Synthesis of chitosan-graft-polyaniline with the conductive potential

Abstract

Chitosan (CS) is one of the most plenteous polymers in nature and gets ubiquitous in many  fields  such  as  pharmaceutical  and  medical  industries,  wastewater  treatment,  agriculture, etc.due  to  its  remarkable biodegradability  and  friendliness  to  human  beings  and  ecology. Recently,  nature-originated  conductive  materials  havebeen  gaining  more  attention  than  other materials because  they  can  be  utilized  in  reality,  while  others are  difficultto  decompose  after use.  Understandably,  polyaniline  (PANI),  which  is  one  of  the  prominent  conductive  polymers with  a  distinguished  conjugated  structure,  simple  synthesis,  cost-effectiveness,  environmental stability,  and  conductivity,  was  grafted  with  CS  (CS-graft-PANI)  to  produce  a  copolymer possessing a combination of properties between CS and PANI. Althoughthere have been several researchesrelated  to  this  copolymer,  the  grafting  efficiency  and  electrical  conductivity  wererelatively  low.  Therefore,  this  paper  aims  at  obtainingahigher  efficiency  and  electrical conductivity of CS-graft-PANI copolymerby systematically adjusting the synthesis parameters including  the  volume  of  acid  solution  to  dissolve  aniline,  initiator  concentration,  acetic  acid concentration to dissolve CS, the initiator methods and dopants. As a result, the best copolymer product reached a graft efficiency of 69.4% and grafting percentage of 78.5% with an electrical conductivity  of 7.9610-3 Scm-1.  The  chemical  composition  and  morphology  were determinedby  Fourier-transform  Infrared  Spectroscopy  and  Scanning  Electron  Microscope  while  the thermal characteristic was also carefully detected via Thermogravimetric Analysis.