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Search Publications by

Anthony Kotula (Fed)

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Displaying 1 - 19 of 19

Percolation implications in the rheology of crystallization

October 26, 2020
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
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
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
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
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


June 19, 2019
Jonathan E. Seppala, Anthony P. Kotula, Chad R. Snyder

Flow-induced crystallization during materials extrusion additive manufacturing

September 10, 2018
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
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
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
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
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