The work presented in this paper comprises synthesis and study of poly(oxine-methylene)s"? The synthesis is based on Friedel-Crafts polyalkylation of 8-quinolinol, commonly known as oxine, with dichloromethane in presence of anhydrous aluminium trichloride. Five polymer samples are prepared by varying molar proportions of the two monomers. The polymer samples are insoluble in commonly used organic solvents. They are soluble in acetic acid, formic acid, and in conc. sulfuric acid. The IR and UV spectral characteristics of the polymer samples are reported. Molecular weight of the polymer samples is estimated by conductometric titration in pyridine against standard sodium methoxide. Viscometric study is carried out both in formic acid and glacial acetic acid at 35 "C. Solutions of polymer samples in formic acid show normal behaviour and those in glacial acetic acid show abnormal behaviour. Various empirical relations are applied to correlate these data in glacial acetic acid. Acetic acid containing water and simple electrolytes is used as a medium to suppress abnormal behaviour. The thermal properties of the polymer samples are also studied. All the results of analysis are adequately correlated. One oxine-formaldehyde polymer sample was also synthesized for comparison.
Experimental Part
Synthesis of polymers
Condensation of 8-quinolinol with dichlorpmethane in presence of anhydrous aluminium chloride:To a well stirred and ice-cooled mixture of 8-quinolinol and dichloromethane (amounts are indicated in Tab. 1) finely powdered aluminium chloride was added portionwise. The reaction mixture was allowed to come to room temperature and heated at 50 "C for 4h. It was poured in ice-cooled 1 : 10 (v/v) conc. hydrochloric acid : water mix-*) Systematic name: poly(8-hydroxyquinolinediy1methylene)s. m % r ? J 2 3 g. Acetic acid Water Salt Reduced viscosity in dl . g-'
