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Thermoplastic polyurethane/organically-modified montmorillonite (TPU/OMMT) nanocomposites were synthesized by the pre-polymer polymerization method using Cloisite® 30B organoclay, 1,6-hexamethylene diisocyanate (HDI), polycaprolactone diol (PCL diol, 2000 g/mol) and 1,4-butanediol (BDO). The hard segment content of the TPU was maintained at ~25.5% while the role of clay content was investigated at 1, 3 and 5 wt.% of clay concentration. The aim of this work was to obtain a high-performance polyurethane system while reaching a general microstructure-property relationship for TPU/OMMT nanocomposites. Clay exfoliation was achieved at 1 and 3 wt.% of clay loadings while some agglomerated clay sheets were observed in samples containing 5 wt.% OMMT. Significant hydrogen bonding occurred between the urethane linkages with unreacted -CH2CH2OH groups of the OMMT particles which resulted in strong matrix-filler interactions. Consequently, the values of tensile modulus were enhanced with clay content; namely a 177% improvement was observed for samples containing 5 wt.% OMMT. On the other hand, samples exhibited more thermoplastic behavior with the increase of clay content which resulted in lower deformability and lower values of tensile strength.

In this article a convenient method for the synthesis of tetrahydrobenzo[b]pyran derivatives using imidazolium-based ionic liquid-stabilized on magnetic nanoparticles [Fe3O4@SiO2@(C3H6)2-(Imidazolium)2-Butyl][MnCl4 2-] as a new heterogeneous catalyst has been described. These compounds were synthesized via onepot three component condensation reaction between several aromatic aldehydes, malononitrile, and dimedone in water under reflux condition. The magnetic nanoparticle catalyst was fully characterized by Fourier transform infrared, scanning electron microscopy, energy dispersive X-ray spectroscopy, and vibrating sample magnetometer. Furthermore, the solid catalyst could be recovered and reused conveniently several times with satisfactory yields.

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In this paper, an azo-containing Schiff base complex of manganese [Mn 2þ -azo ligand@APTES-SiO 2 @Fe 3 O 4 ] immobilized on chemically modified Fe 3 O 4 nanoparticles has been used as a magnetically retrievable catalyst for the alcoholysis of different epoxides to their corresponding alkoxy alcohols with methanol, ethanol and n-propanol. The newly magnetic nanoparticles (MNPs) were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and vibrating sample magnetometry (VSM).