Study Structure and Properties of Nanocomposite Material Based on Unsaturated Polyester with Clay Modified by Poly(ethylene oxide)

In recent years, polymer clay nanocomposites have been attracting considerable interests in polymers science because of their advantages. There are many scientists who researched about this kind of material and demonstrated that when polymer matrix was added to little weight of clay, properties were enhanced considerably. Because clay is a hydrophilic substance so it is difficult to use as filler in polymer matrix having hydrophobic nature, so clay needs to be modified to become compatible with polymer. In this study, poly(ethylene oxide) was used as a new modifier for clay to replace some traditional ionic surfactants such as primary, secondary, tertiary, and quaternary alkyl ammonium or alkylphosphonium cations having the following disadvantages: disintegrate at high temperature, catalyze polymer degradation, and make nanoproducts colorific, and so forth. In order to evaluate modifying effect of poly(ethylene oxide), modified clay products were characterize d by X-ray spectrum. Then organoclay was used to prepare nanocomposite based on unsaturated polyester. Morphology and properties of nanocomposites were measure d by X-ray diffraction, transmission electron microscopy, tensile strength, and thermal stability. The results showed that clay galleries changed to intercalated state in the nanocomposites. Properties of nanocomposites were improved a lot when the loading of the organoclay was used at 1 phr

SYNTHESIS OF STARCH MODIFIED MONTMORILLONITE AS AN EFFECTIVE ADSORBENT FOR Pb (II) REMOVAL FROM WATER

The adsorbent is prepared by the montmorillonite co-modification with starch for the removal of Pb (II) ions from aqueous solution. The Fourier-transformed infrared (FTIR), X-ray diffraction (XRD) spectroscopies were used to determine the structure and characteristics of the adsorbent. The main factors affecting the removal of Pb (II) ions were investigated, including the effect of pH, contact time, adsorbent dosage and the initial concentration of Pb (II). Batch process can be used for adsorption and equilibrium studies. The experimental data were fitted using Freundlich and Langmuir adsorption models. The Langmuir isotherm best fitted the experimental data with R2 0.99 and maximum Pb (II) adsorption capacity of 21.5 mg/g indicated monolayer adsorption. Kinetic studies using pseudo-first-order and pseudo-second-order rate models showed that the process complied well with the pseudo second-order rate model

Separation and purification of montmorillonite and polyethylene oxide modified montmorillonite from Vietnamese bentonites

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Monoglyceride as an effective and friendly modification agent for nano-layered structure of Montmorillonite

International audienceThis study focused on the modification of montmorillonite (Mt) using the new modifying agent monoglyceride(M-Gly). M-Gly formed a self-assembled structure in Mt. interlayers, which may be used for further study in claymineral polymer nanocomposite (CPN) and cosmetic additives. The X-ray diffraction results showed the d001-value of Mt. increasing up to 16 Å in solvent and>60 Å in the melting method compared to 10 Å with neat Mt.This implies that when the melting method is applied using the internal thermomixer device with a high shearrate, the interlayer space of Mt. is expanded considerably. The transmission electron microscopy results showedthere was good dispersion of the organoclay layers in modified Mt. This means that the clay minerals layerstructure was disordered with two- or three-layer stacks that were separated after modification. The thermogravimetricanalysis also showed the thermal stability of the modified specimens in each method and evidencedthe insertion and elimination of M-Gly from the interlayer space of Mt. during the modification process

Effective Synergistic Effect of Treatment and Modification on Spent Coffee Grounds for Sustainable Biobased Composites

International audienceSpent coffee grounds (SCGs) represent a huge amount of global waste whose post-use disposal triggers environmental issues. In this study, SCGs were successfully treated and modified to improve the mechanical properties of biobased composites with epoxy matrix. A two-step treatment was proposed, pretreating by a NaOH solution and modifying by maleic anhydride (MA). MA acts as a coupling agent to create the internal network in composite through the interaction between functional groups. Accordingly, MA improves the interface between phases in composite, ensures a better physical property compared to the composite without modification. Consistently, the two-step treatment depicts improved mechanical properties: flexural modulus and flexural strength increased to 3053 MPa and 45 MPa, respectively, compared to 2429 MPa and 33 MPa for composite with pure SCGs

Valorization of starch nanoparticles on microstructural and physical properties of PLA ‐starch nanocomposites

International audienceStarch nanoparticles, synthesized from native starch through the hydrolysis approach, are considered as potential reinforcers to sustainable biodegradable nanocomposite with poly(lactic)acid. Some properties of nanocomposites are upgraded to expand their applications compared to poly(lactic) acid. As relevant, starch nanoparticles are spherically shaped with mainly distributive sizes under 80 nm. Especially, they are homogeneously dispersed in the matrix polymer at high content, resulting in improving the interfaces between matrix polymer and starch nanoparticles, thermal stability, and mechanical properties of nanocomposites