Building blocks for polymerizations

Monosaccharide a simple sugar a building block for polymeric, complex carbohydrates. 

Conditions of hydrogenolysis can be directed to formation of ethylene glycol, propanediol-1,2, bu-tanediol-1,2 or other diols and tetrols, which, after transformation into epoxides, serve as building blocks for polymerization reactions ... 

Because of its physical properties, polypyrrole has been cited as a unique building block for intelligent polymeric materials, ie, it has characteristics which make it capable of sensing, information processing, and response actuation (48). 

A number of BMI resias based on this chemistry became commercially available through Rhc ne Poulenc for appHcation ia priated circuit boards and mol ding compounds and Rhc ne Poulenc recognized the potential of bismaleimides as building blocks for temperature-resistant thermoset systems. The basic chemistry, however, was not new, because the Michael addition reaction had been employed by Du Pont to obtain elastomeric reaction products from bismaleimides and Hquid polymeric organic diamines (15). 

The small molecules used as the basic building blocks for these large molecules are known as monomers. For example the commercially important material poly(vinyl chloride) is made from the monomer vinyl chloride. The repeat unit in the polymer usually corresponds to the monomer from which the polymer was made. There are exceptions to this, though. Poly(vinyl alcohol) is formally considered to be made up of vinyl alcohol (CH2CHOH) repeat units but there is, in fact, no such monomer as vinyl alcohol. The appropriate molecular unit exists in the alternative tautomeric form, ethanal CH3CHO. To make this polymer, it is necessary first to prepare poly(vinyl ethanoate) from the monomer vinyl ethanoate, and then to hydrolyse the product to yield the polymeric alcohol. 

The optical and electrochemical properties of porphyrins make these chromophores useful building blocks for the synthesis of electro- and photoactive polymers. Two types of linear polymers have been constructed using the self-assembly approach homo-polymeric assemblies and hetero- or shish kebab polymers. 

Application to heterogeneous polymer solids, and elastic composites, is presented in the Section 7 (Gusev, Suter), which is followed by a summary and the outlook for the various methods reviewed here. It will be apparent to the reader that this review thus assembles several building blocks for the difficult task to bridge the gaps from the atomistic to the macroscopic scales in space and times for the simulation of polymeric materials. Integrating these building blocks into one coherent framework still is not fully solved and a matter of current research. 

The thiophene ring is a common building block for novel oligomeric and polymeric materials. The synthesis of monodisperse thiophene oligomers continues to be widely studied and the preparation of one class of oligomers, oligothienylenevinylenes <00CEJ1698,... 

Y.-Z. An, Y. Rubin, C. Schaller, S. W. McElvany, Synthesis and Characterization of Diethynylmethanobuckmins-terfullerene, a Building Block for Macrocyclic and Polymeric Carbon Allotropes J. Org. Chem. 1994, 59, 2927-2929. 

Nylon 66 is made by the condensation polymerization of adipic acid and hexamethylenediamine (HMD). Adipic acid was covered in Chapter 16 (cyclohexane is also the building block for adipic), and HMD shouldn t be such a threatening word to you by now. The hex is six the methylene is —CH2-. The di is two, and amine is the signature group -NH2. Put them all together and they don t spell mother—they spell H2N(CH2)6NH2, which is HMD. The routes to HMD and adipic acid are shown in Figure 24-6. 

Polymers are found in the organic natural world as the building blocks for life itself. They are also found as inorganic building blocks that allow construction of homes, skyscrapers, and roads. Synthetic polymers serve as basic building blocks of society now and in the future. This text includes all three of these critical segments of polymeric materials. 

Olefins are hydrocarbon compounds with at least two carbon atoms and having a double bond. Their unstable nature and tendency to polymerize makes them one of the very important building blocks for the chemical and petrochemical industry (Gary and Handwerk, 1994). Although olefins are produced by fluid catalytic cracking in refineries, the main production source is through steam cracking of liquefied petroleum gas (LPG), naphtha or gas oils. 

The importance of stabilizers for SCF polymerization was briefly outlined in Section 9.1.4. The drawback with existing stabilizers, however, is that most of them are based on fluorocarbons or siloxanes, which are high-cost chemicals. Cheaper polymeric stabilizers are usually only soluble in SCCO2 at pressures too high to make viable their widespread use. Very recently, Beckman and co-workers reported [68] a totally new approach to the problem polymers were prepared by co-polymerization of propene oxide and SCCO2. These polymers are not only much cheaper than fluorinated polymers but are more soluble than these materials in SCCO2. The polyether polymers are likely to have widespread applicability, not only as building blocks for stabilizers for SCF polymerization, but also as the basis of... 

Acrylic Macromers. Thus far we have shown applications of SFC to the characterizations of monomers and crosslinkers. The next couple applications will focus upon the analysis of oligomeric methacrylates, specifically methacrylate macromers. Methacrylate macromers are frequently used as building blocks for larger architecturally designed polymers. Unfortunately, macromers far exceed the capability of GC and do not possess a chromophore for HPLC analysis. Hatada et. al. has used packed column SFC to analyzed the stereoisomers of oligomeric methylmethacrylate (MMA) prepared by anionic polymerization (13). 

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