Polymer-filler blends

Distribution of Filler in Conducting Polymer Composites Based on Polymer Blends... 

Thermoplastic elastomeric compositions from reclaimed NR and scrap LDPE with 50 50 mbber/plastic ratio shows good processability, ultimate elongation, and set properties. Polymer blends of reclaimed mbber and LDPE exhibit higher viscosity over the range of shear rate at various temperatures compared to virgin NR-LDPE blends due to the influence of filler present in the reclaimed mbber (Eigure 38.7) [109]. 

TEM is used to investigate the phase morphology of polymer blends and the dispersion of fillers. See Electron Microscope. 

Dubois, P., Groeninckx, G., Jerome, R., and Legras, R. 2006. Fillers, Filled Polymers, and Polymer Blends. Wiley, Hoboken, NJ. 

The electrical conductivity of two-phase, incompatible polymer blends containing carbon black has been shown to depend on the relative affinity of the conductive particles to each of the polymer components in the blend, the concentration of carbon black in the filler-rich phase, and the structural continuity of this phase [82]. Hence, by judicious manipulation of the phase microstructure, these three-phase filled composites can exhibit double percolation behaviour. 

Coalescence is another reverse process in mixing. Whereas this is a major issue in the formation of polymer blends, it is considered of less significance with carbon black or other solid filler dispersions in polymers [83]. 

For silica, the plasma-pyrrole coating clearly improves the compatibihty of the silica in the polymer blend. In contrast to this, the plasma-acetylene and plasma-thiophene treatments cause a high filler-filler interaction. This can be explained by the differences in compatibility between the plasma coatings and the polymers. In the case of PA-silica, the coating results in a higher compatibility towards EPDM in the blend, which could lead to an overconcentration of silica in the EPDM phase, with increased agglomeration of the filler. 

The higher amounts of bound rubber for all samples filled with plasma-treated silica demonstrate an improved filler-polymer interaction between the plasma-treated silica and the polymers in the blend compared to untreated and silane-treated silica. The highest filler-polymer interaction for the PPy-silica can be due to the best compatibilization effect of PPy-silica with both polymers in the blend, as... 

For silica in SBR, a polyacetylene coating gives the lowest filler-filler interaction, a good filler-polymer interaction, and the best dispersion compared to untreated and the other plasma-treated samples. However, for the stress-strain properties, the polythiophene-treated sample gives the best results. This shows the importance of sulfur moieties on the surface of the filler, which form a secondary network in the cured materials. In the blend of S-SBR and EPDM rubbers, the situation is less conclusive. The Payne effect, the bound rubber, and... 

The effects associated with the influence of the phase border are especially obvious in heterogeneous polymer systems, where both components are of a polymeric nature. Such systems include polymer blends and polymers filled with polymeric filler. These two types of systems differ in that in blends it is difficult to distinguish between the two polymers as a disperse phase and dispersion media due to uniform distribution of both components in the volume. 

Many studies use infrared spectroscopy for quality control and quality analysis in polymer production. It is particularly used for the determination of the composition of copolymers and polymer blends and also for determination of additive and filler contents [90, 91, 92]. 

Among the various materials are crosslinked PAN, polyphosphazenes, polyphe-nylenesulfide, polyetheretherketone, and various polymer blends [28-31]. Particularly interesting is the use of zeolites as filler in organic polymers, which aims at improving the performance of (silicone-based) membranes for separations in nonpolar solvents, by adding more cross-links to the membrane material [32, 33]. 

Plastics as technical materials are based on polymers (or macromolecular substances), but in most cases they contain a number of added components. Such an added material may be another polymer in this case we have a polymer blend. Moreover, there is a large variety of additives and fillers, compounded into the polymer for various purposes, which are roughly categorized below ... 

Polymers blended with non-polymeric additives form subclass Bl. It can be distinguished into subgroup Bll, the plasticized or "soft" PVC and subgroup B12, the filled polymers, with fillers such as carbon black, silica, zinc oxide, etc. A filler usually is cheaper than the polymeric main component it can constitute as much as 40% by weight of the material. Other additives, such as pigments, accelerators, hardeners, stabilisers, flame-retardants, lubricating agents, etc. are used in much lower concentrations (functional composites). 

Polymer-based multicomponent systems are abundant in many applications. The properties and performance of particulate-filled systems, such as elastomers and impact modified polymers, and also polymer blends, block copolymers, and fiber reinforced systems, depend to a large extent on the distribution of the components. Hence the local analysis of these distributions down to sub-100 nm length scales (dictated, e.g., by the size of primary filler particles) is of considerable significance. Materials contrast in several AFM approaches offers the possibility to address these issues directly at the surface of specimens or on bulk samples that have been prepared correspondingly. 

It is concluded that surface modification of mica, produced by exposing the material to microwave plasmas, can create large positive or negative effects in the mechanical properties of filled polymers and polymer blends. Property enhancement is associated with the production of surface layers on the filler which... 

Investigations of polymer blends has developed an increased understanding of interphase organization. In blends two interfaces exists the interface between two matrix types and distribution of filler and its interfaces with this matrices. The interphase of carbon black in blends of natural rubber and EPDM depends on the character of carbon black (surface groups available for interaction), the viscosity,... 

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