Substitution onto the Backbone

Self-doped derivatives of PANI containing an ionizable, negative charged functional group in their structure that acts as an inner dopant anion, hound to the pol nner backbone. There is no anion exchange between the polymer and the solution during the oxidation or reduction process. 

These novel materials exhibit many properties that are different from those of the parent PANI and show promising applications in various fields. For instance, self-doped PANI is highly soluble in alkaline aqueous solutions and many nonaqueous media unlike PANI. Good solubility is essential for a polymer in order to facilitate postsynthetic processing. The solubility of PANI is greatly improved by the presence of the substituted acidic group.  

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Secondly, we see in Table 7.8 a rare example of a side chain polymer with no spacer that is liquid crystalline (n = 0, m=l). Zhou" uses the term mesogen-jacketed to describe the probable microenvironment around the backbone when spacer lengths to lateral mesogens are short, with close proximity of the centres of gravity of the mesogens and the points of substitution onto the backbone. The polymers are then somewhat reminiscent of the longitudinal ( worm ) LCPs dealt with in Chapter 8. 

Chlorosulfonated polyolefins are prepared by interaction of the base resin with chlorine and either sulfur dioxide (18) or sulfiiryl chloride in the presence of a radical initiator (19). Sulfuryl chloride may be used alone as a chlorosulfonating agent, but must be accompanied by a catalytic amount of pyridine or other organic base. It has been proposed that the fimction of the organic base is to catalyze decomposition of the sulfuryl chloride molecule to form SO2 and CI2. However, the chlorosulfonation rate with base-catalyzed sulfuryl chloride is 5-10 times faster than that with gaseous chlorine and sulfur dioxide. So it is possible that the mechanism is more complex. In the latter case, the ratio of sulfonyl chloride to chlorine substituted onto the polymer backbone is, to some extent, a function of the amount of organic base added. The reaction temperature (lower reaction temperatures that result in higher sulfur utilities) also affects it (19). 

Optinuzation of the length of the aliphatic pendant side[Pg.91]

Direction substitution of element notation (Equation 10) representing the grafting of polystyrene side chains onto polybutadiene backbone. An AB-crosslinked copolymer of Bamford and Eastmond (14a)... 

In order to preserve the affinity with the nonpolar polypropylene matrix, the substitution of a small fraction of the matrix by another polypropylene with just a few polar groups grafted onto its backbone has been proven, in the last 20 years, to be a very effective strategy to promote isotactic polypropylene for engineering polymer applications. 

The polyanion is soluble in DMSO, and different substituents were grafted onto the polyamide backbone via this anion. For instance, Cg-Cig alkyl chain, benzyl, 1-naphthylmethyl, 9-anthrylmethyl, carboxymethyl were succesrfully attached. All the substituted polyamides 47, except the carboxymethyl substi-... 

Clearly, a potential advantage of the Mn(ii)-based SOD mimics over the SOD enzymes is the ability of the SOD mimics to permeate the cell membrane. The lipophilicity of the complexes can be controlled by placing the appropriate substituents onto the carbon backbone of the macrocycle. As shown in Table 2, the lipophilicities of mono-substituted Mn(ii)-based complexes can be varied... 

A number of water-soluble polyaniline derivatives have been developed in recent years. Incorporation of sulfonate groups onto the polymer backbone imparts water solubility to the polymer. In one process, this is accomplished by treating the polymer with fuming sulfuric acid which results in a sulfonic acid ring-substituted derivative that is alkali soluble but only upon conversion to the nonconducting sulfonate salt form. 

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