Noncellulosic

The Mississippi cotton was much more difficult to wet out than either the California or Texas cottons. This is apparently related to the nature of noncelluloslc constituents on the fiber surfaces. The Mississippi cotton was a mature, low noncellulose content cotton, whereas, both the California and Texas cottons had high noncellulose contents. The ratio of wax content to total noncellulosics was much higher for the Mississippi cotton than for either the California or Texas cottons. The surface of the Mississippi cotton is thus more hydrophobic and resists wetting, Levels of extractables and dust levels are summarized in Table VIII. 

On the rayon washing system, a minimum water-to-fiber ratio for the batt weights used was about 55/1. The Mississippi cotton was much more difficult to wet out than either the California or Texas cottons. The Mississippi cotton, compared with the California and Texas cotton, was a low noncellulose cotton and had a more hydrophobic surface. Thus, the wettability and, consequently, the washing efficiency of cotton is related to and dependent upon the surface characteristics of the cotton. Configuration of the materials on the fiber surface are related to variety, area of growth, environmental conditions, method and time of harvest, storage conditions, and other factors. 

A plot of 6gp vs 3 for several cellulosic and noncellulosic polymers is shown in Figure 10(b) and, for the same polymers, a plot of 6gp vs <5h/ d sp shown in Figure 10(a). The results show that unique correlations exist between the parameters... 

Typically, water permeates 0.45 p M Tyrann-M/E membranes at least 50% more rapidly than it does conventional membranes and more than twice the rate at which it permeates the noncellulosic membranes of the same pore size. Air and water flow rates and relative filtration capacities (throughputs) for various 0.1,0.2, 0.45 and 0.8 /xM membranes at 10 psid (corr.) are found in Table 1. 

Tyrann-M/E represents a new highly anisotropic class of microfiltration membrane with permeability and dirt holding characteristics which are superior to those of both noncellulosic and conventional mixed ester membranes and with flexibility and thermal stability which are significantly greater than those of conventional membranes. 

FT-30 Membrane. FT-30 is a new thin-film-composite membrane discovered and developed by FilmTec. Initial data on FT-30 membranes were presented elsewhere (23). It was recently introduced in the form of spiral-wound elements 12 inches long and 2 to 4 inches in diameter (24). The barrier layer of FT-30 is of proprietary composition and cannot be revealed at this time pending resolution of patentability matters. The membrane shares some of the properties of the previously described "NS series of membranes, exhibiting high flux, excellent salt rejection, and nonbiodegradability. However, the response of the FT-30 membrane differs significantly from other noncellulosic thin-film-composite membranes in regard to various feedwater conditions such as pH, temperature, and the effect of chlorine. 

Various noncellulosic thln-film-composlte membranes were examined by scanning electron microscopy (SEM). Figure 3 illustrates the type of surface structure and cross-sections that exist in these membranes. Figure 3a shows the surface microporosity of polysulfone support films. Micropores in the film were measured by both SEM and TEM typically pore radii averaged 330 A. Figure 3b is a photomicrograph of a cross-section of a NS-lOO membrane. 

It is important to understand the different types of fibers. Classes are best differentiated based on both the origin of the fiber and its structure. The structure and chemistiy of many of these polymers was discussed earlier in Chapter 14. Table 17.1 contains a list of the three important types of fibers— natural, cellulosic, and noncellulosic— as well as a list of specific polymers as examples of each type. The ones marked with an asterisk are the most important. 

Referring back to Fig. 16.1, we see that the value of U.S. shipments for cellulosic and noncellulosic fibers, though quite small compared to plastics, is still a big industry. While Plastics Materials and Resins (NAICS 325211) in 1998 was 44.9 billion, Noncellulosic Fibers (NAICS 325222) was 10.5 billion and Cellulosic Fibers (NAICS 325221) was 1.5 billion. These two fibers together have a 12.0 billion value, which is 3% of Chemical Manufacturing. We must also remember that many of these fibers are sold outside the chemical industry, such as in Textile Mill Products, Apparel, and Furniture, all large segments of the economy. The importance of fibers is obvious. In 1920 U.S. per capita use was 30 Ib/yr, whereas in 1990 it was 66 Ib/yr. From 1920 to 1970 the most important fiber by far was cotton. 

However, synthetic fibers (cellulosic and noncellulosic) increased much more rapidly in importance, with cellulosics booming between World Wars I and II and noncellulosics dominating after World War II, while all that time cotton showed only a steady pace in comparison. The more recent competition between the various fibers in the United States is given in Fig. 17.1. Nylon was originally the most important synthetic (1950-1971) but polyester now leads the market (1971-present). For a few years (1970-1980) acrylics were third in production, but since 1980 polyolefins have been rapidly increasing. Polyolefins are now second only to polyester in synthetic fiber production. Cotton, being an agricultural crop, certainly demonstrates its variable production with factors such as weather and the economy. It is an up-and-down industry much more so than the synthetics. 

TABLE 9.2 Noncellulosic Textile Fibers Patent Names... 

Lignin is the second most widely produced organic material, after the saccharides. It is found in essentially all living plants and is the major noncellulosic constituent of wood. It is produced at an annual rate of about 2 x 10 ° t with the biosphere containing a total of about 3 x 10" t. It contains a variety of structural units including those pictured in Figure 9.6. 

Lignin is a noncellulosic resinous component of wood. It is the second most abundant renewable natural resource. It has alcohol and ether units with many aromatic units. Much of lignin is sheetlike in structure. 

Five noncellulosic, primary cell-wall polysaccharides from dicots have... 

These polymers are distinguished from cellulose by the presence of both/ -(l— 3)- and / -(l— 4)-linked D-glucosyl residues, lower molecular weights (some noncellulosic glucans are water-soluble), and susceptibility to hydrolysis by / -D-glucanases that cannot hydrolyze cellulose. Unlike cellulose, whose microfibrillar structure and structural role in the cell wall has been clearly established, the function of these polymers as structural components of the wall is still a subject of controversy there is some evidence that they are energy-reserve materials.110-201 202... 

Basic Protocol 1 Determination of Noncellulosic Neutral Sugars by... 

Basic Protocol 2 Determination of Noncellulosic Neutral Sugars and Cellulose Content by Trifluoroacetic Acid Hydrolysis Followed by Sulfuric Acid Hydrolysis E3.2.4... 

Several procedures have been used to hydrolyze polysaccharides in cell walls and cell wall fractions. For example, the noncellulosic polysaccharides can be hydrolyzed using 1 M sulfuric acid for 2 to 3 hr at 100°C (Selvendran and Ryden, 1990). One of the simplest procedures is that of Albersheim et al. (1967) in which hydrolysis of the noncellulosic polysaccharides is achieved by incubating in 2 M trifluoroacetic acid (TFA) at 121 °C for 1 hr. The advantage of the TFA procedure is that it is quick and the acid can be removed by evaporation in a gentle stream of air or nitrogen. However, neither the 1 M sulfuric acid or TFA procedures hydrolyze cellulose. Hydrolysis of cellulose can be achieved by an initial dispersion in 72% (w/w) sulfuric acid (Saeman et al., 1963 Selvendran et al., 1979 Fry, 1988 Harris et al., 1988 Selvendran and Ryden, 1990) followed by hydrolysis in 1 M sulfuric acid. 

This unit provides two protocols (see Basic Protocols 1 and 2) and an alternative procedure (see Alternate Protocol) for estimating neutral sugars. Differences among these protocols are in the method of hydrolysis. The choice of method will depend on the type of information required. Basic Protocol 1 is used when only the amounts of noncellulosic neutral sugars are required. When both the noncellulosic neutral sugars and the cellulose content are required, then Basic Protocol 2 or Alternate Protocol 1 are used. 

DETERMINATION OF NONCELLULOSIC NEUTRAL SUGARS BY TRIFLUOROACETIC ACID (TFA) HYDROLYSIS... 

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