Effect of Variation Aluminum Oxide Concentration on the Modified Novolac Stalk Composite
Table 1
Bending strength and water absorption of the composites prepared from untreated and treated cotton stalk containing novolac and different concentrations of Al2O3. (Conce. polymer 30%, temp. 160°C, pressure 150 kg/cm2, time of press 5 min.).
Type of composite
Bending strength N/mm2 (MOR)
Water absorption
After immersion in boiling water for 2 hr
After immersion in water for 24 hr
After immersion in water for 7 days
Untreated composite containing 30% novolac resin
11.5
27.3
26.8
39.1
Treated composite containing 30% novolac resin
15.7
21.6
21.6
32.1
Treated composite containing 30% novolac resin and 2% aluminum oxide
18.6
20.1
19.7
30.8
Treated composite containing 30% novolac resin and 4% aluminum oxide
23.5
19.5
19.0
27.8
Treated composite containing 30% novolac resin and 6% aluminum oxide
29.7
15.1
15.1
22.4
Treated composite: the composite treated by propionic anhydride.
