Filler nano-, content

When the content of CajfPO ) in the NCPE is increased to 20% the ionic conductivity of the NCPE decreases. This decrease in the ionic conductivity can also be attributed to the change in the crystallinity of PEO in the nanocomposite polymer electrolytes (Capuglia et al., 1999). According to Scrosati and co-workers (Scrosati et al., 2001), the Lewis acid groups of the added inert filler may compete with the Lewis acid lithium cations for the formation of complexes with the PEO chains as well as the anions of the added lithium salt. In the present study, the filler nano CajfPO lj, which has a basic center can react with the Lewis acid centers of the polymer chain and these interactions lead to the reduction in the crystallinity of the polymer host. Nevertheless, the result provides LL conducting pathways at the filler surface and enhances ioiuc transport. 

Linear low density polyethylene (LLDPE) of mark Dowlex-2032, having melt flow index 2.0 g/10 min and density 926 kg/m that corresponds to crystallinity degree of 0.49, used as a matrix polymer. Modified Na -montmorillonite (MMT), obtained by cation exchange reaction between MMT and quatemaiy ammonium ions, was used as nano filler MMT contents makes up 1-7 mass% [4]. 

Clays have long been used as fillers in polymer systems because of low cost and the improved mechanical properties of the resulting polymer composites. If all other parameters are equal, the efficiency of a filler to improve the physical and mechanical properties of a polymer system is sensitive to its degree of dispersion in the polymer matrix (Krishnamoorti et ah, 1996). In the early 1990s, Toyota researchers (Okada et ah, 1990) discovered that treatment of montmorillonite (MMT) with amino acids allowed dispersion of the individual 1 nm thick silicate layers of the clay scale in polyamide on a molecular. Their hybrid material showed major improvements in physical and mechanical properties even at very low clay content (1.6 vol %). Since then, many researchers have performed investigations in the new field of polymer nano-composites. This has lead to further developments in the range of materials and synthesizing methods available. 

Fibers have been widely used in polymeric composites to improve mechanical properties. Cellulose is the major substance obtained from vegetable fibers, and applications for cellulose fiber-reinforced polymers have again come to the forefront with the focus on renewable raw materials. Hydrophilic cellulose fibers are very compatible with most natural polymers. The reinforcement of starch with ceUulose fibers is a perfect example of a polymer from renewable recourses (PFRR). The reinforcement of polymers using rigid fillers is another common method in the production and processing of polymeric composites. The interest in new nanoscale fillers has rapidly grown in the last two decades, since it was discovered that a nanostructure could be built from a polymer and layered nanoclay. This new nanocomposite showed dramatic improvement in mechanical properties with low filler content. Various starch-based nano-composites have been developed. 

Polypropylene (PP500P, SABIC) has melt flow rate of 3.1 (2.16 kg at 230 °C) and density of 905 kg/m3 was used as matrix resin. Nano-sized synthetic ultrafine surface treated precipitated calcium carbonate (Socal 312, Solvay, France) with mean particle diameter of 70 nm used as filler phase. PP-g-MAH compatibiliser (Priex 20097, Solvay, France) with a maleic anhydride content of 0.05 wt % and MFI of 15 (2.16 kg at 230 °C) was employed to promote the interfacial interaction between nano-CaC03 and PP, and to extend the dispersion of nanoparticles in polymer matrix. Compounds used as processing materials are listed in the table 1. 

Hybrid nano-G/CB filler systems were prepared in IR as the matrix. In samples containing 60 phr of CB, a discontinuity was observed for the dependence of the excess of modulus on nano-G content, at about 6 phr as nano-G content, as if nano-G was able to establish a continuous network in the polymer matrix. 

In Section 23.2 was discussed the theory of reinforcement of polymer and elastomers which refers to the Guth-Gold-Smallwood equation (Equation (23.1)) to correlate the compound initial modulus (E ) with the filler volume fraction ( ). Moreover, it was already commented on the key roles played by the surface area and by the aspect ratio (/). Basic feature of nanofillers, such as clays, CNTs and nanographites, is the nano-dimension of primary particles and thus their high surface area. This allows creating filler networks at low concentrations, much lower than those typical of nanostructured fillers, such as CB and silica, provided that they are evenly distributed and dispersed in the rubber matrix. In this case, low contents of nanofiller particles are required to mutually disturb each other and to get to percolation. Moreover, said nanofillers are characterized by an aspect ratio /that can be remarkably higher than 1. Barrier properties are improved when fillers (such as clays and nanographites) made by... 

The progress in the oxidation of LDPE modified with maleic anhydride and alumina proceeds somewhat similar at various doses, because oxygen diffusion is hindered by filler nanoparticles [102]. The noticeable difference between pristine and modified LDPE consists of the presence of maleic anhydride, which interacts with molecular chains due to the electronegativity of oxygen atoms. The same radiation dose affects differently the dielectric behavior of the nanocomposites depending on the filler content. The dose of 50 kGy applied on LDPE-g-AM filled with 5 wt% nano-Al203 leads to a relative permittivity smaller than unfilled LDPE. y-Radiation can lead to a decrease in the dielectric losses of LDPE AI2O3 nanocomposites for properly chosen combination dose-fiUer content. 

In fact, transmission electron microscopy (TEM) observation showed that the size of the dispersed phases increases with increasing filler content in the nanocomposites (Fig. 1.3). It should be noted here that the dispersed phases in the nanocomposites illustrated in Fig. 1.3(b)-(e) are clearly smaller than the untreated Si02 (Fig. 1.3(a)), but they are still much larger than the size of the primary nano-Si02 particles (7mn). Therefore these dispersed phases are actually microcomposite agglomerates consisting of primary particles, grafting polymer, homopolymer, and a certain amount of matrix. 

Filler content [phr] Fe304 micro Fe304 nano... 

The comparison of mechanical properties of EPM vulca-nizates filled with micrometer and nanometer sized Fe304 shows the effect of fillers size and its influence on vulcani-zates tensile strength (Fig. 6). The results suggest, that the optimal content of micro sized Fe304 is 80 phr and 60 phr for nano sized Fe304. 

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