Polypyrrole (PPy) composites containing lignosulfonic acid (LSA) were prepared via the polymerization of pyrrole monomer with different concentrations (wt%) of LSA sodium salt using ammonium persulfate as an oxidant. The strong interaction of LSA with PPy to form PPy-LSA composites was supported by spectral characterization and surface morphological studies. The electrical properties of the composite films were examined through temperature-dependent direct current conductivity measurements at 300-500 K to understand the conduction behavior of the composites. The activation energy for electron transport was also calculated based on the conductivity data. The conductivity of the films was increased by increasing LSA concentration (wt%) in the PPy- LSA composites. The result can be attributed to the increased mobility of the charge carriers by the increased concentration of LSA in the composites. The incorporation of LSA in PPy can cause the cost-effective transformation of the conductive polymer of PPy into a biodegradable polymer.

리그노술폰산(LSA)을 함유한 폴리피롤 복합체를 암모늄퍼셜페이트 개시제를 사용하여 합성하였다. 이 때 포함시키는 리그노술폰산의 양은 달리 하였다. 합성된 폴리피롤 복합체에서 LSA가 폴리피롤 속에서 강한 화학 결합을 하고 있음을 UV와 IR 스펙트럼 방법과 표면성상 분석을 통해 확인하였다. 복합체의 온도 의존성 전도도 특성이 연구되었으며, 아울러 전도도 값을 통하여 전자 이동에 관한 활성화 에너지를 계산해보았다. 전기전도도는 LSA의 양이 증가할수록 증가하였는데, 이 결과는 LSA에 의한 전자 활성에 기인하는 것으로 여겨진다.

Keywords: lignosulfonic acid; electrical conductivity; polypyrrole; polymer composite