Polymer backbone nitrogen

Polyaniline (PANl) was also utilized to develop a conductometric pH sensor. The response mechanism of the polymer film originates from the deprotonation of the polymer backbone nitrogen atoms when exposed to aqueous envirMiments. In acidic solution, emeraldine polyaniline exists in the form of a salt (ES), and in alkaline solution it is converted to the base form (EB). The function of the sensor depends on the change in different forms of polyaniline which arises due to the deprotonation of nitrogen atoms. Thus, the conductivity of the sensitive layer is changed when PANl interacts with the hydronium or hydroxyl ions present in the solution. PANl is an amorphous film, and the electrolyte penetrates into the film and interacts with individual particles of the polymer. The charge carriers can pass... 

The formation of PPD groups on the polymer backbone provides a mechanism to improve the polymer-filler interactions. The nitrogen-hydrogen bonds are capable of hydrogen bonding with polar groups on the surface of the filler. This enhanced interaction provides for somewhat unique dynamic mechanical properties. Under ideal conditions rolling resistance improves when QDI is used in the mix. Also, abrasion characteristics are maintained and in some cases even modest improvements occur. 

Organic polymers claimed to be effective swelling clay and mineral fine particle stabilizers in the patent literature can be divided into four classes. The polymers of class 1 have the quaternary nitrogen atom as part of the polymer backbone (6-10). Polymers in this class include poly(dimethylamine-co-epichlorohy-drin, abbreviated poly(DMA-co-EPl), and poly(N,N,N, N,-tetramethyl-l,4-l,4-diaminobutane-co-l,4-dichlorobutane), abbreviated poly (TMDAB-co- DCB). These low molecular weights are not surprising since these are condensation polymers. Molecular weights cited range from 800 to 800,000 daltons. 

Polymers in which the quarternary nitrogen atom is part of a five- or six-membered ring comprise the second class of polymers. The ring forms part of the polymer backbone as indicated by the second and third polymer repeat units given in Table I. The member of this class cited in several patents is poly(diallyldimethyl-ammonium chloride) abbreviated poly(DMDAAC). 

PVCL is one of several nonionic water-soluble polymers that undergo heat-induced phase separation in water (Fig. 13). It has a repeating unit consisting of a cyclic amide, where the amide nitrogen is connected directly to the hydrophobic polymer backbone. 

Monolayer Polymerization. Polymerization of the highly ori-ented monomer films can simply be achieved by UV irradiation under nitrogen (Figure 8.). The polymerization of the diacetylene monomers (2, 5-9) is a topochemical reaction (32,38) that only takes place, if the monomers are perfectly orderecTT i.e. in the crystalline state or in oriented mono- (32) or multilayers (39) and leads to the formation of conjugated Tlue and red colorecT polymer backbones (Eqn. I.). 

Most acrylonitrile-butadiene styrene terpolymer (ABS) is produced as a graft of SAN onto a butadiene polymer backbone. This graft copolymer may be blended with more SAN or acrylonitrile elastomer (NBR) to improve its properties. ABS is more ductile than SAN. The Tt and the heat deflection temperature of ABS vary with the composition, and ABS may have one set of values for the PBD domains and another set for the SAN matrix. The permeabilities of ABS to oxygen, nitrogen, and carbon dioxide are much less than those of hope. 

Nucleic acids are polymers containing nitrogenous bases attached to sugar-phosphate backbones. The common nitrogenous bases of nucleic acids are the bicyclic purines, adenine and guanine, and the monocyclic pyrimidines, cytosine, uracil, and thymine (Fig. V-l). 

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