Virginia Tech
    • Log in
    View Item 
    •   VTechWorks Home
    • ETDs: Virginia Tech Electronic Theses and Dissertations
    • Masters Theses
    • View Item
    •   VTechWorks Home
    • ETDs: Virginia Tech Electronic Theses and Dissertations
    • Masters Theses
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Tribopolymerization: Anti-Wear Behavior of New High Temperature Additive Classes

    Thumbnail
    View/Open
    1_JJV_Thesis_1_of_3.pdf (796.2Kb)
    Downloads: 256
    2_JJV_Thesis_2_of_3.pdf (1.348Mb)
    Downloads: 37
    3_JJV_Thesis_3_of_3.pdf (725.7Kb)
    Downloads: 30
    Date
    1997-08-19
    Author
    Valentino, Jeffrey Joseph
    Metadata
    Show full item record
    Abstract
    Advanced ceramic materials have found many new applications in the automotive and other industries. To satisfy demands of higher temperatures and inert surfaces, new lubrication methods for these ceramics need explored and evaluated. This thesis focuses on a boundary lubrication method termed tribopolymerization -- the formation of polymers at the tribological interphase. The research evaluated new high-temperature classes of anti-wear additives. The work involved experiments on steel and alumina material pairs with a pin-on-disk tribometer used to explore the anti-wear capabilities of selected additives in the liquid phase at concentrations of 1% by weight in hexadecane.

    New additives included aromatic compounds with various pendant groups adding the design functionality necessary for in-situ polymerization. The amino, hydroxyl, acid, and ester functional groups underwent studies across several aromatic molecular compositions while new heterocyclic additives, in particular the readily available lactams, underwent exploratory tests as a new class under the tribopolymerization design approach. In concentrations of 1%, additives showed significant wear reductions of up to 99.9 %. Anti-wear behavior persisted in select cases at concentrations as low as 0.1% by weight. Compounds from two new classes demonstrated anti-wear behavior at 6x the frictional heat generation of standard exploratory conditions. This surprising effect partially filled a void in the effective range of operating conditions between 0.25 m/s, 40 N and 1.0 m/s, 160 N. Earlier work by Tritt found a complete absence of anti-wear behavior for the previous additive classes at the high-speed conditions.

    In addition, several individual compounds constituent to an A-R-A + B-R'-B condensation polymerization reaction demonstrated significant anti-wear behavior when used alone. In particular, the compound BTDA from DuPont's Kapton ® exhibited higher wear reductions than any other new additive.

    These findings support tribopolymerization as an effective approach to boundary lubricant design. Low wear was often associated with an attached reaction debris layer. This finding is consistent with previous work involving tribopolymerization anti-wear additives with ceramics. Further research into the roles of the debris layer and tribochemistry will help in understanding the complex anti-wear behavior of these new high-temperature additive classes.

    URI
    http://hdl.handle.net/10919/41888
    Collections
    • Masters Theses [19615]

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us
     

     

    VTechWorks

    AboutPoliciesHelp

    Browse

    All of VTechWorksCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Log inRegister

    Statistics

    View Usage Statistics

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us