Natural fiber plastic composites were made from Nigerian grown bamboo (Bambusa vulgaris) and high density polyethylene by extrusion and evaluated for strength, sorption and thermal properties. Composites were manufactured using two different screened bamboo particle size fractions (<2 mm and < 0,5 mm). The composites were tested for flexural properties, water sorption, melt flow and thermal properties. The melt viscosities at 190 o C were 22,3 ± 0,91 kPa•s (<2 mm) and 27,4 ± 1,2 kPa•s (<0,5 mm). The results obtained indicated that the composites made with the smaller particle size fraction had higher flexural strength (37,4 ± 1,0 MPa) and modulus of elasticity (2,0 ± 0,2 GPa) than those made with the larger particle size fraction (29,9 ± 1,1 MPa and 1,7 ± 0,1 GPa). Dynamic mechanical analysis also showed higher dynamic storage modulus for the <0,5 mm particle-based composites than those made from the <2 mm particle size fraction due to higher density and better interfacial interaction between the fiber and matrix. Also, the composites made with the smaller particles and were more dimensionally stable (water absorption of 5,4% versus 18,5% at 61 d). The bamboo composites had thermal stability range of 265-279 o C (onset degradation temperature). The composites made with the smaller bamboo particles possessed the better properties in comparison with those made from the <2 mm. Particle size and density significantly affected the mechanical, physical, thermal and rheological properties of the composites evaluated.

Abstract-

The feasibility of using rattan canes (Laccosperma secundiflorum and Eremospatha macrocarpa) as reinforced fillers for high density polyethylene based plastic composite production was investigated. Extruded composites were tested for water sorption, tensile and thermal properties. The results obtained indicated that the rattan composites were dimensionally (water absorption: 2,2-21,4% thickness swell: 0,9-5,3%) and thermally stable (T c : 116,8-118,2°C) and possessed adequate tensile properties (7,(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)7 MPa). Composites made from L. secundiflorum had higher strength and thermal properties but lower sorption values compared to those of E. macrocarpa. Differences in the densities of the composites and the anatomical structures of the rattans seemed to influence properties of the composites.

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Plastic composites were made from corncobs and high density polyethylene (HDPE) by extrusion and evaluated. The composites were manufactured using two different screened corncob particle size fractions (<2 mm and <0.5 mm) and tested for flexural properties, water sorption, melt flow and thermal properties. The melt viscosities at 190 o C were 18.0 ± 0.8 kPa•s (<2 mm) and 24.0 ± 0.6 kPa•s (<0.5 mm). The results obtained indicated that the composites made with the smaller particle size fraction had higher flexural strength (31.7 ± 1.7 MPa) and modulus of elasticity (1.4 ± 0.1 GPa) than those made with the larger particle size fraction (21.2 ± 1.4 MPa and 1.1 ± 0.1 GPa). Also, the composites made with the smaller particles and were more dimensionally stable. Corncob composites had thermal stability range of 259 -274 o C (onset degradation temperature). The corncob composites made with smaller sized particles possessed better properties in comparison with those made from the <2 mm. Particle size and density significantly affected the mechanical, physical and thermal properties of the composites evaluated.