University of Zagreb. Faculty of Chemical Engineering and Technology.
Abstract
Vodljivi polimeri kombiniraju električna svojstva metala s prednostima polimera kao što su niža masa, jednostavnije oblikovanje, otpornost na koroziju te niža cijena. Zbog navedenih svojstava imaju raznovrsnu primjenu te se koriste kod kemijskih senzora i biosenzora, tranzistora i prekidača, superkondenzatora, fotonaponskih ćelija, elektrokromnih uređaja i dr. Poli(3,4-etilendioksitiofen) (PEDOT) se kao jedan od važnijih vodljivih polimera današnjice vrlo često koristi za izradu senzora za kontrolu i praćenje zdravlja. U radu je provedena sinteza zasebnih komponenti graft kopolimera, PEDOT/polistiren sulfonat (PSS) kao glavnog lanca, PEDOT/poli(metil vinil eter) (PMVE) kao bočnih lanaca, te sinteza dva uzorka PEDOT/PMVE-g-PEDOT/PSS graft kopolimera u trajanju od 15 i 60 minuta. Karakterizacija je provedena infracrvenom spektroskopijom s Fourierovim transformacijama (FT-IR) i termogravimetrijskom analizom (TGA); elektrovodljivost je određena metodom sondi s četiri točke, a digitalnim mikroskopom je snimljena morfologija uzoraka. Rezultati ispitivanja su pokazali da je vrijeme sinteze od 15 min prekratko jer nastaju dvije razdvoje faze, dok nakon 60 min sinteze nastaje PEDOT vodljivi polimer pri čemu dolazi do njegova povezivanja s bočnim lancima i nastajanja graft kopolimera. Sintetizirani PEDOT graft kopolimer je vodljiv, a što je stupanj razgranatosti i veličina bočnih grana veća vodljivost je niža.Conductive polymers combine the electrical properties of metals with the advantages of polymers such as lower mass, simpler shaping, corrosion resistance and lower cost. Due to these properties they have a variety of applications and are used in chemical sensors and biosensors, transistors and switches, supercapacitors, photovoltaic cells, electrochromic devices, etc. Poly(3,4-ethylenedioxythiophene) (PEDOT), as one of the most important conductive polymers today, is very often used to create sensors for health control and monitoring. In this work a synthesis of separate components of graft copolymers, PEDOT/polystyrene sulfonate (PSS) as main chain, PEDOT/poly(methyl vinyl ether) (PMVE) as side chains, and synthesis of two samples of PEDOT/PMVE-g-PEDOT/PSS graft copolymers with 15 and 60 minutes polymerization time was performed. Characterization was performed by infrared spectroscopy with Fourier transforms (FT-IR) and thermogravimetric analysis (TGA); the electrical conductivity was determined by the four-point probe method, and the morphology of the samples was recorded using a digital microscope. The test results showed that the synthesis time of 15 min is too short because two separate phases are formed, while after 60 min of synthesis, PEDOT conductive polymer is formed whereby it is bonded to side chains and the graft copolymer is formed. The synthesized PEDOT graft copolymer is conductive, and the higher the degree of branching and the size of the lateral branches is, the lower is the conductivity
