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Report No. 104
THERMOPLASTIC ELASTOMERS
by ROBERT H. SCHWAAR
with oontxibutions by James J. L. Ma
November 1976
A private report by the
PROCESS ECONOMICS PROGRAM a STANFORD RESEARCH INSTITUTE MENLO PARK, CALIFORNIA I 3
CONTENTS
INTRODUCTION...... 1
3 s-r ...... General Aspects ...... Econmic Aspects...... Technical Aspects ...... Styrenic Thermoplastic Elastomers ...... Hydrogenated Styrenic Block Copolymers...... Blends of Rubber and Thermoplastics ...... Thermoplastic Copolyester Elastomers......
INDUSTRY STATUS ...... 11 Production...... 12 Producers ...... 13 Prices ...... 13 Markets ...... 13
PROPERTIES OF THERMOPLASTIC ELASTOMERS...... 19
STYRENIC BLOCK COPOLYMERS ...... 25 Chemistry ...... 27 Effect of Structure on Product Properties ...... 33 Review of Processes ...... 34 Initiators...... 42 Solvent ...... 42 Raw Materials Purity...... 42 Polymerization Procedures ...... 43 Reactors...... 43 MUDistribution...... 44 Additives ...... 45 Polymerization Monitoring ...... 45 Coupling Living Diblock Polymers...... 46 Linear Triblock Copolymers...... 46 Star-Block Copolymers ...... 48 Conversion of Polymer Solution to Dry Product ...... 52 Process Description ...... 53 Feed Purification ...... 55 Preparation of Coupled Block Copolymer...... 55 Polymer Recovery and Finishing...... 56 Conversion of Crumb to Pellets...... 57 Solvent Recovery...... 58
Vii CONTENTS
5 (Continued) Process Discussion...... 64 Feed Purification ...... 64 Polymerization and Coupling ...... 64 Additives ...... 65 Stripping and Coagulating ...... Polymer Crumb Drying...... :: Solvent Recovery...... 67 Final Processing...... '. ... 68 Materials of Construction ...... 68 Waste Treatment ...... 69 Cost Estimates...... 71 Capital Costs ...... 71 Production Costs...... 71
6 HYDROGENATEDSTYRENIC BLOCK COPOLYMERS...... 81 Chemistry 81 Review of Procesiei...... 82 Control of Diene Polymer Configuration...... 88 Hydrogenation Selectivity ...... 90 Hydrogenation Conditions. ... : ...... 91 Removal of Hydrogenation Catalyst ...... 92 Conversion of Polymer Solution to Dry Polymer Powder. ... 93 Process Description ...... 94 Purification of Monomer and Solvent Feeds ...... 95 Preparation of Coupled Block Copolymer...... 96 Hydrogenation...... 99 Coagulation of Polymer Cement ... c ...... 101 Conversion of Crumb to Pellets...... 101 Solvent Recovery...... 102 Process Discussion...... 108 Impurities in the Butadiene ...... 108 Reaction Temperature...... 108 Diene Polymerization Control Agent...... 109 Coupling Agent...... 109 Catalyst Deactivation ...... 109 Hydrogen Consumption...... 110 Catalyst Removal...... 111 Polymer Recovery...... 111 Waste Treatment ...... 112 CostEstimates ...... 114 Capital Costs ...... 114 Production Costs...... i...... 115
Viii CONCERTS
7 BLENDS OF RUBBER AND THERMOPLASTICS ...... 125 Review of Processes ...... 125 Polyolefin Blends With Partial Curing ...... 125 Polyolefin Blends Without Partial Curing...... 131 Other Polyolefin Blends ...... 131 Process Description ...... 132 Mixing Section Operations ...... 132 Product Finishing Section Operation ...... 134 Extruding and Pelletizing ...... 134 Pellet Dewatering and Drying...... 134 Pellet Blending ...... 135 Product Packaging ...... 135 Process Discussion...... 139 Plant Capacity...... 139 Design Basis...... 139 Batch Versus Continuous Mixing...... 140 Extruding and Pelletizing ...... 140 Additives...... 141 Materials of Construction ...... 141 Cost Estimates...... 143 Capital Costs ...... 143 Production Costs...... 143
8 THERMOPLASTIC COPOLYESTER ELASTOMERS...... 151 Chemistry ...... 151 Reactions ...... 152 Kinetics...... ;$ Review of Processes Development ...... 157 Catalysts :.fi Additives ...... Processing Sequence ...... 167 Ester Interchange and Polycondensation...... 168 Recovery of Methanol and 1,4-Butanediol ...... 169 Final Polymerization in Solid Phase ...... 169 Continuous Polymerization ...... 170 Process Description ...... 170 Polymerization Section...... 171 Charging...... 171 Catalyst Preparation...... 172 Ester Interchange and Polycondensation...... 173 Solvent Recovery Section...... 174 Product Finishing Section ...... 175 CONTENTS
8 (Continued) Process Discussion...... 182 Plant Capacity...... 182 Design Basis...... 182 RawMaterials ...... 183 Materials of Construction ...... 184 Cost Estimates...... 185 Capital Costs ...... 185 Production Costs...... 185
9 OTHER THERMOPLASTIC ELASTOMERS...... 195 Modified EPDM ...... 195 Modified Polybutadiene...... 195 Propylene-Hexene-1 Random Copclymer ...... 196 Other Olefin Copolymers ...... 197 Modification of Thermoplastics...... 197 Ionic Thermoplastic Elastomers...... 197 Polyimidothioether-PolysulfideBlock Copolymers ...... 198 Other Sulfur-Containing Block Copolymers...... 199 Thiourea Copolymers ...... 199 Silicone-Based Thermoplastic Elastomers ...... 199
APPENDIX A DESIGN AND COST BASES...... 201
APPENDIX B RAW MATERIAIS SPECIFICATIONS ...... 205
CITED REFERENCES ...... 215
PATENTREFERENCESBYCOMPANY ...... 225
X ILLUSTRATIONS
4.1 Hardness of Thermoplastic Elastomers, Rubbers and Plastics ...... , ...... 22 4.2 Flexural Elastic Modulus of Thermoplastic Elastomers, Rubbers, and Plastics. . . . . '...... 23 5.1 Diagrammatic Representation of a Linear Styrene-Diene Triblock Thermoplastic Elastomer ...... 26 5.2 Effect of Structure of Block Copolymers on Solution Viscosity ...... 50 5.3 Star-Block Butadiene-StyreneCopolymer Process Flow Diagram ...... 228 5.4 Star-Block Butadiene-StyreneCopolymer Effect of Plant Capacity on Total Fixed Capital...... 78 5.5 Star-Block Butadiene-Styrene Copolymer Effect of Operating Level and Plant Capacity on Production Cost...... 79 5.6 Star-Block Butadiene-Styrene Copolymer Effect of Butadiene and Styrene Prices on Total Production Cost...... 80 6.1 Hydrogenated SBS Copolymer,Production Process Flow Diagram ...... 234 6.2 Hydrogenated SBS Copolymer Production Effect of Plant Capacity on Total Fixed Capital...... 120 6.3 Hydrogenated SBS Copolymer Production Effect of Operating Level and Plant Capacity on Production Cost...... , . . 121 6.4 Hydrogenated SBS Copolymer Production Effect of Butadiene and Styrene Prices on Total Production Cost...... 124 7.1 Blends of Rubber and Thermoplastics Process Flow Diagram ...... 242 7.2 Blends of Rubber and Thermoplastics Effect of Polypropylene and Peroxide Contents on Hardness...... 142 7.3 Blends of Rubber and Thermoplastics Effect of Plant Capacity on Total Fixed Capital...... 146
Xi ILLUSTRATIONS
7.4 Blends of Rubber and Thermoplastics Effect of Operating Level and Plant Capacity on Production Cost...... 149 7.5 Blends of Rubber and Thermoplastics Effect of Raw Material Costs on Total Production Cost. . . . 150 8.1 Thermoplastic Copolyester Elastomers Effect of Time and Temperature on Inherent Viscosity of Melt ...... 155 8.2 Thermoplastic Copolyester Elastomers Process Flow Diagram ...... 244 8.3 Thermoplastic Copolyester Elastomers Effect of Plant Capacity on Total Fixed Capital...... 188 8.4 Thermoplastic Copolyester Elastomers Effect of Operating Level and Plant Cost on ProductionCost...... 192 8.5 Thermoplastic Copolyester Elastomers Effect of Raw Material Costs on Total Production Cost. . . . 193
Xii TABLES
2.1 Suxmnaryof Cost Estimates for Thermoplastic Elastomers...... 4 3.1 Producers of Thermoplastic Elastomers (Other than Polyurethanes) ...... 14 3.2 End-Use Applications of Thermoplastic Elastomers (United States, 1973) ...... 15 4.1 Properties of Thermoplastic Elastomer Gums and Compounds ...... 21 5.1 Styrenic Block Copolymers PatentSumnary ...... 36 5.2 Coupling Agents for Lithium-Initiated Block Copolymers Patent Sunmary...... 40 5.3 Properties of Linear- and Star-Block Copolymers ...... 49 5.4 Star-Block Styrene-Butadiene Copolymer Design Bases and Assumptions...... 54 5.5 Star-Block Styrene-ButadieneCopolymer Major Equipment and Utilities Summary ...... 59 5.6 Star-Block Styrene-ButadieneCopolymer StreamFlows...... 62 5.7 Star-Block Styrene-ButadieneCopolymer Sumnary of Waste Products ...... 70 5i8 Star-Block Styrene-ButadieneCopolymer Production Major Capital Equipment Cost...... 73 5.9 Star-Block Styrene-ButadieneCopolymer Total Capital Investment...... 74 5.10 Star-Block Styrene-ButadieneCopolymer Production Costs...... 76 6.1 Hydrogenated Styrenic Block Copolymers PatentSummary ...... 83 6.2 Hydrogenated SBS Copolymer Design Bases and Assumptions...... 96 6.3 Hydrogenated SBS Copolymer Production Typical Batch Cycles...... 97 6.4 Hydrogenated SBS Copolymer Production Major Equipment and Utilities Summary ...... 103
Xiii TABLES
6.5 Hydrogenated SBS Copolymer Production Stream Flows...... 106 6.6 Hydrogenated SBS Copolymer Production Summary of Waste Products ...... 113 6.7 Hydrogenated SBS Copolymer Production Major Capital Equipment Cost...... 117 6.8 Hydrogenated SBS Copolymer Production Total Capital Investment...... 118 6.9 Hydrogenated SBS Copolymer Production Production Costs...... 122 7.1 Blends of Rubber and Thermoplastics Patents-r-y...... 126 7.2 Blends of Rubber and Thermoplastics Major Equipment and Utilities Summary ...... 136 7.3 Blends of Rubber and Thermoplastics Stream Flows Based on Durometer 77A Blend ...... 138 7.4 Blends of Rubber and Thermoplastics Total Capital Investment...... 145 7.5 Blends of Rubber and Thermoplastics Major Capital Equipment Cost...... 147 7.6 Blends of Rubber and Thermoplastics Production Cost for Durometer 77A Blend ...... 148 8.1 Thermoplastic Copolyester Elastomers PatentS-r-y...... 158 8.2 Thermoplastic Copolyester Elastomers Design Bases and Assumptions...... 172 8.3 Thermoplastic Copolyester Elastomers Major Equipment and Utilities Sunnnary...... 177 8.4 Thermoplastic Copolyester Elastomers Stream Flows for 55D Copolymer...... 180 8.5 Thermoplastic Copolyester Elastomers Total Capital Investment...... 187 8.6 Thermoplastic Copolyester Elastomers Major Capital Equipment Cost...... 189 8.7 Thermoplastic Copolyester Elastomers Production Costs for Durometer 55D Copolymer...... 190
XiV TABLES
B.l Butadiene Specifications (Commercial Grade) ...... 207 B.2 Styrene Specifications...... 208 B.3 Dimethyl Terephthalate Properties ...... 209 B.4 Polytetramethylene Ether Glycol Specifications...... 210 B.5 1,4-Butanediol Properties ...... 211 @ B.6 Agerite White Antioxidant Properties ...... 212 B.7 Tetrabutyl Titanate Properties and Specifications ..... 213
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