Filling modification compositions

Beside mechanical characterization, one important aim of this work is the evaluation of the effects of E-beam modification of PTFE powder on the friction and wear properties of PTFE-filled EPDM composites crosslinked by a radical-initiated peroxide system. Friction and wear properties of EPDM composites were... 

Rothon, R. N. (1995). Surface Modification and Surface Modifiers. Particulate-Filled Polymer Composites. Longman Harlow. 

In summary, the model systems discussed in this part were zero-shear suspensions of disk-shaped particles in Newtonian liquids, mica-filled polymeric composites, LCPs and colloidal suspensions. The TCP model offers a good understanding of the flow behavior of exfoliated CPNCs. In the case of intercalated systems similar behavior is expected but is complicated by stress-induced changes in the degree of the dispersion and aspect ratio, as well as other possible modifications, such as the thermal decomposition of intercalant. 

Some research on the pre-treatment of CNTs and interfacial modification techniques have been reported, which is helpful to the preparation of CNT-filled rubber composites. " But the dispersion of CNTs into rubber materials is still problematic due to possible entanglement of the high aspect ratio CNTs and the high viscosity of rubbers. 

Filling Modification and Fiber-Reinforced Composite Modification... 

Filling modification of polymer is the addition of solid additives with different composition and structure to the polymer matrix material to reduce costs or obviously change the performance of polymer products, which will improve the desired performance at the expense of other kinds of performance at the same time. Such an additive is known as a filler. Because these fillers are mostly inorganic powder, filling modification relates to performance difference and complementation of organic polymer and inorganic matter. This provides diverse areas of research and broad fields of application for filling modification. 

In the blending process, whiskers may become damaged or even broken because of the impact and collision between whiskers and resin particles and the shear caused by the rotation of the screw. The constant length-to-diameter (Z/D) ratio of whiskers is the key for filling modification, so the speed of extrusion, the temperatures of different sections, and the position of the feed inlet of whiskers greatly influence the performance of the composite materials. Ge adds whiskers from the feed inlet of the twin-screw extruder and the first outlet respectively, and the performances of the composite material are shown in Table 4.2. 

Montanari G.C., Fabiani D., Palmier F., Modification of electrical properties and performance of EVA and PP insulation through nanostructure by organophUic silicates , IEEE Transactions on Dielectrics and Electrical Insulation 2004 11 (5) 754-762. Wu C.L., Zhang M.Q., Rong M.Z., Friedrich K., Tensile performance improvement of low nanoparticles filled-polypropylene composites , Composites Science and Technology, 2002 62 1327-1340. 

Impact strength also increased if the adhesion between the polymer and fiber is increased [240, 249]. The most promising method of modification of fiber-filled compositions is by pre-treating the fibers or adding to the matrix of specific depressants or modifiers with the aim of creating a chemical bond at the interphase. This improves the composition service lifetime, strength and thermal stability [250],... 

Earlier we have said that the flow of filled materials can be raised by modification. One of the modification alternatives consists in using a combination ( flexible ) filler. As shown in [366], addition of a small quantity of glass balls to composites filled with chalk caused a sudden increase of the flow of the system, provided the filler concentration is below critical. Similar behavior was also observed in fiber-filled systems when a small quantity of dispersed particles were added [33],... 

Fluoroelastomers Novikova et al. [32] reported unproved physico-mechanical properties of fluoro mbbers by reinforcement with chopped polyamide fibers. Other fiber reinforcements are covered by Grinblat et al. [33]. Watson and Francis [34] described the use of aramid (Kevlar) as short fiber reinforcement for vulcanized fluoroelastomer along with polychloroprene mbber and a co-polyester TPE in terms of improvement in the wear properties of the composites. Rubber diaphragms, made up of fluorosilicone mbbers, can be reinforced using aramid fiber in order to impart better mechanical properties to the composite, though surface modification of the fiber is needed to improve the adhesion between fluorosUicone mbber and the fiber [35]. Bhattacharya et al. [36] studied the crack growth resistance of fluoroelastomer vulcanizates filled with Kevlar fiber. 

An orbital correlation diagram has been presented for linear and bent M—N—O systems in five-co-ordinate tetragonal molecules, and the diagram can be extended to six-co-ordinate complexes with only minor modifications. From this study, it is concluded that the antibonding nature of the level to be filled under symmetry, and not its composition, lead to distortion and bending of the M—N—O unit, and that v(NO) is not a good guide to the linear... 

Encapsulation of other material into carbon nanotubes would also open up a possibility for the applications to electrodevices. By applying the template method, perfect encapsulation of other material into carbon nanotubes became possible. No foreign material was observed on the outer surface of carbon nanotubes. The metal-filled uniform carbon nanotubes thus prepared can be regarded as a novel onedimensional composite, which could have a variety of potential applications (e.g novel catalyst for Pt metal-filled nanotubes, and magnetic nanodevice for Fe304-filled nanotubes). Furthermore, the template method enables selective chemical modification of the inner surface of carbon nanotubes. With this technique, carbon... 

This chapter focuses its attention on the discussion of the most relevant questions of interfacial adhesion and its modification in particulate filled polymers. However, because of the reasons mentioned in the previous paragraph, the four factors determining the properties of particulate filled polymers will be discussed in the first section. Interactions can be divided into two groups, parti-cle/particle and matrix/filler interactions. The first is often neglected although it may determine the properties of the composite and often the only reason for surface modification is to hinder its occurrence. Similarly important, but a very contradictory question is the formation and properties of the interphase a separate section will address this question. The importance of interfacial adhesion... 

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