Poly , VII

Table 5 Molecular weight characteristics and thermal transitions of poly-VII and poly-VIII ...

For a spacer length of 11 methylene units, all polymers showed smectic mesophases except for poly-(II-ll) and poly-(VII). Even the flexible poly-(cy-clooctene) main chain prevented a smectic mesophase. Compared to all of the other polymer architectures, poly-(II-ll) and poly-VII present the lowest ratios of mesogens to atoms in the main chain. It can therefore be assumed that smectic phases will only be formed when there is sufficient mesogen density. For the norbornene chain, it is notable that a high Z/E-ratio and a high tactic-ity increased the stability of the smectic A phase. 

NMR Spectra - The proton NMR spectrum of poly(N-pheny1-3,4-dimethy-lenepyrroline) (VII) had three singlet absorptions at 6 2.56, 4.81 and 7.60 respectively (Figure 10). The integration of these peaks showed a ratio of 4 4 5. The presence of exocyclic olefinic protons was not observed, indicating that 1,4- addition was predominant in the polymerization with little or no 1,2 addition taking place. 

The synthesis of poly(anhydride-co-amide)s (Table VII) of various chemistries was pursued by Hartmann and Schulz (1989) as a means of improving biocompatibility and extending the degradation times of polyanhydrides. This work also contains calorimetry data on the thermal transitions and spectroscopic characterization. 

Table VII. G-values for carbon monoxide and carbon dioxide formed on radiolysis of poly acids at 303 K...

VII) poly (2,4(8-vinylpyridyl)diphenyl terephthalate) [poly(2,4-VPDPT)]... 

Scheme 18. Reagents and Conditions (i) Immobilised poly-(L)-leucine, urea hydrogen peroxide, DBU, THF, 12 h, 76%, 94% e.e. (ii) mCPBA, CH2CI2, 94%. (iii) HCl (g), CH2CI2, 66%. (iv) Amberlite IRA-420 ( OH), THF, 80%. (v) NaNj, MeOH, H20,94%. (vi) H2, Pd/C, EtOAc. (vii) NH3,MeOH. (viii) benzoyl chloride, (ix) trifluoroacetic acid, CH2CI2,74%...

Overberger and coworkers carried out an interesting study on the hydrolysis of various 3-nitro-4-acyloxybenzoic acid substrates (V) catalyzed by imidazole (VI) and poly[4(5)-vinylimidazole] (VII) in ethanol-water mixtures [Overberger et al., 1973]. 

The approach of synthesizing a monomer containing the desired functional group followed by (co)polymerization can be illustrated for the poly[4(5)-vinylimidazole] catalyst (VII) described in Sec. 9-lj. Synthesis involves the sequence of reactions starting from histidine (XXXVII) to yield 4(5)-vinylimidazole (XXXVIII), which is subsequently polymerized by radical initiation [Overberger and Vorchheimer, 1963],... 

The cross sections of dimer formation in poly T have been reported by Deering and Setlow,68 as functions of the wavelength, Figures 8 and 9. The corresponding quantum yields, from the ratios of adjSm where Sm is the absorption cross section, are shown in Table VII. 

When poly acetylene is doped with chloric (VII) acid, HCIO4, part of the acid is used to oxidise the polyacetylene and part to provide a counteranion. The oxidation reaction for the acid is given in Equation (6.6). Write a balanced equation for the overall reaction. 

Only a few bacterial and viral sialidases have been purified to high purity or even to protein homogeneity."0 Complete purification of sia-lidase on a preparative scale from the culture filtrate ofC. perfringens was achieved111 by using poly(acrylamide) gel-electrophoresis as the final purification step (see Section VI,1). It is necessary that such purified sialidases be available, as the presence of proteases or other gly-cosidases in the enzyme preparations would lead to severe errors, not only in studies of substrate specificity, but also in cell biological and medical studies (see Sections VI and VII). 

Andere 1-substituierte Butadiene, die ebenfalls in ditaktische Poly-mere iiberfiihrt wurden, sind 1,3-Hexadien (III), 1,3-Heptadien (IV), 1,3-Octadicn. (V), 5-Methyl-l,3-hexadicn (VI) und 6-Methyl-l,3-hepta-dien (VII) (73). 

Nakahara et al. (4) prepared an electricity storage device consisting of poly(2,2,5,5-tetramethylpyrrolidinoxy methacrylate), (VII), for use as a negative electrode in lithium secondary batteries. 

Kim et al. (1) prepared the energetic agent poly(glycidyl dinitropropyl formal), (VI), by polymerizing the epoxide precursor, (VII), as illustrated in Eq. (2). The preparation of reaction intermediates is discussed by the authors (2). 

Poly(/ -acetamidostyrene) (V) is prepared from p-nitrobenzyl bromide as shown in Scheme 6. Homopolymer V has very little solubility in common organic solvents and thus it is difficult to use attempts at increasing the solubility of V by incorporation of up to 40% styrene units in copolymers such as Va do not result in any significant improvement in solubility. Polyfphenyl methacrylate) (VI) and poly(methacryl anilide) (VII) are prepared from the corresponding monomers according to literature procedures (19-20). 

Finally, in the case of poly(methacryl anilide) (VII), the rearrangement also occurs, but at an extremely slow rate with a decrease in amide carbonyl... 

A similar improvement in sensitivity via copolymerization was observed in the copolymers of methyl methacrylate with a,a-dimethylbenzyl methacrylate (Table VI) and triphenylmethyl methacrylate (Table VII). In the former case the mechanism of sensitivity enhancement should be the same as that for the poly(a,a-diphenylethyl methacrylate-co-methyl methacrylate), although the enhancement of sensitivity with copolymerization is rather low. 

Table VII the electron-beam exposure characteristics are given for the soluble poly (triphenylmethyl methacrylate-co-methyl methacrylate)s. The sensitivity on alkaline development was strongly influenced by the copolymer composition. The highest sensitivity was obtained on the copolymer containing 93.7 mol% methyl methacrylate. The copolymer of highest sensitivity showed the 7-value of 6.3, which was nearly twice as large as that for poly(methyl methacrylate). Formation of methacrylic acid units on exposure is obvious from the infrared spectrum. However, the mechanism of the occurrence should be different from the case of the a,a-dimethylbenzyl methacrylate polymer since there are no /3-hydrogen atoms in the triphenylmethyl group, and may be similar to the case of poly (methyl methacrylate). This will be explored in the near future.

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