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The materials science community has identified nanoparticle dispersion as a primary challenge area for the advancement of polymer nanocomposites technology. Although nanoparticle dispersion can significantly impact important engineering properties, it is not itself a quantifiable property; qualitative TEM image assessments remain as the ‘gold standard’ for dispersion characterization. While numerous...
The helium gas permeation through polyurethanes (PU) having novel microstructures derived from different polyols (varying from linear to hyperbranched) in the presence and absence of modified and unmodified nanoclays has been studied thoroughly in this paper. The permeation rate of helium gas decreases from linear to fourth generation polyols (PU 40 ) by about 80% due to increase in the crosslinking...
A silver–acrylate nanocomposite was prepared using a novel one-pot strategy involving eosin dye as visible sensitizer and an amine derivative as radicals' source. The mechanism highlighted by steady state photolysis and time-resolved absorption spectroscopy lies on the initial formation of a strong ion-pair complex between eosin and Ag + . Upon visible irradiation, the excited triplet state...
Bacterial polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was reinforced with cellulose nanowhiskers (CNW) in 1–5wt.% concentrations using a solvent casting method. The CNW was prepared from microcrystalline cellulose (MCC) using sulfuric acid hydrolysis. The influence of CNW on the PHBV crystallization, thermal, dynamic mechanical and mechanical properties were evaluated using polarized...
Poly(vinylidene fluoride) (PVDF) is an important ferroelectric semi-crystalline polymer with multiple-phase behavior. In this study, remarkable effects of the various crystalline structures of PVDF nanocomposites on alternating current (AC) conductivity were discovered using carbon nanofibers (CNF). It was found that the transformation from α-phase to β-phase in PVDF, induced by the addition of CNFs,...
A new type of multifunctional ammonium modifier with carbonyl group and vinyl group was synthesized to prepare multifunctional montmorillonites (F-MMTs), which were used as multifunctional catalyst supports for in situ ethylene polymerization. High loading of metallocene catalyst in the galleries of F-MMT had been achieved due to the presence of carbonyl group in the multifunctional modifier. XRD...
The understanding of the basic physical relationships between nano-scale structural variables and the macroscale properties of polymer nanocomposites remains in its infancy. The primary objective of this article is to ascertain the state of the art regarding the understanding and prediction of the macroscale properties of polymers reinforced with nanometer-sized solid inclusions over a wide temperature...
This article describes the focused ion beam (FIB)-tomography as a high-resolution three-dimensional (3D) technique to study the morphology of polymer/clay nanocomposites. To establish the structure–property relationship of such composite material, it is very important to visualize the 3D-structure and distribution of clay particles in the polymer matrix. The sequential two-dimensional sectioning by...
Poly(ether ketone) (PEK) was grafted onto few wall carbon nanotube (FWNT) using in-situ polymerization of 4-phenoxybenzoic acid (4-PBA) in poly(phosphoric acid) (PPA), and fibers were processed using dry-jet wet-spinning. The PEK/FWNT weight ratio was in the range of 99/1 to 80/20. The fibers have been characterized for their morphology, structure, mechanical properties, as well as electrical conductivity...
We investigate the gradual changes of the microstructure of two blends of high-density polyethylene (HDPE) and polyamide 6 (PA6) at opposite composition filled with increasing amounts of an organomodified clay. The filler locates preferentially inside the polyamide phase, bringing about radical alterations in the micron-scale arrangement of the polymer phases. When the host polyamide represents the...
We propose a theory for the structure of the interphase in polymeric nanocomposites based on the freely-jointed chain near an impermeable spherical inclusion. The theory considers only the entropic exclusion between a polymer and the inclusion. The radius of gyration of the polymer chain and its distortion from spherical symmetry are perturbed strongly when the chain end is closer than 3R g0 ...
A poly[(butylene succinate)-co-adipate] (PBSA) nanocomposite containing 3 wt% organically modified montmorillonite exhibited an improvement in tenacity (elongation at break) as compared to the neat PBSA. The nanocomposite also showed moderate improvement in tensile modulus and strength. The small-angle X-ray scattering and transmission electron microscopy were used to investigate the exact tenacity...
Local glass transition temperatures (T g ) have been measured in the interfaces of solution blended silica/poly(methyl methacrylate) (PMMA) nanocomposites using florescence spectroscopy and compared with T g measured by differential scanning calorimetry (DSC). It was found that the two types of measurements yielded significantly different information. Combinations of silanes and poly(propylene...
55-nm rubber particles significantly toughened two epoxy systems without loss of Young’s modulus, tensile strength and glass transition temperature. Transmission Electron Microscopy (TEM) showed that the nanoparticles are uniformly dispersed in matrix and have blurred interface with epoxy. 5wt% rubber nanoparticles increased the critical strain energy release rate (G 1c ) of Jeffamine D230...
Dynamic mechanical analysis and tensile test have been used to characterize the mechanical behaviour of hybrid composites. Barium titanate (BaTiO 3 ) is the submicron filler and polyamide 11 (PA 11) the matrix. The influence of volume fraction and particles size (ranging from 100 nm to 700 nm) of the inorganic phase on the composites mechanical properties have been checked. BaTiO 3 ...
The orientation distribution of layer-shaped nanoclays (e.g. organoclays and pristine clays) dispersed in a polymer matrix is an important parameter to control the properties of polymer nanocomposites. In this study, we demonstrate that the use of multi-directional 2-D small-angle X-ray scattering (SAXS) can quantitatively describe the orientation distribution of organoclays (e.g. Cloisite C20A) in...
High performance silanized silica/epoxy nanocomposites were prepared through mixing epoxy, tetraethyl orthosilicate (TEOS), (3-aminopropyl)trimethoxysilane (APTMS) and ammonia solution at 50 °C. This all-in-one “Solvent-Free One-Pot Synthesis” results in nanocomposites with uniform dispersion of oval shaped silica nanoparticles and strong adhesion between silica and epoxy matrix. The influence of...
We describe the influence of calcium copper titanate (CCTO), and montmorillonite (MMT) on the thermo-mechanical and dielectric properties of poly(methyl methacrylate) PMMA-based composites prepared by an in-situ, thermally activated, radical polymerization for multifunctional structural capacitor applications. MMT was used for its ability to disperse and suspend the CCTO particles through the generation...
Biodegradable nanocomposites consisting of poly(ɛ-caprolactone) (PCL) reinforced by PEGylated silica (polyethylene-glycol/SiO 2 ) nanoparticles were prepared by a melt-extrusion process. The PEGylated silica nanoparticles were prepared in a facile, one-pot synthesis process. Transmission electron microscopy (TEM) observations of the PEGylated silica nanoparticles inside the PCL matrix indicated...
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