Poly polymer chain direction

Yamaguchi, I., Osakada, K., Yamamoto, T., Polyrotaxane containing a blocking group in every structural unit of the polymer chain. Direct synthesis of poly(alkylenebenzimidazole) rotaxane from Ru complex-catalyzed reaction of 1,12-dodecanediol and 3,3-diaminobenzidine in the presence of cyclodextrin. J. Am. Chem. Soc. 1996, 118, 1811-1812. 

Fig. 3.15 Atomic force microscopy images of poly(oxy methylene) with molecular resolution (a) raw data (b) image obtained from Fourier reconstruction. The arrow indicates the polymer chain direction (image size 7x7 nm2 Reproduced with permission from [38]). Copyright 1992. American Chemical Society, (c) AFM height image and (d) corresponding autocorrelation-filtered image acquired on POM crystals obtained by solid state polymerization [39]. Reproduced with permission from [39]. Copyright 1994. The Royal Society of Chemistry...

In order to avoid misunderstanding, we emphasize here that the parallel aligned lamellar structure is not the sole morphology of parallel chain polymer epitaxy. As an example, when crystallizing the poly(ethylene adipate) (PEA) on uniaxially oriented PE substrate [97], a cross-hatched edge-on lamellar structure of PEA with its lamellae ca. 66.5° apart from the chain direction of the PE substrate film is observed (see Fig. 12.10), indicating the occurrence of epitaxial crystallization of PEA on oriented PE substrate. Known from the experience of PE/iPP epitaxy, where the 50° intersect of both polymer chain directions leads to the formation of a cross-hatched lamellar structure of PE (see Fig. 12.9a), one may conclude that the PEA and PE molecular chains... 

These pioneer studies laid dormant until 1977 and, influenced by Kondo and colleagues [59] reports on the synthesis of po]y(vinylsulfonium yiide) with a trivaient sulfur attached directly to the polymer chain, poly[ethyl-vinylsulfonium bis-(methoxycarbonyl) methylide] (Scheme 25) was prepared by irradiation of a benzene... 

Fig. 17 (a) Molecular arrangement of 2,5-DSP and l OEt in the molecular complex (2,5-DSP l OEt). (b) Schematic representation of the photoproduct of the molecular complex (2,5-DSP l OEt). Black and white rods represent single polymer chain of poly-2,5-DSP and poly-1 OEt, respectively. Three arrows represent the direction of the a-, b-, and c-axes of the original complex before irradiation. 

We now report that in the region of the absorption band the flow linear dichroism of a solution of 1 is positive (Fig. 3). Assuming that the nature of the flow orientation is of the usual kind, i.e., that the polymer chains in a random coil conformation which dominates in solution (34) tend to align with the flow direction, this observation provides additional support for the absolute assignment of the transition moment direction along the chain direction, even in solution. Similar conclusions based on polarization studies on a stretched film of poly(di-n-hexyl silane) have recently been reported (36). 

The tacticity or distribution of asymmetric units in a polymer chain can be directly determined using NMR spectroscopy and infrared (IR) spectroscopy and has been studied for a variety of polymers. Figure 5(a) and 5(b) show the proton NMR spectra [26,27] and IR spectra [28,29], respectively, for the two stereoisomers of poly(methyl methacrylate) (PMMA), syndiotactic and isotactic PMMA. These two structures in a polymer like PMMA give rise to different signatures in both the techniques. In the case of the NMR spectra [26,27], the... 

Here m is the mode order (m — 1,3,5. .., usually 1 for polyethylenes), c the velocity of light, p the density of the vibrating sequence (density of pure crystal) and E the Young s modulus in the chain direction. The LAM band has been observed in many polymers and has been widely used in structural studies of polyethylenes [94—99,266], as well as other semi-crystalline polymers, such as poly (ethylene oxide) [267], poly(methylene oxide) [268,269] and isotactic poly(propylene) [270,271], The distribution of crystalline thickness can be obtained from the width of the LAM mode, corrected by temperature and frequency factors [272,273] as ... 

Recently, two new poly(3HB) depolymerase sequences from A. faecalis AE122 and from P. stutzeri were published which contain two instead of only one poly(3HB)-binding domain [57, 64]. Two types of poly(3HB) binding domains can be differentiated by amino acid alignment (types A and B in Fig. 4). Several amino acids are strictly conserved in both types of binding domains. It is not known whether these conserved amino acids are necessary to constitute a particular three-dimensional structure or whether these amino acids are directly involved in the interaction with the polymer chain. 

The technique of atomic force microscopy (AFM) has permitted the direct observation of single polysilane molecules. Poly[//-decyl-(high molecular weight (4/w = 5,330,000 and Mn = 4,110,000), PSS, helicity, and rigid rod-like structure due to the aliphatic chiral side chains, was deposited from a very dilute (10-10 Si-unit) dm-3] toluene solution onto a (hydrophobic) atomically flat (atomic layer steps only present) sapphire (1012) surface. After drying the surface for a few minutes in a vacuum, AFM images were taken at room temperature in air in the non-contact mode.204,253 An example is shown in Figure 22, in which the polymer chain is evident as a yellow trace. 

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