Organic Filler Reinforcement

Organic fillers have the added advantage of being biodegradable. Among the natural organic fillers that have been used with a PLA matrix, the most important ones are wood flour [43, 44], starch, rice hulls [45], sugar beet pulp (SBP) [46, 47], oilseed crops [48], and so on. 

FIGURE 18.2 Scanning electron micrograph fracture surface of PLA-wood flour composite. The arrows indicate fiber pullout [61]. 

4 Cellulose Whisker Microcrystalline cellulose (MCC) has been used as a whisker reinforcement with PLA as a matrix [61, 62]. MCC (particle size 10-15/ m) is crystalline cellulose derived from high-quality wood pulp (WP), and disintegrates into cellulose whiskers by acid 

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The materials being reviewed in this book, as in the industry, are identified by different terms such as polymer, plastic, resin, elastomer, reinforced plastic (RP), and composite unreinforced or reinforced plastic. They are somewhat synonymous. Polymers, the basic ingredients in plastics, can be defined as high molecular weight organic chemical compounds, synthetic or natural substances consisting of molecules. Practically all of these polymers are compounded with other products (additives, fillers, reinforcements, etc.) to provide many different properties and/or processing capabilities. Thus plastics is the correct technical term to use except in very few applications where only the polymer is used to fabricate products. 

U.S. Pat. No. 7,022,751 [111] describes a fiber-reinforced composite plastic material comprising thermoplastic polymers such as HDPE, LDPE, polypropylene, PVC, and polystyrene a high melting point waste polymer fiber material such as polyethylene terephthalate and nylon, an inorganic filler, such as glass and other material, and an organic filler such as wood or particles of a thermoset plastic, such as rubber and polyurethane foam. 

The filler then contributes to reinforcement, thixotropy, and bulk. Since most of the fillers are mineral-like inorganic materials, they generally don t add or detract from the intrinsic silicone properties for which the sealants are most often sold, such as good electrical insulating properties, weather resistance, heat stability and low temperature serviceability. Organic fillers (polymers, resins, rubbers) have been added to some silicones and indeed enhance certain properties or reduce cost but always at the expense of another property. The property most often sacrificed is thermal stability. 

Physical and thermal properties UF is a thermoset. It is brittle and stiff, so requires filler or reinforcement. Organic fillers are required for UF because it is more sensitive to the high temperatures required for inorganic fillers than MF. High tensile strength. Low water absorption. 

Reinforcing agents mineral or organic filler particles, glass microspherea mica flake , whiskers composites... 

Crystallites may also be considered to act as reinforcing fillers. For example, the rubbery modulus of poly(vinyl chloride) was shown by lobst and Manson (1970,1972,1974) to be increased by an increase in crystallinity calculated moduli in the rubbery state agreed well with values predicted by equation (12.9). Halpin and Kardos (1972) have recently applied Tsai-Halpin composite theory to crystalline polymers with considerable success, and Kardos et al (1972) have used in situ crystallization of an organic filler to prepare and characterize a model composite system. More recently, the concept of so-called molecular composites —based on highly crystalline polymeric fibers arranged in a matrix of the same polymer—has stimulated a high level of experimental and theoretical interest (Halpin, 1975 Linden-meyer, 1975). 

Inorganic or organic filler Silica, carbon black Reinforces the mechanical strength... 

The infrared spectrophotometer can provide information concerning the composition of a compound as well as its degradation products, fillers, reinforcing agents, etc. It can also be used to evaluate the purity of organic components that are used in a plastic s manufacturing or processing. 

Lee K (2007) Organic aerogels reinforced with inorganic fillers. US Patent 2007/0259979. 

Common to the preparation of natural fibre-reinforced thermoplastics made by melt processing, is the need to maximise fibre-matrix interfacial bonding, minimise the moisture content and heat history of the organic filler and reduce odour arising from exposure to processing temperatures of around 200 °C. 

This section of the book also presents aspects of the flow behavior of some polymer mixture solutions containing a lyotropic phase as a function of system composition, shear intensity, and tanperature. The correlation between phase separation and the changes in iheological properties induced by the anisotropic component of the systan is discussed. Also, viscoelastic solution properties are reviewed in electrooptics with regard to their practical uses. Finally, we discuss polymer composite materials, where mineral and organic fillers are used as reinforcing materials. 

The barrier properties of 70/30 acrylonitrile-butadiene mbber/ethylene propylene diene monomer rubber (NBR/EPDM) vulcanizates, when loaded with carbon black fillers [e.g., I SAP (intermediate super-abrasion furnace), HAF (high-abrasion furnace) and SRF (semi-reinforcing furnace)] and using benzene, toluene and xylene as penetrants, have been examined with reference to the type of filler employed [66]. The filled samples were found to exhibit a better resistance to uptake of the three organic solvents when compared to the respective unfilled blends for any given blend ratio. With regards to the three types of carbon black used, solvent uptake was in the order SRF-> HAF-> ISAF-filled samples. The reason for this order was attributed to the better filler reinforcements and enhanced crosslink densities of the matrix as the size of the carbon black particles used was decreased. A similar behavior was also identified for NR/EVA composites [52]. 

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