title: Development of Bloodmeal Protein Thermoplastic Blends

authors: Marsilla, K. I. Ku

abstract: This study investigated the compatibilization of Novatein® Thermoplastic Protein (NTP) blends with other polymers. NTP was blended with three different types of polymers;a petroleum-based polyolefin, (low-linear density polyethylene, LLDPE); a biodegradable synthetic polyester, (polybutylene succinate, PBS) and a bioderived, compostable polyester, (poly (lactic acid), PLA). It was a relatively straightforward process to produce a compatible blend of LLDPE and NTP using a compatibilizer, regardless of the obvious difference in chemical structure between these polymers. Blending NTP with PBS, on the other hand, was much more challenging. It required two compatibilizers, added at different stages of blending to produce a compatible blend. For blends with PLA, a novel copolymer, itaconic anhydride grafted PLA (PLA-g-IA) was produced to be used as a compatibilizer and initial results suggested that PLA-g-IA may be a successful approach. 
Two different methods of compatibilization pathways were explored: the addition of a graft copolymer based on one of the components (in the case of NTP/LLDPE blends) or using compatibilizers that are not chemically the same as either component (in the case of NTP/PBS blends). Polyethylene grafted maleic anhydride (PE-g-MAH) was added to NTP/LLDPE blends and produced a blend with synergistic mechanical properties (the elongation at break exceeded the raw LLDPE properties). The water resistance of NTP was improved after blending with LLDPE, but it may compromise the compostability of the material. For NTP/PBS blends, two compatibilizers with different functional end-groups were used; these were (poly-2-ethyl-2-oxazoline)(PEOX) and (polymeric diphenyl diisocyanate)(pMDI). Using either of the compatibilizers individually in blends containing 50 % NTP resulted in poor mechanical properties. Compatibilization was accomplished with the addition of both two compatibilizers at different stages of blend preparation; PEOX dissolved in water and added during NTP production, while pMDI was added during injection moulding. This approach led to a tensile strength greater than that of pure PBS (24 MPa compared to 22 MPa). Dissolving PEOX in water improved the dispersion of the NTP phase throughout the PBS matrix via hydrogen bonding between water, PEOX and NTP. The addition of pMDI during injection moulding stabilized and strengthened the interactions between PBS and NTP, thereby leading to a superior blend.  
The compatibility between NTP and LLDPE or NTP and PBS were characterized using thermal and morphological properties as well as water resistance. Two Tgs were obtained for all blends, however, the addition of compatibilizers improved the adhesion between phases, evident from broader and lower height of Tg peaks. The morphology provided evidence of a homogenous dispersion of NTP in LLDPE. In NTP/PBS blends, the fracture mechanism changed from brittle to ductile with the addition of PEOX. Both NTP/LLDPE and NTP/PBS blends showed a phase inversion from a particle- dispersed morphology to a co-continuous morphology at compositions greater than 50% NTP. The water resistance also improved with the addition of LLDPE and PBS.   
Reactive extrusion was used to produce a copolymer, itaconic anhydride grafted poly (lactic acid) (PLA-g-IA). Different initiator (dicumyl peroxide) and monomer (IA) concentrations were used to optimize the degree of grafting. 0.75% was the highest degree of grafting and showed minimal chain scission evident from the polymer’s intrinsic viscosity. The reaction kinetics of grafting and the effect of grafting on thermal and mechanical properties were investigated. Grafting increased the crystallization rate of PLA, increased the crystallinity and also raised the thermal decomposition temperature. The mechanical properties of PLA-g-IA blended with PLA were also improved.
Crystallization of PLA and PLA-g-IA were investigated during annealing at different annealing temperatures and durations using differential scanning calorimetry (DSC) and wide angle X-ray scattering (WAXS). The rate of crystallization increased after grafting and affected the formation of PLA crystals by increasing the lattice spacing at the (110) plane, suggesting an expanded helical structure of PLA. The crystallinity of PLA-g-IA was also higher than that of neat PLA.  
Although polymer blending offers an attractive route to modify selected polymer properties, it is not always successful without the addition of compatibilizers. Despite the subtle differences in methods to incorporate compatibilizers, development of NTP blends with different polymers, whether a petroleum based polymer, synthetic biodegradable polyester or bioderived compostable polyester, offers material with improved mechanical properties and thermal stability. Water resistance is also improved, however, biodegradability will likely be compromised if the second polymer is not also biodegradable. These blends offer a potentially wider range of commercial NTP grades.

text: Development of Bloodmeal Protein Thermoplastic Blends This study investigated the compatibilization of Novatein® Thermoplastic Protein (NTP) blends with other polymers. NTP was blended with three different types of polymers;a petroleum-based polyolefin, (low-linear density polyethylene, LLDPE); a biodegradable synthetic polyester, (polybutylene succinate, PBS) and a bioderived, compostable polyester, (poly (lactic acid), PLA). It was a relatively straightforward process to produce a compatible blend of LLDPE and NTP using a compatibilizer, regardless of the obvious difference in chemical structure between these polymers. Blending NTP with PBS, on the other hand, was much more challenging. It required two compatibilizers, added at different stages of blending to produce a compatible blend. For blends with PLA, a novel copolymer, itaconic anhydride grafted PLA (PLA-g-IA) was produced to be used as a compatibilizer and initial results suggested that PLA-g-IA may be a successful approach. 
Two different methods of compatibilization pathways were explored: the addition of a graft copolymer based on one of the components (in the case of NTP/LLDPE blends) or using compatibilizers that are not chemically the same as either component (in the case of NTP/PBS blends). Polyethylene grafted maleic anhydride (PE-g-MAH) was added to NTP/LLDPE blends and produced a blend with synergistic mechanical properties (the elongation at break exceeded the raw LLDPE properties). The water resistance of NTP was improved after blending with LLDPE, but it may compromise the compostability of the material. For NTP/PBS blends, two compatibilizers with different functional end-groups were used; these were (poly-2-ethyl-2-oxazoline)(PEOX) and (polymeric diphenyl diisocyanate)(pMDI). Using either of the compatibilizers individually in blends containing 50 % NTP resulted in poor mechanical properties. Compatibilization was accomplished with the addition of both two compatibilizers at different stages of blend preparation; PEOX dissolved in water and added during NTP production, while pMDI was added during injection moulding. This approach led to a tensile strength greater than that of pure PBS (24 MPa compared to 22 MPa). Dissolving PEOX in water improved the dispersion of the NTP phase throughout the PBS matrix via hydrogen bonding between water, PEOX and NTP. The addition of pMDI during injection moulding stabilized and strengthened the interactions between PBS and NTP, thereby leading to a superior blend.  
The compatibility between NTP and LLDPE or NTP and PBS were characterized using thermal and morphological properties as well as water resistance. Two Tgs were obtained for all blends, however, the addition of compatibilizers improved the adhesion between phases, evident from broader and lower height of Tg peaks. The morphology provided evidence of a homogenous dispersion of NTP in LLDPE. In NTP/PBS blends, the fracture mechanism changed from brittle to ductile with the addition of PEOX. Both NTP/LLDPE and NTP/PBS blends showed a phase inversion from a particle- dispersed morphology to a co-continuous morphology at compositions greater than 50% NTP. The water resistance also improved with the addition of LLDPE and PBS.   
Reactive extrusion was used to produce a copolymer, itaconic anhydride grafted poly (lactic acid) (PLA-g-IA). Different initiator (dicumyl peroxide) and monomer (IA) concentrations were used to optimize the degree of grafting. 0.75% was the highest degree of grafting and showed minimal chain scission evident from the polymer’s intrinsic viscosity. The reaction kinetics of grafting and the effect of grafting on thermal and mechanical properties were investigated. Grafting increased the crystallization rate of PLA, increased the crystallinity and also raised the thermal decomposition temperature. The mechanical properties of PLA-g-IA blended with PLA were also improved.
Crystallization of PLA and PLA-g-IA were investigated during annealing at different annealing temperatures and durations using differential scanning calorimetry (DSC) and wide angle X-ray scattering (WAXS). The rate of crystallization increased after grafting and affected the formation of PLA crystals by increasing the lattice spacing at the (110) plane, suggesting an expanded helical structure of PLA. The crystallinity of PLA-g-IA was also higher than that of neat PLA.  
Although polymer blending offers an attractive route to modify selected polymer properties, it is not always successful without the addition of compatibilizers. Despite the subtle differences in methods to incorporate compatibilizers, development of NTP blends with different polymers, whether a petroleum based polymer, synthetic biodegradable polyester or bioderived compostable polyester, offers material with improved mechanical properties and thermal stability. Water resistance is also improved, however, biodegradability will likely be compromised if the second polymer is not also biodegradable. These blends offer a potentially wider range of commercial NTP grades.

year: 2015

title: Phosphorus Distribution In Relation To Soil Landscape Groups In Steep North Island Hill Country In New Zealand

authors: Arrowsmith, Max

subjects: Phosphorus

abstract: Phosphorus fertiliser is necessary to maintain the production of New Zealand hill country pastures. Technological advances in GIS and GPS have given aerial fertiliser applicators more precision than ever before.  The key question is; to what extent do soil chemical properties vary within hill country landscapes, and is a knowledge of the variability able to be used to differentially apply fertiliser, maximise P fertiliser use efficiency, and minimise P loss to waterways? The objective of this thesis was to quantify the phosphorus variability on Blue Duck Station, a summer-moist hill-country farm located in the Central North Island of New Zealand. The soil comprised Allophanic Soil (Andisols) on the flat to low slopes with Brown Soil (Inceptisols) on the steeper hills.
Blue Duck Station was delineated into six soil-landscape groups (north facing medium slopes, north facing steep slopes, south facing steep slopes, south facing medium slopes, flat ridge tops, and flat valley floors, based on slope, aspect, and elevation using GIS. Three replicate units were randomly selected from each of the six soil-landscape groups, which gave 18 study-sites in total. For each study site, one transect sample and five grid samples were collected. Olsen P, Anion Storage Capacity, pH, Sulphate-sulphur and Cations (Mg, Na, K, Ca) were determined.
The Olsen P ranged from a mean of 6.8 in the south facing medium slopes to 21.2 in the north facing medium slopes. North facing medium slopes and valley low floors had higher mean Olsen P values than all other landscape groups (P<0.01) and also had the greatest variability in Olsen P values. The majority of Olsen P values were considered ‘low’ or ‘very low’. Soil pH was consistent, ranging between 5 and 5.4, whilst anion storage capacity (ASC) levels ranged from 35% to 85%. High ASC levels indicated soils of volcanic origin, containing tephra, whereas low ASC levels were associated with soil predominantly derived from tertiary sedimentary rock.
At Blue Duck Station, the application of higher rates of P fertiliser to south facing steep slopes and south facing medium slopes, with medium rates of P fertiliser addition to north facing steep slopes and ridge low slopes would optimise fertiliser use. There is limited benefit in applying fertiliser to north medium slopes and flat valley floors as Olsen P is near optimal for this environment and stock transfer will continue to add nutrients to these areas.
The variability within a sample site (between grid and transect samples) was often greater than the range of variability the means across all the landscape groups. Due to such large sample variability, difficulties arise when attempting to recommend accurate fertiliser regime, or sampling programs. The soil analysis results from a small number of samples should be treated with caution.  
The Best Management Practice for soil sampling the Central North Island Hill Country would be to avoid sampling small exceptional areas like flat valley floors and flat ridge tops. Focusing sample regimes on a number of transects across northern and southern slopes would give more representative results.

text: Phosphorus Distribution In Relation To Soil Landscape Groups In Steep North Island Hill Country In New Zealand Phosphorus fertiliser is necessary to maintain the production of New Zealand hill country pastures. Technological advances in GIS and GPS have given aerial fertiliser applicators more precision than ever before.  The key question is; to what extent do soil chemical properties vary within hill country landscapes, and is a knowledge of the variability able to be used to differentially apply fertiliser, maximise P fertiliser use efficiency, and minimise P loss to waterways? The objective of this thesis was to quantify the phosphorus variability on Blue Duck Station, a summer-moist hill-country farm located in the Central North Island of New Zealand. The soil comprised Allophanic Soil (Andisols) on the flat to low slopes with Brown Soil (Inceptisols) on the steeper hills.
Blue Duck Station was delineated into six soil-landscape groups (north facing medium slopes, north facing steep slopes, south facing steep slopes, south facing medium slopes, flat ridge tops, and flat valley floors, based on slope, aspect, and elevation using GIS. Three replicate units were randomly selected from each of the six soil-landscape groups, which gave 18 study-sites in total. For each study site, one transect sample and five grid samples were collected. Olsen P, Anion Storage Capacity, pH, Sulphate-sulphur and Cations (Mg, Na, K, Ca) were determined.
The Olsen P ranged from a mean of 6.8 in the south facing medium slopes to 21.2 in the north facing medium slopes. North facing medium slopes and valley low floors had higher mean Olsen P values than all other landscape groups (P<0.01) and also had the greatest variability in Olsen P values. The majority of Olsen P values were considered ‘low’ or ‘very low’. Soil pH was consistent, ranging between 5 and 5.4, whilst anion storage capacity (ASC) levels ranged from 35% to 85%. High ASC levels indicated soils of volcanic origin, containing tephra, whereas low ASC levels were associated with soil predominantly derived from tertiary sedimentary rock.
At Blue Duck Station, the application of higher rates of P fertiliser to south facing steep slopes and south facing medium slopes, with medium rates of P fertiliser addition to north facing steep slopes and ridge low slopes would optimise fertiliser use. There is limited benefit in applying fertiliser to north medium slopes and flat valley floors as Olsen P is near optimal for this environment and stock transfer will continue to add nutrients to these areas.
The variability within a sample site (between grid and transect samples) was often greater than the range of variability the means across all the landscape groups. Due to such large sample variability, difficulties arise when attempting to recommend accurate fertiliser regime, or sampling programs. The soil analysis results from a small number of samples should be treated with caution.  
The Best Management Practice for soil sampling the Central North Island Hill Country would be to avoid sampling small exceptional areas like flat valley floors and flat ridge tops. Focusing sample regimes on a number of transects across northern and southern slopes would give more representative results.

year: 2013

title: Exploring the potential of Te Whāriki in supporting a decolonising educational reform in classroom

authors: Corlett, Melissa Jane

abstract: This thesis begins with a deep belief in the potential of Te Whāriki, a bicultural curriculum document born of the dual heritages of Aotearoa/New Zealand, to support the educational reform needed. There is a need to decolonise our classrooms and create contexts for learning where Māori students feel they can belong and also thrive. The pathway to achieving this reality is complex. It requires a deep foundational understanding of our shared histories in order to move from deficit positions about Māori learners to ones of agency and hope. While strong relationships are important it was by connecting with Māori metaphors that we were able to move beyond the rhetoric and begin to build shared understandings and greater respect for knowledge from te ao Māori. The process of whakawhiti kōrero or dialogic and iterative sense making furthered our combined theorising. The whakataukī and metaphors embedded in Te Whāriki were foundational to these contexts as they strengthened our collective abilities as teachers to make the learning more meaningful and fun.
This research process provided me with valuable insights into the way my own power and beliefs can inhibit potential collective learning. Despite this it was the content of Te Whāriki that helped to enable the learning of myself and my participants, creating safe and supportive contexts for our collective learning to begin to grow. 
While this research strengthened my own beliefs in the potential of Te Whāriki it also assisted my participants to become more open to this potential as well. In this endeavour, time was required to engage with the more expert other, whether this was from other people or through the use of artefacts. The relational and culturally responsive pedagogy that we had learned to implement in our classrooms was also able to be connected with, as our shared unlearning and learning flowed.

text: Exploring the potential of Te Whāriki in supporting a decolonising educational reform in classroom This thesis begins with a deep belief in the potential of Te Whāriki, a bicultural curriculum document born of the dual heritages of Aotearoa/New Zealand, to support the educational reform needed. There is a need to decolonise our classrooms and create contexts for learning where Māori students feel they can belong and also thrive. The pathway to achieving this reality is complex. It requires a deep foundational understanding of our shared histories in order to move from deficit positions about Māori learners to ones of agency and hope. While strong relationships are important it was by connecting with Māori metaphors that we were able to move beyond the rhetoric and begin to build shared understandings and greater respect for knowledge from te ao Māori. The process of whakawhiti kōrero or dialogic and iterative sense making furthered our combined theorising. The whakataukī and metaphors embedded in Te Whāriki were foundational to these contexts as they strengthened our collective abilities as teachers to make the learning more meaningful and fun.
This research process provided me with valuable insights into the way my own power and beliefs can inhibit potential collective learning. Despite this it was the content of Te Whāriki that helped to enable the learning of myself and my participants, creating safe and supportive contexts for our collective learning to begin to grow. 
While this research strengthened my own beliefs in the potential of Te Whāriki it also assisted my participants to become more open to this potential as well. In this endeavour, time was required to engage with the more expert other, whether this was from other people or through the use of artefacts. The relational and culturally responsive pedagogy that we had learned to implement in our classrooms was also able to be connected with, as our shared unlearning and learning flowed.

year: 2022