Pannipa

Chaowana

Materials Science and Engineering School of Engineering and Resources

Walailak

University, Thailand

Gluability

Variation of Dendrocalamus

asper

for Bamboo Composites

“9th

World Bamboo Congress”11 April 2012

University of Antwerp, Antwerp, Belgium

Introduction

Figure

Culm

characteristic of D. asper

Internode

NodeDiaphragm

2 cm25 cm

Culm-wall thickness

2 cm

Figure

Microstructure of D. asper

Outer surface

Inner surface

Metaxylem

vessel Phloem

Parenchyma cells

Fiber cells

Fiber cells

Outer layer

Middle layer

Inner layer

Horizontal direction Vertical direction

Figure

Variation of microstructure of bamboo culm

Top

Middle

Bottom

Table

Variation of chemical composition of D. asper

Chemical compositions

Top Middle Bottom

Node Internode Node Internode Node Internode

Holocellulose 75.65 76.72 76.36 77.36 75.59 76.31

Alphacellulose 67.07 67.33 68.53 67.67 68.59 69.64

Lignin 30.08 26.47 30.86 27.19 30.41 27.21

Ash 2.29 1.07 1.95 0.95 1.59 0.92Alco.+Benzene

Solubility 5.55 7.44 6.67 6.18 3.75 5.85

Hot WaterSolubility 7.39 9.63 7.51 8.36 6.47 8.86

Cold Water Solubility 5.10 6.87 5.43 14.05 4.23 6.50

1% NaOHSolubility 26.78 25.82 24.38 23.40 24.99 24.07

Source: Kamthai, S. 2003. Alkaline sulfite pulping and ECF-

bleaching of sweet bamboo (Dendrocalamus

asper

Backer). M.S. Thesis, Kasetsart

University, Thailand

Objectives

To determine the pH value and buffer capacity in each location of bamboo culms

To investigate the surface wettability through contact angle measurement

To measure the effective penetration of liquid adhesive into bamboo in different locations and surfaces of the culms.

Materials

D. apser

culms were cut from plantation in Thailand.

Methods and Results

pH value and buffer capacity

Bottom

Middle

Top

Bamboo powder

Soaked in distilled water and then stirred

Titrated with

0.01 N H2

SO40.01 N NaOH

Record the pH change after acid or alkaline addition

Figure

The initial pH value of D. asper

in relation to the culm

location

Figure

The pH changes of D. asper, in relation to the culm

location, during the acid and alkaline addition.

0.01 N H2 SO4 (ml) 0.01 N NaOH (ml)

2550

Acid addition

Alkaline addition

Wettability

Bottom

Middle

Top

Outer surface

Inner surface

Culm

wall surface

Bamboo

Distilled water

Measure the contact angle after drop the distilled

water on bamboo surface

Figure

Average value of contact angle of D. asper, separated by culm

location and surface

Adhesive penetration

Bottom

Middle

Top

Outer surface

Inner surface

Culm

wall surface

Image and measure the average adhesive penetration into bamboo surface

Bamboo

UF adhesive layer

X1 X2 X3

Figure

Average value of adhesive penetration on the surface of D. asper, separated by culm

location and surface

Conclusions

The pH value of D. asper

is on acid side. It does not vary

along the location of the culm.

Buffer capacity of D. asper

is more stable toward alkaline

rather than acid. There are slightly differences in the values along the culm

location.

Wettability

of D. asper

decreases from the bottom to the top

part of the culm. Furthermore, wettability

of bamboo culm outer surface is found to be lower than inner part.

The adhesive penetration of D. asper

at different culm

location and surface is signification different from one other. The penetration also decreases from the bottom to the top part of the culm. Moreover, the penetration on culm

inner surface is

greater than that of outer and the culm

wall surface.

Further forecasts

The appropriate layer structure for production of

Laminated Bamboo Lumber and Plybamboo

Figure

The possibility of layered structure on laminated bamboo lumber and plybamboo

manufacture

Type 1 Type 2 Type 2

The further study of the density varitaion

of bamboo strand that influence on physical and mechanical properties of Oriented Strand Board and Oriented Strand Lumber

Acknowledgements

School of Engineering and Resources, Walialk

University, Thailand

Wood Science and Engineering Research Unit, Walilak

University

Dynea

Krabi, Co., Ltd

Thank you for your attention

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