Abstract
The large-scale entry of bio-based polymers, such as poly(hydroxybutyrate-co-valerate) (PHBV), in applications commonly occupied by petroleum-based plastics is heavily limited by their poorer mechanical properties, thus, hindering efforts to reduce harmful plastic waste. Prior work to improve these properties has involved short natural fibre reinforcements, which do not produce substantial improvements. In this work, PHBV was simultaneously reinforced with unidirectional flax and toughened with poly(butylene adipate-co-terephthalate) (PBAT) or epoxidized natural rubber (ENR) to produce well-rounded composites. Toughened unidirectional composites were prepared by cryogenic grinding, powder layup and compression moulding. Unidirectional flax addition resulted in 4-fold increases in tensile properties, 3-fold increases in flexural properties and 20-fold increases in impact properties, whilst producing minimal change in the thermal properties. PBAT and ENR phases appeared well bonded to the PHBV within the composite. The addition of PBAT did not cause any significant changes in thermal or mechanical properties. The addition of ENR, however, reduced the tensile modulus and the flexural properties but produced a significant increase in impact strength, attributed to the coarse particle size of ENR. Unidirectional flax reinforcement of PHBV widens the scope of application of PHBV considerably where mechanical properties are of concern, while ENR has significant potential as a bio-based toughening agent for biocomposites.
Highlights
The harmful impact of disposed plastics on the environment has become of increasing concern and this has led to the development of environmentally benign ‘green’ polymers [1]
PHBV was simultaneously reinforced with unidirectional flax and toughened with poly(butylene adipate-co-terephthalate) (PBAT) or ENR50
The Tm decreased slightly with incorporation of the flax fibres into PHBV. This is consistent with the findings of Srithep et al [17] for PHBV/cellulose composites who attributed the decrease to degradation of the PHBV caused by hydroxyl groups on the cellulose fibres triggering hydrolysis of the PHBV at elevated temperature
Summary
The harmful impact of disposed plastics on the environment has become of increasing concern and this has led to the development of environmentally benign ‘green’ polymers [1]. One area of waste disposal which has become of particular concern in recent years is electronic waste, often referred to as e-waste [2] In the e-waste stream, the casings of items such as mobile phones, computers and printers are of particular interest since these items have only short lives but are made from materials which degrade only slowly. This is an area that could benefit considerably from the use of green materials
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
