Newsprint Research• This is a summary of research conducted at the

Smithsonian Center for Materials Research and Education (SCMRE) during the summer of 2003.

• This work was conducted by two interns, Evan Quasney and Kathy Hufford, under the supervision of David Erhardt and Charles Tumosa.

• Drs. Erhardt and Tumosa may be contacted at SCMRE via these methods:

Charles Tumosatumosac@scmre.si.edu(301) 238-3700 x 118

W. David Erhardterhardtd@scmre.si.edu(301) 238-3700 x 116

Permanence and Degradation: Newsprint Over the Last 100 Years

Kathy HuffordMassachusetts Institute of Technology

Evan QuasneyUniversity of Michigan

Charles Tumosa, Ph.D.W. David Erhardt, Ph. D.

IntroductionPrinted material on paper dominates written communication

Paper records have finite life … how finite?

Mechanical concepts addressed and discussed

Chemical concepts linked to mechanical properties

Scope of research newsprint-specific

06/01/2003 Washington Post11/17/2001 Washington Post11/27/2000 Washington Post08/03/1999 Washington Post12/02/1998 Washington Post11/02/1997 Washington Post07/10/1997 Washington Post01/26/1997 Washington Post05/07/1995 Washington Post11/14/1993 Washington Post02/08/1983 Washington Post10/20/1983 Washington Post07/07/1985 Washington Post09/11/1985 Washington Post12/14/1988 Washington Post12/15/1988 Washington Post10/25/1999 Washington Post07/01/1975 Vineland Times Journal12/11/1960 New York Times09/13/1950 Christian Science Monitor12/02/1934 Topeka Daily Capital04/11/1915 Detroit Free Press10/07/1905 Detroit Free Press01/03/1890 The World05/07/1875 New York Semi-Weekly Times

Wood-based Newspapers Tested

Definitions

Tensile (Young’s) Modulus- Numeric value of the flexibility / stiffness of the paper

E = σ / ε

Stress = Force / Area- ‘strength’ of the paper- randomized based on sizing or technology

σ = F / A

Stress-Strain Curve- Graph of stress versus strain- Basis for finding plastic and elastic regions

Strain = ∆ length / length- extensibility of paper- change in length

ε = ∆ L / L

Definitions

Isotropic:- Specimen behaves the

same in all directions

Orthotropic:- Specimen behaves

differently in mutually perpendicular directions

Breaking Strain:- Percent elongation at which

a specimen fails

Breaking Stress:- Pressure at the breaking

strain; tensile strength of specimen

Region Deformation:Elastic – Flexible Modulation of Specimen

Plastic – Permanent Irreparable Damage to Specimen

General Stress-Strain CurveMancellinus Antonius, circa 1500, Vertical Dir

0

5

10

15

20

25

0 0.005 0.01 0.015 0.02 0.025

Stre

ss (M

Pa)

Strain (mm/mm)

ε = 0.004

σ = 10.25

Plastic Deformation

Elastic Deformation

Slope = E

Method

Tests performed on screw-driven tensile tester in environmental chambersIncremental length change standard: 30-seconds, 1/200 (0.005) inchesTests performed between 42 – 52% RH and 22.5 – 24.2 deg. C4 distinctly different sub-variations of each specimen examined

0

2

4

6

8

10

0 0.003 0.006 0.009 0.012 0.015

Strain (mm/mm)

Stre

ss (M

Pa)

Machine Dir Cross Dir

Directional Comparison of Century Magazinecirca Feb. 1925

Machine v. Cross Direction

Initial Application

0

5

10

15

20

25

0 0.002 0.004 0.006 0.008 0.01Strain (mm/mm)

Stre

ss (M

Pa)

Inked Uninked

Tensile Strength of The Washington PostJune 1, 2003, Average Value, Cross & Machine Dir.

Initial Application

0

5

10

15

20

25

0 0.002 0.004 0.006 0.008 0.01

UninkedInked

0

1

2

3

4

5

0 0.005 0.01 0.015 0.02 0.025 0.03

UninkedInked

Individual Axial Comparison of Inked v. Uninked PaperThe Washington Post, June 1, 2003

Orthotropic behavior present in specimensVery little difference between inked and uninked strains

Machine Direction Cross Direction

00.005

0.010.015

0.020.025

0.03

0 5 10 15 20 25Age (Years)

Stra

in (m

m/m

m)

Mach. Inked Mach. Uninked Cross Uninked Cross Inked

20 Year Study in Lab Environment

No great change, but a slight decreasing trend is exhibited Degradation small enough that overall damage is minimalSpecimens could last 100-150 years

20 Year Study in Lab Environment

No great change, but a slight decreasing trend is exhibited Degradation small enough that overall damage is minimalSpecimens could last 100-150 years

00.005

0.010.015

0.020.025

0.03

0 5 10 15 20 25Age (Years)

Stra

in (m

m/m

m)

Mach. Inked Mach. Uninked Cross Uninked Cross Inked

20 Year Study in Lab Environment

No distinguishable change in strength of specimensSpecimens will last a long time under Standard Laboratory Conditions

07

14212835

0 5 10 15 20 25Age (Years)

Stre

ss (M

Pa)

Mach. Inked Mach. Uninked Cross Uninked Cross Inked

07

14212835

0 5 10 15 20 25Age (Years)

Stre

ss (M

Pa)

Mach. Inked Mach. Uninked Cross Uninked Cross Inked

20 Year Study in Lab Environment

No distinguishable change in strength of specimensSpecimens will last a long time under Standard Laboratory Conditions

012345678

0 0.002 0.004 0.006 0.008 0.01 0.012Strain (mm/mm)

Stre

ss (M

Pa)

UninkedInked

T.S. Comparison of The New York TimesDec. 11, 1960, Cross dir.

Inked v. Uninked Paper

Strain v. Time

00.005

0.010.015

0.020.025

0.03

0 20 40 60 80 100 120Age (Years)

Stra

in (m

m/m

m)

Vert. Uninked Vert. Inked Horz. Uninked Horz. Inked

120 Year Variable Test

• Loss of elastic region occurs when breaking strains drops below 0.005• Acute fragility not present until samples are 80 years old• Total specimen disintegration only occurs after ALL breaking strains

are less than 0.003

Scientific SignificanceNewsprint can last 100 years if given nominal attention

Archival facilities can provide up to an additional 50 –100 years of viable storage

Flexibility and elasticity data will help build an accurate model to predict degradation

Chemical Composition of Wood

Wood

LigninSoftwood: 25%Hardwood: 21%

CarbohydratesExtractives

2-8%

Cellulose45%

HemicelluloseSoftwood: 25%Hardwood: 35%

GlucoseXylan, Xylose, Arabinose, etc.

Cellulose:Glucose Glucose Glucose Glucose Glucose

Glucose Trimer:

Glucose Glucose Glucose

Glucose Dimer:Glucose Glucose

Glucose:O

CH2-OH

OHOH

OH

HO

Xylan:

Xylose Xylose Xylose Xylose Xylose

Arabinose

Arabinose

Xylose: Arabinose:

O O

CH2-OH CH2-OH

OHOH

HO

OH

OH

HO

Glucose Glucose Glucose Glucose Glucose

Hydrolysis of Cellulose

H2O H2O

Glucose

GlucoseGlucose

H2O

GlucoseGlucoseGlucose

Monomer

Dimer

Trimer

Method

Samples prepared, extracted in water, filtered, and evaporated under vacuumDerivatized with STOX (commercial reagent containing internal

standard), HMDS, and trifluoroacetic acidSupernatant analyzed by gas chromatographySugars identified by comparison of retention times against internal

standards

Standard

Glucose

Xylose

Arabinose

Xylose Dimer

Xylose TrimerGlucose Dimer

Glucose Trimer

Approximate Retention Times of Sugar Peaks

Standard: 16.70

Glucose: 12.57

Xylose: 10.43

Arabinose: 10.20

Glucose Dimer: 19.45

Glucose Trimer: 24.55

Xylose Dimer: 17.45

Xylose Trimer: 22.55

Glucose and xylose levels highest in newspapers from the Industrial RevolutionOf interest are the spikes around World War I and the relative stability

of the past 20 years

Sugar Content in Wood-based Newspapers

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1860 1880 1900 1920 1940 1960 1980 2000 2020

Year

Mic

rogr

ams/

g

GlucoseXylose

History of Papermaking Technology

The Industrial Revolution (1875-1950) brought commercial use of wood-pulp paper and mass production processes

Commercial use of the acid sulfite process (1880s) and Kraft process with bleaching (1930s) caused a transition from mechanical to chemical processing

Glucose and xylose levels peak in the World War I era

After World War I, new technology and processing techniques were invented

Pre-1980 glucose ratio shows a different mechanism than post-1980Kinetics study?Changes in data from 1980 to present are particularly interesting

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1860 1880 1900 1920 1940 1960 1980 2000

Year

Glu

cose

/(Glu

cose

+Xyl

ose)

Glucose Fraction in Wood-based Newspapers

History of Papermaking Technology

•The USA Today Effect: Launching of the USA Today in 1982 and the use of color in newspapers

•The environmental movement and recycling of newspapers

•Advanced machinery requires thinner material

•Multitude of processes for newspaper manufacturers to choose from: refiner, chemical, thermo, chemothermo, isothermo, etc.

•Further research

Xylose is more hydrolytic and more likely to hydrolyze to monomer than is glucose

Sugar PolymersDetroit Free Press, 1905

0

500

1000

1500

2000

2500

3000

3500

4000

4500

0 1 2 3 4

Polymer

Suga

r, M

icro

gram

s/gr

am

Glucose PolymersXylose Polymers

Initial, sharp increase in arabinose, and then nearly constant valueArabinose molecules must be located at the end of the molecule or

on branches, and are hydrolyzed first

Arabinose and Xylose in Wood-based Newspapers

0

50

100

150

200

250

300

350

400

450

500

0 1000 2000 3000 4000 5000 6000

Xylose, Micrograms/gram

Arab

inos

e, M

icro

gram

s/gr

am

050

100150

200250

0 100

Similar trends appear across other sugar dataIllustrates the presence of a surface phenomenon

Total Measured Sugar Content vs. Breaking Strain

0

2000

4000

6000

8000

10000

12000

14000

0 0.005 0.01 0.015 0.02 0.025 0.03

Breaking Strain

Mic

rogr

ams/

gram

Glucose Polymers vs. Breaking Strain

Dimer

0

500

1000

1500

2000

2500

0 0.005 0.01 0.015 0.02 0.025 0.03

Breaking Strain

Dim

er, M

icro

gram

s/gr

am

Trimer

0

400

800

1200

1600

0 0.005 0.01 0.015 0.02 0.025 0.03

Breaking Strain

Trim

er, M

icro

gram

s/gr

am

Monomer

0

800

1600

2400

3200

4000

0 0.005 0.01 0.015 0.02 0.025 0.03

Breaking Strain

Glu

cose

, Mic

rogr

ams/

gram

Hydrolysis Mechanism Conclusions

Issue of dueling factors of technology and time in the process of degradation

Xylan hydrolysis vs. cellulose hydrolysis

Order of degradation, illustration of mechanistic details of hydrolysis

Surface phenomenon

Ideas for further research in kinetics and the history of papermaking technology

Summary

Mechanical and physical properties of specimens directly related to hydrolysis of cellulose and hemicellulose

Hydrolysis of cellulose and hemicellulose affects breaking strain and plasticity of specimen

Remaining life span of specimen can be estimated via sugar content analysis and/or mechanical testing