Electrically Conductive Poly(DL‐lactide)/Chitosan/Polypyrrole Complexes

Summary: The fabrication of novel conductive poly(DL ‐lactide)/chitosan/polypyrrole complex membranes is reported. Using poly(DL ‐lactide)/chitosan blends as matrices and polypyrrole as a conductive component, several kinds of membranes with various compositions are prepared. A percolation threshold of polypyrrole as low as 1.8 wt.‐% is achieved for some membranes by controlling the chitosan proportion between 40 and 50 wt.‐%. SEM images exhibit that the membranes with a low percolation threshold show a two‐phase structure which consists of poly(DL ‐lactide) and chitosan phases. Dielectric measurements indicate that there is limited miscibility between the poly(DL ‐lactide) and chitosan but polypyrrole is nearly immiscible with the other two components. Based on the structural characteristics of the membranes, the polypyrrole particles are suggested to be localized at the interface between two phases.

Dependence of conductivity of complex membranes on the PPy content. (○) PDLLA/PPy, (▪) PDLLA/ch(10)/PPy, (▵) PDLLA/ch(20)/PPy, (•) PDLLA/ch(30)/PPy, (□) PDLLA/ch(40)/PPy, and (▴) PDLLA/ch(50)‐PPy.