Mechanical properties of conductive polymer composites with coated copper flakes

Za izdelavo funkcionalnih senzoričnih sistemov potrebujemo materiale s tremi različnimi lastnostmi, to so strukturni, senzorični in prevodni materiali. Strukturni material je neprevodni polimer, ki senzoričnemu sistemu nudi trdnost in togost. Senzorni material je običajno material na osnovi ogljika, kot so na primer grafen, saje in ogljikove nanocevke. Prevodni material pogosto predstavlja največji izziv. Pri prenosu signala lahko njegova upornost povzroča zamik, šum ali pregrevanje elementov, posledica tega je lahko velika merilna napaka ali nedelovanje sistema. V diplomski nalogi smo se osredotočili na visoko prevodne kompozitne filamente za 3D tisk na polimerni osnovi s kovinskimi delci. Opredelili smo njihove mehanske lastnosti, poleg tega pa smo opredelili tudi mehanizme, ki vplivajo na vzpostavitev geometrijskega in prevodnega omrežja. V eksperimentalnem delu so prikazani rezultati, ki potrjujejo, da je mogoče z dodajanjem kovinskega polnila v polimerno matrico vzpostaviti prevodno omrežje znotraj kompozita in pri tem obdržati ugodne mehanske lastnosti polimera.To create functional sensor systems, we need materials with three distinct properties: a structural material, a sensoric material and a conductive material. The structural material is a non-conductive polymer which provides rigidity, stiffness and solidity to sensor system. The sensoric material is usually based on carbon in forms of graphene, soot or carbon nano-tubes. The conductive material is often the biggest challenge. When transmitting the signal, its resistance can cause noise, delay or overheating of elements which can result in large measurement errors or system failure. The thesis will focus on highly conductive polymer composite filaments for 3D printing which are based on polymer matrix with metal particles. The mechanical properties of such composites and mechanisms that affect the establishment of a geometric and conductive mesh will be defined. Results in the experimental part of this thesis will confirm that it is possible to add metal particles to a polymer material in order to form a conductive mesh without losing the favorable mechanical properties of the polymer