An exploratory research of PVC-Chlorella composite material (PCCM) as effective utilization of Chlorella biologically fixing CO2

A new PVC-Chlorella composite material (PCCM) was investigated aiming at th e effective utilization of biological CO2 fixing Chlorella. The microalga C hlorella, after fixing CO2, was molded with PVC. Molding conditions of PCCM , and physical properties of Chlorella were studied using tensile strength as an index for estimating the properties of PCCM. The optimum parameters f or molding of PCCM were as follows: temperature = 180 degrees C, pressure = 4.4 MPa and time = 5 min. The following physical parameters of Chlorella b est enhance high tensile strength: water content of 2%, average particle si ze of 30-80 mu m and a relatively homogeneous distribution of particle size . Chlorella, maintaining its original shape, exists in PCCM as an empty bal l inlaid in the matrix of PVC. The PCCM shows a lower elongation and is mor e brittle than PVC, possibly as a result of gas and residual PVC primary pa rticles around Chlorella grains. A comparison between theoretical and exper imental results show that there is an effective combination between the PVC matrix and the Chlorella surface in PCCM. PCCM has a tensile strength high er than 30 MPa which meets the requirements for rigid PVC products, if Chlo rella content is less than 20%. Chlorella can thus be effectively utilized as a practical filler. (C) 2000 Kluwer Academic Publishers.