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Full-Text Articles in Engineering Science and Materials

Effects Of Nanoscale Aggregation On Mechanical Properties And Local Dynamics Of Precise Acid- And Ion-Containing Polymers, Luri Robert Middleton Jan 2016

Effects Of Nanoscale Aggregation On Mechanical Properties And Local Dynamics Of Precise Acid- And Ion-Containing Polymers, Luri Robert Middleton

Publicly Accessible Penn Dissertations

Acid- and ion-containing polymers have interchain interactions that alter polymer behavior at the nano, micro, and bulk length scales. Strong secondary-bonds act as thermo-reversible physical crosslinks between chains which drive self-assembly. Tuning theses interactions can modify bulk polymer properties including stiffness, toughness, melt viscosity, resilience, clarity, abrasion resistance and puncture resistance. Furthermore, understanding and improving the relevant factors that control transport properties would have vast implications on developing solid polymer electrolytes (SPEs) for technologically important applications including water desalination, ion exchange membranes and microelectronics. This thesis explores the structure – processing – morphology - property relationships of acid and ionic functionalized polymers.

Improvements ...


Morphologies And Dynamics In Low-Tg Single-Ion Conductors: Effects Of Comonomers, Plasticizers, And Functionalized Nanoparticles, Michael Vincent O'Reilly Jan 2014

Morphologies And Dynamics In Low-Tg Single-Ion Conductors: Effects Of Comonomers, Plasticizers, And Functionalized Nanoparticles, Michael Vincent O'Reilly

Publicly Accessible Penn Dissertations

ABSTRACT

MORPHOLOGIES AND DYNAMICS IN LOW-Tg SINGLE-ION CONDUCTORS: EFFECTS OF COMONOMERS, PLASTICIZERS, AND FUNCTIONALIZED NANOPARTICLES

Michael V. O'Reilly

Karen I. Winey

Single-ion conducting polymers, or ionomers, are under extensive investigation for applications as solid electrolytes in battery applications. Slow segmental dynamics of viscous ionomers make them inadequately poor conductors. Faster segmental dynamics are attained by decreasing the glass transition temperature (Tg) of the ionomer. Three compositional avenues are presented to reduce the Tg of a PEO-based lithium conducting ionomer (Tg ~ -12 °C): copolymers, blends, and nanocomposites. A fourth study employs weak-binding salts and flexible siloxanes to achieve a ...


Morphologies Of Precise Polyethylene-Based Acid Copolymers And Ionomers, Francisco Buitrago Jan 2013

Morphologies Of Precise Polyethylene-Based Acid Copolymers And Ionomers, Francisco Buitrago

Publicly Accessible Penn Dissertations

Acid copolymers and ionomers are polymers that contain a small fraction of covalently bound acidic or ionic groups, respectively. For the specific case of polyethylene (PE), acid and ionic pendants enhance many of the physical properties such as toughness, adhesion and rheological properties. These improved properties result from microphase separated aggregates of the polar pendants in the non-polar PE matrix. Despite the widespread industrial use of these materials, rigorous chemical structure - morphology - property relationships remain elusive due to the inevitable structural heterogeneities in the historically-available acid copolymers and ionomers.

Recently, precise acid copolymers and ionomers were successfully synthesized by acyclic ...