Fibres production additives

Salicylic acid is manufactured on a large scale. In the dye industry it serves for the production of valuable azo-dyes which exhibit great fastness. To some extent these dyes are applied to mordanted fibres. In addition, the acid and its derivatives are widely used in pharmacy. Being a phenolcarboxylic acid it has a powerful disinfecting action (preservative). It has further proved itself an important antirheumatic and an analgetic. The derivative in which the phenolic hydroxyl group is acetylated (aspirin) has become especially popular. The first medicament of the series was the phenyl ester of salicylic acid, salol, which is produced as a by-product in the technical process. The preparation of salicylaldehyde has been described above (p. 235). 

Rowell and Rowell (1989) acetylated Scandinavian spruce Picea abies) wood chips, then subsequently reduced these to fibres in a laboratory disc refiner, fibre production did not result in loss of acetyl content, but it was found that new water sorption sites were produced as a consequence of the refining process. In addition, these workers modified a variety of lignocellulosic materials and found that all of the materials studied exhibited the same reduction in EMC at comparable WPGs. 

This subject is discussed in Chapter 15, but a brief summary is given here, as an introduction to fat metabolism. The three major components of a human diet are meat, fish and plants, and the fats associated with each component can be different. Meat usually comprises the muscle of mammals and birds but it is always associated with fat. Even apparently lean meat may have a high fat content a 250 g beef steak may contain 60 g fat in addition to its 80 g protein. Some of this will be adipose tissue between muscles the remainder is triacylglycerol (TAG) within the fibre. In addition, milk and other dairy products contain significant amounts of fat about a quarter of the fat in the average UK diet comes from dairy produce. 

By-products of starch refining and HFCS prodnction are significant and rednce HFCS production costs by 30 5% (Table 4.2). This is because the com is 70% starch on a dry weight basis, it also contains 10% protein, 4.5% fat and 2.7% erode fibre. In addition much of the glucose syrup produced is fermented to produce ethanol for fuel use. 

Polymeric microfibre mat. Until recently, the production of absorptive separators from 100% polymeric fibres was limited by the fact that fibre diameters of less than 1 pm could not be produced at reasonable cost. Further developments in polymers, as well as refinements in fibre production, have resulted in the manufacture of mats with a high percentage of fine fibres with a diameter below 1 pm [41]. As these organic fibres (usually polypropylene) are hydrophobic by nature, wettability has to be imparted by additional treatments such as grafting with hydrophilic agents or by co-extrusion with hydrophilic polymers [1]. 

For many applications, fibres are more suitable than bulk materials. In addition, fibre production techniques tend to be suited to the alignment of nanotubes with in the fibre. A number of studies have focused on the production of composite fibres by melt processing. Fibre processing is generally similar to melt processing, but usually involves a process such as extrusion to produce an elongated sample which can then be drawn into a... 

Pulp represents the major raw material basis for the two main applications a) about 95% for paper and board production, where the pulp fibres are additionally modified to give a coherent paper sheet and b) about 5% for chemical... 

Comparison of the absorption spectra of these products with those of benzophenones and benzotriazoles shows a marked difference [85]. The diphenylcyanoacrylates have a maximum absorption at 303 nm, whereas benzophenones have two peaks, at 280 nm and 340 nm, and benzotriazoles at 300 nm and 350 nm. The last two types also exhibit an absorption tail up to 400 nm, giving a yellowish tinge in some substrates. The diphenylcyanoacrylates are also said to be insensitive to metal ions, and to be equally effective under different pH conditions. Uvinul 3030, with its tetrameric functionality and low volatility is likely to be useful in thin polyester structures, such as films and fibres. This additive has also gained FDA approval for food contact use [86]. 

After separating the natural component from the blend, the remaining polyester may be garnered to obtain staple fibre products, for the manufacture of nonwoven products, or may be recycled in the melt spinning method. Formation of filament or films occurs without problems when the product of degradation is used as an addition to the standard polyester material. ... 

Samples from many industrial sources are often contaminated at the surface by processing agents or adventitious post-process contaminants. Detection of specific contaminant molecules on surfaces by SSIMS is, of course, an exercise similar to detection of additive molecules migrating to polymer surfaces. However, in case of contaminants the problem is often localised and the microanalytical/imaging capability of SSIMS is called upon. As the primary ion beam can be focused to a very small spot size (a few /xm) even very small defects can be analysed allowing locally resolved chemical surface identification by microanalytical SSIMS. Additive mapping has been used for the identification of contaminations [823]. Lloyd et al. [794] have described identification of a hexamethylene tetra-methyldiamine deposit on interior automotive parts. Another typical example concerns the behaviour of a non-woven PP fibre product with surface contamination by dimethylsilicone (DMS). The distribution of DMS over the 30 /xm PP fibres was mapped [824]. The sensitivity of SSIMS to molecular additives and surface contamination has been illustrated by Weng et al. [825] who identified PDMS (m/z 28, 73, 147, 207, 221, etc.) and palmitic/stearic acids (m/z 239, 257, 267, 285) in polybutadiene copolymers (Fig. 5.25) by means of ToF-SIMS. SSIMS is... 

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