Conformational Analysis of Polymers
Comprehensive resource focusing on theoretical methods and experimental techniques to analyze physical polymer chemistry
Connecting varied issues to demonstrate the impact on areas like biodegradability, environmental friendliness, structure-property relationship, and molecular design, Conformational Analysis of Polymers introduces theoretical methods and experimental techniques to analyze physical polymer chemistry.
Opening with a description of fundamental concepts and then describing the conformational characteristics of various polymers, including different heteroatoms and chemical species, the text continues onto the applications of density functional theory (DFT) to polymer crystals and structure-property relationships. The book concludes by bringing these issues together to demonstrate their practical impact on different areas of the field.
Various methods and techniques, including DFT, statistical mechanics, NMR, spectroscopy, and molecular orbital theory, are also covered.
Written by a highly qualified author, Conformational Analysis of Polymers explores sample topics such as:
- Fundamentals of polymer physical chemistry: stereochemistry of polymers, models for polymeric chains, Flory-Huggins theory, and rubber elasticity
- Quantum chemistry for polymers: ab initio molecular orbital theory, DFT, NMR parameters, and periodic DFT of polymer crystals
- Statistical mechanics of polymeric chains: basic rotational isomeric state (RIS) scheme, refined RIS method, inversional-rotational isomeric state method, and probability theory for RIS scheme
- Experimental techniques: NMR and scattering methods
Providing a timely update to the field of chain conformations of synthetic polymers and connecting fundamental theoretical approaches, experimental techniques, and case study applications; Conformational Analysis of Polymers is an essential resource for polymer chemists, physicists, and material scientists, industrial engineers who synthesize and process polymers, and academic researchers.
Table of Contents
Preface xii
Acknowledgments xvi
About the Author xvii
Acronyms xviii
Part I Fundamentals of Polymer Physical Chemistry 1
1 Stereochemistry of Polymers 3
1.1 Configuration 3
1.2 Connection Type of Monomeric Units 5
1.3 Nitrogen Inversion 5
1.4 Conformation 8
1.5 Secondary Structure 9
1.6 Double Helix 11
2 Models for Polymeric Chains 13
2.1 Spatial Configuration of Polymeric Chain 13
2.2 Freely Jointed Chain 13
2.3 Freely Rotating Chain 15
2.4 Simple Chain with Rotational Barrier 16
2.5 Gaussian Chain 17
3 Lattice Model 21
3.1 Lattice Model of Small Molecules 21
3.2 Flory-Huggins Theory 22
3.2.1 Entropy of Polymeric Chain 22
3.2.2 Enthalpy of Mixing 25
3.2.3 Chemical Potential 26
3.2.4 Excluded-Volume Effect I 28
3.2.5 Excluded-volume Effect II 32
3.2.6 Phase Equilibrium 35
3.3 Intrinsic Viscosity 36
3.3.1 Stockmayer-Fixman Plot 37
Exercise 38
4 Rubber Elasticity 41
4.1 Thermodynamics of Rubber Elasticity 41
4.2 Adiabatic Stretching: Gough-Joule Effect 45
4.3 Phenomenological Theory: Affine Model 46
4.4 Temperature Dependence of Chain Dimension in Rubber 48
Part II Quantum Chemistry 51
5 Ab Initio Molecular Orbital Theory 55
5.1 Schrödinger Equation 55
5.2 Wave Function 56
5.3 Basis Set 57
5.4 Hartree-Fock Method 58
5.5 Roothaan-Hall Equation 59
5.6 Electron Correlation 60
6 Density Functional Theory 63
6.1 Exchange and Correlation Functionals 65
6.2 Dispersion-force Correction 67
7 Solvent Effect 69
8 Statistical Thermodynamics for Quantum Chemistry 75
8.1 Translational Motion 76
8.2 Rotational Motion 77
8.3 Vibrational Motion 78
8.4 Electronic Excitation 80
8.5 Thermochemistry 81
9 NMR Parameters 85
9.1 Chemical Shift 86
9.1.1 Example: Determination of Reaction Process from NMR Chemical Shifts 88
9.2 Indirect Spin-Spin Coupling Constant 92
9.2.1 Example 1: Calculation of Vicinal Coupling Constants of Cyclic Compound 93
9.2.2 Example 2: Derivation of Karplus Equation and Its Application 95
10 Periodic Quantum Chemistry 99
10.1 Direct Lattice and Reciprocal Lattice 99
10.2 Bloch Function 100
10.3 One-electron Crystal Orbital 101
10.4 Structural Optimization 102
10.5 Crystal Elasticity 104
10.6 Vibrational Calculation 108
10.7 Thermal Chemistry 110
10.8 Cohesive (Interchain Interaction) Energy 112
Part III Statistical Mechanics of Chain Molecules: Rotational Isomeric State Scheme 115
11 Conventional RIS Scheme 117
11.1 Chain Dimension 121
12 Refined RIS Scheme 125
12.1 RIS Scheme Including Middle-range Intramolecular Interactions 129
13 Inversional-Rotational Isomeric State (IRIS) Scheme 137
13.1 Pseudoasymmetry for Polyamines 137
13.2 Inversional-Rotational Isomerization 137
13.3 Statistical Weight Matrices of Meso and Racemo di-MEDA 138
13.4 Statistical Weight Matrices of PEI 139
13.5 Diad Probability and Bond Conformation 142
13.6 Characteristic Ratio 144
13.7 Orientational Correlation Between Bonds 145
13.8 Solubility of Polyamines 148
14 RIS Scheme Combined with Stochastic Process 151
14.1 Polymeric Chains with Internally Rotatable Side Chains 153
Part IV Experimental Methods 161
15 Nuclear Magnetic Resonance (NMR) 163
15.1 Conformational Analysis of Isotactic Poly(propylene oxide) 163
15.1.1 1 H NMR Vicinal Coupling Constant 164
15.1.2 Ab initio MO Calculation 168
15.1.3 RIS Analysis of Bond Conformations 171
15.1.4 Configuration-dependent Properties 172
15.2 Carbon-13 NMR Chemical Shifts of Dimeric Propylene Oxides 173
15.2.1 Theoretical Basis 175
15.2.2 13 C NMR Spectra and Assignment 176
15.2.3 Calculation of Chemical Shift by RIS Scheme 179
15.3 Model Compound of Poly(ethylene terephthalate) 181
16 Scattering Methods 187
16.1 Static Light Scattering (SLS) 187
16.1.1 Instrumentation and Sample Preparation for SLS 189
16.1.2 Application of SLS: Chain Dimensions of Polysilanes in the Θ
State 191
16.2 Dynamic Light Scattering (DLS) 195
16.2.1 Application of DLS: Size Distribution of Polystyrene Latex Particles 197
16.2.2 Application of SLS and DLS to Poly(N-methylethylene imine) Solutions 198
16.3 Small-angle Neutron Scattering (SANS) 201
16.3.1 Application of SANS to Amorphous PET 204
Part V Applications: Conformational Analysis and Elucidation of Structure-property Relationships of Polymers 207
17 Polyethers 215
17.1 Poly(methylene oxide) (PMO) 215
17.2 Poly(ethylene oxide) (PEO) 217
17.3 Poly(propylene oxide) (PPO) 226
17.4 Poly(trimethylene oxide) (PTrMO) 228
17.5 Poly(tetramethylene oxide) (PTetMO) 229
18 Polyamines 235
18.1 Poly(ethylene imine) (PEI) 236
18.2 Poly(N-methylethylene imine) (PMEI) 237
18.3 Poly(trimethylene imine) (PTMI) and Poly(N-methyltrimethylene imine) (pmtmi) 238
19 Polyphosphines 241
19.1 Possibility of Phosphorus Inversion 241
19.2 Intramolecular Interactions Related to Phosphorus 243
19.3 RIS Calculation 244
19.4 Functions and Stability 248
20 Polysulfides 249
20.1 Poly(methylene sulfide) (PMS) 249
20.1.1 Crystal Structure of PMS 253
20.2 Poly(ethylene sulfide) (PES) 253
20.3 Poly(propylene sulfide) (PPS) 260
20.4 Poly(trimethylene sulfide) (PTrMS) 265
21 Polyselenides 269
21.1 Poly(methylene selenide) (PMSe) 269
21.1.1 Crystal Structure of PMSe 270
21.2 Poly(ethylene selenide) (PESe) 274
21.3 Poly(trimethylene selenide) (PTrMSe) 276
21.4 Summary 277
22 Alternating Copolymers Including Ethylene-imine, Ethylene-oxide, and Ethylene-sulfide Units 279
22.1 Synthesis of P(EI-ES) 286
23 Aromatic Polyester (PET, PTT, and PBT) 289
23.1 Correction for MP2 Energy of π-π Interaction 290
23.2 Dipole Moment and Molar Kerr Constant 293
23.3 Configurational Properties 296
23.4 Crystal Structure 297
24 Aliphatic Polyesters 301
24.1 Poly(glycolic acid) (PGA) and Poly(2-hydroxybutyrate) (P2HB) 301
24.1.1 MO Calculation and NMR Experiment 302
24.1.2 RIS Calculation 305
24.1.3 Periodic DFT Calculation on PGA Crystal 309
24.2 Poly(lactic acid) (Poly(lactide), PLA) 312
24.2.1 MO Calculation and NMR Experiment 313
24.2.2 RIS Calculation 317
24.3 Poly((R)-3-hydroxybutyrate) (P3HB) 321
24.3.1 NMR Experiment 321
24.3.2 MO Calculation 323
24.3.3 RIS Calculation and Comparison with Experiment 325
24.3.4 Crystal Structure 326
24.4 Poly(ε-caprolactone) (PCL) 327
24.4.1 MO Calculation 328
24.4.2 NMR Experiment 330
24.4.3 RIS Calculation 330
24.4.4 Crystal Structure 332
24.4.5 Crystal Elasticity 333
24.5 Poly(ethylene succinate) (PES) and Poly(butylene succinate) (PBS) 336
24.5.1 NMR Experiment 337
24.5.2 MO Calculation 338
24.5.3 RIS Calculation 339
24.5.4 Crystal Structure 340
24.6 Biodegradability of Polyesters 342
25 Polycarbonates 347
25.1 Poly(ethylene carbonate) (PEC) and Poly(propylene carbonate) (ppc) 348
25.1.1 NMR Experiment 351
25.1.2 MO Calculation 351
25.1.3 RIS Calculation 353
25.2 Poly(cyclohexene carbonate) (PCHC) 357
25.2.1 MO Calculation 358
25.2.2 NMR Experiment 360
25.2.3 RIS Calculation 361
25.2.4 Coherence Number 364
26 Nylon 4 367
26.1 MO Calculation 368
26.2 NMR Experiment 370
27 Aromatic Polyester, Polythionoester, Polythioester, Polydithioester, Polyamide, and Polythioamide 373
27.1 MO Calculation 375
27.2 Bond Conformation 377
27.3 RIS Calculation, Thermal Properties, and Solubility 380
28 Polysilanes 383
28.1 Molecular Dynamics 384
28.1.1 General Procedures 384
28.1.2 PDBS and PDHS 384
28.1.3 PMPrS 387
28.2 RIS Calculation 387
28.3 Physical Properties 388
29 Polyethylene (PE) 391
A FORTRAN Computer Program for Refined RIS Calculations on Polyethylene 399
B Answers of Problems 423
Bibliography 431
Index 465
