title: The Effect of Heat Treatment on the Structure and Properties of Hemp/PLA Composites

authors: Jayaraman, Jeevan

subjects: PLA

abstract: This 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.

text: The Effect of Heat Treatment on the Structure and Properties of Hemp/PLA Composites This 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.

year: 2010

title: Catnesses

authors: Legg, Catherine

subjects: philosophy

abstract: An introduction to cat metaphysics.

text: Catnesses An introduction to cat metaphysics.

year: 2008

title: Lessons learned from the MV Rena: Reimagining maritime and resource management law

authors: Paul, Adrienne Joy

subjects: Resource Management Law - New Zealand

abstract: The main research question in this thesis is what lessons can Aotearoa New Zealand learn from the MV Rena grounding accident? This research is an historical account of the legal framework existing at the time of the MV Rena grounding. In addition, the thesis will outline the surrounding marine environment to examine the relevant regulatory system.
In the early morning of 5th October 2011, the MV Rena vessel struck Ōtāiti (Astrolabe Reef).  Initially, the accident concerned a response to the safety of the crew on board the MV Rena. However, the seriousness of the damage to the hull with part of Ōtāiti reef protruding through the keel, presented issues concerning the recovery strategy for the vessel and cargo from the coastal marine area.  The MV Rena grounding released oil, cargo, and equipment into the surrounding marine environment of Ōtāiti. The oil, cargo and equipment travelled by the ocean currents, spreading across large areas of the ocean. This caused environmental effects across the coastal marine area in the Bay of Plenty region. The grounding was the “worst maritime environmental disaster” Aotearoa New Zealand had ever seen. 

The government of the day and the MV Rena owner are committed to international obligations for preparing and responding to maritime disasters and marine pollution. However, the government of Aotearoa New Zealand was not a party to international obligations addressing groundings relative to bunker oil. In addition, when responding to environmental effects from the grounding the legal processes regulating the maritime and resource management system, caused distress to the local community in the Bay of Plenty region. Specifically, the people of Motiti Island (“Motiti”), relative to preserving and protecting their cultural and spiritual relationship with Ōtāiti and Motiti.

An analysis of maritime and resource management law at the international level and domestic level is explored in this thesis. Such as, marine pollution, and indigenous peoples’ rights (iwi Māori) in connection with the Maritime Transport Act 1994, the Resource Management Act 1991, the Waitangi Tribunal process and related planning and policy instruments.  The research concludes that, had the government of the day ratified relevant conventions prior to the MV Rena grounding incident, the outcome of the location of the ship may have been a completely different result, such as a full wreck removal, without opposition. Additionally, the research concludes that the gap in the laws regulating marine environments did not equip iwi Māori with protecting their interests, resulting in a spiritual injustice to the people of Motiti. This research reveals that maritime and resource management law still has a long way to go with supporting the indigenous people’s voice in Aotearoa New Zealand for sustainable marine solutions. This thesis conclude with recommendations directed at better maritime and resource management regulations and indigenous peoples’ involvement.

text: Lessons learned from the MV Rena: Reimagining maritime and resource management law The main research question in this thesis is what lessons can Aotearoa New Zealand learn from the MV Rena grounding accident? This research is an historical account of the legal framework existing at the time of the MV Rena grounding. In addition, the thesis will outline the surrounding marine environment to examine the relevant regulatory system.
In the early morning of 5th October 2011, the MV Rena vessel struck Ōtāiti (Astrolabe Reef).  Initially, the accident concerned a response to the safety of the crew on board the MV Rena. However, the seriousness of the damage to the hull with part of Ōtāiti reef protruding through the keel, presented issues concerning the recovery strategy for the vessel and cargo from the coastal marine area.  The MV Rena grounding released oil, cargo, and equipment into the surrounding marine environment of Ōtāiti. The oil, cargo and equipment travelled by the ocean currents, spreading across large areas of the ocean. This caused environmental effects across the coastal marine area in the Bay of Plenty region. The grounding was the “worst maritime environmental disaster” Aotearoa New Zealand had ever seen. 

The government of the day and the MV Rena owner are committed to international obligations for preparing and responding to maritime disasters and marine pollution. However, the government of Aotearoa New Zealand was not a party to international obligations addressing groundings relative to bunker oil. In addition, when responding to environmental effects from the grounding the legal processes regulating the maritime and resource management system, caused distress to the local community in the Bay of Plenty region. Specifically, the people of Motiti Island (“Motiti”), relative to preserving and protecting their cultural and spiritual relationship with Ōtāiti and Motiti.

An analysis of maritime and resource management law at the international level and domestic level is explored in this thesis. Such as, marine pollution, and indigenous peoples’ rights (iwi Māori) in connection with the Maritime Transport Act 1994, the Resource Management Act 1991, the Waitangi Tribunal process and related planning and policy instruments.  The research concludes that, had the government of the day ratified relevant conventions prior to the MV Rena grounding incident, the outcome of the location of the ship may have been a completely different result, such as a full wreck removal, without opposition. Additionally, the research concludes that the gap in the laws regulating marine environments did not equip iwi Māori with protecting their interests, resulting in a spiritual injustice to the people of Motiti. This research reveals that maritime and resource management law still has a long way to go with supporting the indigenous people’s voice in Aotearoa New Zealand for sustainable marine solutions. This thesis conclude with recommendations directed at better maritime and resource management regulations and indigenous peoples’ involvement.

year: 2022