. The presence of Sb2O3 with higher MMT content showed agglomeration, and increased TPP showed low crystalline properties. These results provide that rPET can be altered to manufacture feedstock to suit different 3D printing techniques for prototyping.

Polyamideimide dielectric with montmorillonite nanosheets coating for high-temperature energy storage

To meet the ever-increasing demand for electric power storage and conversion under harsh environment, polymer dielectrics, as the functional component in electrostatic capacitors, are required to serve at high temperatures. However, it is challenging to maintain favorable electrical insulation in polymer dielectrics with the temperature rise because of the high conduction loss at elevated temperature, which will lead to reduced breakdown strength, energy density, and service life. Here, a versatile surface engineering method is presented to enhance the high-temperature electrical insulation and energy storage performance of polymer dielectric via dip-coating montmorillonite (MMT) nanosheets. At 150 °C, a significantly enhanced breakdown strength of 551MV/m is achieved in a MMT coated polyamideimide (PAI) with optimized coating thickness and MMT content, resulting in a high energy density of 2.9 J cm−3 and a charge-discharge efficiency >80% that outperform existing high-temperature polymers and polyimide-based composites. Finite element simulation demonstrates that this superior performance is attributed to the anisotropic electrical properties of MMT nanosheets, which not only blocks charges injected from electrodes but also regulates the transport of charges to dissipate along the in-plane direction. This work offers a versatile and scalable approach for enabling high-temperature electrostatic energy storage and high-temperature insulation of a wide range of polymer dielectrics.

Physicomechanical, thermal and dielectric properties of eco‐friendly starch‐microcrystalline cellulose‐clay nanocomposite films for food packaging and electrical applications

AbstractPotato starch (PS) films reinforced with microcrystalline cellulose (MCC) were prepared with casting solution, and the effect of montmorillonite (MMT) clay in different proportions (1, 3, 5 and 10 wt%) using nanofiller was established. The films were investigated by Fourier transform ınfrared (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), tensile strength, opacity, colour, water vapour permeability and solubility. Tensile strength for nanocomposite films depending on the clay content was increased significantly from 0.64 to 1.89 MPa. The water vapour permeability of nanocomposite films was improved compared to the PSMCC blend without MMT. Also, dielectric properties and electrical conductivity of films were studied. The dielectric permittivity (έ), the dielectric loss (ε˝) and the electrical conductivity (σ) increased with increasing MMT content at frequencies between 100 Hz to 10 kHz. This nanocomposite with improved functional properties could be used in potential food packaging materials and electrical applications.

The effect of synthesis parameters on density and thermal conductivity of MMT based aerogel. Application of experimental design model

Aerogels are a class of materials largely composed of air with very low bulk densities. Due to their extremely porous nature, aerogels are very promising materials for thermal and acoustic insulation applications. While their majority described in the literature are silica-based, there are a limited number of references to clay-based aerogels. The abundance of clay and its limited toxicity make them particularly attractive. Clay aerogels formation involves mixing of clay with water, freezing of the suspension and freeze-drying of the frozen gel. This work concerns the use of montmorillonite as a raw material for the synthesis of aeroclays with low density. Clay aerogels were synthesized by mixing montmorillonite clay and water and their density was measured. Various agents were used for the reinforcement of the brittle structure of clay aerogel. A multifactorial experimental design model is applied in order to study the combined effect of synthesis parameters on the density of aeroclays. The thermal conductivity of the optimized sample was determined by means of the Heat Flow method, on a Netzsch HFM 436 lamda Heat Flow Meter. As it is concluded, aeroclays, derived from a solution of montmorillonite clay and water alone were brittle so the addition of reinforcement agent is crucial. Depending on the synthesis conditions, a density range from 0.05 to 0.4 g/cm3 and thermal conductivity in the range of 0.04 W/mK was achieved. The factors with the highest impact on the density of the final product were the content of MMT and reinforcement agent in the precursor solution. The optimized synthesis in terms of density and thermal conductivity was proved to be inflammable.

Study on insulating properties of polyethylene terephthalate/montmorillonite nanocomposites

Photovoltaic (PV) power is one of the most effective green energies, which has attracted extensive attention from the industry and the international community. Polyethylene terephthalate (PET) is the main material of the PV backsheet, providing insulation protection for PV modules. Although PET has excellent optical properties, weather resistance, and chemical resistance, its relatively weak insulation properties restrict its application in engineering plastic. In this paper, the insulating properties of PET/montmorillonite (MMT) are studied. PET/MMT nanocomposites with an MMT content of 1%, 3%, and 5% are prepared by the melt blending method, and their insulating properties are tested. The results show that the addition of MMT can change the distribution of the electric field inside PET, thus, increasing the breakdown voltage. Furthermore, it can reduce the number of times of partial discharge (PD) and weaken the intensity of PD in PET/MMT composites to some extent. When the MMT content is 3%, PET/MMT composites have the best insulation performance. This study can provide a reference for the application of nanocomposites in the field of green energy.

Poly(ethylene glycol) Diacrylate Iongel Membranes Reinforced with Nanoclays for CO2 Separation.

Despite the fact that iongels are very attractive materials for gas separation membranes, they often show mechanical stability issues mainly due to the high ionic liquid (IL) content (≥60 wt%) needed to achieve high gas separation performances. This work investigates a strategy to improve the mechanical properties of iongel membranes, which consists in the incorporation of montmorillonite (MMT) nanoclay, from 0.2 to 7.5 wt%, into a cross-linked poly(ethylene glycol) diacrylate (PEGDA) network containing 60 wt% of the IL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][TFSI]). The iongels were prepared by a simple one-pot method using ultraviolet (UV) initiated polymerization of poly(ethylene glycol) diacrylate (PEGDA) and characterized by several techniques to assess their physico-chemical properties. The thermal stability of the iongels was influenced by the addition of higher MMT contents (>5 wt%). It was possible to improve both puncture strength and elongation at break with MMT contents up to 1 wt%. Furthermore, the highest ideal gas selectivities were achieved for iongels containing 0.5 wt% MMT, while the highest CO2 permeability was observed at 7.5 wt% MMT content, due to an increase in diffusivity. Remarkably, this strategy allowed for the preparation and gas permeation of self-standing iongel containing 80 wt% IL, which had not been possible up until now.

The synthesis and characterization of phenolic resin with a high content of dimethylene ether bridges

Phenolic resins were synthesized using sodium montmorillonite (MMT) as a catalyst at a concentration of 3%, 5%, and 10%, the reaction time was 24 and 48 h, respectively. The phenolic resin yield was up to 69%. The chemical structure of the resins was determined by NMR, the thermal properties were determined by DSC and TGA, and molar masses were determined by SEC. The resins could not be easily classified as resol or novolac because the most common type of bonding between the aromatic rings was dimethylene ether (DME) bridges. Due to near neutral pH (6.7–7.1), some methylol groups were also present in the structure. Increasing the MMT concentration increased the molar mass of the resin; however, no influence of reaction time was observed. Increased MMT concentration, as well as longer reaction time, decreased the glass transition temperatures, which were very low, in the range of 8–24 °C. Increased content of DME increased the thermal stability of the resins.