Conformations Connecting the Chemical Structures and Material Behaviors of Polymers

Among the materials found in Nature?s many diverse living organisms or produced by human industry, those made from polymers are dominant. In Nature, they are not only dominant, but they are, as well, uniquely necessary to life. Conformations: Connecting the Chemical Structures and Material Behaviors of Polymers explores how the detailed chemical structures of polymers can be characterized, how their microstructural-dependent conformational preferences can be evaluated, and how these conformational preferences can be connected to the behaviors and properties of their materials.

The authors examine the connections between the microstructures of polymers and the rich variety of physical properties they evidence. Detailed polymer architectures, including the molecular bonding and geometries of backbone and side-chain groups, monomer stereo- and regiosequences, comonomer sequences, and branching, are explicitly considered in the analysis of the conformational characteristics of polymers.

This valuable reference provides practicing materials engineers as well as polymer and materials science students a means of understanding the differences in behaviors and properties of materials made from chemically distinct polymers. This knowledge can assist the reader design polymers with chemical structures that lead to their desired material behaviors and properties.

Contents

Preface ...................................................................................................... ix

Authors ...................................................................................................xiii

Chapter 1 Polymer Physics or Why Polymers and Their Materials

Can Behave in Unique Ways ................................................ 1

Introduction .......................................................................... 1

References ............................................................................ 7

Discussion Questions ............................................................ 7

Chapter 2 Polymer Chemistry or the Detailed Microstructures

of Polymers ........................................................................... 9

Polymerization ...................................................................... 9

Step-Growth Polymers ..................................................... 9

Chain-Growth Polymers .................................................11

Chain-Growth Polymer Microstructures ................... 12

Branching and Cross-Linking ....................................14

Comonomer Sequences ...............................................17

References ...........................................................................18

Discussion Questions ...........................................................18

Chapter 3 Determining the Microstructural Dependent

Conformational Preferences of Polymer Chains .................19

Introduction .........................................................................19

References ...........................................................................41

Discussion Questions .......................................................... 42

Appendix: Fortran Program for Hexane “by-hand”

Conformational Populations and Distances ........................43

Chapter 4 Experimental Determination of Polymer

Microstructures with 13C-NMR Spectroscopy ................... 57

Introduction ........................................................................ 57

Substituents Effects ............................................................ 58

References .......................................................................... 67

Discussion Questions .......................................................... 67

Appendix 4.1: Polymer Macrostructures and the

Kerr Effect .......................................................................... 68

Appendix 4.2: Access to Program (FORTRAN) Used

to Calculate Molar Kerr Constants for Polymers ............... 84

Chapter 5 Connecting the Behaviors/Properties of Polymer

Solutions and Liquids to the Microstructural

Dependent Conformational Preferences of Their

Polymer Chains .................................................................109

Introduction .......................................................................109

Intrinsic Viscosities of Dilute Polymer Solutions ..............112

Polymer Entanglement ......................................................115

Dynamic Behaviors of Polymer Solutions and Melts ....... 120

References ........................................................................ 120

Discussion Questions .........................................................121

Chapter 6 Connecting the Behaviors/Properties of Polymer Solids

to the Microstructural Dependent Conformational

Preferences of Their Individual Polymer Chains ..............123

Introduction .......................................................................123

Solid Polymer Properties and Zconf ................................... 124

Copolymer Tgs and Their Comonomer-Sequence

Dependence ...................................................................... 125

Melting Temperatures of Semi-crystalline Polymers ........132

The Flexibilities of Polymers with

1,4-attached Phenyl Rings in Their Backbones ................140

Poly(ethylene phthalates) ...............................................140

Polymers with High Impact Strengths Well

Below Their Glass-Transition Temperatures .................144

Elastic Polymer Networks .................................................149

Thermodynamics of Polymer Networks .......................151

Polymer Network Topology ..........................................152

Modulus of a Polymer Network ....................................167

References .........................................................................174

Discussion Questions .........................................................177

Appendix 6.1 .....................................................................178

Chapter 7 Biopolymer Structures and Behaviors

with Comparisons to Synthetic Polymers ..........................179

Introduction .......................................................................179

Polysaccharides .................................................................179

Proteins ..............................................................................184

Polynucleotides ................................................................. 200

References .........................................................................212

Discussion Questions .........................................................215

Index ......................................................................................................217

Alan Tonelli, born in Chicago in 1942,

received a BS in Chemical Engineering

from the University of Kansas, in 1964 and

a PhD in Polymer Chemistry from Stanford

in 1968, where he was associated with the

late “Father of Polymer Science” and

Nobelist Professor Paul J. Flory. He was a

member of the Polymer Chemistry Research

Department at AT&T-BELL Laboratories,

Murray Hill, NJ for 23 years. In 1991, he

joined the Textile Engineering, Chemistry, & Science Department and the

Fiber & Polymer Science Program in the College of Textiles at North

Carolina State University in Raleigh, where he is currently the

INVISTA Prof. of Fiber & Polymer Chemistry. Professor Tonelli’s research

interests include the conformations, configurations, and structures of synthetic

and biological polymers, their determination by NMR, and establishing

their effects on the physical properties of polymer materials. More

recently, the formation, study, and use of inclusion complexes formed with

polymers and small molecule guests, such as urea and cyclodextrins, to

nanostructure and safely deliver biologically active molecules to polymer

materials have been the focus of his research.

Jialong Shen, born in Hangzhou, China, in

1987, received a PhD in Fiber and Polymer

Science from North Carolina State

University, North Carolina, United States,

in 2017. His research interests include the

molecular basis of polymer glass transitions,

host-guest supramolecular chemistry, and

the applications of bio-macromolecules

such as carbohydrate polymers and enzymes.

He is currently a postdoctoral research

scholar in the Textile Engineering, Chemistry, & Science Department at

North Carolina State University.