Optimization of Alkyl Methacrylate Terpolymer Properties as Lubricating Oil Rheology Modifier

Abstract

Solution terpolymerization processes of methyl methacrylate, dodecyl methacrylate, and octadecyl methacrylate using bifunctional 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane or monofunctional tert-butylperoxy-2-ethylhexanoate initiator were investigated. The first set of terpolymerizations was performed in 2 M xylene solutions, isothermally at 91, 100, 105, and 115 °C. The terpolymerization kineticsconcentrations of molecular species, kinetic chain length, molar mass averages as functions of the reaction timewas modeled by the Villermaux−Blavier tendency kinetic model for radical polymerization. Complete monomer conversions and high molar masses of terpolymers were achieved in a simple batch process with bifunctional initiator. The second set of polymerization reactions was performed in 2 M mineral base oil solutions, under isothermal conditions at 115 and 120 °C, using the bifunctional initiator. By varying the monomer mixture composition and concentrations of the initiator and chain transfer agent, n-dodecyl mercaptan, the terpolymers of different composition and molar mass were obtained. The solution properties of alkyl methacrylate terpolymers as lubricating oil rheology modifierskinematic viscosity, viscosity index, shear stability, and pour pointwere established. A strong correlation between molar mass distribution of synthesized polymers and rheological properties of polymer solutions was revealed by an applied optimization procedure.

Terpolymerization kinetics of methyl methacrylate or styrene/dodecyl methacrylate/octadecyl methacrylate systems

“…10, to confirm again that insignificant departures of x F (MMA) from x f (MMA) values are to be expected in the system studied. Moreover, it has been shown previously that even a pseudo‐homopolymerization approximation may be efficient in describing the kinetics of similar systems 30, 31. To confirm this, we used the Alfrey–Goldfinger equation for the calculation of unitary ( x f = x F ) and binary ( x f / x f = x F / x F ) azeotropic curves 32–34.…”

Reactivity ratios and copolymer properties of 2‐(diisopropylamino)ethyl methacrylate with methyl methacrylate and styrene

“…the attached functional group does not significantly influence the polymerization reactivity. Therefore, copolymerization of methacrylate monomers is very often considered as a pseudo‐homopolymerization even if there are three different monomers involved . Methacrylate monomer copolymerizations are particularly useful from the practical point of view: functionalization of the monomer ester group substantially changes the properties of the polymer product (e.g.…”

“…Therefore, copolymerization of methacrylate monomers is very often considered as a pseudo-homopolymerization even if there are three different monomers involved. 33 Methacrylate monomer copolymerizations are particularly useful from the practical point of view: functionalization of the monomer ester group substantially changes the properties of the polymer product (e.g. by changing the length of the alkyl chain, T g can be varied from 100 ∘ C for wileyonlinelibrary.com/journal/pi poly(methyl methacrylate) (PMMA) to −100 ∘ C for poly(octadecyl methacrylate) 34 ) while at the same time the polymerization mechanism and reactivity ratios do not change much.…”

A Comparative Study of the Influence of Different Types of Polymers on Viscosity Index and Pour Point of Iraqi Base Oils

“…The molecules of this family members are hydrocarbons that have the ability to extend forming big size arrangements that raise the viscosity of the oil at higher temperatures i.e. increase the stability of oil viscosity against temperature change [25], [26].…”