Synthesis and tribological testing of poly(methyl methacrylate) particles containing encapsulated organic friction modifier

Abstract

The tribological behaviour of polymer particles containing an encapsulated, organic friction modifier (FM) is presented. Particles comprising of a poly (methyl methacrylate) (PMMA) shall and a methanol core, into which FM was dissolved, were produced via a dispersion polymerization producing a core-shell morphology. The inclusion of these particles dramatically increased the overall concentration of FM which could be blended into dodecane. The tribological behaviour of the particles produced, both with and without encapsulated FM, was tribologically tested in pure dodecane. The addition of as little as 1.5 wt% particles was found to decrease the friction coefficient and measured wear volumes below those for dodecane saturated with FM. Data suggests that the FM delivery method may be dominated by a bursting mechanism.

Effect of Molecular Weight on Tribological Properties of Polyether Amine Derivatives under Different Contact Modes

“…OFMs do not contain harmful and metallic elements, which can meet the requirements of environmental protection and energy conservation. Thus, they have application value in the development of future additives [9,[20][21][22][23][24][25][26][27][28][29][30]. So far, reports on OFMs mainly focus on the performance comparison, formulation development and mechanism research of existing molecular structures.…”

Smart-Responsive Colloidal Capsules as an Emerging Tool to Design a Multifunctional Lubricant Additive

“…The microencapsulation technique has been implemented in lubricant additive research and development to reduce the use of the harmful organic substances, , which shows potential applications in automotive engine oil and hot metal working lubricants, respectively. Such a technique will not only unite all functional additives in one formula but it also limits the interaction between the added components, therefore maintaining the functions of the core active ingredients.…”

“…26 It leads to the use of several organic surfactants or dispersants (potentially harmful to the environment) to prevent the agglomeration and unexpected interactions at large concentrations, while ensuring the uniform dispersion of such functional additives in the base lubricant. 28,29 The microencapsulation technique has been implemented in lubricant additive research and development to reduce the use of the harmful organic substances, 30,31 which shows potential applications in automotive engine oil and hot metal working lubricants, respectively. Such a technique will not only unite all functional additives in one formula but it also limits the interaction between the added components, therefore maintaining the functions of the core active ingredients.…”

“…On the one hand, it is not clear that encapsulated additives work better in terms of friction than the conventional form of additives as the improved friction cannot be clearly attributed to either a polymeric shell or functional core or a combination of both. 30 On the other hand, the original strategy from the reported literature 31 and patent 30 utilizes the permeable polymeric shell (e.g., poly urea-formaldehyde, polymethyl methacrylate...) and the concentration gradient to control the release of the coreactive ingredients, 34 without considering the possibility of the capsule breakage under mixed/boundary lubrication. It has been demonstrated that the majority of the added microcapsules (∼70%) are likely squeezed then crumbled under mixed and boundary lubrication regimes.…”