8

Report No. 39

POLYSTYRENE

by WING SIEN FONG;

June, 1968

1 8 8

A private report by the

PROCESS ECONOMICS PROGRAM

STANFORD RESEARCH INSTITUTE

I MENLO PARK, CALIFORNIA

i 5 1 1 8 I

I 8

1 INTRODUCTION........................

2 SUMMARY ., . . . . . . . . . . . . . . . . . . . . . . . .

3 INDUSTRY STATUS . . . . . . . . . . , . . . . . . . . . . . 19

4 CHEMISTRY .........................

Introduction ........................ Free-Radical Polymerization ................

Initiation ........................ Propagation ....................... Termination ....................... Kinetic Equations .................... Inhibition and Retardation ................ Gel Effect ........................ Effect of Oxygen ..................... Effect of Pressure ....................

Degradation ........................ Branching ......................... Structure ......................... Mass Polymerization .................... Suspension Polymerization ................. Emulsion Polymerization .................. Solution Polymerization .................. Polymerization by Irradiation ............... Graft Copolymerization ................... Ionic Polymerization .................... General Chemistry .................... Metallic Sodium-Catalyzed Polymerization .........

5 MANUFACTURING PROCESSES ..................

Introduction ........................ Monomer Handling ...................... Quality Control .......................

6 POLYSTYRENE BY MASS POLYMERIZATION .............

Review of Processes .................... Equipment ........................ Material Used in Construction .............. Processing Conditions and Compositions ..........

3

35

35 36 36 40 41 46 50 65 66 68 68 77 79 79 85 85 95 95 107 116 116 120

123

123 129 130

131

131 131 136 137

iii

CONTENTS

6 (Continued)

Process Description .................... 147

General Purpose Polymer ................. 147

High Impact Polymer ................... 148

Expandable Polymer .................... 148

Process Discussion ..................... 155

Cost Estimates ....................... 158

7 POLYSTYRENE BY SUSPENSION POLYMERIZATION ..........

Review of Processes ....................

Process Description ....................

General Purpose Polymer .................

High Impact Polymer ...................

-Expandable Polymer ....................

Demineralized Water System ................

Process Discussion ......................

Cost Estimates .......................

8 POLYSTYRENE BY EMULSION POLYMERIZATION ...........

Review of Processes ....................

Process Description ....................

General Purpose Polymer .................

High Impact Polymer ...................

Process Discussion .....................

Cost Estimates .......................

9 POLYSTYRENE BY SOLUTION POLYMERIZATION ...........

Review of Processes ....................

Process Description .................... Process Discussion ..................... Cost Estimates .......................

10 POLYSTYRENE FOAMS . . . . . . . . . . . . . . . . . . . . . 285

Introduction ........................ 285

Expanding Mechanism ..................... 287

Molding of Expandable Polystyrene Beads .......... 289

Review of Processes ................... 289

Process Description ................... 295

Process Discussion .................... 299

Cost Estimates ...................... 300

iv

177

177 185 185 186 187 188 197 200

219

219 229 229 230 241 245

259

259 265 271 274

10 (Continued)

I B I II

Extrusion of Expandable Beads ............... Review of Processes ................... Process Description ................... Process Discussion .................... Cost Estimates ......................

Direct-Injection Extrusion of General Purpose Polystyrene . Review of Processes ................... Process Description ................... Process Discussion .................... Cost Estimates ......................

11 GENERAL PROPERTIES OF POLYSTYRENE . . . . . . . . . . . . . 329

12 FACTORS AFFECTING THE PROPERTIES OF POLYSTYRENE . . . . . . 335

Polystyrene ........................ Mechanical Properties .................. Molecular Weight and Its Distribution ......... Molecular Chain Structure ............... Orientation ...................... Temperature ...................... Annealing ....................... Rubber-Modified .................... Residues, Impurities, and Additives .......... Fabrication Methods ..................

Viscosity and Rheological Properties ........... Molecular Weight and Its Distribution .......... Branching ....................... Solvent and Polymer Concentration ........... Temperature ...................... Flow Behavior .....................

Thermal Properties .................... Vapor Pressure ...................... Electrical Properties .................. Flammability. ...................... Electrostatic Charge ................... Weatherability ...................... Solubility and Diffusivity of Gases ...........

Polystyrene Foam ......................

306 306 307 311 312 319 319 320 321 322

335 335 335 338 339 339 340 341 342 342 343 343 347 347 347 351 351 354 359 359 359 363 364 364

V

CONTENTS

APPENDIX A DESIGN AND COST BASIS ............... 367

APPENDIX B RAW MATERIAL SPECIFICATIONS ............ 373

APPENDIX C PROPERTIES OF RAW MATERIALS ............ 375

CITED REFERENCES ........................ 377

SUPPLEMENTARY REFERENCES .................... 451

Vi

ILLUSTRATIONS

3.1 Polystyrene Production Data and Projection . . . . . . . . 25

6.1 Polystyrene by Bass Polymerization . . . . . . . . . . . , 151

6.2 Effect of Styrene Price on Production Cost of General Purpose Polymer . . . . . . . . . . . . . . . . . . . . . 169

6.3 Effect of Styrene and Rubber Prices and Rubber Content on Production Cost of High Impact Polymer . . . . . . . . . . 170

6.4 Effect of Blowing Agent Content and Prices of Styrene and Blowing Agent on Production Cost of Expandable Polymer . . 171

6.5 Effect of Utilities, Fixed Capital-Related and Labor- Related Costs on Production Cost . . . . . . . . . . . . . 172

6.6 Effect of Polymerization Cycle Time on Production Cost . . 173

6.7 Effect of Operating Rate and Plant Capacity on Production Cost . . . . . . . . . . . . . , . . . . . . . 174

7.1 Polystyrene by Suspension Polymerization . . . . . . . . . 189

7.2 Effect of Styrene Price on Production Cost of General Purpose Polymer . . . . . . . . . . . . . . . . . . . . . 211

7.3 Effect of Styrene and Rubber Prices and Rubber Content on Production Cost of High Impact Polymer . l . l l l . . g . 212

7.4 Effect of Styrene, Pentane, and Polyvinylpyrrolidone Prices on Production Cost of Expandable Polystyrene . . . 213

7.5 Effect of Utilities, Fixed Capital-Related, and Labor- Related Costs on Production Cost . . . . . . . . , . . . . 214

7.6 Effect of Amount of Water Used in Polymerization Recipe on Production Cost . . . . . . . . . . . . . . . . . . . , . 215

7.7 Effect of Polymerization Batch Time on Production Cost . . 216

7.8 Effect of Operating Rate and Plant Capacity on Production Cost . . . . . . . . . . . . . . . . . . . . . 217

8.1 Polystyrene by Emulsion Polymerization . . . . . . . . . . 233

8.2 Effect of Styrene Price on Production Cost of General Purpose Polymer . . . . . . . . . , . . . . . . . . . . . 251

8.3 Effect of Styrene and Rubber Prices and Rubber Content on Production Cost of High Impact Polymer . . . . . . . . . . 252

8.4 Effect of Utilities, Fixed Capital-Related, and Labor- Related Costs on Production Cost . . . . . . . . ; . . . . 253

Vii

8.5 Effect of Polymerization Cycle Time on Production Cost . . 254

8.6 Effect of Amount of Water Used in Recipe on Production cost........................... 255

8.7 Effect of Operating Rate and Plant Capacity on Production Cost . . . . . . . . . . . . . . . . . . . . . 256

9.1 Polystyrene by Solution Polymerization . . . . . . . . . . 267

9.2 Effect of Styrene Price on Production Cost . . . . . . . . 280

9.3 Effect of Quantity of Solvent Used and Solvent Loss on Production Cost . . . . . . . . . . . . . . . . . . . . . 281

9.4 Effect of Polymerization Cycle Time on Production Cost . . 282

9.5 Effect of Utilities, Fixed Capital-Related, and Labor- Related Costs on Production Cost . . . . . . . . . . . . . 283

9.6 Effect of Operating Rate and Plant Capacity on Production Cost . . . . . . . . . . . . . . . . . . . . . 284

10.1 Molding of Expandable Polystyrene Beads . . . . . . . . . 297

10.2 Molding of Expandable Polystyrene Beads Effect of Plant Capacity and Operating Level on Production Cost . . . . . . . . . . . . . . . . . . . . . 305

10.3 Extrusion of Expandable Polystyrene Beads . . . . . . . . 309

10.4 Extrusion of Expandable Polystyrene Beads Effect of Plant Capacity and Operating Level on Production Cost . . . . . . . . . . . . . . . . . . . . . 318

10.5 Direct-Injection Extrusion of General Purpose Polystyrene Effect of Plant Capacity and Operating Level on Production Cost . . . . . . . . . . . . . . . . . . . . . 328

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2.1

2.2

3.1

3.2

3.3

3.4

3.5

3.6

3.7

3.8

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

4.9

Comparison of Costs of Various Processes for Manufacturing Polystyrene . . . . . . . . . . . . . . , . 7

Comparison of Costs of Various Processes for Foaming Polystyrene . . . . . . . . . . . . . . . . . . . 12

Typical Commercial Classifications of Polystyrene and Their Applications . . . . . . . . . . . . . . . . . . . . 21

Consumption of Polystyrene in United States . . . . . . . 23

Consumption of Styrene Polymer and Copolymer in the United States . . . . . . . . . . . . . . . . . . . . . . 24

End-Use Forecast for Polystyrene Foam . . . . . . . . . . 27

Producers and Plant Capacity for Polystyrene United States . . . . . . . . . . . . . . . . . . . . . . 28

Trade Names for Polystyrene and Related Products . . . . . 30

Production and Consumption of Polystyrene for 1966 in Countries Other Than the United States . . . . . . . . . . 32

Producers and Plant Capacities . . . . . . . . . . . , . . 33

Some Publications on Catalyzed Polymerization of Styrene . 51

Some Publications on the Inhibition and Retardation of Styrene Polymerization . . . . . . . . . . . , , . . . . . 59

Some Publications on the Effect of Oxygen on Styrene Polymerization . . . . . . . . . . . . . . . . . . . . . . 67

Some Publications on the Effect of Pressure on Styrene Polymerization . . . . , . . . . . . . . . . . . . . . . , 69

Some -Publications on the Degradation Reactions of Polystyrene . . . . . . . . . . . . . . , . . . . . . . . 71

Some Publications on the Mass Polymerization of Styrene . 81

Some Publications on the Emulsion Polymerization of Styrene . . . . . . . . . . . . . . . . . . . . . . . . . 89

Some Publications on the Solution Polymerization of Styrene . . . . . . . . . . . . . . . . . . . . . . . . . 97

Some Publications on Chain-Transfer Reactions and Chain- Modifier Additions in the Solution Polymerization of Styrene . . . . . . . . . . . . . . . . . . . . . . . . . 101

ix

TABLES

4.10 Some Publications on the Photopolymerization of Styrene . 105

4.11 Some Publications on Gamma and X-Ray Initiated Styrene Polymerization . . . . . . . . . . . . . . . . . . . . . . 109

5.1 Some Patents on Impact Polystyrene by Polyblend . . . . . 126

5.2 Some Patents on Expandable Polystyrene by Steeping or Mixing of Polystyrene with Blowing Agents . . . . . . . . 127

6.1 Some Patented Compositions and Processing Conditions for Mass Polymerization of Styrene . . . . . . . . . . . . . . 139

6.2 Some Catalyst Systems Reported for Mass Polymerization of Styrene . . . . . . . . . . . . . . . . . . . . . . . . . 143

6.3 Polystyrene by Mass Polymerization Major Process Equipment and Utilities Summary . . . . . . 150

6.4 Polystyrene by Mass Polymerization Stream Flows....................... 153

6.5 Polystyrene by Mass Polymerization Process Unit and Utilities Investment . . . . . . . . . . 163

6.6 Polystyrene by Bass Polymerization Total Capital Investment . . . . . . . . . . . . . . . . . 165

6.7 Polystyrene by Mass Polymerization Production Costs . . . . . . . . . . . . . . . . . . . . . 167

6.8 Effect of Change in Product Mix on Production Cost . . . . 175

7.1 Some Patents on the Suspension Stabilizing System for Suspension Polymerization of Styrene . . . . . . . . . . . 179

7.2 Some Patents on Catalysts for Suspension Polymerization of styrene........................ 181

7.3 Some Patents on Composition of Matter for Suspension Polymerization of Styrene . . . . . . . . . . . . . . . . 183

7.4 Polystyrene by Suspension Polymerization Major Process Equipment and Utilities Summary . . . . . . 189

7.5 Polystyrene by Suspension Polymerization Stream Flows . . . . . . . . . . . . . . . . . . . . . . . 193

7.6 Polystyrene by Suspension Polymerization Process Unit and Utilities Investment . . . . . . . . . . 205

X

TABLES

7.7 Polystyrene by Suspension Polymerization Total Capital Investment . . . . . . . . . . . . . . . . . 207

7.8 Polystyrene by Suspension Polymerization Production Costs . . . . . . . . . . . . . . . . . . . . . 209

7.9 Effect of Change in Product Mix on Production Cost . . . . 218

8.1 Some Patents on the Emulsifying Agent for Emulsion Polymerization of Styrene . . . . . . . . . . . . . . . , 223

8.2 Some Patents on Catalyst Systems for Emulsion Polymerization of Styrene . . . . . . . . . . . . . . . . 225

8.3 Some Patents on the Composition of Batter for Emulsion Polymerization of Styrene . . . . . . . . . . . . . . . . 227

8.4 Polystyrene by Emulsion Polymerization Major Process Equipment and Utilities Summary . . . . . . 232

8.5 Polystyrene by Emulsion Polymerization Stream Flows....................... 237

8.8 Polystyrene by Emulsion Polymerization Process Unit and Utilities Investment . . . . . . . . . . 247

8.7 Polystyrene by Emulsion Polymerization Total Capital Investment . . . . . . . . . . . . . . . . . 248

8.8 Polystyrene by Emulsion Polymerization Production Costs . . . . . . . . . . . . . . . . . . . . . 249

8.9 Effect of Change in Product Mix on Production Cost . . . . 257

9.1 Some Patents on Catalyst Systems in Solution Polymerization of Styrene . . . . . . . . . . . . . . . . 263

9.2 Polystyrene by Solution Polymerization Major Process Equipment and Utilities Summary . . . . . . 267

9.3 Polystyrene by Solution Polymerization Stream Flows . . . . . . . . . . . . . . . . . . . . . . . 269

9.4 Polystyrene by Solution Polymerization Process Unit and Utilities Investment . . . . . . . . . . 277

9.5 Polystyrene by Solution Polymerization Total Capital Investment . . . . . . . . . . . . . . . . . 278

9.6 Polystyrene by Solution Polymerization Production Costs . . . . . . . . . . . . . . . . . . . . . 279

Xi

10.1

10.2

10.3

10.4

10.5

10.6

10.7

10.8

10.9

10.10

10.11

10.12

10.13

10.14

11.1

Molding of Expandable Polystyrene Beads Major Process Equipment and Utilities Summary . . . . . ,

Holding of Expandable Polystyrene Beads Process Unit and Utilities Investment . . . . . . . . . .

Molding of Expandable Polystyrene Beads Total Capital Investment . . . . . . . . . . . . . . . . .

Holding of Expandable Polystyrene Beads Production Costs . . . . . . . . . . . . . . . . . . . . .

Some Nucleating Additives for the Extrusion of Polystyrene Foams . . . . . . . . . . . . . . . . . . . .

Extrusion of Expandable Polystyrene Beads Major Process Equipment and Utilities Summary . . . . . .

Extrusion of Expandable Polystyrene Beads Process Unit and Utilities Investment . . . . . . . . . .

Extrusion of Expandable Polystyrene Beads Total Capital Investment . . . . . . . . . . . . . . . . .

Extrusion of Expandable Polystyrene Beads Production Costs . . . . . . . . . . . . . . . . . . . . .

Extrusion of Expandable Polystyrene Beads Effects of Various Hypothetical Cost Reduction Possibilities on Production Cost . . . . . . . . . . . . .

Direct-Injection Extrusion of General Purpose Polystyrene (Foamed Sheet) Process Unit and Utilities Investment . . . . . . . . . .

Direct-Injection Extrusion of General Purpose Polystyrene (Foamed Sheet) Total Capital Investment . . . . . . . . . . . . . . . . .

Direct-Injection Extrusion of General Purpose Polystyrene (Foamed Sheet) Production Costs . . . . . . . . . . . . . . . . . . . . .

Direct-Injection Extrusion of General Purpose Polystyrene (Foamed Sheet) Effects of Various Hypothetical Cost Reduction Possibilities on Production Cost . . . . . . . . . . . . .

Physical Properties of Polystyrene . , . . . . . . . . . .

Xii

297

302

303

304

308

309

314

315

316

317

324

325

326

327

333

TABLE8

12.1 Published Observations on the Relationship of Viscosity and Molecular Weight of Polystyrene . . . . . , . . . . . 345

12.2 Published Observations on the Effects of Solvent and Polymer Concentration on Viscosity . . . . . . . . . . . . 348

12.3 Published Observations of the Flow Behavior of Polystyrene . . . . . . . . . . . . . . . . . . . . . . . 352

12.4 Published Thermodynamic Data for Polystyrene . . . . . . . 355

12.5 Published Observations on the Relationships of Certain Thermodynamic Properties and Influencing Factors . . . . . 356

12.6 Patents on Fire-Retarding Polystyrene . . . . . . . . . . 360

12.7 Patents of Antistatic Formulations for Polystyrene . . . . 362

xiii