Električna provodnost i karakterizacija polimernih kompozita punjenih hemijski i elektrohemijski dobijenim prahovima metala
Electrical conductivity and characterization of polymer composites filled with chemically and electrochemically obtained metal powders
Метаподаци
Приказ свих података о дисертацијиСажетак
Povezivanje dva ili više različitih sastojaka u jednu supstancu daje gotovo
beskrajne mogućnosti za stvaranje novih inženjerskih materijala. Ovi materijali, koji se
zovu kompozitni materijali, mogu se karakterizovati nizom različitih osobina, stoga ova
čuda inženjerstva se široko koriste u skoro svim oblastima industrije i nauke, posebno u
automobilskoj, električnoj i elektronskoj, vazduhoplovnoj, građevinskoj i mašinskoj
industriji, sportu i razonodi itd. Primena kompozitnih materijala je svestrana i u svim
sferama industrije i života, te se elektroprovodni kompoziti koriste u industriji računara
i elektronskih komponenti, elektroopremi, avioindustriji, kao hladni varovi. Ovi
materijali se koriste i kao prekidači, elektromagnetni štitovi, kao zaštita od strujnog i
naponskog udara, provodni lepkovi, u građevinarstvu., kao elektrode za solarne ćelije na
bazi boja. Oni su takođe našli tehnološku primenu kao grejači sa samoregulatorima,
elektronski i hemijski nosevi i senzori, ...fototermički optički snimači, kao adsorbensi i
hemijski i elektrohemijski katalizatori, i u novije vreme u uređajima za skladištenje i
konverziju električne energije. Elektroprovodni polimerni kompoziti imaju nekoliko
prednosti u odnosu na svoje polazne gradivne supstance, a te prednosti uklјučuju manje
troškove i lakoću proizvodnje, manju težinu, visoku fleksibilnost, veću apsorpcionu
moć kada su u pitanju mehanički udari i mehanička naprezanja, imaju povećanu
otpornost prema koroziji i izrazitu kontrolu provodnosti.
U ovoj doktrorskoj disertaciji su prikazani eksperimentalni rezultati istraživanja
svojstava kompozitnih materijala na bazi poli(metil metakrilatne) - PMMA,
poli(laktidne)-PLA i poli(hidroksi butiratne)-PHB matrice punjenih elektrolitičkim
bakarnim prahom. Udeо metalnog punioca, odnosno elektrolitički dobijenog bakarnog
praha u ispitivanim kompozitnim uzorcima variran je u opsegu od 0.5-8.8 vol. %, a
uzorci su pripremljeni u molderu na povišenim temperaturama. U eksperimentalnom
delu za analizu i karakterizaciju metalnog punioca i polimernih matrica, te pripremljenih
kompozita korišćene su različite eksperimentalne metode i tehnike. Ove tehnike su
uključivale skening elektronsku mikroskopiju (SEM) i mikroskopiju atomskih sila
(AFM), čijom primenom su urađene mikrostrukturne i morfološke analize, a određena
je veličina i raspodela čestica konstituenata, kao i i električna provodnost kompozita u
zavisnosti od udela punioca metodom impedansne spektroskopije (IS)...
Connecting two or more different ingredients into one substance gives almost
endless possibilities for creating new engineering materials. These materials, which are
called composite materials, can be characterized by a variety of different properties,
and, therefore these engineering wonders are widely used in almost all areas of industry
and science. In particular, these materials are widely used in automotive industry,
electrical and electronic industry, aerospace, civil construction and mechanical
engineering, sports and leisure, etc. Composites with metal fillers have found their use
as electromagnetic protection of computers and electronic equipment, conductive
adhesives for electronic equipment, cold welds, switches, devices for removal of static
electricity, voltage protection devices, in dye based solar cells. They also found
technological applications in self-regulating heaters, as photothermic optical recorders,
chemical sensors and electronic noses, chemical and ...electrochemical catalysts and
adsorbents, supercapacitors. The electroconductive polymer composites have several
advantages over their constituents, and these advantages include lower costs and ease of
production, high flexibility, lower weight-to-price ratio, greater ability to absorb
mechanical impacts, corrosion resistance and conductivity control.
The experimental results of the properties’ investigations of composite materials
based on poly (methyl methacrylate) - PMMA, poly (lactide) - PLA and poly
(hydroxybutyrate) - PHB matrices filled with electrolytic copper powder are shown in
this thesisr. The volume fraction of metal filler in investigated composite materials was
varied in the range of 0.5-8.8 vol. %, and the samples were prepared in laboratory
molder at elevated temperatures. Various experimental methods and techniques were
used in the experimental part for the analysis and characterization methods and
tecniques were performed on the starting constituents and investigated composites.
Microstructural and morphological analysis was performed using scanning electron
microscopy (SEM) and atomic force microscopy (AFM). The size and particle
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distribution of the constituent was investigated, as well as the electrical conductivity of
the composites in dependance on volume fraction of filler.
The thesis deals with the synthesis and characterization of electroconductive
composite materials, primarily based on biodegradable polymers. Polymers were mixed
with electrochemically, i.e. galvanostatically produced copper powder. The effects of
particle size and morphology on the conductivity and percolation threshold of the
obtained composites was studied. Characterization included different testing techniques:
SEM, AFM, TGA, DSC, FTIR, particle size distribution and conductivity measurement
by the impedance spectroscopy method...