The preparation of a series of 1,3,5-triarylbenzenes from substituted acetophenones is described. The effect of solvent and concentration on the yield of product and the course of reaction is noted.
SynopsisA new class of polymeric materials has been prepared and subjected to preliminary These materials were obtained by hydroformylation of diene-based poly-evaluation. mers. The olefinic bonds were saturated and aldehyde groups attached:The extent of reaction may be varied a t will up to 100% double bond conversion. The properties of these polymers are dominated by the active aldehyde groups. One of the chief characteristics of simple aldehydes is their ability to polymerize forming mainly aldehyde trimers and tetramers. This same phenomenon has been shown to occur with polymeric aldehydes with consequent gel formation. The gelling tendency has been closely related to the aldehyde content per unit volume which may be conveniently varied by (1) the concentration of the initial polymer, (2) the degree of unsaturation in the polymer, and (3) the extent of double bond conversion. Any combination which gives a free aldehyde concentration in excess of 1 X 10-4 mole/ml. is very prone to gel. The loose gels can be readily reversed by conditions which depolymeriae aldehydes. The propensity of the aldehyde polymers to crosslink upon evaporation of the solvent was used to form films. These films were not discolored by ultraviolet light but under such treatment became quite brittle. The products may be stmabilked by conversion of the aldehyde groups to more stable derivative, in particular the acetal. The extent of acetal formation has been shown to be controlled by steric factors. Complete polyacetal formation was possible only when the aldehyde groups were well dispersed along the polymer chain. Certain aldehyde derivatives (metals, oximes) are thermoplastic. They soften at lower temperature than commercial plastics.
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