Ⅰ．Introduction

Ⅱ．The Evolution of Lignin Chemistry

Ⅲ．The Definition and Distribution of Lignin

Ⅳ．Color Reaction of Lignified Materials

A．Introduction

B．Preparation of the Material

C．Color Reactions with Aliphatic Compounds

D．Color Reactions with Phenolic Compounds

E．Color Reactions with Aromatic Amines

F．Color Reactions with Heterocyclic Compounds

G．Color Reactions with Inorganic Reagents

1．The M？ule Test

2．Other Color Reactions Involving Chlorination

3．Color Reactions with Inorganic Acids

4．Other Inorganic Color Reagents

H．Color Reactions with Dyestuffs

Ⅴ．The Isolation of Lignin

A．Preparation of the Plant Material

B．Native Lignin

C．Insoluble Lignins

1．Acid Lignins

a．Sulfuric Acid or Klason Lignin

ⅰ．Preparation of Sulfuric Acid Lignin

b．Hydrochloric Acid or Willst？tter Lignin

ⅰ．Preparation of Hydrochloric Acid Lignin

ⅱ．Modified Methods

c．Hydrofluoric Acid Lignin

2．Cuoxam or Freudenberg Lignin

a．Preparation of Cuoxam Lignin

3．Periodate or Purves Lignin

D．Organosolv Lignins

1．Alcohol Lignins

a．Methanol Lignin

b．Ethanol Lignin

c．Butanol and Amyl Alcohol Lignins

d．Cyclohexanol Lignin

e．Benzyl Alcohol Lignin

f．Glycol Lignins

g．Glycol Monomethyl Ether Lignin

h．Chlorohydrin Lignins

2．Aldehyde Lignins

a．Formaldehyde Lignin

b．Chloral Lignin

3．Ethyl Acetoacetate Lignin

4．Dioxane Lignins

5．Phenol Lignins

a．Unsubstituted Phenol Lignins

ⅰ．Preparation of Phenol Spruce Lignin

b．Substituted Phenol Lignins

6．Mercapto Lignins

a．Butylmercapto Lignin

b．Benzylmereapto Lignin

c．Thioglycolie Acid Lignin

ⅰ．Preparation of Thioglycolic Acid Lignin

7．Organic Acid Lignins

a．Formic Acid Lignin

b．Acetic Acid Lignin

ⅰ．Preparation of Acetic Acid Lignin

c．Chloroacetic Acid Lignins

d．Other Organic Acid Lignins

8．Organic Amine Lignins

E．Lignins Extracted with Inorganic Reagents

1．Introduction

2．Lignins Isolated by Alkaline Reagents

a．Ammonia Lignin

b．Hydrazino Lignin

c．Alkali or Soda Lignins

ⅰ．Isolated with Aqueous Alkaline Solutions

ⅱ．Commercial Alkali Lignins

ⅲ．Isolated with Alcoholic Alkaline Solutions

d．Thiolignin

3．Lignin Isolated by Bisulfites

a．Lignosulfonic Acid

ⅰ．Isolation as Basic Lignosulfonate

ⅱ．Isolation by the Salting Out Method

ⅲ．Isolation by Dialysis

F．Lignin Isolated by Hydrotropic Solvents

G．Lignin Isolated by a Mild Hydrogenation

Ⅵ．The Determination of Lignin

A．Introduction

B．Interfering Substances

1．Polysaccharides

2．Pectins

3．Proteins

4．Fats,Waxes,and Resins

5．Tannins and Phlobaphenes

6．Coloring Matters

7．Other Organic Substances

8．Inorganic Matters

C．The Effect of Pretreatments on the Lignin Determination

1．Organic Solvents

2．Water

3．Dilute Alkali

4．Dilute Acid(Prehydrolysis)

5．Summary

D．Preparation of the Sample

E．Lignin Determination Methods

1．Direct Methods

a．Determination with Strong Mineral Acids

ⅰ．Sulfuric Acid Method

ⅱ．Hydrochloric Acid Method

ⅲ．Hydrofluoric Acid Method

ⅳ．Mixed Acids

b．Determination as Alkali Lignin

2．Indirect Methods

a．By Removing the Lignin and Weighing the Carbo-hydrate Residue

b．By Reaction with Halogens

c．By Reduction of Nitric Acid

d．By Determining the Methoxyl Content

e．By the Reaction with Phloroglucinol

f．Mehta＇s Colorimetric Method

g．By Extraction with Phenol

3．Determination of Lignin in Spent Liquors

a．Lignin in Soda and Sulfate Spent Liquor

b．Lignin in Sulfite Spent Liquor

F．Comparison of Lignin Determination Methods

Ⅶ．The Physical Properties of Lignin

A．Introduction

B．Solubility

C．Melting Point

D．Heat of Combustion

E．Color

F．Density

G．Viscosity

H．Molecular Weight

1．Determination of the Unit Molecular Weight by Chemical Means

2．Determination of the Molecular Weight by Physical Means

3．Molecular Weight of Lignosulfonic Acids

I．Spreading Experiments

J．The Colloidal Nature of Lignin

K．The Conductivity of Lignosulfonic Acid

L．X-Ray Investigations of Lignin

M．Refractive Index

N．Optical Activity

O．The Fluorescence of Lignin

P．Ultraviolet Absorption Spectra

Q．Infrared Absorption Spectra

Ⅷ．The Elementary Composition and Constituent Groups of Lignin

A．Elementary Composition

B．The Phenylpropane Carbon Structure

C．Methoxyl Groups

D．Methylenedioxy Group

E．Hydroxyl Groups

F．Aromatic Hydrogen Atoms

G．The Carbonyl Group

H．Terminal CH3C-Groups

I．Double Bonds

Ⅸ．The Acylation and Acylysis of Lignin

A．Acylation

1．Introduction

2．Protolignin

3．Isolated Lignins

a．Insoluble Lignins

b．Organosolv Lignins

e．Alkali Lignin

d．The Xanthation of Lignin

e．Lignosulfonic Acid

B．Acylysis

1．Formolysis

a．Protolignin

2．Acetolysis

a．Protolignin

ⅰ．With Acetic Acid in the Presence of Catalysts

ⅱ．With Acetic Anhydride in the Presence of a Catalyst

ⅲ．With Acetyl Bromide

b．Isolated Lignin

Ⅹ．The Alkylation of Lignin

A．Introduction

B．Protolignin

1．Diazomethane

2．Dimethyl Sulfate

C．Isolated Lignins

1．Isolated Native Spruce Lignin

2．Acid Lignins

3．Organosolv Lignins

4．Lignosulfonic Acid

D．The Stability of the Methoxyl Groups in Methylated Lignin

Ⅺ．The Halogenation of Lignin

A．Fluorination

B．Chlorination

1．Protolignin

a．In an Aqueous Medium

b．In Methanol

2．Isolated Lignin

a．In an Aqueous Medium with Chlorine Gas

b．In Organic Solvents with Chlorine Gas

c．With Other Chlorinating Agents

3．Lignosulfonic Acid

C．Bromination

1．Protolignin

2．Isolated Lignin

3．Lignosulfonic Acid

D．Iodination

1．Protolignin

2．Isolated Lignin

3．Lignosulfonic Acid

E．Thiocyanogenation

Ⅻ．The Nitration of Lignin

A．The Action of Nitric Acid on Protolignin

B．Nitrolignins from Isolated Lignins

C．The Nitration of Lignosulfonic Acid

D．Theoretical Aspects of the Nitration of Lignin

ⅩⅢ．The Sulfonation of Lignin

A．Introduction

B．Protolignin

1．With Sulfurous Acid

2．With Bisulfites

3．Sulfonation by Sulfolysis

4．The Effect of Pretreatment of Protolignin on its Sulfonation

C．Isolated Lignin

D．Reactive Groups in Lignosulfonic Acid

E．Theories on the Sulfonation of Lignin and the Sulfonation of Model Substances

F．Conclusions

ⅩⅣ．The Hydrolysis of Lignin

A．In an Aqueous Neutral Solution

B．In an Alkaline Medium

1．Protolignin

2．Isolated Lignins

3．Lignosulfonates

4．Alkali Lignin

a．Introduction

b．From Protolignin

c．From Isolated Lignin

5．Thiolignin

a．From Protolignin

b．From Isolated Lignin

c．The Reaction Mechanism between Lignin and Sodium Sulfides

C．Acid Hydrolysis

1．Demethylation of Lignin

ⅩⅤ．The Alcoholysis of Lignin

A．Introduction

B．Alcohol Lignins

1．Protolignin

a．The Action of Alcohols and Mineral Acids

b．Methanolysis

c．Ethanolysis

d．Alcoholysis with Other Alcohols

2．Isolated Lignins

3．Theories on the Formation of Alcohol Lignin

C．Polyalcohol Lignins

1．Protolignin

2．Isolated Lignins

D．Alcobolysis to Monomolecular Lignin Building Stones

ⅩⅥ．The Mercaptolysis of Lignin

A．Introduction

B．Protolignin

1．With Mercaptans

2．With Thioglycolic Acid

3．With Other Mercapto Fatty Acids

C．Isolated Lignins

D．The Reaction Mechanism

ⅩⅦ．The Phenolysis of Lignin

A．Protolignin

B．Isolated Lignins(Secondary Phenol Lignins)

C．The Reaction Mechanism of Phenol Lignin Formation

ⅩⅧ．Reduction,Hydrogenation,and Hydrogenolysis of Lignin

A．Reduction

1．Introduction

2．Reduction with Hydriodie Acid and Red Phosphorus

3．Reduction by the Wolff-Kishner Method

B．Hydrogenation and Hydrogenolysis

1．Introduction

2．Hydrogenation at Low Temperatures(below 300°C．)

a．In Neutral Solution

b．In Alkaline Solution

3．Pressure Hydrogenation at High Temperatures(over 300°C．)

a．In Neutral Solution,without Catalysts

b．In Neutral Solution,with Catalysts

c．In Alkaline Solution

d．With Primary Alcohols in the Presence of Alkali

ⅩⅨ．The Oxidation of Lignin

A．Introduction

B．Oxidation in a Neutral Solution

1．Protolignin

2．Isolated Lignin

3．Lignosulfonates

C．Oxidation in an Acid Medium

1．Protolignin

2．Isolated Lignin

D．Oxidation in an Alkaline Medium

1．Protolignin

2．Isolated Lignin

3．Vanillin Formation

ⅩⅩ．The Alkali Fusion of Lignin

A．Introduction

B．Protolignin and Isolated Lignins

C．Lignosulfonic Acids

ⅩⅪ．Special Reactions with Lignin

A．The Action of Benzaldehyde on Lignin

B．The Effect of Grignard Reagent on Lignin Preparations

C．The Action of Diazobenzenesulfonic Acid on Lignin

D．The Action of Potassium in Liquid Ammonia on Lignin

E．Condensation of Lignin with Nitrodimethylaniline

F．The Dehydrogenation of Lignin

G．Sulfuric Acid Lignin Ester

ⅩⅫ．The Thermal Decomposition of Lignin

A．Dry Distillation in the Absence of Catalysts

B．Dry Distillation in the Presence of Zinc Dust(Zinc Dust Distillation)

C．Destructive Distillation in the Presence of Silver

D．Thermal Decomposition in the Presence of Nickel

E．Destructive Distillation in the Presence of Hydrogenation Catalysts

F．Thermal Decomposition with Lime in the Presence of Alcohol

ⅩⅩⅢ．The Biological Decomposition of Lignin

A．By Digestive Microorganism(Metabolism of Lignin)

B．By Soil Microorganisms

C．By Wood-destroying Fungi

D．The Biological Decomposition of Lignosulfonates

E．Coal Formation

ⅩⅩⅣ．Theories on the Structure of Lignin

A．Introduction

B．Lignin Formulas without Basic Building Stones

1．Cross and Bevan＇s Formula

2．Dorée and Barton-Wright＇s Formula

3．Fuchs＇ Formulas

C．Lignin Formulas with Basic Building Stones

1．Klason＇s Theory

2．Kürschner＇s Lignin Formula

3．Pavolini＇s Formula

4．Rassow and Gabriel＇s Formula

5．Chambovet＇s Formula

6．Freudenberg＇s Theory

7．Hibbert＇s Theory

8．Erdtman＇s Theory

D．Conclusions

ⅩⅩⅤ．The Linkage of Lignin in the Plant

A．Introduction

B．Lignin in a Physical Mixture with Other Plant Constituents

C．Lignin in Chemical Combination with Other Plant Constituents

D．Conclusions

ⅩⅩⅥ．Theories on the Formation of Lignin

A．Introduction

B．Lignin,a Reaction Product Formed during its Isolation

C．The Formation of Lignin in the Growing Plant

D．Formation of Lignin by Direct Assimilation Synthesis

E．Cellulose as the Precursor of Lignin

F．Pentosans or Pentoses as Precursors of Lignin

G．Pectins as Precursors of Lignin

H．Water-soluble Sugars as Lignin Precursors

1．Wislicenus＇ Theory

2．The Jonas-Schrauth Theory

3．Phillips＇ Theory

4．Vanzetti＇s Theory

ⅩⅩⅦ．Synthetic Lignins

Appendix

A．Purification of Lignin Derivatives

B．Methoxyl Determinations in Lignin and Lignin Derivatives

C．Purification of Dioxane

D．Preparation of Cuprammonium Hydroxide Solution(Schweizer Reagent)

1．Analysis for Copper

2．Analysis for Ammonia

E．Preparation of Ethylenediamine Copper Hydroxide Solution

F．Preparation of Hydrogenation Catalysts

1．Nickel-Kieselguhr Catalyst

2．Raney Nickel Catalyst

3．Copper-Chromium Oxide Catalyst

G．Preparation of a Saturated Aqueous Chlorine Dioxide Solution

H．Preparation of Periodic Acid

Author Index

Subject Index