Glucose, from wood sugars

Mention has already been made of two polymers that can be obtained naturally from living animals silk (from the silkworm) and wool (from sheep). They are proteins made of various amino acids both are used in textiles. Other biologically derived polymers are also familiar such as wood, starch, and some sugars. We will not cover these in detail here. However, certain cellulosics we will discuss briefly since they are compared to synthetic fibers later. Cellulose is the primary substance of which the walls of vegetable cells are constructed and is largely composed of glucose residues. It may be obtained from wood or derived in very high purity from cotton fibers, which are about 92% pure cellulose. 

Glucose is also used as the reducing agent in the preparation of organic compounds. Wood sugars have reducing properties that are equivalent to those of products for like purposes from any source. 

The saccharification-fermentation (SF) method for the derivation of fuels and chemicals from wood is based on the breakdown or hydrolysis of the polysaccharides in wood to the constituent monomeric sugars. The six carbon or hexose sugars (glucose, galactose, and mannose) then are fermentable to ethyl alcohol... 

Hydrolyzes wood pulp or paper to make glucose or fermentable sugars. Bagasse from spent sugar cane has significant potential. Several processes potentially can solve or alleviate waste problems. 

The quantitative data obtained by Isbell and Frush on hydrolysis by dilute hydrochloric acid of methyl glycosides are of interest in this connection. From these studies, it may be deduced that the rates of hydrolysis of the methyl /3-D-pyranosides of the wood sugars are in the following order D-xylose = D-galactose > n-mannose > D-glucose. The extreme acid-... 

Carbohydrates also play a structural role in living things. You have learned that cellulose, also a glucose polymer, provides the strength and support needed in plants. Chitin, a natural polymer made from a sugar similar to glucose, forms the hard exteriors of insects and other arthropods, as shown in Figure 19.7. Carbohydrates are also found in cotton and rayon fabrics, wood, and paper. 

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