2 Experimental
2.1 Materials
Extrusion grade of PLA with a density of 1.24 g·cm−3 and a melting point of 165 ˚C was used as polymer matrix
due to its biodegradability and commercial availability. Fine particles of CSR (ParaloidTM BPM-520, Dow
Chemicals Company) were added to PLA and PLA/rubber wood composites for the purpose of toughening.
The bulk density and the average particle size of CSR are 0.4 g·cm−3 and 2.5 micrometer respectively. The rubber wood (Hevea brasiliensis) sawdust was obtained from the waste from a sawmill in Ayutthaya, Thailand. The wood flour was further grinded by a ball mill and sieved to the top cut sizes of 500 m.