Aminated polyacrylonitrile blends with cellulose acetate

Polyacrylonitriles (PANs) were synthesized and aminated with ethylene diamine (2DA), hexamethylene diamine (6DA), and dodecane diamine (12DA), followed by blending with cellulose acetate (CA). Effects of amination and chain length of diamine on the miscibility of the aminated PAN with CA were studied. Scanning electron microscopy (SEM) micrographs of cryogenically fractured surfaces of the blends showed coarse elliptical dispersions of CA in PAN. The dispersed CA domains decreased in size with an increase in aminated PAN content. The dispersed domain size further decreased with increasing chain length of diamine. and eventually the morphology became almost homogeneous with 12DA-modified PAN blends. With increasing chain length of the diamines, the dynamic loss peak temperature of PAN in blends showed a movement toward that of CA. Fourier transform infrared (FTIR) measurements showed that the specific interaction between the aminated PAN and cellulose acetate is the hydrogen bonding between aprotic hydrogen in aminated PAN and the ester carbonyl of CA, the interactions being increased with increasing chain length of diamine.