Solubility polymer

The process of post-chlorinating PVC was carried out during World War II in order to obtain polymers soluble in low-cost solvents and which could therefore be used for fibres and lacquers. The derivate was generally prepared by passing chlorine through a solution of PVC in tetrachloroethane at between 50°C and 100°C. Solvents for the product included methylene dichloride, butyl acetate and acetone. These materials were of limited value because of their poor colour, poor light stability, shock brittleness and comparatively low softening point. 

Liquid solvent/polymer Solubility parameter, <5, (J/cm ) / Molar volume, V (cm /mol)... 

Polybenzothi azoles Stable in air at 600°C (1112°F) cured polymer soluble in concentrated sulfuric acid. 

Tractable polymers can be prepared when amino and anhydride functions are not located on the same aromatic ring, and different strategies were employed to obtain soluble polymer. AB benzhydrol imide was prepared by polycondensation of 4-(3-amino-l-hydroxymethylene) phtlialic acid monomethyl ester in NMP. The polymer soluble in NMP has been used as adhesive and coating.56 A second approach was based on an ether imide structure. AB aminophenylether phthalic acids (Fig. 5.34) were prepared by a multistep synthesis from bisphenols.155 The products are stable as hydrochloride, and the polycondensation takes place by activation with triphenylphosphite. The polymers are soluble in an aprotic polar... 

Fluorinated poly(arylene edier)s are of special interest because of their low surface energy, remarkably low water absorption, and low dielectric constants. The bulk—CF3 group also serves to increase the free volume of the polymer, thereby improving various properties of polymers, including gas permeabilities and electrical insulating properties. The 6F group in the polymer backbone enhances polymer solubility (commonly referred to as the fluorine effect ) without forfeiture of die thermal stability. It also increases die glass transition temperature with concomitant decrease of crystallinity. 

The polymer solubility can be estimated using solubility parameters (11) and the value of the critical oligomer molecular weight can be estimated from the Flory-Huggins theory of polymer solutions (12), but the optimum diluent is still usually chosen empirically. 

When using this approach to polymer solubility, we need to remember that the basis is thermodynamics. In other words, this approach gives information about the energetics of solubility, but does not give any insight in the kinetics of the process. In order to promote rapid dissolution, it may be more helpful to employ a solvent that is less good thermodynamically, but that consists of small, compact molecules that readily diffuse into the polymer and hence dissolve the polymer more quickly. 

Microspheres and microcapsules of lactide/glycolide polymers have received the most attention in recent years. Generally, three microencapsulation methods have been employed to afford controlled release formulations suitable for parenteral injection (1) solvent evaporation, (2) phase separation, and (3) fluidized bed coating. Each of these processes requires lactide/glycolide polymer soluble in an organic solvent. 

Various bisphenol derivatives were also polymerized by peroxidase under selected reaction conditions, yielding soluble phenolic polymers. Bisphenol-A was polymerized by peroxidase catalyst to give a polymer soluble in acetone, DMF, DMSO, and methanol. The polymer was produced in higher yields using SBP as a catalyst. This polymer showed a molecular weight of 4 x 10 and a 7g at 154°C. The HRP-catalyzed polymerization of 4,4 -biphenol produced a polymer showing high thermal stability. ... 

The same results were obtained with calcium for a more charged pectin. These results may be interpreted as above by a decrease of the polymer solubility and in this case resolubilisation by an excess of sodium cannot be expected. 

To remove water, the benzene was azeotroped and distilled over CaH2. The n-pentane was stored over LiAlH and distilled over CaH2. Toluene was distilled over CaH2. Toluene from Burdick Jackson, Muskegon, MI could also be used for dilute solution characterization without any adverse effects on polymer solubility. Tetrahydrofuran (THF) was dried over molecular sieves and doubly distilled over CaH2. The solvents were blanketed with nitrogen to maintain dryness. 

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