Poly(1,3,4-oxadiazole-amide)s with pendant acetoxybenzamide or imide groups

Abstract

Two series of aromatic poly(1,3,4-oxadiazole-amide)s containing various pendant groups were synthesized by solution polycondensation of aromatic diamines having preformed 1,3,4-oxadiazole rings with diacid chlorides incorporating acetoxybenzamide, phthalimide or tetrachlorophthalimide side units. These polymers were soluble in polar amidic solvents and gave transparent flexible films. They showed good thermal stability, with initial decomposition temperature being about 300 • C for polyamides with pendant acetoxybenzamide units and 400 • C for the polyamides having pendant phthalimide or tetrachlorophthalimide groups. The glass transition temperatures of the polymers were in the range of 245-327 • C. The polymer films showed the dielectric constant in the range of 3.32-4.90 and good mechanical properties with tensile strength in the range of 35-86 MPa, tensile modulus in the range of 0.235-2.66 GPa and elongation to break in the range of 15-24%. Conformational parameters of the polymers were calculated by using the Monte Carlo method with allowance for hindered rotation. Several physical properties of these polymers such as solubility, glass transition temperature and initial decomposition temperature were measured and discussed in relation with the rigidity of their chains.

Influence of moieties on morphology, thermal, and dielectric properties in polyamide‐polyhedral oligomeric silsequioxanes nanocomposites

“…To overcome these limitations, various approaches have been tried to include different functional groups (or substituents) onto the polymer backbone capable of reducing the chain rigidity and further increasing their tractability [7–13]. Recently, polymer nanocomposites have attracted much interest for the development of high‐performance materials using fillers having at least one‐dimension in the nanometer range [14].…”