Novel Organo Soluble Polyimides and Polyimide Nanocomposites Based on 1,4-bis((4-aminophenyl)-1,3,4-oxadiazolyl)benzene, baob, via baobmodified Organoclay

Abstract

New, thermally stable polyimides (pi) containing a 1,3,4-oxadiazole ring in the polymer backbone based on 1,4-bis((4-aminophenyl)-1,3,4-oxadiazolyl)benzene, baob, were synthesized. The prepared polymers were soluble in polar and aprotic solvents. The obtained results reveal that within the prepared polymers, polyimide (7) which has been obtained from baob and 4,4’-oxydiphthalic dianhydride, odpa, has the most improved thermal properties. In the next part, thermally stable organophilic clay was obtained via cation exchange reaction between sodium montmorillonite (Na-mmt) and the hydrochloride salt of baob. Then, a series of pi/clay nanocomposite materials (pcns) were synthesized from the in situ polymerization reaction of baob and odpa via thermal imidization. baob-mmt was used as the filler at different concentrations. Intercalation of polymer chains within the organoclay galleries was confirmed by wxrd. The glass transition temperature is increased with respect to pristine pi for pcns 1-3 wt%. At high clay loadings, the aggregation of organoclay particles results in a decrease in Tg. In the sem images of the pure polymer too many micro-cracks were observed in the background,
while surface homogeneity of pcn 1 wt% is increased and microcracks are reduced.