title: Processing Extrudable Sheets using Decoloured Bloodmeal

authors: Izuchukwu, Sandra C.P.

subjects: polymer processing

abstract: This study investigated the feasibility of blending decoloured bloodmeal thermoplastic (DBT), a thermoplastic protein material, with poly (lactic acid) (PLA), a semi-crystalline polymer, and subsequently processing the blend into a sheet using extrusion. Free radical grafting was used to graft itaconic anhydride onto PLA to create reactive side groups. Blends of DBT and PLA compatibilized with itaconic anhydride were produced using different processing conditions, different formulations of DBT and different blend compositions. Decoloured bloodmeal thermoplastic powder (DBTP) was easier to process into injection mouldable samples than were decoloured bloodmeal thermoplastic granules (DBTG). 

The compatibility between the produced material blends was investigated using mechanical testing, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and wide-angle X-ray scattering (WAXS). Blending DBT with PLA increased the tensile strength and modulus of DBT while strain at break decreased. The glass transition temperature of the blends increased compared to neat DBT. SEM revealed a more homogenous microstructure, which provided evidence of enhanced interfacial adhesion between both phases in the blends with PLA grafted with itaconic anhydride (PLA-g-IA). An insignificant decrease in the crystallinity of the blends compared to neat material was observed in the WAXS result, indicating that blending with PLA has no structural effect on DBT.

Ratios (DBP:PLA) of 30:70 (DP37), 50:50 (DP55), 70:30 (DP73) and 90:10 (DP91), with and without compatibilizer (PLA-g-IA), were examined to determine the optimal blend ratio for DBT/PLA blends. DBP content below 30 wt.% was considered to defeat the main aim of maximizing the use of decoloured bloodmeal.  Below 50 wt.% and above 70 wt. % DBT content, either DBT or PLA overwhelmed the compatibilizing effect of itaconic anhydride resulting in poor mechanical properties of the blends. Four DBT formulations with varying water, SDS and TEG content were blended with PLA or PLA-g-IA to determine the best DBT formulation for DBT/PLA blend system. From the mechanical properties and digested surface morphology obtained, a compatibilized DBT formulation containing 40 parts per hundred DBM (pphDBM), 3 pphDBM SDS and 20 pphDBM TEG (F2)/PLA showed a considerable increase in tensile strength, elongation at break and impact strength compared to other formulations trialled. Also, an improvement in interfacial interaction, evidenced by a finer phase structure with relatively uniform void, was observed for this blend. However, a balance can be achieved between this blend and a compatibilized blend containing 40 PPHDBM, 6 PPHDBM SDS and 30 PPHDBM, if elongation at break is compromised depending on the desired material properties and functionality of the desired end product.   

The data obtained from SEM and WAXS of the blends indicated an improvement in the blend’s compatibility with the addition of itaconic anhydride. However, no significant effect was observed in the blend’s mechanical properties with the addition of compatibilizer. This led to the investigation of possible ways to improve the blend’s mechanical properties.

Compatibility between DBT and PLA, the effect of different compatibilizer type, and plasticizer type used were investigated using mechanical testing, SEM and DMA. DBT/PLA blends were produced using three different compatibilizers: itaconic anhydride grafted PLA (PLA-g-IA), poly (2-ethyl-2-oxazoline) (PEOX) and poly (phenyl isocyanate)-co-formaldehyde (pMDI). Compatibilizing DBT/PLA blend with PEOX or PLA-g-IA was relatively straightforward, while using dual compatibilizer (PEOX and pMDI) required the addition of compatibilizer at different stages of blending to achieve a compatible blend. PLA-g-IA produced high tensile and impact strength as well as an evenly dispersed DBT domain and finer morphology compared to PEOX/pMDI and PEOX only. Two compatibilization approaches were used for DBT/PLA blends; one in which a compatibilizer (PLA-g-IA) was added as a third blend component and another in which a reactive group (itaconic anhydride) capable of interacting with the DBT and PLA phase was grafted onto PLA to improve the interfacial interaction between both phases. The data obtained suggested that adding the compatibilizer as a third blend component may be a successful approach. Two plasticizer types, tri ethylene glycol (TEG) and glycerol, were trialled to determine the best for the DBT/PLA blend system. The washed surface morphology of blends plasticized with TEG revealed finer morphology with more evenly distributed pores and small DBT domain sizes than blends plasticized with glycerol.

The feasibility of sheet extruding DBT/PLA blends was assessed, and the properties of the sheets produced were measured. The effects of different processing methods and different processing steps on the produced sheets were investigated in terms of mechanical, structural and water absorption properties. With a fundamental understanding of the blending method for DBT/PLA blends, different sheet processing methods (M1, M2, M3, M4 and M5) and processing steps (2- and 3-step processing) were used to successfully process D463.4.1 (DBT/PLA blend containing 50 parts DBT, 40 parts PLA and 10 parts compatibilizer) into a sheet using extrusion. The viscosity of the blends produced using different methods was measured, to better understand the sheet processing of DBT/PLA blends.   M4 produced the most promising sheet, with better consolidation and a relatively smooth surface, as revealed by SEM topography of DBT/PLA blends sheet. The tensile properties and water absorption of the produced sheets suggested that the collective effects of reduced heat processing (method M4) and  2-step processing improved the  sheet properties.   

This study demonstrated the feasibility of blending DBT with PLA, improving the properties of DBT/PLA blends and processing the produced blends into sheets for use in agricultural (such as weed mat) and packaging applications.

text: Processing Extrudable Sheets using Decoloured Bloodmeal This study investigated the feasibility of blending decoloured bloodmeal thermoplastic (DBT), a thermoplastic protein material, with poly (lactic acid) (PLA), a semi-crystalline polymer, and subsequently processing the blend into a sheet using extrusion. Free radical grafting was used to graft itaconic anhydride onto PLA to create reactive side groups. Blends of DBT and PLA compatibilized with itaconic anhydride were produced using different processing conditions, different formulations of DBT and different blend compositions. Decoloured bloodmeal thermoplastic powder (DBTP) was easier to process into injection mouldable samples than were decoloured bloodmeal thermoplastic granules (DBTG). 

The compatibility between the produced material blends was investigated using mechanical testing, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and wide-angle X-ray scattering (WAXS). Blending DBT with PLA increased the tensile strength and modulus of DBT while strain at break decreased. The glass transition temperature of the blends increased compared to neat DBT. SEM revealed a more homogenous microstructure, which provided evidence of enhanced interfacial adhesion between both phases in the blends with PLA grafted with itaconic anhydride (PLA-g-IA). An insignificant decrease in the crystallinity of the blends compared to neat material was observed in the WAXS result, indicating that blending with PLA has no structural effect on DBT.

Ratios (DBP:PLA) of 30:70 (DP37), 50:50 (DP55), 70:30 (DP73) and 90:10 (DP91), with and without compatibilizer (PLA-g-IA), were examined to determine the optimal blend ratio for DBT/PLA blends. DBP content below 30 wt.% was considered to defeat the main aim of maximizing the use of decoloured bloodmeal.  Below 50 wt.% and above 70 wt. % DBT content, either DBT or PLA overwhelmed the compatibilizing effect of itaconic anhydride resulting in poor mechanical properties of the blends. Four DBT formulations with varying water, SDS and TEG content were blended with PLA or PLA-g-IA to determine the best DBT formulation for DBT/PLA blend system. From the mechanical properties and digested surface morphology obtained, a compatibilized DBT formulation containing 40 parts per hundred DBM (pphDBM), 3 pphDBM SDS and 20 pphDBM TEG (F2)/PLA showed a considerable increase in tensile strength, elongation at break and impact strength compared to other formulations trialled. Also, an improvement in interfacial interaction, evidenced by a finer phase structure with relatively uniform void, was observed for this blend. However, a balance can be achieved between this blend and a compatibilized blend containing 40 PPHDBM, 6 PPHDBM SDS and 30 PPHDBM, if elongation at break is compromised depending on the desired material properties and functionality of the desired end product.   

The data obtained from SEM and WAXS of the blends indicated an improvement in the blend’s compatibility with the addition of itaconic anhydride. However, no significant effect was observed in the blend’s mechanical properties with the addition of compatibilizer. This led to the investigation of possible ways to improve the blend’s mechanical properties.

Compatibility between DBT and PLA, the effect of different compatibilizer type, and plasticizer type used were investigated using mechanical testing, SEM and DMA. DBT/PLA blends were produced using three different compatibilizers: itaconic anhydride grafted PLA (PLA-g-IA), poly (2-ethyl-2-oxazoline) (PEOX) and poly (phenyl isocyanate)-co-formaldehyde (pMDI). Compatibilizing DBT/PLA blend with PEOX or PLA-g-IA was relatively straightforward, while using dual compatibilizer (PEOX and pMDI) required the addition of compatibilizer at different stages of blending to achieve a compatible blend. PLA-g-IA produced high tensile and impact strength as well as an evenly dispersed DBT domain and finer morphology compared to PEOX/pMDI and PEOX only. Two compatibilization approaches were used for DBT/PLA blends; one in which a compatibilizer (PLA-g-IA) was added as a third blend component and another in which a reactive group (itaconic anhydride) capable of interacting with the DBT and PLA phase was grafted onto PLA to improve the interfacial interaction between both phases. The data obtained suggested that adding the compatibilizer as a third blend component may be a successful approach. Two plasticizer types, tri ethylene glycol (TEG) and glycerol, were trialled to determine the best for the DBT/PLA blend system. The washed surface morphology of blends plasticized with TEG revealed finer morphology with more evenly distributed pores and small DBT domain sizes than blends plasticized with glycerol.

The feasibility of sheet extruding DBT/PLA blends was assessed, and the properties of the sheets produced were measured. The effects of different processing methods and different processing steps on the produced sheets were investigated in terms of mechanical, structural and water absorption properties. With a fundamental understanding of the blending method for DBT/PLA blends, different sheet processing methods (M1, M2, M3, M4 and M5) and processing steps (2- and 3-step processing) were used to successfully process D463.4.1 (DBT/PLA blend containing 50 parts DBT, 40 parts PLA and 10 parts compatibilizer) into a sheet using extrusion. The viscosity of the blends produced using different methods was measured, to better understand the sheet processing of DBT/PLA blends.   M4 produced the most promising sheet, with better consolidation and a relatively smooth surface, as revealed by SEM topography of DBT/PLA blends sheet. The tensile properties and water absorption of the produced sheets suggested that the collective effects of reduced heat processing (method M4) and  2-step processing improved the  sheet properties.   

This study demonstrated the feasibility of blending DBT with PLA, improving the properties of DBT/PLA blends and processing the produced blends into sheets for use in agricultural (such as weed mat) and packaging applications.

year: 2019

title: Clio and the economist: Making historian count

authors: Greasley, David

subjects: Anthropometrics

abstract: Cliometrics reconnected economic history and economics in the 1960s. The deeper foundations of cliometrics research lie in the longer standing traditions of quantitative history and the contemporaneous growth of the social sciences and computing. Early cliometrics research reinterpreted economic history through the lens of neo-classical economics. Over the past half century cliometrics has matured and now utilizes a broad array of theoretical perspectives and statistical methods to help understand the past. The papers introduced here illustrate the achievements of several key areas of cliometrics research and show how new theoretical perspectives, innovative data construction and sophisticated econometric methods are the hallmarks of the discipline.

text: Clio and the economist: Making historian count Cliometrics reconnected economic history and economics in the 1960s. The deeper foundations of cliometrics research lie in the longer standing traditions of quantitative history and the contemporaneous growth of the social sciences and computing. Early cliometrics research reinterpreted economic history through the lens of neo-classical economics. Over the past half century cliometrics has matured and now utilizes a broad array of theoretical perspectives and statistical methods to help understand the past. The papers introduced here illustrate the achievements of several key areas of cliometrics research and show how new theoretical perspectives, innovative data construction and sophisticated econometric methods are the hallmarks of the discipline.

year: 2010

title: Tito Waiata-Tito Pūoro: extending the Kīngitanga music tradition.

authors: Rollo, Te Manaaroha Pirihira

subjects: Kīngitanga

abstract: Since 1858, music has always been an integral part of the Kīngitanga movement in New Zealand. As this music tradition evolves with the introduction of new musical idioms, genres and digital technology, so too do the practices of composing new works. 

The objective of this research was to construct a model for combining waiata, taonga pūoro and New Zealand electroacoustic music, in order to create new works that enhance the Kīngitanga music tradition.  Developing a model for composing and integrating these idioms within a Māori context presented problems, as traditional Māori music conflict with contemporary Western forms. 

To generate a framework and practical model for composing hybrid music, an examination of selected New Zealand works was first carried out through: a) the collection of 50 traditional and contemporary waiata relating to the Kīngitanga b) the collection of 10 New Zealand taonga pūoro works and c) a collection of 10 New Zealand electroacoustic music. An analysis of the music and compositional processes of each idiom implementing the ‘de-construct in order to re-construct’ approach to understand how they work musically and compositionally was accomplished. 

To demonstrate the outcome of my models, six original compositions were presented exploring different aspects of musical composition. These models focused on sound architecture and explored a) communicative relationships between composer, performer, and audience b) Holistic Co-hear-ence, implementing the horizontal and vertical layering model, and c) technical approaches using digital technology. To comply with Māori principles of composition and performance, each model and new work demonstrated Kaupapa Māori , Wairua  and Te Mana - Te Ihi - Te Wehi - Te Tapu . 

The findings and original contributions of this research provide a model that combines two musical traditions and three music idioms, and in turn, may guide contemporary composers in creating new works that extend the Kīngitanga music tradition.

text: Tito Waiata-Tito Pūoro: extending the Kīngitanga music tradition. Since 1858, music has always been an integral part of the Kīngitanga movement in New Zealand. As this music tradition evolves with the introduction of new musical idioms, genres and digital technology, so too do the practices of composing new works. 

The objective of this research was to construct a model for combining waiata, taonga pūoro and New Zealand electroacoustic music, in order to create new works that enhance the Kīngitanga music tradition.  Developing a model for composing and integrating these idioms within a Māori context presented problems, as traditional Māori music conflict with contemporary Western forms. 

To generate a framework and practical model for composing hybrid music, an examination of selected New Zealand works was first carried out through: a) the collection of 50 traditional and contemporary waiata relating to the Kīngitanga b) the collection of 10 New Zealand taonga pūoro works and c) a collection of 10 New Zealand electroacoustic music. An analysis of the music and compositional processes of each idiom implementing the ‘de-construct in order to re-construct’ approach to understand how they work musically and compositionally was accomplished. 

To demonstrate the outcome of my models, six original compositions were presented exploring different aspects of musical composition. These models focused on sound architecture and explored a) communicative relationships between composer, performer, and audience b) Holistic Co-hear-ence, implementing the horizontal and vertical layering model, and c) technical approaches using digital technology. To comply with Māori principles of composition and performance, each model and new work demonstrated Kaupapa Māori , Wairua  and Te Mana - Te Ihi - Te Wehi - Te Tapu . 

The findings and original contributions of this research provide a model that combines two musical traditions and three music idioms, and in turn, may guide contemporary composers in creating new works that extend the Kīngitanga music tradition.

year: 2014