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EN
Poly (ethylene oxide), PEO, which was used for a wide variety of applications is a flexible, crystalline, thermoplastic, water-soluble and non-ionic polymer. The most of studies on surfactant-modified activated carbon (SM-PAC) have been generally focused on the removal of contaminants. This study aims the preparation of PEO/(SM-PAC) composites, using solution-intercalation method. Firstly activated carbon was modified with cationic surfactant, Cetyltrimethylammonium Bromide (CTAB). Then PEO/(SM-PAC) composites were prepared using solution-intercalation method, with two different (SM-PAC) contents (1.0 and 2.0 wt.%). The characterization of the composites was made by X-ray diffraction (XRD), Fourier Infrared Spectroscopy (FT-IR), thermal analysis and tensile tests. The XRD patterns revealed that 2θ positions of the broad peaks belonging to the composites significantly shift to left compared with those of virgin PEO. The SEM images of the surfactant-modified powdered activated carbon (SM-PAC)/PEO composites prepared with the two different SM-PAC contents show that there is an intensive interaction between the CTA^{+} ions of modified activated carbon surface and the polymer chains. From the tensile tests, it was found that the unmodified powdered activated carbon dispersed into the polymer matrix made the ductile polymer more brittle. However, the tensile and yield strengths of the composite, prepared with modified powdered activated carbon, have decreased, and the strain percent value has significantly increased.
EN
In this study, the synthesis of aniline-formaldehyde resin, and its thermal and structural characterization, as well as the preparation and characterization of the resin-organoclay composites were carried out. For this, first, at 70°C and acidic conditions the aniline formaldehyde prepolymer was prepared and then cured at 120°C under vacuum. The structural and thermal characterization of the resin was made using FTIR and DSC techniques. By using the Cetyltrimethylammonium Bromide modified Montmorillonite (OMMT) and the synthesized resin, the resin-organoclay composites were prepared by melt intercalation method. Characterization of the resin-organoclay composites prepared with the different ratios of organoclay is made with the same techniques. The FTIR and thermal analysis results of the composites indicate that a cross-linked polymeric matrix was formed. The thermal behavior of the composites has also significantly changed compared to pure resin.
EN
Recently PF resins can be also prepared by the addition of urea because urea accelerates cure process of PF resin, reduces the cost and improves its strength performance. Clays have long been used as inorganic fillers in polymer systems because of low cost, availability and improved thermal properties of resulting polymer composites. Clay nanocomposites of different types yield a marked increase in a number of properties of thermoplastic and other resins and composites. This study investigates the variation of thermal properties of PUF/colored organoclay nanocomposites with increased colored clay ratio. For this the DSC, XRD, FT-IR and HRTEM analyses were made. The XRD patterns and HRTEM images showed that clay platelets were exfoliated at the lower contents of organoclay, whereas at the higher content of organo clay tactoids were observed. The XRD analysis results implied that the amorphous behaviour increased with increased content of colored organoclay. The DSC thermograms indicated that glassy transition temperature (T_{g}) was increased, appearing prominent crystallization peaks at the lower ratios of organoclay. The T_{g} value was partially decreased and the peak intensities gradually decreased with increased content of clay. The thermogram for composite with clay content of 20% was similar to the thermogram of virgin resin. This can be attributed to the shifting of the textural structure for this composite from prominent crystalline structure to amorphous one.
EN
Urea-formaldehyde (UF) resin which is one of the most important wood adhesives is a polymeric condensation product of the chemical reaction of formaldehyde with urea, and considered as the most important type of adhesive resins for the production of particleboards. The present study is aimed to preparation and characterization of urea/formaldehyde/Rosa Canina sp. seeds - and urea/formaldehyde/ Rosa Canina sp. seeds/organo clay composites and also to determine the utility as an alternative and low cost material to manufacture particleboard. The synthesis of various composites was carried out using fresh Rosa Canina sp. seeds, typical agricultural waste, in its changing ratios from 7.7 to 83.3 wt%. Also, some of the composite mixtures were prepared by adding organo clay (0.17-3.3 wt%) in a constant ratio of 1/1 wt of urea and formaldehyde. The structural and mechanical characterization of samples was performed by X-ray diffraction, Fourier transform infrared spectra, high resolution transmission electron microscopy images and measurements of Shore D and scratch hardness. The analysis results conclude that organo clay platelets dispersed as simultaneously intercalated and exfoliated in resin matrix and also the increased organo clay ratio led to increase in the hardness values of samples.
EN
Recently, so-called "phenol-formaldehyde-urea resins", which are generally made only by mechanical blending of UF resin and alkaline type PF resins, have been used as adhesives for the manufacturing of wood products. Faster curing PF resins can be also prepared by the addition of urea during or after the resin synthesis to yield co-condensed phenol-urea-formaldehyde (PUF) resins. In this study, resin/clay composites were prepared by in situ polymerization of phenol(18.2%)-urea(36.3%)-formaldehyde(45.5%) (PUF) with the various ratios of organoclay (7.69-45.45%) and colored organoclay (3.22-20.0%). The objective of our work is the investigation of the effect of addition of both organoclay and colored organoclay at different ratios on the textural characteristics. The composites are characterized by X-ray diffraction, Fourier transform infrared spectroscopy techniques and using high resolution transmission electron microscopy images of the samples. It was found that clay layers exfoliated in the resin matrix.
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