KINETICS AND MECHANISM OF VINYL CHLORIDE POLYMERIZATION: EFFECTS OF ADDITIVES ON POLYMERIZATION RATE, MOLECULAR WEIGHT AND DEFECT CONCENTRATION IN THE POLYMER by KUN SI Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Advisors: Dr. Morton Litt and Dr. Jerome Lando Department of Macromolecular Science and Engineering CASE WESTERN RESERVE UNIVERSITY May, 2007 UMI Number: 3244786 UMI Microform 3244786 Copyright 2007 by ProQuest Information and Learning Company. All rights reserved.
This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P. Box 1346 Ann Arbor, MI 48106-1346 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the dissertation of Kun Si ______________________________________________________ candidate for the Ph. Morton Litt (signed)_______________________________________________ (chair of the committee) Jerome B.
Mann ________________________________________________ Regan Silvestri ________________________________________________ ________________________________________________ ________________________________________________ December 05, 2006 (date) _______________________ *We also certify that written approval has been obtained for any proprietary material contained therein. DEDICATION To my parents, Jinxing Si and Yuzhen Liu, who never went to college and sacrificed many things to give their all four children an opportunity of higher educations. With their unconditional love, support, understanding and patience, I can make this dissertation possible and finish the final step of my education. 謹獻給我的父母，司金星和劉玉真，他們沒有機會接受高等教育 卻送四個子女進了大學。 因他們的大愛，理解，支持與耐心，我得以 完成此論文並結束學業。 TABLE OF CONTENTS List of Tables…………………………………………………………………….
x List of Figures…………………………………………………………………… xviii List of Schemes…………………………………………………………………. xxx Acknowledgements……………………………………………………………… xxxi List of Abbreviations & Acronyms…………………………………………… xxxii Abstract………………………………………………………………………. xxxv Chapter 1 Introduction…………………………………………………….2 A brief History of PVC……………………………………………….3 Methods of Vinyl Chloride Polymerization…………………………… 8 1.1 Polymerization in Bulk…………………………………………….2 Polymerization in Suspension…………………………………….3 Polymerization in Emulsion……………………………………….4 Polymerization in Solution………………………………….4 Structure and Properties of PVC………………………………….5 Structural Defects in PVC…………………………………………….1 Short-chain Branching…………………………………………….2 Long-chain Branching…………………………………………….4 Head-to-head Structures………………………………………….6 Stereoregularity of PVC……………………………………………….7 Dissertation Goals and Summary……………………………………… 23 1. 27 Chapter 2 Free Radical Polymerization of Vinyl Chloride in the presence of Organic Additives……………………………………………………….3 Bulk Polymerization of Vinyl Chloride………………………….4 Suspension Polymerization of Vinyl Chloride…………………….5 GPC Characterization of PVC Samples………………………….6 Dynamic Thermal Stability Test of PVC Samples……………….7 Static Thermal Stability Test of PVC Samples…………………… 40 2.3 Results and Discussion………………………………………………… 40 2.1 Molecular Weight and Molecular Weight Distribution of PVCs….1 Polymer aggregation in solution…………………………….2 GPC data for bulk polymerized PVCs……………………….3 PVC/DMT01b and PVC86k aggregation in solution……….4 GPC data for suspension polymerized PVCs……………….5 PVC dynamic thermal stability……………………………… 53 2.2 Two-phase Literature Model for Bulk Polymerization of Vinyl Chloride………………………………………………………….3 Bulk Polymerization of Vinyl Chloride at 55 oC initiated by AIBN…………………………………………………………….4 New Kinetic Model for Vinyl Chloride Bulk Polymerization initiated by AIBN………………………………………………… 65 2.5 Kinetic Parameters for Bulk Polymerization of Vinyl Chloride at 55 oC…………………………………………………………….6 Kinetics and Mechanism of Vinyl Chloride Polymerization in the presence of Additives…………………………………………….7 Bulk Polymerization of Vinyl Chloride at 55 oC in the presence of Pyridine, its Derivatives, Pyrazine, Benzothiazol, or Imidazolidinone………………………………………………….8 Bulk Polymerization of Vinyl Chloride at 55 oC in the presence of Phosphine Oxides………………………………………………… 92 2.9 Bulk Polymerization of Vinyl Chloride at 55 oC in the presence of Dimethoxybenzene, Carbonates, Carboxylates or Lactones…….1 Polymerization in the presence of 1,4-Dimethoxybenzene….2 Polymerization in the presence of Ethylene Carbonate…….3 Polymerization in the presence of 2-Coumaranone………….4 Polymerization in the presence of γ-Butyrolactone………….5 Polymerization in the presence of Dimethyl Terephthalate….6 Polymerization in the presence of Trimethyl 1,3,5- Benzenetricarboxylate……………………………………… 115 2.
121 Chapter 3 Differential Scanning Calorimetry and Thermogravimetric Analysis of Poly(vinyl chloride)s………………………………………….2 DSC Measurement of PVC Samples……………………………… 129 3.3 TGA Measurement of PVC Samples…………………………….3 Results and Discussion………………………………………………… 130 3.1 Crystallinity of PVCs prepared in the presence of Additives …….1 Crystallinity of PVCs prepared in the presence of 2- Coumaranone……………………………………………….2 Crystallinity of PVCs prepared in the presence of 2,6- Dichloropyridine…………………………………………….3 Crystallinity of PVCs prepared in the presence of 1,4- Dimethoxybenzene………………………………………….4 Crystallinity of PVCs prepared in the presence of Dimethyl Terephthalate……………………………………………….5 Crystallinity of PVCs prepared in the presence of γ- Butyrolactone……………………………………………….6 Crystallinity of PVCs prepared in the presence of Trimethyl- 1,3,5-Benzenetricarboxylate……………………………….2 Effect of Annealing Time and Temperature on the Crystallinity of PVCs…………………………………………………………….1 Effect of Annealing on the Crystallinity of PVC/AIBN416… 158 3.2 Effect of Annealing on the Crystallinity of PVC/DMB0001a & DMB001b……………………………………………….3 Effect of Annealing on the Crystallinity of PVC/DMT01d….4 Effect of Annealing on the Crystallinity of PVC/EC01c…….5 Effect of Annealing on the Crystallinity of PVC/SBP124….6 Effect of annealing on the crystallinity of PVC/SDMT01a….3 Kinetics of PVC Crystallization…………………………….4 Thermal Degradation Behavior of PVC Samples………………… 208 3.1 Evaluation of Degradation Activation Energy of PVC samples by single-heating-rate TGA Curve………………… 215 3.2 Evaluation of Degradation Activation Energy of PVC samples by FR, WFO and KAS methods…………….3 Evaluation of Degradation Kinetic Parameters (Ea, A, n) of PVC samples by Coats-Redfern method………. 238 Chapter 4 Correlation between Structural Defects and the Dehydrochlorination of Poly(vinyl chloride)s…………………………… 243 4.2 Dehydrochlorination Measurements of PVC samples…………….3 1D & 2D NMR Measurements of PVC Samples………………….3 Results and Discussion………………………………………………… 249 4.1 Two-parameter Kinetic Model for PVC Dehydrochlorination…… 249 4.2 Dehydrochlorination of PVCs prepared in Bulk without Additives 257 4.3 Dehydrochlorination of PVCs prepared in Bulk in the presence of Additives………………………………………………………….1 Dehydrochlorination of PVCs prepared in the presence of 2- Coumaranone……………………………………………….2 Dehydrochlorination of PVCs prepared in the presence of 2,6-Dichloropyridine……………………………………….3 Dehydrochlorination of PVCs prepared in the presence of 1,4-Dimethoxybenzene…………………………………….4 Dehydrochlorination of PVCs prepared in the presence of Dimethyl Terephthalate…………………………………….5 Dehydrochlorination of PVCs prepared in the presence of γ- Butyrolactone……………………………………………….6 Dehydrochlorination of PVCs prepared in the presence of Trimehtyl-1,3,5-Benzenetricarboxylate…………………….4 Dehydrochlorination of PVCs prepared in Suspension…………… 272 4.5 Activation energies for PVC Dehydrochlorination at early stage… 275 ix 4.6 Identification of PVC Structural Defects using 1D &2D NMR….7 Determination of PVC Structural Defects using 1D 1H NMR…….8 Correlation between the Dehydrochlorination Rate and the Structural Defects of PVCs………………………………………. 332 LIST OF TABLES Chapter 2 Table 2.1 A selected recipe for suspension polymerization of vinyl chloride at 53 oC…………………………………………………………….2 Molecular weights and molecular weight distributions for PVCs prepared by bulk polymerization at 55 oC in the presence of organic additives………………………………………………….3 Suspension polymerization of vinyl chloride at 53 oC initiated by diisobutyl peroxydicarbonate in the presence of γ-butyrolactone, dimethyl phthalate or dimethyl terephthalate …………………….4 Bulk polymerization of vinyl chloride initiated by AIBN at 55oC.5 Molecular weights and molecular weight distributions for PVCs prepared by bulk polymerization at 55 oC initiated by AIBN…….6 Chain transfer constant to monomer for vinyl chloride polymerization…………………………………………………….7 Summary of kinetic parameters for bulk polymerization of vinyl chloride initiated by 2,2’-azobisisobutyronitrile at 55 oC………… 78 Table 2.8 Bulk polymerization of vinyl chloride at 55oC initiated by AIBN in the presence of pyridine, its derivatives, pyrazine, benzothiazol, and imidazolidinone……………………………………………….9 Molecular weights and molecular weight distributions for PVCs prepared at 55oC in the presence of pyridine, its derivatives, pyrazine, benzothiazol, and imidazolidinone……………………… 91 Table 2.10 Bulk polymerization of vinyl chloride at 55oC initiated by AIBN in the presence of phosphine oxides……………………………….11 Molecular weight and molecular weight distributions for PVCs prepared at 55oC in the presence of phosphine oxides…………….12 Bulk polymerization of vinyl chloride at 55oC initiated by AIBN in the presence of 1,4-dimethoxybenzene (DMB)………………… 99 Table 2.13 Molecular weights and molecular weight distributions for PVCs prepared at 55 oC initiated by AIBN in the presence of DMB…….14 Bulk polymerization of vinyl chloride at 55oC initiated by AIBN in the presence of ethylene carbonate…………………………….15 Molecular weights and molecular weight distributions for PVCs xi prepared at 55oC in the presence of ethylene carbonate…….16 Bulk polymerization of vinyl chloride at 55oC initiated by AIBN in the presence of 2-coumaranone (CMN)………………………… 105 Table 2.17 Molecular weights and molecular weight distributions for PVCs prepared at 55 oC initiated by AIBN in the presence of CMN…….18 Bulk polymerization of vinyl chloride at 55oC initiated by AIBN in the presence of γ-butyrolactone (GBL)………………………… 109 Table 2.19 Molecular weights and molecular weight distributions for PVCs prepared at 55oC initiated by AIBN in the presence of GBL……… 110 Table 2.20 Bulk polymerization of vinyl chloride at 55oC initiated by AIBN in the presence of dimethyl terephthalate (DMT)………………….21 Molecular weights and molecular weight distributions for PVCs prepared at 55 oC initiated by AIBN in the presence of DMT…….22 Bulk polymerization of vinyl chloride at 55 oC initiated by AIBN in the presence of trimethyl 1,3,5-benzenetricarboxylate (TMB)….23 Molecular weights and molecular weight distributions for PVCs prepared at 55 oC initiated by AIBN in the presence of TMB…….24 Values of K, ktr2/ktr1 and CA for vinyl chloride polymerization at 55 o C in the presence of 2-Coumaranone, dimethyl terephthalate, γ- butyro-lactone or trimethyl 1,3,5-benzenetricarboxylate………….1 DSC difference curve data for PVCs prepared in bulk at 55 oC in xii the absence of additives…………………………………………….2 DSC difference curve data for PVCs prepared at 55 oC in the presence of 2-coumaranone (CMN)……………………………….3 DSC data for PVCs prepared at 55 oC in the presence of 2,6- dichloropyridine (DCPY)………………………………………….4 DSC difference curve data for PVCs prepared at 55 oC in the presence of 1,4-dimethoxybenzene (DMB)……………………….5 DSC difference curve data for PVCs prepared at 55 oC in the presence of dimethyl terephthalate (DMT)……………………….6 DSC difference curve data of PVCs prepared at 55 oC in the presence of γ-butyrolactone (GBL)……………………………….7 DSC difference curve data for PVCs prepared at 55 oC in the presence of trimethyl-1,3,5-benzenetricarboxylate (TMB)……….8 Weight-average molecular weights and the tacticity of selected PVCs used for the crystallization kinetics studies………………… 158 Table 3.9 DSC difference curve data for PVC/AIBN416 annealed for 120 minutes at different temperatures………………………………….10 DSC difference curve data for PVC/AIBN416 annealed at 100 oC for different periods of time……………………………………….11 DSC difference curve data for PVC/AIBN416 annealed at 125 oC for different periods of time……………………………………….12 DSC difference curve data for PVC/DMB0001a annealed for 60 minutes at different temperatures………………………………….13 DSC difference curve data for PVC/DMB0001b annealed for 60 minutes at different temperatures………………………………….14 DSC difference curve data for PVC/DMB0001a annealed at 100 o C for different periods of time…………………………………….15 DSC difference curve data for PVC/DMB0001a annealed at 125 o C for different periods of time…………………………………….16 DSC difference curve data for PVC/DMB0001b annealed at 100 o C for different periods of time…………………………………….17 DSC difference curve data for PVC/DMB0001b annealed at 125 o C for different periods of time…………………………………….18 DSC difference curve data for PVC/DMT01d annealed for 60 minutes at different temperatures………………………………….19 DSC difference curve data for PVC/DMT01d annealed at 125 oC for different periods of time……………………………………….20 DSC difference curve data for PVC/EC01c annealed for 60 minutes at different temperatures………………………………….21 DSC difference curve data for PVC/EC01c annealed at 125 oC for different periods of time…………………………………………… 189 Table 3.22 DSC difference curve data for PVC/SBP124 annealed for 60 minutes at different temperatures………………………………….23 DSC difference curve data for PVC/SBP124 annealed at 125 oC for different periods of time……………………………………….24 DSC difference curve data for PVC/SDMT01a annealed for 60 xiv minutes at different temperatures………………………………….25 DSC difference curve data for PVC/SDMT01a annealed at 125 oC for different periods of time……………………………………….26 Observed maximum crystallization temperature ((Tc)max) and maximum crystallinity((Xc)max ) for some PVC samples annealed at (Tc)max for 60 minutes………………………………………….27 Equilibrium values of crystallinity (Xc) and melting temperature (Tm) for some PVCs annealed at 125 oC………………………….28 Results of the exponent n+1, crystallization rate constant K/(n+1), crystallization half-time t1/2, and heat of fusion at infinity ΔH∞ for some PVC samples………………………………………………… 206 Table 3.29 The activation Energies (Ea) and the degradation temperatures for some PVC samples at different percentage of weight loss at a heating rate of 20 oC/min………………………………………….30 Degradation temperatures of PVC/CMN001a under different degrees of degradation at heating rates of 5 , 10 and 15 oC/min.31 The derivative weight (dα/dt) of PVC/CMN001a under different degrees of degradation (α) at heating rates of 5 , 10 and 15 oC/min 223 Table 3.32 Apparent Activation Energies (Ea) for PVC/CMN001a calculated by three isoconversional methods………………………………….33 Degradation temperatures of PVC/EC01c with different degrees of degradation (α) at heating rates of 2, 5 , 10, 15 oC/min…………… 227 Table 3.34 The derivative weight (dα/dt) of PVC/EC01c with different xv degrees of degradation (α) at heating rates of 2, 5 , 10, 15 oC/min 228 Table 3.35 Apparent Activation Energies (Ea) for PVC/EC01c calculated by three isoconversional methods…………………………………….36 Comparison of the kinetic parameters for PVC degradation obtained by different authors……………………………………….1 Values of Ka and Kb for the dehydrochlorination of PVCs prepared in bulk using 2,2’-Azobisisobutyronitrile (AIBN) as initiator…….2 Values of Ka and Kb for the dehydrochlorination of PVCs prepared in the presence of 2-coumaranone (CMN)……………….