Macromolecules side chain

Schneider J, Erdelen C, Ringsdorf H and Rabolt J F 1989 Structural studies of polymers with hydrophilic spacer groups. 2. Infrared-spectroscopy of Langmuir-Blodgett multilayers of polymers with fluorocarbon side-chains at ambient and elevated temperatures Macromolecules 22 3475-80... 

To understand the function of a protein at the molecular level, it is important to know its three-dimensional stmcture. The diversity in protein stmcture, as in many other macromolecules, results from the flexibiUty of rotation about single bonds between atoms. Each peptide unit is planar, ie, oJ = 180°, and has two rotational degrees of freedom, specified by the torsion angles ( ) and /, along the polypeptide backbone. The number of torsion angles associated with the side chains, R, varies from residue to residue. The allowed conformations of a protein are those that avoid atomic coUisions between nonbonded atoms. 

From the data of DTA and TGA analyses illustrated in Fig. 4, its evident that the visible exo-peaks in the range of 140-150°C appear in DTA curves (Fig. 4a), which can be taken as evidence of a crosslinking reaction of acylated macromolecules at the expense of side chain... 

Ayres L, Vos MRJ, Adams P et al (2003) Elastin-based side-chain polymers synthesized by atrp. Macromolecules 36 5967-5973... 

Thus, important structure/property relationships are emerging that are relevant to electronic and optical materials applications for these materials. In a different vein, side chain crystallization has resulted in the first liquid crystalline inorganic and organometallic macromolecules, viz., unusual poly(dialkoxy-phosphazenes) described by Allcock (p. 250) and Singler (p. 268). 

The IR spectra of thin films from an alternating copolymer of tri-n-butyl-stannyl methacrylate and maleic anhydride at various stages of UV irradiation were also studied l09). It can be expected that cross-linking results in hindered rotational and oscillatory mobility of the backbone chain and of side chains in the macromolecule. Indeed, a decrease in the peak intensity of most absorption bands is observed in the IR spectra of an irradiated copolymer 1770 and 1840 cm-1 (vc=0 anhydride), 1406 cm-1 (Sq, in CH2—Sn), 1285 and 1080 cm-1 (vc 0 c), 1115, 850, 750cm-1, etc. At the same time, there is an increase in the intensity of absorption bands near 1720 (vc=0 in — COOSnR3) and 1580 cm-1 (vc Q in -C=Q... SnRa). 

Macromolecules have also been specifically designed and synthesized for use as emulsifiers for lipophilic materials and as stabilizers in the colloidal dispersion of lipophilic, hydrocarbon polymers in C02. We have demonstrated the amphiphilicity of fluorinated acrylate homopolymers, such as PFOA, which contain a lipophilic, acrylate like backbone and C02-philic, fluorinated side chains (see Fig. 3) [103]. It has been demonstrated that a homopolymer which physically adsorbs to the surface of a polymer colloid prevents agglomeration by the presence of loops and tails (see Fig. 4) [113]. The synthesis of this type of... 

The formation of an aldehyde group on a macromolecule can produce an extremely useful derivative for subsequent modification or conjugation reactions. In their native state, proteins, peptides, nucleic acids, and oligonucleotides contain no naturally occurring aldehyde residues. There are no aldehydes on amino acid side chains, none introduced by post-translational modifications, and no formyl groups on any of the bases or sugars of DNA and RNA. To create reactive aldehydes at specific locations within these molecules opens the possibility of directing modification reactions toward discrete sites within the macromolecule. 

The screw models of Figure 7.4 are, of course, an abstraction, and real macromolecules are much more complex. In particular, apart from DNA and G-wires, which have sugar-phosphate backbones as external ridges, but are also charged, most natural and synthetic polymers have external side chains which could generate a secondary chiral surface, which might interfere with the chirality of the polymer backbone.28 Even if the qualitative estimate of Sq based on the models of Figure 7.4 seems rather primitive, the estimate of Hq... 

H. Meng, W. Yu, and W. Huang, Facile synthetic route to a novel electroluminescent polymer — poly(p-phenylene vinylene) containing a fully conjugated aromatic oxadiazole side chain, Macromolecules, 32 8841-8847, 1999. 

Q. Fang and T. Yamamoto, New alternative copolymer constituted of fluorene and triphenyla-mine units with a tunable -CHO group in the side chain. Quantitative transformation of the -CHO group to -CH=CHAr groups and optical and electrochemical properties of the polymers, Macromolecules, 37 5894-5899, 2004. 

Kameda, T., Ohkawa, Y., Yoshizawa, K., Nakano, E., Hiraoki, T., Ulrich, A. S., and Asakura, T. (1999). Dynamics of the tyrosine side chain in Bombyx mori and Sarnia cynthia ricini silk fibroin studied by solid state H-2 NMR. Macromolecules 32, 8491-8495. 

Strictly speaking, the term polyester ought to refer to a chemical compound containing many ester groups in each molecule. In practice, however, it usually refers to polymeric materials containing ester groups as major structural components of the main chains of the macromolecules of which the polymer is composed, and this is the sense in which it is used here. The term is not now usually applied to polymers that contain ester groups attached to the main chain either directly, as in cellulose triacetate, poly(vinyl acetate) or poly(methyl acrylate), or within short side-chains. 

S. Tazuke, R. Kun Guo, and R. Hayashe, How does the polymer main chain influence the side-chain mobility A fluorescence probe study by means of twisted intramolecular charge-transfer phenomena, Macromolecules 21, 1046 (1988). 

This section on the contraction factor may be concluded with an example of a comb macromolecule [136]. Due to the route of preparing this comb, unattached side chains also occurred in the system. Figure 27 shows the result of the molar mass dependence of [rj] which was obtained from a SEC/LALLS/VISC fractionation. One observes at low molar masses a straight line with an exponent of 11 =0 JO that coincides with the exponents of linear side chains. It follows a... 

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