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dc.contributor.advisorPickering, Kim L.
dc.contributor.authorJayaraman, Jeevanen_NZ
dc.date.accessioned2011-02-02T02:16:49Z
dc.date.available2011-02-02T02:16:49Z
dc.date.issued2010en_NZ
dc.identifier.citationJayaraman, J. (2010). The Effect of Heat Treatment on the Structure and Properties of Hemp/PLA Composites (Thesis, Master of Engineering (ME)). The University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/5000en
dc.identifier.urihttps://hdl.handle.net/10289/5000
dc.description.abstractThis project focuses on bio-derived composites made from poly(lactic acid) (PLA) and hemp as well as the influence of PLA crystallinity on material properties. It is known that crystallinity can occur as spherulites within a polymer matrix bulk and as transcrystallinity on fibre surfaces in thermoplastic matrix composites. In addition, thermal history is known to influence the degree of crystallinity of polymer materials. The aim of this project was to study the effect of heat treatment or annealing on crystallinity and the influence of this on properties of hemp/PLA composites. Composites were observed to become more opaque during heat treatment and increased crystallinity after heat treatment was seen using optical microscopy. XRD and DSC results showed that crystallinity was much higher for composites than PLA, supporting the fibre acting as a nucleating agent. There was no apparent change to tensile strength with increased heat treatment for PLA, however, for composite samples, increased heat treatment led to a small reduction in average tensile strength. Although there was no discernable trend for change of fracture toughness with increased crystallinity for PLA, it decreased for composite materials. It appears that the increased crystallinity present in the composite in combination with increased stress concentration due to the presence of fibres is reducing composite toughness as well as leading to premature failure in tensile tests due to PLA brittleness explaining lower strengths for composites. DMTA suggests that increase in crystallinity contributes to thermal stability of the composite.en_NZ
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherThe University of Waikatoen_NZ
dc.rightsAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectPLAen_NZ
dc.subjectpolymersen_NZ
dc.subjectcrystallinityen_NZ
dc.subjecthemp fibresen_NZ
dc.subjectcompositesen_NZ
dc.titleThe Effect of Heat Treatment on the Structure and Properties of Hemp/PLA Compositesen_NZ
dc.typeThesisen_NZ
thesis.degree.disciplineEngineeringen_NZ
thesis.degree.grantorUniversity of Waikatoen_NZ
thesis.degree.levelMasters
thesis.degree.nameMaster of Engineering (ME)en_NZ
uow.date.accession2010-04-19en_NZ
uow.identifier.adthttp://adt.waikato.ac.nz/uploads/adt-uow20100419.145816
pubs.place-of-publicationHamilton, New Zealanden_NZ


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