Residual fibers

The agitation studies for PET depolymerization were performed in the Atlas Launder-ometer. The Launder-ometer is a device for rotating closed containers in a thermostatically controlled water bath. The procedure used in these experiments was adapted from an American Association of Textile Chemists and Colorists (AATCC) standard test method. The 5% sodium hydroxide solution (250 mL) was preheated to 80°C in a 1-pint stainless steel jar. The catalysts were added in the following amounts in separate experiments TOMAC (0.04 g, 0.0001 mol) TOMAB (0.045 g, 0.0001 mol) and HTMAB (0.045 g, 0.0001 mol). The PET fiber specimens (1.98 g, 0.01 mol) were placed in the containers along with ten -in. stainless steel balls to aid in the agitation process. The jars were sealed in the Launder-ometer, whose bath was at the desired temperature (80°C). The machine was allowed to run for the allowed treatment times (i.e., 30, 60, 90, 150, and 240 min) at 42 rpm. Upon decanting, any residual fibers... 

Diarrhea Drug related Antibiotic-induced bacterial overgrowth Hyperosmolar medications administered via feeding tubes Antacids containing magnesium Malabsorption Hypoalbuminemia/gut mucosal atrophy Pancreatic insufficiency Inadequate GIT surface area Rapid GIT transit Radiation enteritis Tube feeding related Rapid formula administration Formula hyperosmolalty Low residue (fiber) content Lactose intolerance Bacterial contamination... 

Constipation Dehydration Drug induced (anticholinergics) Inactivity Low residue (fiber) content Obstruction/fecal impaction... 

Fig. 3.14. Schematic drawings of slice compression test on a single fiber composite (a) before loading (b) peak loading with a maximum fiber protrusion length, (c) after unloading with a residual fiber protrusion length, After Hsueh (1993),...

Residual fiber from hydrolysate prepared for FBR5 fermentation. 

HI. The level of HI matter is one measure of the purity of lecithin products. HI matter usually consists of residual fiber, but also particulate contaminants that may be introduced during processing (e.g., filter aids). The level of HI matter in crude lecithin should never exceed 0.3% and rarely exceeds 0.1%. HI matter in lecithin is detrimental to clarity and use in specific applications. HI is measured by an official Food Chemicals Codex (FCC) (1996) method (54) or by AOCS Official Method Ja 3-87 (77). 

FIGURE 11.23 Successive decrease of aromatic methoxyl groups and organically bound chlorine in the residual fiber lignin when a softwood kraft pulp is bleached according to the sequence OD(EO)DD. 

Corn and wheat bran contain considerable amounts of hemlcellulose but not at the high levels found in psyllium. Furthermore, the water-holding capacity of these two fiber sources were not as high as those for psyllium. Hence, it would appear that fecal residual fiber is perhaps not a good index of functionality of... 

A potential problem with this type of composite system is the possibility of reaction or sintering between matrix partieles and the fibers at points of contact. Exposure tests of UCSB Nextel 610 composite at 1,200°C (2,192°F) for 100 hours shows reasonable mechanical property retention (Figure 6-11). Similar tests have yet to be performed on Nextel 720 eomposites. Therefore, the data on long-term exposure is insufficient to address the issue of matrix-fiber bonding (Levi et al., 1997). Beeause degradation is likely to be kinetically driven, residual fiber strength will be dictated by time at temperature. 

Chapters 2-10 discuss in detail the different properties of natural lignocellulosic fibers, their processing and fabrication of polymer composites. Chapter 11 summarizes the structure, chemistry and properties of different agro-residual fibers such as wheat straw corn stalk, cob and husks okra stem banana stem, leaf, bxmch reed stalk nettle pineapple leaf sugarcane oil palm bunch and coconut husk along with their processing. 

Exploiting natural fibers from new sources, however, presents the new question of whether these fibers mechanical, morphological, and thermal characteristics would let them act as effective reinforcement elements for utilization in composites [15]. This necessitates the close study of agro-residual fibers. 

This chapter has been written in order to investigate agro-residual fibers in terms of their performance as reinforcing elements for polymer composites. This study excludes agro-residual fibers which replace wood fibers as fillers or are suitable for pulping applications rather than reinforcing polymer composites due to their small dimensions. Nevertheless, several representative examples are given. The chapter is... 

Agro-Residual Fibers as Potential Reinforcement Elements 235... 

Figure 11.1 Examples of some agro-residual fibers, (a) okra fiber (From 1. M. De Rosa et al. Composites Science and Technology, 2011 [14]. With Permission from Elsevier) (b) banana fiber (From A. V. R. Prasad, K. M. Rao, G. Ragavinirasulu, Indian Journal of Fibre and Textile Research, 2009 [30]. With permission from Indian Journal of Fibre and Textile Research)-, (c) corn husk fiber [31].

Table 11.1 List of Academic Literature on Agro-Residual Fibers, Extraction Methods, Studied Characterics. 

Waxes which constitute the secondary components together with pectin consist of different types of alcohols [8] that are water soluble and dissolve in acids [63]. Different kinds of agro residual fibers include varying amoimts of these chemical consitutents. Table 11.2 gives the chemical composition of agro residual fibers and compared it with conventional plant fibers. 

It is essential to know the fiber characteristics in order to expand the use of agro-residual fibers in biocomposites and to improve their performance [3]. 

Table 11.2 Chemical Composition of Agro-Residual Fibers Compared to Some Selected Conventional Fibers.

Mechanical properties of some agro residual fibers are compared with important bast, leaf and seed fibers in Table 11.4. 

---