Sawdust Treatment by Silane Coupling Agents
The silane concentration was 2.0 wt % and 5.0 wt % of sawdust and it was
dissolved in ethanol. Wood sawdust fibres were dried prior to use by heating in oven at
80 °C for 24 h until the weight was constant with a moisture content about 3 %. They
were mixed in silane solution for 2 h at 25 °C and were then dried at room temperature
and heated at 80 °C for 24 h in order to promote the actual chemical coupling [4].
Wood sawdust fibres were dried in an oven at 80 °C for 24 h to expel moisture.
Mixing was carried out on a conventional laboratory 2 roll mill (Yong Fong Machinery
Co., Ltd. Thailand) according to ASTM D3184-80. The composites with various wood
sawdust loadings and with different types and amounts of compatibilizers were prepared
using the formulations given in Tables 1 and 2, respectively. The sheeted rubber
compound was conditioned at a temperature of 23 ± 2 °C for 24 h in a closed container.
The minimum torque, maximum torque, scorch time and cure time of the rubber
compounds were determined using an Oscillating Disk Rheometer (GT7070S2
GOTECH Testing Machine, Inc., Taiwan) at a test temperature of 170 °C. The rubber
compound was then compression moulded to a 90 % cure using a hydraulic press
(Carver, Inc., USA) at 2500 kgf and 170 °C.