Development of useful composite materials out of agricultural waste has become an expedient option in recycling. This led to the production of composite wooden boards being used in the construction industry.

The purpose of this study is to utilize the Caesalpinia pulcherrima pods as particleboard. The researcher utilized True- Experimental Method with four replicates of different particle sizes of caballero pods within the polyethylene to produce particleboards. The DOST-ITDI Material Science Division made 12 replicates of particleboards with three particle sizes made from caballero pods using two-roll mill and molding machine. The Physical Tests: Flexure Test, Tension Test and Water Absorption Test were conducted at DOST-ITDI Standard Testing Division. The Scanning Electron Microscope Analysis was done by the Research Center for the Natural and

Applied Sciences of the University of Santo Tomas.

The photomicrographs investigated the interaction exist between the polyethylene as binder and the three different particle sizes of caballero pods using the Scanning Electron Microscopy in 400 magnification using the scale of 200 microns, 1000 magnification using the scale of 100 microns, and 1800 magnification using the scale of 50 microns. It revealed that the distribution of the caballero pods within the polyethylene depends on the particle size of the caballero pods.
The flexural strength showed that the particleboard with particle size C (710 micrometers) obtained the highest mean of 26.8 MPa and the A (Control Group) attained the lowest mean of 25.7 MPa. Similarly, particleboard with particle size C (710 micrometers) also got the highest mean of 1.63 GPa in terms of flexural elasticity and A (Control Group) ranking as the lowest with 0.94 GPa. On the contrary, A (Control Group) acquired the highest mean of 21.5 MPa under tensile strength but particle size D (2 millimeters) got the lowest mean of 13.6 MPa. The result of the Modulus Elasticity for tensile shows that particleboard with particle size D (2 millimeters) started to deform at 2,08 GPa, while particle size 8 (350 micrometers) rank last with 0.95 GPa. in water absorption test, A (Control Group) obtained the lowest average difference in weight of 0.429% while the particleboard with particle size D (2 millimeter) has an average difference in weight of 1.16%

Using the Statistical treatment of One Way Analysis of Variance (ANOVA) the researcher has the computed value for both flexural strength 7.7658 and modulus elasticity 26.2257 are both greater than the critical value of 2.92 hence, there is a significant difference on the flexural strength and modulus elasticity of the particle sizes of the designed particleboard. In terms of tensile strength, the computed value is -24.7519 which is less that the critical value of 2.92 accepting the null hypothesis, there is no significant difference on the tensile strength of the particle sizes of the designed particleboard. Additionally, in terms of tensile elasticity the computed value of 1.1135 is less than the critical value of 2.92, accepting null hypothesis that there is no significant difference on the tensile elasticity. Lastly, in terms of water absorption it was shown that the computed value of 3.8783 is greater that the critical value of 2.92, therefore the null hypothesis is rejected and the alternative hypothesis is accepted that there is a significant difference on the water absorption of the particle sizes of the designed particleboard.