Block, polymer synthesis 296 Subject

Many micellar catalytic applications using low molecular weight amphiphiles have already been discussed in reviews and books and will not be the subject of this chapter [1]. We will rather focus on the use of different polymeric amphiphiles, that form micelles or micellar analogous structures and will summarize recent advances and new trends of using such systems for the catalytic synthesis of low molecular weight compounds and polymers, particularly in aqueous solution. The polymeric amphiphiles discussed herein are block copolymers, star-like polymers with a hyperbranched core, and polysoaps (Fig. 6.3). 

We are currently initiating three research projects that include (1) the synthesis of reflective liquid crystal/polymer composite films, (2) a study of microphase separation in hyperbranched block copolymers, and (3) the design and synthesis of polar organic thin films, which is the subject of this proposal. (47 words aim for 41 words)... 

The mechanical synthesis of block and graft copolymer is a method of sizable versatility. It can be performed (as already stated) during polymer processing and in standard equipment. The reaction, also, can be carried out by subjecting a mixture of two or more polymers to mechanical degradation in either the solid, elastic-melt, or solution states. It is, also, possible to induce reaction mechanically between polymers and monomers. 

Our understanding of the physics of block copolymers is increasing rapidly. It therefore seemed to me to be timely to summarize developments in this burgeoning field. Furthermore, there have been no previous monographs on the subject, and some aspects have not even been reviewed. The present volume is the result of my efforts to capture the Zeitgeist of the subject and is concerned with experiments and theory on the thermodynamics and dynamics of block copolymers in melt, solution, and solid states and in polymer blends. The synthesis and applications of these fascinating materials are not considered here. 

Tetraethynylethene (20) and its differentially protected derivatives are versatile building blocks for two-dimensional all-carbon networks and carbon-rich nanomaterials [1]. In addition, they attract interest for their fully cross-conjugated 7c-electron system [33], The first tetraethynylethene derivative, 21a, was reported in 1969 by Hori and co-workers [34], and the persilylated and peralkylated derivatives 21b-d were prepared in the mid-1970 s by Hauptmann [35]. In 1991, Hopf et al. [36] summarized this early synthetic work (Scheme 13-5) and reported the X-ray crystal structure of 21a the authors also suggested in their paper the potential of substituted tetraethynylethenes as monomers for new polymers. Also In 1991, Rubin et al. [37] reported the first synthesis of the parent compound 20 by a synthetic route, which, after suitable modifications, provided access to tetraethynylethenes with any desired substitution and protection pattern. These transformations are the subject of this Section the application of these compounds as precursors to two-dimensional all-carbon networks tmd carbon-rich nanomaterials will be discussed in the following sections. 

Double hydrophilic block copolymers (DHBCs) are a class of polymers that combine the self assembly ability of block copolymers with the water solubility of hydrophilic macromolecular chains. Numerous sophisticated works have been already described in the literature, indicating the potential of this class of copolymers in emerging technologies. The synthesis of novel DHBCs, using either new monomers or post polymerization functionalization schemes, is the subject of intense investigation during the current years. 

The synthesis of an ampholytic block copolymer, namely PMAA-PDEAEMA, carrying carboxylic and tertiary amino side groups, has been also realized by ATRP, as has been reported by Tam and coworkers [15]. Initially, the synthesis of the tert-butyl protected PMAA block was performed using p-toluenesulfonyl chloride as an initiator and CuCl complexed with N,N,N ,N ,N ,N -hexamethyltriethylenetetraamine as a catalyst in 50 vol % anisole at 90 °C. The obtained polymer was used as the macroinitiator for the subsequent polymerization of the second monomer, DEAEMA, imder similar reaction conditions. Figure 3. The resulted copolymer was subjected to selective hydrolysis, imder acidic conditions, for removal of the tert-butyl protecting group. 

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