Advanced Polyimide Materials: Synthesis, Characterization, and Applications

Cover
Advanced Polyimide Materials
Copyright
List of Contributors
About the Editor
Preface
1 Advanced Polyimide Films
	1.1 Introduction
	1.2 Chemistry of Polyimide Films
		1.2.1 Thermal Imidization
			1.2.1.1 Reactivity of Monomers
			1.2.1.2 Effect of Solvents
			1.2.1.3 Effect of Moisture
			1.2.1.4 Monomer Adding Mode
			1.2.1.5 Effect of Molecular Weight Distribution
		1.2.2 Chemical Imidization
			1.2.2.1 Effect of Temperature on Viscosity and Gelation Time
			1.2.2.2 Effect of Molar Ratio of Pyridine to Acetic Anhydride on PAA Viscosity
			1.2.2.3 Effect of Catalysts on PAA Imidization
			1.2.2.4 Effect of Initial Viscosity on Gelation Time
			1.2.2.5 Properties of the Chemically Imidized Films
	1.3 Thermal Curing of Polyimide Films
		1.3.1 Thermal Imidization Process
			1.3.1.1 Solvent Evaporation Stage (T%3c150°C)
			1.3.1.2 Imidization Stage (T=150–250°C)
			1.3.1.3 Annealing Stage (T%3e250°C)
		1.3.2 Influence of Curing Temperatures on Film’s Properties
	1.4 Structures and Properties of Polyimide Films
		1.4.1 Advanced Polyimide Films
			1.4.1.1 Film-forming Ability of Molecular-weight-controlled PAAs
			1.4.1.2 Mechanical Properties of Fully Cured Polyimide Films
			1.4.1.3 Effect of Thermal Curing on Aggregation State of Polyimide Films
			1.4.1.4 Effect of Thermal Curing on Molecular Orientation and CTE of PI Films
			1.4.1.5 Effect of Thermal Curing on Mechanical Properties of Polyimide Films
		1.4.2 Low-CTE Polyimide Films
			1.4.2.1 Ester-Bridged Low-CTE Polyimide Films
			1.4.2.2 Fluorinated Low-CTE Polyimide Films
				1.4.2.2.1 Film Forming Ability
				1.4.2.2.2 Film Mechanical Properties
				1.4.2.2.3 Water Uptake
				1.4.2.2.4 Thermal Dimension Stabilities
		1.4.3 Transparent Polyimide Films
		1.4.4 Atomic Oxygen-resistant Polyimide Films
	1.5 Surface Modification of Polyimide Films
	1.6 Applications of Polyimide Films
		1.6.1 Electric Insulating Applications
		1.6.2 Electronic and Optoelectronic Applications
			1.6.2.1 Electronic Applications
			1.6.2.2 Optoelectronic Applications
		1.6.3 Aerospace Applications
			1.6.3.1 Multilayer Thermal Blanket
			1.6.3.2 Flexible and/or Rigid Extendable Structures
			1.6.3.3 Large Deployable Antenna
	1.7 Summary
	References
2 Advanced Polyimide Fibers
	2.1 Introduction
	2.2 Synthesis of Spinning Resin Solutions
		2.2.1 “Two-Step” Polymerization Method
			2.2.1.1 Synthesis of Poly(Amic Acid) Solution
			2.2.1.2 Imidization Reaction
		2.2.2 “One-Step” Polymerization Method
	2.3 Preparation of Polyimide Fibers
		2.3.1 Wet-Spinning Method
			2.3.1.1 “Two-Step” Wet-Spinning Method
			2.3.1.2 “One-Step” Wet-Spinning Method
		2.3.2 Dry-Spinning Method
		2.3.3 Other-Spinning Methods
			2.3.3.1 Liquid-Crystal Spinning Process
			2.3.3.2 Melt-Spinning Process
	2.4 Structure and Properties of Polyimide Fibers
		2.4.1 Aggregation Structure of Polyimide Fibers
		2.4.2 Chemical Structure–Property Relationship
			2.4.2.1 Typical Homo-Polyimide Fibers
			2.4.2.2 Copolyimide Fibers with Hydrogen Bonding Interactions
			2.4.2.3 Copolyimide Fibers Containing Ether Units
			2.4.2.4 Copolyimide Fibers Containing Benzoxazole Units
			2.4.2.5 Copolyimide Fibers Containing Fluorinated Groups
		2.4.3 Properties of Polyimide Fibers
			2.4.3.1 Mechanical Properties
			2.4.3.2 Thermal Stability
			2.4.3.3 Chemical Resistance
			2.4.3.4 Flame-Retardant Properties
			2.4.3.5 Other Properties
	2.5 Applications of Polyimide Fibers
		2.5.1 Production of Polyimide Fibers
		2.5.2 Application of Polyimide Fibers
	2.6 Summary
	References
	Further Reading
3 Polyimide Matrices for Carbon Fiber Composites
	3.1 Introduction
	3.2 NA-endcapped Thermoset Matrix Resins
		3.2.1 Chemistry
		3.2.2 Structures and Properties
			3.2.2.1 NA-endcapped Polyimides for 316°C/600°F Applications
			3.2.2.2 NA-endcapped Polyimides for 371°C/700°F Applications
	3.3 PE-endcapped Oligoimide Resins
		3.3.1 Chemistry
		3.3.2 Structures and Properties
			3.3.2.1 PE-endcapped Oligoimides for Autoclave Processing
			3.3.2.2 PE-endcapped Oligoimides for RTM Processing
	3.4 Properties of Polyimide/Carbon Fiber Composites
		3.4.1 Preparation of PMR-type Resin Prepregs
		3.4.2 Fabrication of Carbon Fiber Composites
			3.4.2.1 Compression Molding
				3.4.2.1.1 Autoclave Molding
				3.4.2.1.2 Resin Transfer Molding
		3.4.3 Properties of NA-Endcapped Polyimide Composites by Autoclave
		3.4.4 Properties of PE-Endcapped Polyimide Composites by Autoclave
		3.4.5 Properties of PE-Endcapped Polyimide Composites by RTM
	3.5 Applications of Polyimide/Carbon Fiber Composites
	3.6 Summary
	References
4 Super Engineering Plastics and Forms
	4.1 Introduction
	4.2 Compression-Molded Polyimide Materials
	4.3 Injection and Extrusion Processed Polyimide Materials
	4.4 Structures and Melt Processabilities of Aromatic Polyimide Resins
		4.4.1 Polyimide Backbone Structures
		4.4.2 Controlled Molecular Weights
	4.5 Meltable Thermoplastic Polyimide Composites
	4.6 Reactive End-Capped Meltable Polyimide Resins
		4.6.1 NA-end-capped Meltable Polyimide Resins
		4.6.2 PE-end-capped Meltable Polyimide Resins
	4.7 Heat-resistant Polyimide Foams
		4.7.1 Introduction
		4.7.2 Opened-Cell Soft Polyimide Foams
		4.7.3 Closed-Cell Rigid Polyimide Foams
			4.7.3.1 Preparation of NAIO Powders
			4.7.3.2 Preparation of Rigid Closed-cell PIFs
			4.7.3.3 Foam Formability of NAIO Powders
			4.7.3.4 Combined Properties of the Rigid PIFs
			4.7.3.5 Thermal Foaming Properties of NAIOs With Different Backbone Structures
			4.7.3.6 Effect of Calc’d Mw on NAIO’s Thermal Foaming Properties
			4.7.3.7 Closed Cell Percent and Thermal Properties of Polyimide Rigid Foams
			4.7.3.8 Mechanical Properties of the Polyimide Rigid Foams
			4.7.3.9 Mechanical Properties of Polyimide Foams With Different Densities
			4.7.3.10 Closed-cell Percent and Thermal Properties of Polyimide Foams With Different Densities
	4.8 Thermally Stable Flexible Polyimide Aerogels
	4.9 Summary
	References
5 Polyimides for Electronic Applications
	5.1 Introduction
	5.2 Polyimide Materials for Microelectronics
		5.2.1 Combined Property Requirements
			5.2.1.1 Dielectric Properties
			5.2.1.2 Thermal Properties
			5.2.1.3 Mechanical Properties
		5.2.2 Typical Applications
			5.2.2.1 Encapsulates and Coatings
			5.2.2.2 Passivation Layers
			5.2.2.3 Interlayer Dielectrics
			5.2.2.4 Alpha-particle Barrier
		5.2.3 Structures and Properties of Polyimide Materials for Microelectronics
			5.2.3.1 Conventional Polyimides
			5.2.3.2 Photosensitive Polyimides (PSPI)
				5.2.3.2.1 Negative PSPIs
				5.2.3.2.2 Positive PSPIs
	5.3 Polyimide Materials for Optoelectric Planar Displays
		5.3.1 Liquid Crystal Alignment Layers
		5.3.2 Mechanical Rubbing Alignment Polyimides
		5.3.3 Photoinduced Alignment PIs
			5.3.3.1 Photodegradation of PIs
			5.3.3.2 Photopolymerization of PIs
				5.3.3.2.1 Cinnamate-contained Polyimides
				5.3.3.2.2 Coumarin-contained Polyimides
			5.3.3.3 Photoisomerization of Polyimides
		5.3.4 The Microgroove Polyimide Surfaces
		5.3.5 Langmuir–Blodgett Polyimide Films
	5.4 Polyimide Materials for Optoelectronic Flexible Displays
		5.4.1 Combined Property Requirements
			5.4.1.1 High Thermal Stability
			5.4.1.2 High Thermal Dimensional Stability
			5.4.1.3 High Flexibility
			5.4.1.4 Low Water-vapor Transmission Rate and Oxygen Transmission Rate
			5.4.1.5 Surface Smoothness
		5.4.2 Polyimides for Flexible Electronic Substrates
	5.5 Polyimide Materials for Electronic Memories
		5.5.1 Introduction
			5.5.1.1 Resistor-type Memories
				5.5.1.1.1 Device Performance
				5.5.1.1.2 Mechanism
					Charge Transfer
					Space Charge Traps
					Filament Conduction
			5.5.1.2 Transistor-type Memories
		5.5.2 Polyimides for Resistive-type Memory Devices
			5.5.2.1 Volatile Memory Devices
			5.5.2.2 Nonvolatile Memory Devices
			5.5.2.3 PI Hybride Materials for Resistive Memories
		5.5.3 Polyimides for Transistor-type Memory Devices
	5.6 Summary
	References
6 Polyimide Gas Separation Membranes
	6.1 Introduction
	6.2 Mechanisms of Gas Separation and Testing Methods
		6.2.1 Gas Transport Mechanism
		6.2.2 Apparatus for Testing Gas Transport Properties
	6.3 Structures and Properties of Polyimide Membranes
		6.3.1 Isomer Structure Effects From Diamines
		6.3.2 Substitution and Geometric Effects From Diamines
		6.3.3 Chemical Structure Effects of Dianhydrides
	6.4 Intrinsically Microporous Polyimide Membranes
	6.5 Hydroxyl-functionalized Polyimide and Its Derived Polybenzoxazole Membranes
		6.5.1 Hydroxyl-functionalized Polyimide Membranes
		6.5.2 Thermally Rearranged Polybenzoxazole (TR-PBO) Membranes
		6.5.3 Applications of TR-PBO Membranes
	6.6 Polyimide-Derived Carbon Molecular Sieve Membranes
		6.6.1 Formation of CMSMs
		6.6.2 Conversion From Polyimide to CMSMs
		6.6.3 Structures and Properties of CMSMs
			6.6.3.1 Structures of the Polyimide Precursors
			6.6.3.2 Effect of Pyrolysis Conditions on Gas Separation Properties
	6.7 In Summary
	References
7 Polyimide Proton Exchange Membranes
	7.1 Introduction
	7.2 Monomer Synthesis
		7.2.1 Synthesis of Sulfonated Diamines
		7.2.2 Synthesis of Six-membered Ring Dianhydrides
	7.3 Polyimide Preparations
		7.3.1 Preparation From Sulfonated Diamines
		7.3.2 Preparation From Sulfonated Dianhydrides
		7.3.3 Synthesis via Postsulfonation
		7.3.4 Block Copolymerization
	7.4 Ion Exchange Membrane Properties
		7.4.1 Solubility
		7.4.2 Thermal Stability
		7.4.3 Water Uptake and Swelling Ratios
		7.4.4 Proton Conductivity
		7.4.5 Water Resistance
			7.4.5.1 Methods for Evaluation of Water Resistance
			7.4.5.2 Effect of IEC
			7.4.5.3 Hydrolytic Stability
			7.4.5.4 Effect of Crosslinking in SPI
		7.4.6 Radical Oxidative Stability
		7.4.7 Methanol Permeability
	7.5 Fuel Cell Performance
	7.6 Summary
	References
8 Soluble and Low-κ Polyimide Materials
	8.1 Introduction
	8.2 Structures and Properties of Soluble Aromatic Polyimides
		8.2.1 Soluble Polyimides With Flexible Backbones
		8.2.2 Soluble Polyimides With Asymmetric Structures
		8.2.3 Soluble Polyimides With Alicyclic Structures
		8.2.4 Soluble Polyimides With Side Groups
			8.2.4.1 Soluble Polyimides With Halogens or Halogenated Side Groups
			8.2.4.2 Soluble Polyimides With Aliphatic Side Groups
			8.2.4.3 Soluble Polyimides With Aromatic Side Groups
	8.3 Applications of Soluble Aromatic PIs
		8.3.1 Second-order Nonlinear Optical (NLO) Materials
			8.3.1.1 Guest–host NLO Polyimides
			8.3.1.2 Main-chain NLO Polyimides
			8.3.1.3 Side-chain NLO Polyimides
			8.3.1.4 Crosslinked NLO Polyimides
		8.3.2 Memory Device Materials
			8.3.2.1 Soluble Polyimides With Triphenylamine (TPA) Groups
			8.3.2.2 Soluble Polyimide with Carbazole Moieties
			8.3.2.3 Other Soluble Polyimides
		8.3.3 Compensator Materials for Liquid Crystal Displays
		8.3.4 Gas Separation Materials
		8.3.5 Other Applications
	8.4 Low-κ Polyimide Materials
		8.4.1 Introduction
		8.4.2 Impact Factors on Dielectric Properties [143]
			8.4.2.1 Capacitance and Relative Permittivity
			8.4.2.2 Polarization Phenomena
			8.4.2.3 Film Density and Relative Permittivity
			8.4.2.4 Relative Permittivity and Frequency
		8.4.3 Structures and Dielectric Properties of Polyimides
		8.4.4 Low-κ Polyimides With Porous Structures
			8.4.4.1 Porous Fillers—Added Polyimides
			8.4.4.2 Nanoporous Polyimides
			8.4.4.3 Polyimide Aerogels
			8.4.4.4 POSS-containing Polyimides
			8.4.4.5 Controlling Methods of the Porous Structures in Polyimides
		8.4.5 Organic–Inorganic Hybrid Polyimide Materials
		8.4.6 Intrinsic Low-κ Polyimide Materials
			8.4.6.1 Multimethyl-substituted Copolyimides
			8.4.6.2 Hyperbranched and Crosslinked Polyimides
			8.4.6.3 Bulky Structure-contained Polyimides
			8.4.6.4 Fluorinated Polyimides
			8.4.6.5 Alicyclic and Steric-substituted Polyimides
			8.4.6.6 Asymmetric Structure-Contained Polyimides
			8.4.6.7 Polyimides With Rigid and Nonplanar Large Conjugated Structures
		8.4.7 Summary
	References
Index