Polymers from Popular Carbohydrates

The most popular carbohydrate obtained from plants is sucrose. Glucose, maltose, and cellobiose are also popular because they are obtained from starch and cellulose by hydrolysis. Despite its abundant production by plants, it is difficult to use them as monomers for synthetic polymers. These carbohydrates have three or four hydroxyl groups per one glucose unit, and they are very hydrophilic. Therefore they are insoluble in most major organic solvents. 

Preparation of cross-linked sucrose-based polymers by photopolymerization was achieved by Acosta Ortiz et using thiol-ene reaction. They synthesized sucrose allyl ether, mainly diallyl sucrose, and polymerized the sucrose-based monomers with dithiothreitol by UV irradiation in the absence or presence of a photoinitiator. 

Condensation polymers containing sucrose or glucose units in the main chain were also reported. Cross-linked polyurethanes prepared from polyethylene glycol (PEG), diphenylmethane diisocyanate (MDl) and a sugar (glucose, fructose, or sucrose), were reported by Zetterlund et The storage modulus, the Tg, and the stress at break increased with an increase of sucrose content and the strain at break decreased with an increase of sucrose content. 

Synthetic Green Polymers from Renewable Monomers 53 

Donnely synthesized mono- or bisglucoside-modified polytetrahydrofuran (PTHF) polyols and cured them with MDI. When the glucoside-modified PTHF was cured with MDI in the presence of ethylene glycol as a chain extender, the cured polyurethanes exhibited good mechanical properties comparable to commercial reaction injection molding polyurethanes. Kurita and 

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Hydrophilic size separation columns for use with aqueous samples are very popular choices for purifying proteins and carbohydrates. Protein separation columns are available on both silica and polymeric supports. It is surprising that the best of these protein purification columns in terms of resolution and in recovery of native protein are silica-based columns. One would expect that protein release from silica would be a real problem. It certainly is in many other silica columns. These columns, however, especially the TSK family of columns, give excellent recovery of enzymatic activity. I have talked to other column manufacturers who have investigated the problem. They say that when you remove the bonded phases from these columns they appear to be identical to bonded phases from a number of other, less successful, columns designed for protein purification. All of these bonded phases are primarily diol ether polymers, very hydrophilic, but of intermediate polarity. Some modification of... 

Sephadex is one of the most popular materials for gel chromatography. It is widely used by biochemists for separating proteins, nucleic acids, enzymes, and carbohydrates. Most often, water or aqueous solutions of buffers are used as the moving phase. Chemically, Sephadex is a polymeric carbohydrate that has been cross-linked. The degree of cross-linking determines the size of the "holes" in the polymer matrix. In addition, the hydroxyl groups on the polymer can adsorb water, which causes the material to swell. As it expands, "holes" are created in the matrix. Several different gels are available from manufacturers, each with its own set of characteristics. 

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