Synthesis by polycondensation

Cutinase A Powerful Biocatalyst for Polyester Synthesis by Polycondensation of Diols and Diacids and ROP of Lactones... 

Sokolov, L. B. (1979). The grounds for the polymers synthesis by polycondensation method. Moscow Himia, 264p [in Russian]. 

Other examples of telechelic synthesis by polycondensation reactions involving an excess of one of the reactants, followed by modification of the resulting end groups, have also been described (477-481). 

L. B. Sokolov, Synthesis of Polymers by Polycondensation, Israel Program for Scientific Translation, Jemsalem, Israel, 1968, pp. 60—71. 

The main reactions involved in alkyd lesin synthesis are polycondensation by estetitication and ester interchange. Figure 1 uses the following symbols to... 

Tractable polymers can be prepared when amino and anhydride functions are not located on the same aromatic ring, and different strategies were employed to obtain soluble polymer. AB benzhydrol imide was prepared by polycondensation of 4-(3-amino-l-hydroxymethylene) phtlialic acid monomethyl ester in NMP. The polymer soluble in NMP has been used as adhesive and coating.56 A second approach was based on an ether imide structure. AB aminophenylether phthalic acids (Fig. 5.34) were prepared by a multistep synthesis from bisphenols.155 The products are stable as hydrochloride, and the polycondensation takes place by activation with triphenylphosphite. The polymers are soluble in an aprotic polar... 

Fatty acids have also been converted to difunctional monomers for polyanhydride synthesis by dimerizing the unsaturated erucic or oleic acid to form branched monomers. These monomers are collectively referred to as fatty acid dimers and the polymers are referred to as poly(fatty acid dimer) (PFAD). PFAD (erucic acid dimer) was synthesized by Domb and Maniar (1993) via melt polycondensation and was a liquid at room temperature. Desiring to increase the hydrophobicity of aliphatic polyanhydrides such as PSA without adding aromaticity to the monomers (and thereby increasing the melting point), Teomim and Domb (1999) and Krasko et al. (2002) have synthesized fatty acid terminated PSA. Octanoic, lauric, myristic, stearic, ricinoleic, oleic, linoleic, and lithocholic acid acetate anhydrides were added to the melt polycondensation reactions to obtain the desired terminations. As desired, a dramatic reduction in the erosion rate was obtained (Krasko et al., 2002 Teomim and Domb, 1999). 

Generally, two common methods, the Stober method and the reverse microemulsion method are used for synthesis of silica nanoparticles. As derivatives of a sol-gel process, both methods involve hydrolysis of a silicon alkoxide precursor to form a hydroxysilicate followed by polycondensation of the hydroxysilicate to form a silica nanoparticle [44]. 

Synthetic peptides have been extensively used to study the thermal stability and folding of the triple helix. These peptides can be synthesized as either single chains or cross-linked peptides. Early on, such peptides were synthesized by polycondensation of tri- or hexapeptides, which led to a broad mass distribution that was difficult to separate. With the advances of solid-phase synthesis methods, peptides with defined chain length became available. The most studied collagen-like peptides are (Gly-Pro-Pro) or (Pro-Pro-Gly) and (Gly-Pro-4(if)Hyp) or (Pro-4(if)Hyp-Gly) with n varying from 5 to 15. Sutoh and Noda" " introduced the concept... 

Mikami, M. Shinkai, S. Synthesis of helical polymers by polycondensation of diboronic acid and chiral tetrols. Chem. Lett. 1995, 603-604. 

The rearrangement accompanied by the elimination of ketone R OMe gave, as a rule, good yields of naphthalenes 556 (Table XII)438,439 and was extended to the synthesis of polycondensed aromatic systems 557, 558, and (559), as demonstrated by Eqs. (36-38). 

The above synthetic method for well-defined aromatic polyamides, however, needs a peculiar base, N-oclyl-N-triethylsilylaniline, along with CsF and 18-crown-6, and the monomer has a phenyl ester moiety as an electrophilic site, which is not that common compared with a methyl ester or an ethyl ester. Furthermore, it is necessary to separate the obtained polyamide from by-products, such as AT-octylaniline and phenol, by HPLC. For convenient synthesis, the polycondensation of the corresponding methyl ester monomer 22b with a commercially available base has been developed [301]. The methyl ester 22b polymerized with LiHMDS in the presence of an initiator in THF at -10 °C (Scheme 86). The highly pure polyamide with a defined molecu-... 

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