Polymer matrix composites, filled

Performance Analysis of Polymer Matrix Composites Filled with Inorganic Whiskers... 

A more common and widely used process involves the preparation of short-fiber polymer composite materials and particulate composite polymeric materials, where the fibers or particles act as reinforcement of the polymer. In this particular case, when a polymer matrix is filled with fibers or particles, which in general possess higher mechanical properties than the polymer matrix, the resultant composite material presents properties that are between those of the soft polymer matrix and the rigid filler. 

W.A. Hanna, RE. Gharib, I.I. Marhoon, Characterization of ceramic filled polymer matrix composite used for biomedical applications, J. Miner. Mater. Character. Eng. 10 (2011) 1167-1178. 

Polymer-matrix composites have been used as one of the most common packaging materials for encapsulating a variety of electronic components for dissipating heat [14]. In this section, 3D AlN nanowhiskers with brush-hke structure were filled into the polymer matrix to enhance its thermal conductivity. The 3D brush-hke AlN fiUers were fabricated by CS process [7a], as iUustrated in Section 3.2. The use of AlN as a filler candidate to enhance the thermal conductivity of the polymer is attributed to its attractive properties such as high thermal conductivity, high electrical resistivity, and good chemical stabihty with polymers [1]. To explore the promoting effect of the 3D brush-hke AIN fillers on thermal conductivity, three types of AIN fillers with different brush-hke filler aspect ratio were added into polymer matrix to fabricate a series of composites and their thermal conductivities were measured. The results demonstrated that the 3D brush-hke AIN nanowhiskers fillers can effectively enhance the thermal conductivity of the polymer composite. 

The thermal characteristics of NR-metal composites are close to the properties of metals, whereas the mechanical properties and the processing methods are typical of polymers.Thermally conducting, but electrically insulating, polymer-matrix composites are increasingly important for electronic packaging because the heat dissipation ability limits the reliability, performance and miniaturization of electronics.Thermal properties such as thermal conductivity, thermal dilfusivity and specific heat of metal (copper, zinc, Fe and bronze) powder-filled polymer composites are investigated experimentally in the range of filler content 0-24% by volume. ... 

A composite material is a multiphase system composed of matrix material and dispersed material. The matrix material is usually a continuous phase, which consolidates the dispersion material such as fiber or particles. The composite material is commonly categorized into the class of materials that the matrix material belongs to metal matrix composites, inorganic nonmetal matrix composites, and polymer-based composites. For example, the metal matrix composite material is a material included in the scope of metallic materials, while the polymer matrix composite material is included in the scope of the polymer material. The inorganic whiskers filled and modified... 

The new materials combined by two or more kinds of polymers in some way are customarily called polymer blends, or polymeric alloys, and have structures and properties different from those of the original component. The composite materials composed of polymer and inorganic materials are called polymer matrix composites. Inorganic materials, especially inorganic fillers such as calcium carbonate, talcum powder, and mica powder, which use inorganic minerals as raw materials, are widely used because of their low cost and convenient filling. 

We briefly discuss the following mechanical properties of a polymer matrix composite material filled with whiskers. 

According to the general principle of filling modified polymer matrix composites, the packing material must reach a certain... 

Guo et al. 5 ook resin matrix composites filled with SIC whiskers as an example and analyzed the effect of the inter-facial zone state on mechanical properties of composite materials by finite element method. They hold that when whiskers are randomly distributed in a resin matrix with a certain volume fraction, they demonstrate a periodic distribution from the statistical point of view. It is assumed that the SIC whisker-reinforced phase in resin matrix composites is arranged in one direction without considering the effect of whisker orientation, the analysis model can be simplified as a rotator shape with the large cylindrical part as the polymer matrix and the small cylindrical part as the whisker. Therefore, a three-dimensional problem turns into an axisymmetric problem, and only a quarter part of the body model is taken in the calculation. 

Coupling agents can provide benefits as processing aids for polymer matrix composites. Dramatic reductions in viscosity can occur in some highly filled liquid polymers when a relatively small quantity of an appropriate coupling agent is added to the formulation. 

Fig. 6. Variation of elasticity modulus (E) under tension and yield strain (es) of the polymer matrix (I, I ) and polyethylene-based composites polymerization filled with kaolin (2,20 in function of polymer MM [320], Kaolin content 30% by mass. The specimens were pressed 0.3-0.4mm thick blates stretching rate e = 0.67 min-1...

The most important thing is to get the microspheres evenly distributed in the polymer matrix. It is therfore recommended to vibrate fluid compositions in the mold, especially in the case of large articles 2). Since molding compositions do not easily fill the molds, tamping and low pressures (0.5-2 MPa) are used for small, simple objects, while the molds for large or complicated objects are filled layer by layer1). The molds are made from plastic, reinforced with metal, wood or fibre their surfaces are degreased or covered with a separation layer. 

In an attempt to provide compatibility between the FR and polymer matrix, Wang et al. reported recently on a novel microencapsulated intumescent system containing 4A zeolite as a potential flame retardant for natural rubber (NR).61 The flame-retardant properties of NR composites loaded with different amounts of intumescent flame retardant (IFR), IFR-4A zeolite, and microencapsulated intumescent flame retardant (MIFR)-4A zeolite agents were studied and compared. The LOI data demonstrate that the NR composite filled with 50phr of MIFR-4A zeolite agent and 50phr of IFR-4A zeolite shows better FR properties as compared to NR and 50phr of IFR-filled systems. 

BPA/DC-based composition served as a polymer matrix in carbon fiber composites [24]. Metal powder or fiber filled molding compounds were also described. The molding compounds, which can contain, moreover, numerous other components, bismaleimides (cf. Sect. 5) in particular, are used for the manufacturing of heat conductive molds for injection molding [25],... 

An explanation of the observed relaxation transition of the permittivity in carbon black filled composites above the percolation threshold is again provided by percolation theory. Two different polarization mechanisms can be considered (i) polarization of the filler clusters that are assumed to be located in a non polar medium, and (ii) polarization of the polymer matrix between conducting filler clusters. Both concepts predict a critical behavior of the characteristic frequency R similar to Eq. (18). In case (i) it holds that R= , since both transitions are related to the diffusion behavior of the charge carriers on fractal clusters and are controlled by the correlation length of the clusters. Hence, R corresponds to the anomalous diffusion transition, i.e., the cross-over frequency of the conductivity as observed in Fig. 30a. In case (ii), also referred to as random resistor-capacitor model, the polarization transition is affected by the polarization behavior of the polymer matrix and it holds that [128, 136,137]... 

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