PROCESSING AND CHARACTERIZATION OF A NEW BIODEGRADABLE COMPOSITE MADEOF A PHB V MATRIX AND REGENERATED CELLULOSIC FIBERS/

In this study, a biodegradable composite consisting of a degradable co ntinuous cellulosic fiber and a degradable polymer -poly(3-hydroxybuty rate)-co-poly(3-hydroxyvalerate (PHB/V with 19% HV)-was developed. The composite was processed by impregnating the cellulosic fibers on-line with PHB/V powder in a fluidization chamber. The impregnated roving w as then filament wound on a plate and hot-pressed. The resulting unidi rectional composite plates were mechanically tested and optically char acterized by SEM. The fiber content was 9.9 +/- 0.9 vol% by volumetric determination. The fiber content predicted by the rule of mixture for unidirectional composites was 13.8 +/- 1.4 vol%. Optical characteriza tion showed that the fiber distribution was homogeneous and a satisfac tory wetting of the fibers by the matrix was achieved. Using a blower to remove excess matrix powder during processing increased the fiber c ontent to 26.5 +/- 3.3 vol% (volumetric) or 30.0 +/- 0.4 vol% (rule of mixture). The tensile strength of the composite parallel to the fiber direction was 128 +/- 12 MPa (10 vol% fiber) up to 278 +/- 48 MPa (26 .5 vol% fiber), compared to 20 MPa for the PHB/V matrix. The Young's m odulus was 5.8 +/- 0.5 GPa (10 vol% fiber) and reached 11.4 +/- 0.14 G Pa (26.5 vol% fiber), versus 1 GPa for the matrix.