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Volume 8, Issue 6 (Suppl) J Bioremediat Biodegrad, an open access journal
ISSN:2155-6199 Biopolymers & Bioplastics 2017
October 19-20, 2017
October 19-20, 2017 San Francisco, USA
7th International Conference and Exhibition on
Biopolymers and Bioplastics
Mechanical stability of wood flour / polyhydroxyalkanoate (PHA) composites modified by boron nitride
and talc
Clement Chan1, Luigi-Jules Vandi 1, Steven Pratt1, Peter Halley1, Desmond Richardson2, Alan Werker1,3 and Bronwyn Laycock1
1The University of Queensland, Australia
2Norske Skog Paper Mills (Aust) Ltd, Australia
3Promiko AB, Sweden
The wood plastic composites (WPCs) market has been rapidly expanding over the past few decades. Recently, the use of
polyhydroxyalkanoates (PHAs) as the polymer matrix in WPCs has been of increasing interest, as these polymers are renewable,
biodegradable and have a low melt viscosity. However, there have been concerns over the slow crystallisation rate and in-service
stability of such bioderived and biodegradable materials. The aim of this study is to investigate the individual and combined effect
of boron nitride (BN), a nucleating agent, and talc, a micron-sized inorganic filler, on the properties of a composite made from
radiata pine wood flour and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) polymer (50/50 by weight) and their in-service
mechanical stability. In this study, wood composites were manufactured using twin screw extrusion and their mechanical and thermal
properties were experimentally determined initially and after 1 year of conditioning under a controlled temperature of 25oC and
humidity of 50%. The nucleating effects of both BN and talc were demonstrated through isothermal crystallisation kinetic analysis,
with BN being more effective. No further observable improvements were noted when these additives were combined compared to
the use of BN alone. However, the addition of 1 wt% of BN was not found to affect the tensile properties initially nor after 1 year of
controlled aging. After conditioning, the mechanical properties of the composite without additives were retained. Inherent in-service
mechanical stability for such biocomposites is therefore possible. The addition of talc improved the initial tensile strength and tensile
modulus of the composite. However, such initial improvement in mechanical performance was reduced after 1 year of conditioning.
It is proposed that the combination effects of multiple factors such as the swelling of wood through moisture uptake, the shrinkage of
PHBV through secondary crystallisation and the localised stress around talc particles could led to a weakened talc-PHBV interface.
Biography
Clement is currently a PhD student at the School of Chemical Engineering, the University of Queensland, Australia. His major experiences are in functional materials
and composites. He graduated with a Bachelor's of Chemical Engineering from the University of Minnesota - Twin Cities, U.S.A. During his studies, he also involved
in a project focused on the toughening of graphene-epoxy nanocomposites through the functionalisation of graphene. After working as a production engineering in
a pharmaceutical company in Hong Kong, he started his PhD at UQ in early-2015 focusing on the processing and characterisation of high performance bioderived
and biodegradable polyhydroxyalkanoates (PHAs)-based wood plastic composites. His primary research interests are in the area of biodegradable polymers,
composite materials and sustainable engineering.
Clement Chan et al., J Bioremediat Biodegrad 2017, 8:6 (Suppl)
DOI: 10.4172/2155-6199-C1-011