Synthetic polymers introduction

The preparation of synthetic polymers is hardly suitable for the ordinary organic laboratory. However, a few simple demonstration experiments are described below which, it is hoped, will provide an elementary introduction to the subject. 

Acrylic Resins. The first synthetic polymer denture material, used throughout much of the 20th century, was based on the discovery of vulcanised mbber in 1839. Other polymers explored for denture and other dental uses have included ceUuloid, phenolformaldehyde resins, and vinyl chloride copolymers. Polystyrene, polycarbonates, polyurethanes, and acryHc resins have also been used for dental polymers. Because of the unique combination of properties, eg, aesthetics and ease of fabrication, acryHc resins based on methyl methacrylate and its polymer and/or copolymers have received the most attention since their introduction in 1937. However, deficiencies include excessive polymerization shrinkage and poor abrasion resistance. Polymers used in dental appHcation should have minimal dimensional changes during and subsequent to polymerization exceUent chemical, physical, and color stabiHty processabiHty and biocompatibiHty and the abiHty to blend with contiguous tissues. 

Polymer (Sections 7.10, 21.9, Chapter 31 introduction) A large molecule made up of repeating smaller units. For example, polyethylene is a synthetic polymer made from repeating ethylene units, and DNA is a biopolymer made of repeating deoxyribonucleotide units. 

Whereas cellulose structure is now known in considerable detail [18,19], and the introduction of new solvent systems for dissolving cellulose has intensified the interest in studying point (ii), less is known about point (iii). Such knowledge, however, is a pre-requisite to control the properties of these polymers, hence increase their competitiveness as possible substitutes for synthetic polymers. 

I. M. Campbell, Introduction to Synthetic Polymers , Oxford University Press, 1994. 

Henry I. Bolker, Natural and Synthetic Polymers, An Introduction, p. 580, Marcel Dekker,New York, 1974 ISBN 0-8247-1060-6. 

Dry strength additives are usually water soluble, hydrophilic natural or synthetic polymers, the commercially most important of which are starch, natural vegetable gums and polyacrylamides. These polymers are often made in cationic form by the introduction of tertiary or quaternary amino groups into the polymer, and are therefore polyelectrolytes. They are thus also able to function to some extent as drainage and retention aids. 

THE USE OF SYNTHETIC POLYMERS to accumulate organic components from water for analytical and bioassay purposes is reviewed in this chapter. This review is given perspective by including a brief history of adsorption chromatography, the use of activated carbons in water research, and the recent introduction of bonded phases for aqueous sample preparations. 

In a rational approach to the reproduction of enzyme-like catalytic behavior with a synthetic polymer one should use, therefore, a two-step plan (1) fabrication of binding sites on a suitable macromolecular framework (2) introduction of groups to provide an environment of specific functional side chains that facilitate formation of the transition state in the catalytic step. 

Campbell, I. M. 2000. Introduction to synthetic polymers. 2nd ed. New York, NY Oxford University Press. 

Precipitation is a common technique used to isolate and purify polymers. For synthetic polymers, this often involves dissolving the polymer in an organic liquid that is a good solvent for the polymer and then adding this solution slowly to a large excess of a poor solvent (or nonsolvent), a liquid in which the polymer is insoluble. Introduction to the poor solvent causes the polymer chains to collapse, aggregate, and come out of solution. 

J.M.G. Cowie Polymers Chemistry and Physics of Modem Materials (Chapman and Hall, New York, 1991) I.M. Campbell Introduction to Synthetic Polymers (Oxford University Press, New York, 1997)... 

Introduction of a novel probe DNA method is required to develop selective and efficient DNA chips. Some reports have adopted an indirect immobilization method of probe ssDNA on the substrate using hydrophobic synthetic polymers [64,65]. 

The simplest examples of so-called functional or functionalized polymers are perhaps those with pendant functional groups. The introduction of pendant functional groups to synthetic polymers, in general, may be achieved by two methods (1) polymerization of monomers with pendant functional groups and (2) chemical transformation of the pendant groups in preformed polymers. Both of them involve advantages and disadvantages, and most of the currently available polymers of this type are pro-... 

The book is divided into eight chapters. The Introduction is a primer for both synthetic polymer chemistry in general, and cationic polymerizations in particular. More advanced readers may go directly to the following chapters. The second chapter covers the reactions of carbenium ions with various nucleophiles and focuses on the ionization of covalent species and the addition of carbenium ions to alkenes, arenes, and other ir-nucleo-... 

Synthetic polymer materials are so ubiquitous in modem life that we now take them for granted. But, the first commercially significant, completely synthetic plastic was only introduced at the beginning of the 20th century. This was Bakelite, invented by Leo Baekeland and a short account of his contributions will form the subject of one of our Polymer Milestones in the next chapter. The introduction of this new material was preceded by roughly 40 years of the development of what can be called semi-synthetics based on chemically modified forms of cellulose. 

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