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Search Publications by: Anthony Kotula ()

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Displaying 1 - 23 of 23

Reaction-Induced Phase Separation (RIPS) in Amine-Cured Epoxy/Epoxy Thermosets.2. Visualization of Heterogeneity using Fluorescence Lifetime Imaging Microscopy (FLIM)

February 25, 2023
Author(s)
Jeremiah Woodcock, Stephan J. Stranick, Anthony Kotula, Gale A. Holmes
The strategic integration of a rhodamine-spirolactam (RS) mechanophore into a transparent bis-epoxide/bis-epoxide/amine and corresponding bis-epoxide/amine networks has revealed, for the first time using fluorescence lifetime imaging microscopy (FLIM)

Crystallization Kinetics in an Immiscible Polyolefin Blend

December 12, 2022
Author(s)
Derek Huang, Anthony Kotula, Chad R. Snyder, Kalman Migler
Motivated by the problem of brittle mechanical behavior in recycled blends of high density polyethylene (HDPE) and isotactic polypropylene (iPP), we employ optical microscopy, rheo-Raman, and differential scanning calorimetry (DSC) to measure the

Time-gated Raman spectroscopy of recovered plastics

July 1, 2022
Author(s)
Anthony Kotula, Sara Orski, Kayla Brignac, Jennifer Lynch, Bryan Heilala
Raman spectroscopy is a powerful non-destructive technique for the identification and characterization of plastics. The technique often has limited use due to fluorescence emission, which often occurs in polymer samples containing colorants or that have

Engineering 3D Printed Scaffolds with Tunable Hydroxyapatite

June 15, 2022
Author(s)
Yoontae Kim, Eun Jin Lee, Anthony Kotula, Shozo Takagi, Laurence C. Chow, Styliani Alimperti
Bone grafting is a surgical procedure to bone repair due to trauma or diseases in the craniofacial and dental area. Current limitations of autogenous and allogeneic grafts are often associated with reduced host-graft integration due to geometrical confor

Percolation implications in the rheology of crystallization

October 26, 2020
Author(s)
Anthony P. Kotula, Kalman D. Migler
The rheology of polymer crystallization is an old problem that often defies explanation due to the complex interrelationships between crystallization and flow properties. Although separate measurements of rheology and crystallinity can give some

Rheology of Crystallizing LLDPE

October 8, 2020
Author(s)
Marat Andreev, David Nicholson, Anthony Kotula, Jonathan D. Moore, Jaap Den Doelder, Gregory C. Rutledge
Polymer crystallization occurs in many plastic manufacturing processes, from injection molding to film blowing. Linear low-density polyethylene (LLDPE) is one of the most commonly processed polymers, wherein the type and extent of short chain branching

Precision, Tunable Deuterated Polyethylene via Polyhomologation

July 22, 2019
Author(s)
Wesley Farrell, Sara Orski, Anthony Kotula, Kathryn Beers, Daniel Baugh
Polyhomologation (also known as "C1 polymerization") of a deuterated ylide has been performed, which yields linear polyethylene of high deuterium content. Copolymerization with the protonated analog allows for the preparation of sta-tistical copolymers, in

Measuring & Predicting Crystal Morphology in Fused Deposition Modeling

June 19, 2019
Author(s)
Claire McIlroy, Jonathan Seppala, Anthony Kotula
Semi-crystalline polymer melts are commonly used in fused deposition modeling. Although flows have a profound effect on polymer crystallization, the relationship between typical fused deposition modeling (FDM) deformation rates and printed-part crystal

Polymer Additive Manufacturing: Confronting Complexity

June 19, 2019
Author(s)
Anthony P. Kotula, Jonathan E. Seppala, Chad R. Snyder
Since its development and commercialization in the 1980s, polymer additive manufacturing (AM) has become a disruptive technology. In this chapter we describe the ever-increasing demands for polymer AM in industry, academia, and government, as well as the

Preface

June 19, 2019
Author(s)
Jonathan E. Seppala, Anthony P. Kotula, Chad R. Snyder

Flow-induced crystallization during materials extrusion additive manufacturing

September 10, 2018
Author(s)
Lily Northcutt, Sara Orski, Kalman D. Migler, Anthony Kotula
Material extrusion additive manufacturing processes force molten polymer through a printer nozzle at high (> 100 s-1) wall shear rates prior to cooling and crystallization. These high shear rates can lead to flow-induced crystallization in common polymer

Raman Identification of Multiple Melting Peaks of Polyethylene

August 1, 2017
Author(s)
Ying Jin, Anthony P. Kotula, Chad R. Snyder, Angela R. Hight Walker, Kalman D. Migler, Young J. Lee
Multiple melting peaks of high-density polyethylene produced by complex thermal pre-treatment are investigated with variable temperature Raman spectroscopy and differential scanning calorimetry (DSC). We examine the origin of the observed multiple melting

The rheo-Raman microscope: Simultaneous chemical, conformational, mechanical, and microstructural measures of soft materials

October 4, 2016
Author(s)
Anthony P. Kotula, Matthew Meyer, Francesca De Vito, Jan Plog, Angela R. Hight Walker, Kalman D. Migler
We describe the design and demonstrate performance of an instrument capable of simultaneous Raman spectroscopy, rheology, and optical microscopy of materials. The instrument couples a Raman microscope with a rotational rheometer through an optically

Bottom Up Approaches to Improved Polyolefin Measurements

February 4, 2016
Author(s)
Sara Orski, Thomas W. Rosch, Anthony Kotula, Richard J. Sheridan, Frederick R. Phelan Jr., Kalman Migler, Chad R. Snyder, Luis F. Vargas Lara, Jack F. Douglas, Kathryn L. Beers
As a class of materials, polyolefins remain the largest production volume polymer in the world, as well as a highly desirable medium from which to engineer high performance and advanced properties for new applications. After decades of research, there are

Mesomorphic Pathway in Early Stage Crystallization of Polyethylene

June 18, 2015
Author(s)
Kalman D. Migler, Angela R. Hight Walker, Anthony P. Kotula
The kinetic pathway by which a molten polymer transforms into a multi-length scale semi-crystalline structure upon cooling is an unsolved problem in polymer physics, yet it is critical to the processing, properties and ultimate performance of these