Cellulose fiber filled

For convenience, multicomponent polymeric materials based on cellu-losics may be grouped into three classes, namely (a) combinations of wood with plastics (WPC), (b) mechanical mixtures in the form of fibers, such as cotton/polyester staple-mixed fibers and cellulosic fiber-filled polymer sheets, and (c) incorporations of cellulosics at a hyperfine structural level. The latter can be further ramified, for instance as follows ... 

Microcellular foams can be produced by noncontinuous processes such as a batch process [2, 12, 15, 16, 31, 32, 34, 35], continuous processes such as extrusion and injection molding [24,33,36,37], orby asemicontinuousprocess [38]. Since the semicontinuous process is not extensively used in the scientific community or in the industry, it will not be described in this chapter. Readers are encouraged to refer Ref. 38 for detailed information on this process. To date, microcellular foams have been produced in amorphous polymers [12, 31, 32, 34], semicrystalline polymers [35], and in elastomers [16]. Recently, MCF structures have also been produced in plastics filled with inorganic nanoparticles (montmorillonite) [39-43], as well as organic cellulosic fiber filled plastic composites [12, 31, 32, 34]. 

Fahmy, T. Y. A. and Mobaiak, F. (2008). Nanocomposites fiom natural cellulose fibers filled with kaolin in presence of sucrose. Carbohydrate Polymers 72,751755. 

Maleic anhydride or maleic anhydride-grafted polypropylene are used for improving mechanical properties of cellulose fiber-filled compounds [39 to 42]. 

In 1989 quantity costs, which reflect the lowest cost, of urea molding compounds, were approximately 1.41 /kg ( 0.035/in. for black and brown colors, 1.58/kg ( 0.039/in.for white and ivory special colors are somewhat higher in price. The approximate cost of cellulose-filled melamine molding compound is 1.74/kg ( 0.043/in. ). Glass fiber-filled melamine sells for 7.70/kg ( 0.22/in. ). 

Fiber(s), 77 163-188. See also Acrylic fibers Carbon fibers Filled fibers High performance fibers New fibers Olefin fibers Optical fiber(s) Polyamide fibers Regenerated cellulose fibers Vegetable fibers antimicrobial acrylic, 77 215-219... 

The First plastic sabots were made of glass-fiber filled diallylphthalate sheathed in nylon and they included metal reinforcements whenever it was felt necessary to redistribute the stresses. The nylon sheath was necessitated by the abrasive nature of glass-filled materials. Nylon also is used for rotating bands on projectiles and on metal sabots. Other plastics used for the structural portions of sabots include poly propylenes, polycarbonates, celluloses, epoxies and phenolics. Polyethylene, neoprene, and silicone rubbers are used for seals and obturators... 

Fig. 11. SE micrographs of nanoscale, silicate networks, which faithfully reproduce the original structure of their organic substrates following immersion in 7— 1S% silicone resin solution, a Cellulose from fiber-fill after calcination at 450 °C. b, c Cotton nafddn after ashing, b by calcination at 450 °C, and c after cold ashing.

Materials. Scoured cotton cellulose fibers of the Acala variety supllied by Kanebo Co Ltd. were piirified by extracting with hot benzene-ethanol mixture (l l vol. ratio) for 2kh. Then the cotton fibers were washed with methanol and distilled water and air-dried. Acrylamide (AM) was purified by recrystallization from benzene for several times. Bis-(beta-chloroethyl) vinylphosphonate (Fy) was purified by passing the monomer through a column filled up with activated alumina to remove inhibitors of polymerization. Other chemicals used were reagent grade, and were used without further purification. 

Wood-plastic composite (WPC) deck boards are extruded or molded products of a specified shape and, by definition, represent plastic filled with cellulose fiber and other ingredients. In this context wood is a proxy for fibrous materials of plant origin. These materials will be considered in the next chapter. This chapter deals with a plastic component of composite deck boards, with an understanding that the plastic is thermoplastic. 

Earlier attempts—in the 1970s—to make cellulose-filled thermoplastic compositions had identified a serious obstacle. It became recognized that fillers, particularly cellulose fibers, do not disperse easily throughout the plastic formulations during compounding and molding. Accordingly, the finished products typically do not exhibit the desirable physical characteristics ordinarily associated with fiber-reinforced plastic composites. This problem has been dealt with in a number of patents. 

U.S. Pat. No. 6,337,138 [101] (by Crane Plastics Company, TimberTech) discloses a cellulosic, inorganic-filled plastic composite, comprising 25-40% of polyethylene, 30-70% of cellulosic material, such as wood fiber, seed husks, rice hulls, newspaper, kenaf, coconut shells, and 1-20% (by weight) of talc. 

Cellulose fiber is a good reinforcing tiller. In fact, this is one of the two major factors of the very existence of WPC materials (a) to make the composite material less expensive and (b) to obtain material with overall better properties compared to neat plastic, on the one hand, and wood, on the other. For example, tensile modulus of a particular sample of neat polypropylene was 203,000 psi, whereas for the same polypropylene filled with 40% of jute it was 1,030,000 psi. For a comparison, for the same polypropylene filled with 40% glass fiber it was 1,100,000 psi. Tensile modulus for natural fiber itself is in the range of 3,800,000-17,400,000 psi [135]. Table 3.4 shows data in more detail. 

Reinforcing effect of cellulose fiber on Nylon is shown in Table 3.7 Often (but not always), the higher the aspect ratio of wood fiber, the higher the flexural strength and flexural modulus of filled WPC (Table 3.8). 

One can see that a transition from rice hulls filled boards (abont 11% of a natnral mineral filler presented in rice hulls) to Biodac /rice hulls hlled boards (about 21% of combined mineral fillers) leads to 19 + 4% increase in flexnral strength and 43 + 17% increase in flexural modulus on average. This increase may be attributed not only to increase of minerals but also to morphology of Biodac porous granules and different in kind cellulose fibers in Biodac (delignihed and differently packed into the filler). 

TABLE 4.2 Effect of specific gravity of fillers on density of the filled plastic. Cellulose fibers (wood Hour, rice hulls) typically have specific gravity of 1.3 g/cm calcium carbonate and talc typically have specific density of 2.8 g/cm. ... 

One can see that the presence of 20-40% of mineral fillers significantly increases density of filled HDPE and polypropylene compared with the plastics filled with cellulose fiber. 

It was logical to suggest that maleated polymers introduced into a polymer matrix filled with cellulose fiber form—at hot melt temperature—covalent ester links between the anhydride groups of the coupling agents and hydroxyl groups on the surface of wood fiber, as they do in model chemical systems. However, studies into the matter have presented no conclusive evidence of such covalent bonds in WPC, except maybe in some isolated cases. 

TABLE 10.8 The linear coefficient of thermal expansion-contraction for extruded WPCs, filled with rice hulls (20-80 mesh size) or 40 mesh sawdust, determined in accordance with ASTM D 6341. Biodac (granular porous filler having 50% cellulose fiber and 50% mineral, see Chapter 4) was 28% in all the cases. MFI for the HDPE was 0.3. Data by Dr. Tatyana Samoylova, LDI Composites... 

TABLE 10.9 The linear coefficient of thermal expansion-contraction for LDPE and HDPE filled with cellulose fiber (wastepaper). The published article [2] indicated only the absolute expansion values (in mm) per 1°C, without providing the size (length) of the samples. It was assumed that all the samples were of 60 mm in length, and the data were recalculated to CTE (1/°F)... 

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