Richard Kotek

Professor Kotek graduated from the Man-Made Fibers Institute at Lodz Polytechnic in Poland where he specialized in man-made fiber technology and polymer chemistry. He developed flame-retardant polyester fibers and completed his Ph. D. thesis under the direction of Professor B. Laszkiewicz.
Following completion of his Ph. D., he worked at the Man-Made Fibers Institute and then came to the United States to work as a postdoctoral research associate for Professor W. R. Krigbaum at Duke University.

While with Professor Krigbaum, Dr. Kotek carried out a liquid crystalline polymer research program. His work involved a new monomer and polymer synthesis. Soon after completing his postdoctoral assignment, he joined the R&D department at BASF Corporation (where he gained valuable industrial experience). He was involved in expanding fundamental understanding of spinning processes and also carried out studies on fiber morphology and molecular orientation. He developed and patented a new semi-continuous process for the depolymerization of nylon 6 polymer. Dr. Kotek also holds patents for making hollow fibers. He has extensive experience in fiber extrusion, particularly nylon and polyester fibers.

Dr. Kotek joined the Wilson College of Textiles at North Carolina State University in August 1999.

He is married and has two children, Magdalena and Kristof.

His wife, Elizabeth, is a licensed mechanical engineer practicing in the Triangle. Magdalena is a graduate of the School of Foreign Service at Georgetown University, and Kristof is a student at Athens Drive High School.

Dr. Kotek enjoys reading and playing tennis and golf. He is a youth soccer coach.

Research

Dr. Kotek is a polymer chemist with an interest in fundamental research on the structure/property, processing, and manufacturing (or synthesis) of fiber forming polymers particularly:

• Biopolymers and liquid crystalline polymers for specialized end uses.
• Nylon, polyester and polypropylene for use in industrial applications
• Fundamental research on the formation of hollow fibers.
• Molecular orientation of complex filaments by using sound propagation techniques.
• Adhesion of polymer melts to metal surfaces.
• Efficient depolymerization and/or recovery of monomers from fibrous materials.

Publications

Melt-spun PLA liquid-filled fibers: physical, morphological, and thermal properties

Naeimirad, M., Zadhoush, A., Neisiany, R. E., Salimian, S., & Kotek, R. (2019), JOURNAL OF THE TEXTILE INSTITUTE, 110(1), 89–99. https://doi.org/10.1080/00405000.2018.1465336

A review on aerogel: 3D nanoporous structured fillers in polymer-based nanocomposites

Salimian, S., Zadhoush, A., Naeimirad, M., Kotek, R., & Ramakrishna, S. (2018), POLYMER COMPOSITES, 39(10), 3383–3408. https://doi.org/10.1002/pc.24412

Recent advances in core/shell bicomponent fibers and nanofibers: A review

Naeimirad, M., Zadhoush, A., Kotek, R., Neisiany, R. E., Khorasani, S. N., & Ramakrishna, S. (2018), Journal of Applied Polymer Science. https://doi.org/10.1002/app.46265

Development of high-tenacity, high-modulus poly(ethylene terephthalate) filaments via a next generation wet-melt-spinning process

Yoon, J. H., Avci, H., Najafi, M., Nasri, L., Hudson, S. M., & Kotek, R. (2017), Polymer Engineering and Science, 57(2), 224–230. https://doi.org/10.1002/pen.24406

Production of polyolefins

Kotek, R., Afshari, M., Avci, H., & Najafi, M. (2017), Polyolefin Fibres: Structure, Properties and Industrial Applications, 2nd Edition, 189–264. https://doi.org/10.1016/b978-0-08-101132-4.00007-2

Novel cellulose-collagen blend biofibers prepared from an amine/salt solvent system

Boy, R., Narayanan, G., Chung, C. C., & Kotek, R. (2016), International Journal of Biological Macromolecules, 92, 1197–1204. https://doi.org/10.1016/j.ijbiomac.2016.08.010

Properties of cellulose-soy protein blend biofibers regenerated from an amine/salt solvent system

Boy, R., Bourham, M., & Kotek, R. (2016), Cellulose, 23(6), 3747–3759. https://doi.org/10.1007/s10570-016-1072-1

Properties of chitosan/soy protein blended films with added plasticizing agent as a function of solvent type at acidic pH

Boy, R., Maness, C., & Kotek, R. (2016), International Journal of Polymeric Materials and Polymeric Biomaterials, 65(1), 11–17. https://doi.org/10.1080/00914037.2015.1038821

Controlling of threadline dynamics via a novel method to develop ultra-high performance polypropylene filaments

Avci, H., Kotek, R., & Toliver, B. (2015), Polymer Engineering and Science, 55(2), 327–339. https://doi.org/10.1002/pen.23908

High-performance filaments by melt spinning low viscosity nylon 6 using horizontal isothermal bath process

Najafi, M., Avci, H., & Kotek, R. (2015), Polymer Engineering and Science, 55(11), 2457–2464. https://doi.org/10.1002/pen.24135

View All Publications

Grants

hIB MELT SPINNING PROCESS for PRODUCTION of ULTRA-HIGH TENACITY NYLON 6 TECHNICAL YARNS

Honeywell International, Inc.(8/15/15 - 4/15/16)

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hIB MELT SPINNING PROCESS for PRODUCTION of ULTRA-HIGH TENACITY NYLON 6 TECHNICAL YARNS

Sponsor: Honeywell International, Inc.

Start Date: 8/15/15

End Date: 4/15/16

Abstract

novel, NCSU-discovered technology, the horizontal liquid isothermal bath (hIB) process, is proposed to substantially promote the performance to cost ratio of the existing melt spin-draw process. The enhancement is accomplished via a scientifically pronged approach: ï‚· Improved fiber properties. Specifically, the world's strongest polyester fibers have been produced by using hIB in a practicable viable way; ï‚· Reduced production cost. The complex and expensive draw unit of the traditional melt spin-draw process is discarded and replaced by hIB ï‚· Sustainable and eco-friendly process. Liquid bath does not contain any chemicals harmful to the environment. The significantly improved fiber properties are attributed to a unique fiber morphology developed by using (hIB) which then transforms readily into a highly oriented, ordered crystalline structure under mild drawing and heatsetting. Thus, the fiber properties can be further improved by judiciously manipulating the threadline morphology under optimized (hIB) conditions. In brief, this proposal is intended to demonstrate an industrially applicable (hIB) technology with overwhelming superiority over the traditional melt draw processes to produce ultra-high performance fibers. In our process (hIB), we utilize only renewable and environmentally friendly media. The objective for the proposed technology development is to demonstrate a two-step hIB-drawing process for Honeywell nylon 6 polymers with a varying molecular weight. The multifilament (10 denier per filament) shall be spun at spinning speed in the vicinity of 3,000 m/min and subsequently drawn. The target tenacity up to 15 g/d is our goal.

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hIB Melt Spun/Melt Ordered Process for Production of Ultra-High Tenacity/Modulus Pet Technical Yarns

Truetzschler Group(11/01/15 - 12/31/16)

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hIB Melt Spun/Melt Ordered Process for Production of Ultra-High Tenacity/Modulus Pet Technical Yarns

Sponsor: Truetzschler Group

Start Date: 11/01/15

End Date: 12/31/16

Abstract

A novel, NCSU-discovered technology, the horizontal liquid isothermal bath (hIB) process, is proposed to substantially promote the performance to cost ratio of the existing melt spin-draw process. The enhancement is accomplished via a scientifically pronged approach: • Improved fiber properties. Specifically, the world's strongest polyester fibers have been produced by using hIB in a practicable viable way; • Reduced production cost. The complex and expensive draw unit of the traditional melt spin-draw process is discarded and replaced by hIB • Sustainable and eco-friendly process. Liquid bath does not contain any chemicals harmful to the environment. The significantly improved fiber properties are attributed to a unique fiber morphology developed by using (hIB) which then transforms readily into a highly oriented, ordered crystalline structure under mild drawing and heat-setting. Thus, the fiber properties can be further improved by judiciously manipulating the threadline morphology under optimized (hIB) conditions. In brief, this proposal is intended to develop an industrially applicable (hIB) technology with overwhelming superiority over the traditional melt spin-draw process to produce ultra high performance fibers. In our process (hIB), we utilize only renewable and environmentally friendly media. The objective for the proposed technology development is to develop a continuous (one-step) hIB-drawing process with the former SwissTex draw panel, and to demonstrate a target, polyester, 10-filament yarn (10 denier per filament) with a final take-up speed in the vicinity of 3,000 m/min and tenacity over 10 g/d. While the original process (US Patent Application 2013/0040521A1) for drawn high tenacity monofilaments and yarns has been recently licensed, we are confident that new IP [Intellectual Property] can be created suitable for this project.

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Understanding Macro-Structural Differences of a Nike Provided Set of Sport Knit T-Shirt Fabrics

Nike, Inc.(5/01/14 - 8/31/15)

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Understanding Macro-Structural Differences of a Nike Provided Set of Sport Knit T-Shirt Fabrics

Sponsor: Nike, Inc.

Start Date: 5/01/14

End Date: 8/31/15

Abstract

The objective of this research project will be to develop an understanding of the differences between a Nike provided selected set of polyester and cotton and polyester/cotton blend knit t-shirt fabrics and the impact those differences have on their tactile and sensorial properties such as hand, drape, softness/scratchiness, bending, surface texture, warm versus cool touch, sponginess/compression/loft, thermal conductivity and moisture management performance. It will take the first essential step towards addressing the following practical question: what is the optimum combination of fiber or yarn composition, construction, and finish for a polyester knit t-shirt fabric that is perceived to feel more like a cotton t-shirt knit? By more "cotton like" we mean having tactility, surface texture and softness more charcteristic of cotton knit materials.

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Development of Solvent Systems and Product Screening Samples In Support of High Soy Protein Content Cellulose Fibers

NC Soybean Producers Association, Inc.(11/30/-1 - 6/30/12)

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Development of Solvent Systems and Product Screening Samples In Support of High Soy Protein Content Cellulose Fibers

Sponsor: NC Soybean Producers Association, Inc.

Start Date: 11/30/-1

End Date: 6/30/12

Abstract

The long-term goal of this research is to develop stabilized (crosslinkable) cellulose blends with soy protein for making films (and eventually fibers) by using an ethylenediamine/KSCN (ED/KSCN) green solvent system. The investigation of cellulose crosslinkable blend membranes prepared this way has not yet been systematically and fully reported. This is a continuation of the work done at NCSU making and characterizing cellulose / soy protein membranes. The blending of cellulose with proteins and inexpensive soy meal with subsequent crosslinking will improve films stability enhanced physical (ex. high toughness), biological properties, and tunable biodegradability properties. The nonporous materials can be used as a fiber, film or non-woven products. Example applications include as a filter aid or membrane, in bio-separations, in pharmaceutical purification processes and other numerous medical applications. The ED/KSCN cellulose solvent has recently been developed in Kotek?s lab. Our method has significant advantages over Rayon or Lyocell commercial processes that include a) Fast cellulose and protein dissolution at 80 to 90oC within 2-4 hrs, b) Environmentally friendly, non-toxic solvent, c) No cellulose degradation, and f) No stabilizer is needed. By controlling coagulation of cellulose with water or alcohol/water solution a variety of novel cellulose (and blends) materials such as textile fibers or porous structures can be created.

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Development of Solvent Systems and Product Screening Samples In Support of High Soy Protein Content Cellulose Fibers

NC Soybean Producers Association, Inc.(12/01/09 - 12/01/10)

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Development of Solvent Systems and Product Screening Samples In Support of High Soy Protein Content Cellulose Fibers

Sponsor: NC Soybean Producers Association, Inc.

Start Date: 12/01/09

End Date: 12/01/10

Abstract

The development of a cost effective system for the production of fibers with a substantial soy protein (30% or greater) content is a major objective of work being carried out under the support of the United Soy Bean Board. The most cost effective route to such a product would be wet spinning of the fibers in a process that would be closely related to traditional Rayon or Lyocell process. Success in this area would generate a natural fiber based on the combination of cellulose and soy protein which would be able to be produced in existing fiber production facilities with little or no modification. Dr. Kotek?s research group at NC State University has considerable experience in the production of cellulose and cellulose/natural polymer film structures via a solution casting process. The objective of this short project would be to use their existing technical capabilities, facilities and laboratory production methods to produce cast films based of the combination of cellulose and various grades of soy protein/modified soy protein. This work will allow us to quickly screen a range of soy protein and modified protein materials in combination with cellulose to determine the most promising path forward for the development of solution spun, high soy protein content fibers based on the combination of cellulose and soy protein.

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Novel Melt Spun/Melt Ordered Process for Producing High Performance Polyester Fibers

Atex Technologies, Inc.(11/30/-1 - 8/31/12)

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Novel Melt Spun/Melt Ordered Process for Producing High Performance Polyester Fibers

Sponsor: Atex Technologies, Inc.

Start Date: 11/30/-1

End Date: 8/31/12

Abstract

A novel recently discovered technology, horizontal liquid isothermal bath (HLIB), is proposed to substantially promote the performance to cost ratio of the existing melt spin-draw process. The enhancement is accomplished via a two-pronged approach: ? Improved fiber properties. Specifically, the world's strongest polyester fibers have been produced by using the (HLIB) process in a practicable viable way; ? Reduced production cost. The complex and expensive draw unit of the traditional melt spin-draw process is discarded and replaced by (HLIB). The significantly improved fiber properties are attributed to a unique fiber morphology developed by using (hLIB) which then transforms readily into a highly oriented ordered crystalline structure under mild drawing and heat-setting. Thus, the fiber properties can be further improved by judiciously manipulating the threadline morphology under optimized (HLIB) conditions. In brief, this proposal is intended to develop an industrial applicable (HLIB) technology with an overwhelming superiority over the traditional melt spin-draw process in producing ultra high performance fibers. Although the original LIB process (vertical liquid isothermal bath) has proved successful breaking through the bottlenecks, limited control of the threadline dynamics and limited fiber physical properties, of the traditional melt spin-draw process, it was suitable only for laboratory scale work. It was not until recently, when the original LIB process was modified to a horizontal liquid isothermal bath (HLIB) in our research group, that the production of fibers with superior properties became industrially feasible. The (HLIB) process produces fibers combining first the simplicity of melt-spinning to form the fibers and second the versatility of wet-spinning (the fluid is not aqueous but might be) in that several additional controllable processing variables can be applied. For example, with (HLIB) in the spin line threadline variables such as tension, temperature and time of attendant morphological rearrangement and development are under close control. In other words, by using the (HLIB) process the polymer molecules remain in the mobile molten state a longer time providing the opportunity to more thoroughly extend, orient and order the polymer chains. More importantly, the (HLIB) process seems to lend itself to scale-up to industrial capacity, seems relatively easy to maintain and may be more economical to install and run than the standard spin-draw process. Therefore, the time is now ripe for a concerted research effort on optimization of (HLIB) and extending it to industrial process status for producing advanced fiber products, such as polyester fibers and yarns and other flexible chain polymers.

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New Dynamics Controlled Melt Spun/Melt Ordered Process Yielding Ultra-High Tenacity/Modulous Fibers

SwissTex Filament Yarn Technologies(11/30/-1 - 12/31/12)

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New Dynamics Controlled Melt Spun/Melt Ordered Process Yielding Ultra-High Tenacity/Modulous Fibers

Sponsor: SwissTex Filament Yarn Technologies

Start Date: 11/30/-1

End Date: 12/31/12

Abstract

A novel recently discovered technology, horizontal liquid isothermal bath (HLIB) process, is proposed to substantially promote the performance to cost ratio of the existing melt spin-draw process. The enhancement is accomplished via a two-pronged approach: Improved fiber properties. Specifically, the world's strongest polyester fibers have been produced by using (HLIB) in a practicable viable way; Reduced production cost. The complex and expensive draw unit of the traditional melt spin-draw process is discarded and replaced by (HLIB). The significantly improved fiber properties are attributed to a unique fiber morphology developed by using (hLIB) which then transforms readily into a highly oriented ordered crystalline structure under mild drawing and heat-setting. Thus, the fiber properties can be further improved by judiciously manipulating the threadline morphology under optimized (HLIB) conditions. In brief, this proposal is intended to develop an industrial applicable (HLIB) technology with an overwhelming superiority over the traditional melt spin-draw process in producing ultra high performance fibers. Although the original LIB process (vertical liquid isothermal bath) has proved successful to break through the bottleneck of the traditional melt spin-draw process, it was suitable only for laboratory scale work. It was not until recently, when the original LIB process was modified to a horizontal liquid isothermal bath (hLIB) in our research group, that the production of fibers with superior properties became industrially feasible. The (HLIB) process produces fibers combining first the simplicity of melt-spinning to form the fibers and second the versatility of wet-spinning (the fluid is not aqueous but might be) in that several additional controllable processing variables can be applied. For example, with (HLIB) in the spin line threadline variables such as tension, temperature and time of attendant morphological rearrangement and development are under close control. In other words, by using the (HLIB) process the polymer molecules remain in the mobile molten state a longer time providing the opportunity to more thoroughly extend, orient and order the polymer chains. More importantly, the (HLIB) process seems to lend itself to scale-up to industrial capacity, seems relatively easy to maintain and may be more economical to install and run than the standard spin-draw process. Therefore, the time is now ripe for a concerted research effort on optimization of (HLIB) and extending it to industrial process status for producing advanced fiber products, such as polyester fibers and yarns and other flexible chain polymers.

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The National Textile Center: High Modulus Aliphatic Nylon Fibers via Lewis-Acid Complexation (M05-NS05)

NCSU National Textile Center Program(4/01/08 - 3/31/09)

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The National Textile Center: High Modulus Aliphatic Nylon Fibers via Lewis-Acid Complexation (M05-NS05)

Sponsor: NCSU National Textile Center Program

Start Date: 4/01/08

End Date: 3/31/09

Abstract

We seek to obtain ultra-high modulus and high strength fibers using aliphatic polyamides to replace the current generation of high strength fibers made from polyethylene (Spectra®) and aromatic polyamides (Kevlar®), which suffer, respectively, from a relatively low melting temperature and elaborate production requirements. By comp-lexing high molecular weight (~200,000 g/mol) nylon 6,6 obtained by solid state polymerization and ultra-high molecular weight (~400,000 g/mol) nylon 6, obtained by anionic polymerization of å-caprolactam, with the Lewis acids GaCl3, LiCl to disrupt the amide group hydrogen-bonds between chains, we are able to spin the complexed nylon 6,6 fibers and draw them well beyond the DR ~ 5 typically obtained for melt-spun nylon 6,6 fibers. We will form complexes with other salts such as CaCl2, LiBr and SnCl4 and fibers will be spun using the same spinning method as used earlier. Following decomplexation/regeneration the drawn nylon 6,6 fibers obtained by soaking them in water yielded dramatically high initial moduli (20-30 GPa) and tenacities (1-1.5 GPa), which are in fact the highest values ever reported. We plan to obtain mechanical properties of fibers obtained from other complexes and will be compared to those from GaCl3 and LiCl. We also plan to produce fibers via gel spinning using benzyl alcohol or dimethyl sulfoxide (DMSO) and melt spinning of nylon complexes. As a consequence, we seek to optimize our highly encouraging preliminary results and to understand further the role played by the amide group hydrogen-bonds between nylon 6,6 chains during their spinning/drawing into high strength fibers. We believe that the spinning/drawing/decomplexation of nylon 6,6 fibers from spin dopes complexed with Lewis acids, will aid in achieving this objective. In addition, we are investigating both the coagulation step in the wet/dry spinning of the complexed nylon fibers and the production of ultra-high molecular weight aliphatic nylons, which appear to play significant roles in the ultimate production of high strength fibers.

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Preparation and Characterization of Cellulose Microcellular Foams for Pigment Applications

NCSU Faculty Research & Professional Development Fund(7/01/08 - 6/30/09)

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Preparation and Characterization of Cellulose Microcellular Foams for Pigment Applications

Sponsor: NCSU Faculty Research & Professional Development Fund

Start Date: 7/01/08

End Date: 6/30/09

Abstract

The long-term goal of this research is the development of a novel utilization of cellulose-based microcellular foam (CMCF) as an opacifying agent in paper, paint and coating applications. An outcome of this project is the development of highly opaque, bright, moderately hydrophobic, inexpensive CMCF materials for use as fillers and pigments. The research objectives are focused on the following: ? Understand the processing conditions and composition on the resulting CMCF structure. ? Understand and model the effect of foam structure on the optical properties of CMCF. ? Understand how structure and composition impact the interaction of water with CMCF.

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Production of New Biocidal Textiles Using Advanced Nano and Melt Spinning Techniques

National Science Foundation (NSF)(9/01/08 - 8/31/10)

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Production of New Biocidal Textiles Using Advanced Nano and Melt Spinning Techniques

Sponsor: National Science Foundation (NSF)

Start Date: 9/01/08

End Date: 8/31/10

Abstract

Nowadays, biocidal textiles are very important due to the appearance of fatal diseases in the world. Production and functionalization of these textiles which are produced from non-woven or woven synthetic fibres & their blends are done with the aim to be introduced to the textile industry. Melt spinning process of synthetic fibres in presence of biocidal nano-particles (inorganic or organic compounds or ploy active monomers) to create biocidal fibres containing quaternary ammonium salts sites or others. Biocidal textiles of antimicrobial & insecticidal activities will be produced from polypropylene, polyamide & polyester on a pilot scale & then transferred to the industry. The effectiveness of antimicrobial finish and its durability to repeated washing or dry cleaning is determined. Improvement properties of synthetic fabrics to thermal treatment, moisture regain and dyeing are evaluated. Production cost and end-uses of the fibres specified. Elemental micro-analyses, FTIR, TGA & SEM for characterization of the new biocidal textiles will be done. The antimicrobial and insecticidal activities of these fibres will be effected and compared to the blanks.

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Teaching

• TC461 - Laboratory Exercises for Fiber Forming Polymers ,