Degree Type

Thesis

Date of Award

2019

Degree Name

Master of Science

Department

Mechanical Engineering

Major

Mechanical Engineering

First Advisor

Sriram Sundararajan

Abstract

EFFECT OF PLASTICIZER ON THE WEAR BEHAVIOR AND ICE ADHESION OF ELASTOMERIC COATINGS

The aim of this paper is to study the effect of wear on the ice adhesion of elastomeric coatings. Approaches in designing surfaces with lower ice adhesion include imparting hydrophobicity, lubrication, crosslink density reduction or induction of interfacial slippage. For icephobic surfaces to find widespread use, it is imperative that they are durable. In the current work, a suitable plasticizer is used to modify the cross-link density and stiffness of a polyurethane elastomeric coating. The wear behavior of the modified elastomer under two body abrasion is studied in terms of its weight loss and topography evolution. The wear loss varies with the coating stiffness, wherein the elastomer with lower stiffness exhibits higher weight loss. The evolution of surface topography as a function of wear is analyzed in terms of roughness parameters and autocorrelation length, and its effect on the ice adhesion behavior of the coating. The results show that wear initially increases ice adhesion, but adhesion reduces as wear propagates due to the evolution of surface topography. The study shows that, among the samples tested, a 20% - 30% plasticizer content produces a good combination of icephobicity and wear resistance.

AN INVESTIGATION ON ICE ADHESION AND WEAR OF SURFACES WITH DIFFERENTIAL STIFFNESS

Ice adhesion is known to be higher on stiff metallic surfaces and lower on compliant polymeric surfaces. In designing icephobic surfaces, one approach is to use surfaces with lower stiffness. However, surfaces with lower stiffness typically exhibit poor wear resistance. The aim of this study is to create a patterned surface with differential stiffness in such a way that there is always a shared contact between stiff and compliant surfaces, and to study the possibility of such surfaces having an optimal balance of low ice adhesion and favorable wear resistance. The paper proposes a novel approach in designing durable icephobic surfaces for contact applications. Patterned surfaces with alternating layers of stiff aluminum and compliant polyurethane elastomer were fabricated. The ice adhesion and wear behavior of such patterned surfaces are reported. The ice adhesion as a function of the metal-polymer contact area ratio is studied, and patterned surfaces show reduced ice adhesion compared to a plain aluminum surface. Reciprocating ball-on-flat sliding tests is used to study the wear behavior of the surfaces. The wear resistance of the patterned surfaces is presented in terms of the wear depth, and patterned surfaces show increased wear resistance compared to a plain polyurethane surface. The surface engineering approach outlined in the paper shows promise in realizing icephobic surfaces with durability under contact conditions.

Copyright Owner

Jocelyn Lachelle Jackson

Language

en

File Format

application/pdf

File Size

56 pages

Available for download on Wednesday, July 21, 2021

Included in

Engineering Commons

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