Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1991 Interfacial Adhesion in Rayon/Nylon Sheath/Core Composite Fibers. Weiying Tao Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Tao, Weiying, "Interfacial Adhesion in Rayon/Nylon Sheath/Core Composite Fibers." (1991). LSU Historical Dissertations and Theses. 5213. https://digitalcommons.lsu.edu/gradschool_disstheses/5213 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. 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Ann Arbor, MI 48106 INTERFACIAL ADHESION IN RAYON/NYLON SHEATH/CORE COMPOSITE FIBERS A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Interdepartmental Programs in Engineering by Weiying Tao B.S., China Textile University, 1984 M.S., Ohio University, 1989 August 1991 ACKNOWLEDGEMENTS I would like to express my sincere thanks to my advisors, Drs. John and Billie Collier for their invaluable advice and encouragement during this research. I would also like to thank Drs. Ann Doucet, Edward Overton, Mehdy Sabbaghian, and David Wetzel for serving on my graduate committee. Their suggestions and help are appreciated. I thank Dr. Frank Cartledge for helping with selection of the Petrarch silane coupling agent. I also wish to thank Mr. Charles Patrick for setting up the coating line and assisting in part of the sample production, and Margaret Smith for helping with statistical data analysis and adhesion testing using the carrier fabric method. Thanks are also due Dr. loan Negulescu for helping with the Fourier transform infrared analysis. I thank International Paper Company for supplying the viscose solution, Shakespeare Monofilament Division of Anthony Industries for supplying the nylon core fibers used in this study, and the National Science Foundation for funding the Reinforced Rayon Fibers Project (grants MSM8514131 and INT8514111) . I wish to express my appreciation to LSU Chemical Engineering Shop technical staff, especially Mr. Drew Vincik and Mr. Paul Rodriguez, for setting up and modifying the experimental equipment. They also helped solve the problems that occasionally occurred with the equipment, thereby enabling me to continue this research efficiently. TABLE OF CONTENTS Page Acknowledgements........................................ ii List of Tables.............. vi List of Figures........................................ vii Abstract................................................ xii Chapter 1. Introduction. .............. l Chapter 2. Review of Literature......................... 4 Fiber Spinning. ................................. 4 R a y o n................................................ 5 N y l o n............................................... 10 Fiber Finishing.................................... 13 Modification of Fiber Properties.................. 14 Fiber Blends and Core Yarns.................. 15 Bicomponent and Bigeneric Fibers............ 17 Internally Reinforced RayonFibers ........... 22 Adhesion Testing................................... 28 Chapter 3. Experimental................................. 32 Materials and Equipment....................... ....32 Experimental Design............... 35 Sample Production.................................. 44 Fiber Pretreatment........................... 44 Removal of Spin Finish..................45 Coupling Agent Pretreatment............ 45 Fiber Coating................................. 45 iii Sample Analysis and Testing....................... 49 Linear Density................................49 Interfacial Adhesion......................... 50 Carrier Fabric Method................... 50 Fiber Pull Adhesion Test by Weight Loss.......................... 51 Determination of Interfacial Shear Strength............. 55 Scanning Electron Microscope (SEM) Observation. .................... 59 Specimen Preparation.................... 60 Surface Morphology Observation by SEM..60 Chemistry Analysis by Fourier Transform Infrared Spectroscopy (FTIR).................61 Moisture Regain.............................. 62 Fabric Bending Properties................... .63 Statistical Analysis ................... 63 Chapter 4. Results and Discussion...................... 66 Effect of Coupling Agent.......................... 66 Effect of Acid Bath Residence Time................72 Effect of Post Water Wash......................... 73 Effect of Drying Temperature...................... 76 Application Conditions of FA ...................... 77 Effect of Concentration of FASolution. 77 Effect of FA Pretreatment Time....... 78 Effects of Interaction and Overall Pretreatment......................... 79 Interfacial Shear Strength...................83 Longitudinal and Cross Sectional Surface....84 Effect of Coating on Moisture Regain............ 108 Evaluation of Fiber Pull Adhesion Test Method...109 Bending Rigidity and Hysteresis of Fabrics...... 110 Chapter 5. Conclusions and Recommendations........... 115 Conclusions....................................... 115 Recommendations................................... 117 References................................... .......... 119 Appendices..............................................124 A. Sample Production Procedures................. 124 B. Experimental Data............................. 130 C. Results and Statistical Analysis............. 137 D. Determination of Interfacial Shear Strength..149 V i t a .................................................... 152 v LIST OF TABLES Table Page 1. Spin Finish Components.............................. 13 2. Pretreatment and Coating Conditions................ 40 3. Experimental Design for Curing Effect...,..........42 4. Experimental Design of Application Conditions for FA ....................... 44 5. Effect of Acid Bath Residence Time on Adhesion.... 73 6. Effect of Drying Temperature on Adhesion...........76 7. Duncan's Multiple Range Test for Temperature...... 77 8. Duncan's Multiple Range Test for Concentration/Time Interaction Effect.............. 79 9. Interfacial Shear Strength of the Composite Fiber..85 10. Moisture Regain of Coated Fibers.................. 109 11. Bending Rigidity and Hysteresis................... Ill LIST OF FIGURES Figure Page 1. Molecular Structure of Cellulose................... 5 2. Rayon Production Process............................ 6 3. Apparatus for Production of Viscose Fiber........... 8 4. Reaction for Synthesis of Nylon 66 ................ 11 5. Molecular Structure of Nylon 66 ................... 11 6. Types of Bicomponent or Bigeneric Fiber........... 18 7. Cross Section of Filament.......................... 21 8. Fiber Mounting...................................... 26 9. Fiber Bending Curves............................... 27 10. Single Fiber Pullout Test.......................... 29 11. Arrangement of Shear Debonding (top) and Enlarged Schematic of a Resin Droplet on a Fiber Under the Shearing Plates (bottom)........................... 30 12. Viscose Viscosity vs. Time at Room Temperature....37 13. Structures of APDMSB and FA ........................39 14. Spin Finish Removal by Water Wash ................. 46 15. Coupling Agent Pretreatment........................47 16. Fiber Coating Process Schematic................... 48 17. Fiber Pull Adhesion Test .................. 52 18. Mounting of Calibrase Wheels...................... 53 19. Wheel Deflection..... 57 20. Measurement of Coefficient of Friction............58