Utjecaj molne mase polimernog aditiva na sniženje tecišta motornog ulja

master's thesis

• Title (english): Effect of molecular weight of polymer additive on pour point depression of motor oil
• Author: Lucija Lovreškov
• Mentor: Ante Jukić (mentor)
• Committee member: Ante Jukić (predsjednik povjerenstva)
• Committee member: Fabio Faraguna (član povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2015-12-14, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Reaction Engineering

Abstract

U ovom radu istraživana su svojstva polimernih aditiva mazivih ulja na osnovi poli(metil-metakrilat-co-dodecil-metakrilat-co-oktadecil-metakrilata) različitih sastava. Sinteza polimernih aditiva provela se kopolimerizacijom triju monomera radikalskim mehanizmom uz monofunkcionalni peroksidni inicijator i n-dodecil merkaptan kao prijenosnik rasta lanca, u otopini mineralnog baznog ulja, pri izotermnim uvjetima (91 °C). Udjel monomera u otopini bio je u 50 mas. %. Polimerizacije su provedene u šaržnom kotlastom reaktoru. Sintetizirano je 13 polimernih aditiva različitih sastava i uz različite koncentracije prijenosnika lančane reakcije. Konverzija monomera i sastav sintetiziranih polimernih aditiva određeni su 1H-NMR spektroskopijom. Dobivene su konverzije od 97-99,5 % te je utvrđeno da sastav reakcijske smjese nema značajnog utjecaja na konverziju provedenih reakcija. Sastavi kopolimera ne razlikuju se znatno od početnih sastava smjesa monomera. Raspodjele molekulskih masa polimera određene su kromatografijom isključenja prema veličini. Dobivene su unimodalne krivulje raspodjele, a maseni prosjeci za sintetizirane polimere se kreću od 239 do 451kg mol^-1. Diferencijalnom pretražnom kalorimetrijom istražena su toplinska svojstva otopina polimera u ulju (polimerizacijskih šarži). Smanjenjem udjela metil-metakrilata i povećanjem dodecil-metakrilata i oktadecil-metakrilata u terpolimeru dolazi do pomaka temperatura taljenja i kristalizacije prema višim vrijednostima. Povećanjem udjela komonomera s dugolančanim bočnim skupinama raste udio kristalne faze. Dobiveni rezultati iskorišteni su za modeliranje svojstava polimernih aditiva upotrebom računalnog programa Design Expert kako bi se odredilo optimalno područje primjene aditiva. Modeliranjem su dobiveni značajni modeli za međuovisnost temperature kristalizacije i viskoznosti razrijeđenih otopina o strukturi i sastavu polimera. Iz dobivenih rezultata zaključuje se da se sintetizirani polimerni aditivi mogu koristiti kao snižavala tecišta kako bi se unaprijedila primjenska svojstva mineralnog baznog ulja.

Abstract (english)

In this thesis properties of poly(methyl-methacrylate-co-dodecyl-methacrylate-co-octadecyl-methacrylate) with different compositions were added to base mineral oil and were investigated as pour point depressant. Synthesis of polymeric additives was conducted by free-radical copolymerization with monofunctional peroxide initiator and n-dodecyl mercaptan as chain transfer agent, in mineral oil as a solvent, under isothermal conditions (91 °C). Monomers share in a solution was 50 wt. %. Polymerizations were conducted in batch reactor. Total of 13 polymer additives were synthesized with different share of monomers and with different amount of chain transfer agent. Conversion and composition of additives were determined by 1H-NMR spectroscopy. Conversion ranged from 97.0 to 99.5 % and there was no influence of composition on the obtained conversion. Composition of polymer additives did not differ a lot from initial monomer mixture. Molecular weight distributions were determined with gel permeation chromatography. Unimodal distribution curves were obtained and molecular weight averages of synthesized polymer additives ranged from of 239 to 451 kg mol^-1. Differential scanning calorimetry was used to determine thermal properties of polymers in mineral oil. Share decreases of of methyl methacrylate in polymer causes increase of melting temperature and crystallization temperatures. Crystalline phase share in polymer increases with share of long side chain comonomers. Obtained results were processed by Design Expert program to determine optimal application properties of pour point depressants. Valid models were obtained that show corelation between crystallization temperature and viscosity of diluted solutions with polymer composition. The results indicate that synthesized polymers have adequate (satisfactory) abilities to be used as pour point depressants.

• Keywords: mineralno bazno ulje; metil-metakrilat; dodecil-metakrilat; oktadecil-metakrilat; polimerni aditiv; tecište
• Keywords (english): base mineral oil; methyl-methacrylate; dodecyl-methacrylate; octadecyl-methacrylate; polymer additive; pour point
• Language: croatian
• URN:NBN: urn:nbn:hr:149:134394
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-03-20 14:12:34