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SaraSara PourabbasiPourabbasi

IUFRO Division 5 ConferenceIUFRO Division 5 Conference5.03.00 Forest Products5.03.00 Forest ProductsIRG/Wood ProtectionIRG/Wood Protection

Sara Pourabbasi* A. Karimi, M. Tajvidi, D. Parsapajouh, M. SoleymaniA. Karimi, M. Tajvidi, D. Parsapajouh, M. Soleymani

Effect of compatibilizer on the natural durability of Effect of compatibilizer on the natural durability of wood flour/high density polyethylene composites wood flour/high density polyethylene composites

against the rainbow fungusagainst the rainbow fungus((Coriolus versicolorCoriolus versicolor))

Islamic Azad University Of MalayerIslamic Azad University Of Malayerlecturer at Malayer Islamic Azad Universitylecturer at Malayer Islamic Azad UniversityP.O.Box 65718/117, Malayer, Iran.P.O.Box 65718/117, Malayer, Iran. E-mail:E-mail: saraabbasi7@yahoo.com

MALAYER

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Determining whether or not a compatibilizer can enhance natural durability of wood plastic composites and to what extent the mechanical properties are affected by the fungus in the presence or absence of a compatibilizer...

Aim of work and methods

Materials

Number CodeFiber Type

Fiber

content

HDPE MAPE

Content Content

1 WF-25-0 WF 25 75 0

2 WF-25-1 WF 2574 1

3 WF-50-0 WF 50 50 0

4 WF-25-2 WF 50 48 2

Culture Medium (Malt extract agar)

Purified Rainbow Fungus

Wood flour/high density polyethylene composites

METHODS:

- Preparation of Composite Specimens

- Fungus Culture

- Contamination of Composite Specimens with The Purified Fungus

Materials

Durability Assessment

Apparent Damage ( Willeitner criterion )

No Code Sample

size Average mycelium

cover (%) Damage class

(Willeitner criterion)

1 WF-25-1 12 10.5 1

2 WF-25-0 12 13 1

3 WF-50-2 12 22 1-2a

4 WF-50-0 12 75 2b

The Kolle dishes containing the fungus and the specimens were stored in an incubator for 14 weeks at 25 Ċ and 75% relative humidity.

The percentage of the area of the specimens (WF-50-2) and (WF-50-0) covered by fungus mycelium

after14 weeks

(WF-50-2)

(WF-50-0)

Weight Loss

Weight loss (%) = dry weight before incubation

- dry weight after incubation *100 (1)

dry weight before incubation

Findlay (1967)method

Mechanical Tests

Three-Point Bending

Impact Tests

Instron testing machine

Zwick-Material Profong impact tester

Hardness Tests

Water Absorption

Shore D hardness tester

Water absorption (%) = wet weight - dry weight * 100

dry weight

Statistical Analysis

Completely randomized design andDuncan’s Multiple Range Test (DMRT)

Comparison of Weight Loss and Natural Durability of the Composites….

RESULTS AND DISCUSSIONRESULTS AND DISCUSSION

FIG. 1. Average weight losses of different formulations After 14 weeks incubation

Mechanical Properties

FIG. 2. Effect of the compatibilizer on the flexural strength loss of different formulations after 14 weeks incubation.

FIG. 3. Effect of the compatibilizer on the Flexural modulus of different formulations after 14 weeks incubation.

Mechanical Properties

FIG. 4. Effect of the compatibilizer on the hardness of different formulations after 14 weeks incubation.

Mechanical Properties

FIG. 5. Effect of the compatibilizer on the un-notched impact Strength of different formulations after 14 weeks incubation.

Mechanical Properties

Water Absorption

FIG. 6. Effect of the compatibilizer on the water absorption of different formulations after 14 weeks incubation.

CONCLUSIONS

Compatibilizer has considerable effects on the natural durability of wood flour-high density polyethylene composites.

The use of a compatibilizer is inevitable even if improvements in mechanical properties are not of concern.

Weight loss, modulus of elasticity loss, flexural strength loss, and hardness loss were all significantly higher in the absence of the compatibilizer.

The main reason for the higher natural

durability of the compatibilized formulations is seen in better encapsulation of wood particles by the polymer and less accessibility of the nutrients for the fungus.

CONCLUSIONS