Book•
Mechanical Properties of Polymers and Composites
14 Dec 1993-
TL;DR: In this article, the authors discuss various mechanical properties of fiber-filled composites, such as elastic moduli, creep and stress relaxation, and other mechanical properties such as stress-strain behavior and strength.
Abstract: Mechanical Tests and Polymer Transitions * Elastic Moduli * Creep and Stress Relaxation * Dynamical Mechanical Properties * Stress-Strain Behaviour and Strength * Other mechanical Properties * Particulate-Filled Polymers * Fiber- Filled Composites and Other Composites.
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TL;DR: In this article, the preparation and characterization of polymer-clay nanocomposite gels and films containing poly(ethylene oxide) and various ratios of Laponite and Montmorillonite are described.
36 citations
TL;DR: A variety of novel polymeric materials ranging from elastomers to tough, rigid plastics have been prepared by the cationic copolymerization of regular soybean oil, low-saturation soybeans oil, or conjugated low saturation soybean oils with various alkene commonomers.
Abstract: A variety of novel polymeric materials ranging from elastomers to tough, rigid plastics have been prepared by the cationic copolymerization of regular soybean oil, low-saturation soybean oil, or conjugated low-saturation soybean oil with various alkene commonomers. Using appropriate compositions and reaction conditions, 70–100% of the soybean oil is covalently incorporated into the cross-linked polymer networks, contributing significantly to cross-linking during copolymerization. The resulting thermosets exhibit thermophysical and mechanical properties that are competitive with those of their petroleum-based counterparts. In addition, good damping and shape memory properties have been obtained by controlling the degree of cross-linking and the rigidity of the polymer backbone. New materials with similar characteristics have also been produced from other biological oils, including tung, and fish oils using the same technique. The new, more valuable properties of these bioplastics suggest numerous promising applications of these novel polymeric materials.
36 citations
Journal Article•
TL;DR: In this article, the storage modulus (E' was measured using dynamic mechanical thermal analysis (DMTA), and the dynamic Young's modulus was calculated using free-free vibrational testing.
Abstract: By means of dynamic mechanical thermal analysis (DMTA), selected tropical wood species, namely Eugenia spp., Artocarpus rigidus, Artocarpus elesticus, Koompassia malaccensis, and Xylopia spp. have been characterized. The woods were treated with sodium metaperiodate to convert them into wood polymer composites (WPC). After two weeks the WPC were chemically treated with phenyl hydrazine to convert them into secondary wood polymer composites, also called post-treated WPC (PTWPC). The chemical treatment and post-treatment are successful in improving the mechanical properties of the final product. The storage modulus (E’) was measured using dynamic mechanical thermal analysis (DMTA), and the dynamic Young’s modulus (Ed) was calculated using free-free vibrational testing. The results reveal that the elastic properties i.e. stiffness (Ed) and storage modulus (E’) of the composite were dependent on the type of wood species. The E’ of WPC and PTWPC were much higher than raw wood, whereas the glass transition temperatures (Tg) of WPC and PTWPC were much lower than those of raw wood. Free-free vibration testing provided rapid information about the quality of the composite material, such as the stiffness (Ed) of the PTWPC compared to the respective WPC and raw woods. The WPC and PTWPC were characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). FTIR analysis indicated the absorption band of raw wood at 1635 cm-1 due to carbonyl stretching, whereas WPC and PTWPC showed increased absorption bands near 1718 cm-1 and 1604 cm-1, respectively.
36 citations
TL;DR: In this paper, composites with polyurea as the matrix were prepared and the tensile tests were performed using an Instron load frame combined with a digital camera to observe the fracture surfaces of the composites.
Abstract: In this article, composites with polyurea as the matrix were prepared. Fly ash (FA) is a waste product of thermal power stations generated in huge quantities and consists of hollow particles with porous shells. These particles were employed as the filler. The volume fraction and particle size of FA were varied to study their effects on the density and tensile properties of the composites. The tensile tests were performed using an Instron load frame combined with a digital camera. Scanning electron microscopy (SEM) was used to observe the fracture surfaces of the composites. Results indicated that the addition of FA linearly decreased the density of the composites. Tensile stress and elongation at break of all composites decreased with an increasing volume fraction of FA. The moduli at 100 and 300% elongation of the composites with small- or medium-sized FA particles increased up to a certain value and declined with further addition of FA. Fractographic analysis showed that large FA particles were crushed, while finer particles tended to debond.
36 citations
TL;DR: In this article, a modified microdebond test was used to study the influence of interphase microstructure on the fiber-matrix adhesion of Nylon 66 composite.
Abstract: Nylon 66, an aliphatic semicrystalline polyamide, was reinforced with E-glass fibers or high-modulus (AS4) carbon fibers. As in many reinforced semicrystalline thermoplastics, an interphase composed of transcrystallinity developed owing to the high nucleation density of the polymer on the fiber surface. The influence of this region on the fiber–matrix adhesion was studied with a modified microdebond test. E-glass fibers were freshly prepared in our laboratory by traditional glass-forming techniques and embedded in a film of Nylon 66 or a Nylon 66/poly(vinyl pyrrolidone) (PVP) blend. Previous work has shown that PVP, an amorphous polar polyamide, has a dramatic influence on the morphology of Nylon 66. This phenomenon was utilized to manipulate the interphase formation in the Nylon 66 composite from one having a complete transcrystalline interphase to a composite with the absence of an interphase. PVP was introduced to the matrix by solution blending with Nylon 66 and/or to the fibers as a sizing prior to embedment. The resulting morphologies were studied by polarized hot-stage optical microscopy. From the microdebond and morphology results, it was shown that the fiber–matrix adhesion in this composite system is dependent upon interphase microstructure. Composites containing transcrystallinity have higher interfacial shear strength values than those that do not contain this interphase. This has profound implications for the bulk mechanical properties of the composite, which are addressed in Part 2 of this paper.
36 citations