Priprava polimernih aditiva mazivih ulja kopolimerizacijom u baznom ulju

undergraduate thesis

• Title (english): Preparation of lubrication oil polymer additives by copolymerization in base oil
• Author: Mislav Mišetić
• 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: 2019-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada je provesti sintezu devet metakrilatnih terpolimera
poli(metil-metakrilat-co-lauril-metakrilat-co-stearil-metakrilat) i ispitati svojstva koja su ključna za njihovu primjenu kao aditiva za poboljšavanje primjensko-reoloških svojstava mazivih ulja. Sinteza polimernih aditiva vršila se lančanim mehanizmom radikalske polimerizacije u tri otopine baznih ulja (SN-150, Yubase 4, PAO 4) s različitim udjelima prijenosnika rasta lančane reakcije (n-dodecil-merkaptan) tijekom 240 minuta. Polimerizacije su provedene pri izotermnim uvjetima (95 ± 2 °C) u šaržnom kotlastom reaktoru uz monofunkcionalni peroksidni inicijator (tert-butil-peroksi-2-etilheksanoat). Ispitano je kako različiti udjeli prijenosnika rasta lančane reakcije i različita bazna ulja djeluju na konačna svojstva polimernih PAMA aditiva. GPC analizom određene su krivulje raspodjele molekulskih masa i prosjeci molekulskih masa iz kojih vidi kako povećanjem udjela prijenosnika rasta lančane reakcije nastaje polimer prosječno kraćeg lanca i manje molekulske mase. Detaljnom analizom 1H NMR spektara uzoraka praćena je konverzija monomera tijekom reakcije i ustanovljeno je kako vrsta baznog ulja i udio prijenosnika rasta lanca ne utječu značajno na završnu konverziju reakcije (od 98,04 do 99,03 %). Refraktometrijskom analizom zaključeno je kako indeks refrakcije prati sličan trend porasta kao i konverzija reakcije te da se konačan indeks refrakcije postiže već na polovici trajanja reakcije. Iz rezultata DSC analize, kojom su određena toplinska svojstva sintetiziranog aditiva, vidi se kako povećanjem udjela prijenosnika rasta lančane reakcije, odnosno smanjenjem mase polimera rastu entalpija kristalizacije i temperatura maksimuma kristalizacije. Reološkom analizom otopina terpolimera određena je ovisnost smičnog naprezanja te dinamičke viskoznosti o smičnoj brzini iz koje je zaključeno kako vrsta baznog ulja znatno utječe na viskoznost te da se viskoznost polimerizata značajno smanjuje s porastom udjela prijenosnika rasta lančane reakcije.

Abstract (english)

The aim of this study was the synthesis of nine methacrylate terpolymers of
poly(methyl methacrylate-co-lauryl methacrylate-co-stearyl methacrylate) in order to explore properties that are crucial for their application as additives for improving rheological properties of lubrication oil. Synthesis of polymer additives were conducted by radical
chain-growth polymerization in three base oil solutions (SN-150, Yubase 4, PAO 4) with different amounts of the chain transfer agent (n-dodecyl mercaptan) during 240 minutes. Polymerisation of these compounds was performed under the isothermal conditions
(95 ± 2 °C) in batch reactor with monofunctional peroxide initator
(tert-butyl peroxy-2-ethylhexanoate). How different amounts of the chain transfer agent and different base oils affect the final properties of polymer PAMA was examined. GPC analysis defined the molecular weight distribution curves and the averages of molecural weights from which it can be seen that by increasing amount of the chain transfer agent, a polymer with average shorter chain and smaller molecular weight was formed. Conversion of monomers was followed by detailed analysis of 1H NMR spectrum of synthesised compounds and it was established that the type of base oil and amount of the chain transfer agent have very low impact on the final reaction conversion (from 98,04 to 99,03 %). Refractometric analysis confirmed that the refractive index follows a similar upward trend as the conversion of the reaction and that the final refractive index was reached at the half of the reaction time. Results of the DSC analysis, which was used to define the thermal properties of the synthesised additive , indicate that the enthalpy of crystallization and the temperature of the crystallization maximum increase by increasing amount of the chain transfer agent and decreasing molecular weight of the polymer. Rheological analysis was used to determine the correlation of shear stress and dynamic viscosity on shear rate, from which it was concluded that the type of base oil significantly affects the viscosity and that the viscosity of the fluid decreases with the increase of amount of the chain transfer agent.

• Keywords: metakrilatni terpolimer; radikalska kopolimerizacija; aditivi mazivih ulja; GPC; NMR; indeks refrakcije; DSC; viskoznost
• Keywords (english): methacrylate terpolymer; radical copolymerization; lubrication additives; GPC; NMR; refractive index; DSC; viscosity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:043239
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-05-26 09:06:36