Ma. Kotnis et al., PROCESSING AND MECHANICAL-PROPERTIES OF BIODEGRADABLE POLY(HYDROXYBUTYRATE-CO-VALERATE)-STARCH COMPOSITIONS, Journal of environmental polymer degradation, 3(2), 1995, pp. 97-105
Poly(hydroxybutyrate-co-valerate) (PHBV) is a completely biodegradable
thermoplastic polyester produced by microbial fermentation. The curre
nt market price of PHBV is significantly higher than that of commodity
plastics such as polyethylene and polystyrene. It is therefore desira
ble to develop low-cost PHBV based materials to improve market opportu
nities for PHBV. We have produced low-cost environmentally compatible
materials by blending PHBV with granular starch and environmentally be
nign CaCO3. Such materials can be used for specific applications where
product biodegradability is a key factor and where certain mechanical
properties can be compromised at the expense of lower cost. The inclu
sion of granular starch (25 wt%) and CaCO3 (10 wt%) in a PHBV matrix (
8% HV, 5% plasticizer) reduces the cost by approximately 40% and has a
tensile strength of 16 MPa and flexural modulus of 2.0 Gpa, while the
unfilled PHBV/plasticizer matrix has a tensile strength of 27 MPa and
a flexural modulus of 1.6 GPa.