New Polymerization Techniques

D. L (1981) A new polymerization technique for preparing low molecular weight polyether glycols. JANNAF Propulsion Meeting, New Orleans, Louisiana, USA, May 26-28,1981, pp. 29-38. 

We have focused our attention on the prepolymer method for polyurethane development because we feel that it offers the researcher the greatest control of the molecule. We hope to encourage the scientific community to investigate other nonclassical polyurethane tools. If the pin posc of a device is purely physical, the large polyurethane manufacturers and chemists are the best resources for expertise. If, however, the intent is to experiment with a new polymerization technique for a particular medical or environmental application, the researcher must be able to assemble the component parts along lines with which the polyurethane industry may not be familiar. 

Abstract. Polymerization in direct mini-emulsions is a relatively new polymerization technique which allows the preparation of submicron latex particles within the range 100large population of submicron monomer droplets in water (termed the mini-emulsion) by intensive shear force with the aid of an adequate emulsifier and coemulsifier (or hydrophobe). These stable, homogenized monomer droplets have an extremely large surface area and, therefore, can compete effectively with the monomer-swollen micelles, if present, for the oligomeric radicals gen-... 

Acrylic Resins. Low molecular mass acrylic resins (see also Section 2.5) may be obtained by using fairly large amounts of chain-transfer reagents (e.g., thiols). The resultant problems of smell have, however, led to the implementation of new polymerization techniques, such as group-transfer polymerization or dead-end polymerization. Bifunctional (telechelic) polymers [3.38] are obtained and can be used as binders for low-solvent paints. 

M. Biswas and S. S. Ray. Recent progress in synthesis and evaluation of polymer-montmorillonite nanocomposites. In New Polymerization Techniques and Synthetic Methodologies, volitme 155 of Advances in Polymer Science, pages 167-221. Springer-Verlag Berlin, Berlin, 2001. 

Some of these developments can be reahzed by industrial companies alone, as demonstrated by recent BASF product launches in the field of polymers for pharmaceutical applications, or in the field of electronic polymers. However, the point must be made clear that the discovery of new polymers and new polymerization techniques is an area where nonprofit research organizations - not only universities but also institutes such as those operated by the Max-Planck or the Fraunhofer Society - can successfully follow up on new technologies and identify new trends in polymer science, without considering economical boundary conditions. In this way, such institutions can continue to investigate areas that do not necessarily pay out on an industrial ten-year business plan - and this is an extremely important role ... 

Finally, we will give some perspectives on the field opened by new polymerization techniques, and consequently new types of polymers, and on recent discoveries about how to interfere with the expression of specific genes with oligonucleotides. 

Some challenges remain concerning the synthesis and structure of these polymers for instance, finding new biocompatible polymers other than PEG. Moreover, in order to define clear structure-function relationships, it is necessary to use new polymerization techniques to obtain well-defined materials rather than randomized polymers [241]. Similarly, more architecturally controlled macromolecules such as dendronized polymers appear to be promising prospects in the field of polycations for gene delivery [242]. 

The primary objectives of the research have become quite obvious. Initially, a new polymerization technique and/or ultrapurification of monomers must be employed in order to acheive high molecular weights. Secondly, the possibility of synthesizing monomers by a shorter and more facile approach should be investigated. If these goals are accomplished, then there is a possibility of producing a series of new polymers with commercial value. Some of these approaches are under active investigation in the authors laboratory. 

In this chapter, I outlined recent developments of a new polymerization techniques using a asymmetric liquid crystal reaction field of the N -LC phase, focusing on helical polyacetylene with a super-hierarchical spiral structure (H-PA). Chiral binaphthyl axially chiral derivatives are added as a chiral dopant to nematic liquid crystal to produce the chiral N -LC phase. 

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