title: The Effect of Moisture Content and Extrusion Temperature on the Processing, Thermal and Mechanical Properties of Novatein®

authors: Izuchukwu, Sandra C.P.

subjects: Effect of processing on Novatein

abstract: The recent effect of petroleum based synthetic plastic on economy and environment has led to ever increasing study of renewable natural polymers such as proteins. Novatein Thermoplastic (NTP) is a protein based thermoplastic processed from bloodmeal. Bloodmeal is a by-product of the animal slaughter house and it is widely sold and used as low cost fertilizer and animal feed. It contains 90% dry weight of protein and it can biodegrade under suitable conditions making it a better alternative to petroleum based synthetic plastics. The objective of this thesis was to investigate the effect of processing water and extrusion temperature on the processing, thermal and mechanical properties of urea free NTP to optimize processing temperature and formulation for this material.
Literature revealed that extrusion processing of protein applies considerable amount of heat and shear into protein material to form polymer melt requiring sufficient chain mobility which could be achieved through the lowering of the glass transition temperature (Tg) of protein with the addition of water and other additives. Also literature revealed that optimization of material properties of protein thermoplastic is highly dependent on extrusion processing parameters such as extrusion temperature, initial moisture content (processing water), torque, pressure, screw-speed and specific mechanical energy (SME).
Four formulations of Novatein were processed using bloodmeal powder with Sodium Sulfite (SS), Sodium Dodecyl Sulfate (SDS), Tri ethylene glycol (TEG) and varying Water content at 30, 35, 40 and 45pphBM. The resultant thermoplastic was extruded using varying die temperatures of 120 °C, 130 °C, 140 °C and 150 °C. Test pieces were produced using injection moulding and conditioned for 7days
The effect of processing water and extrusion temperature was characterized by
•	Extrusion Processing, processing water between 30 to 35pphBM produced consolidated material because of protein chain unravelling and above this water content, material produced was mostly not consolidated due to irregularities in measured torque and pressure as a result of inconsistent feed-rate which is caused by excessive plasticization of the material.
•	Moisture Content, after conditioning assumed water content measured at oven drying ranged between 4% to 15% with 9 out of the 16 experiments falling within the accepted narrower range of 8% to 11%. The remaining 7, all experiment in formulation 4 had higher moisture content than the acceptable range and all experiment extruded at die temperature of 150 °C had lower moisture content than the acceptable range.
•	Mechanical properties, water was shown to be critical for processing as it    acted as plasticizer lowering the glass transition temperature (Tg) and denaturing temperature of the protein material. During conditioning moisture was lost resulting to a brittle material because of the new interaction between the protein chains after conditioning. There was no clear trend when considering the effect of extrusion die temperatures used on the mechanical properties of Novatein.
•	DMA, increasing processing water decreased Tg while increasing temperature, the 9 experiment with the acceptable range, at 30pphBM showed increase in Tg and at 35 and 40pphBM no increase was observed, the 7 experiments outside the acceptable narrower range showed no significant difference in Tg within their range. There was an insignificant difference in Tg when considering the effect of added water and processing temperature therefore the difference is as a result of water remaining in the sample when they were tested.
•	TGA, showed varying residual moisture content as after freeze drying and milling the mass loss observed varied between 3% to 17% for all experiments which could be as a result of samples not freeze dried to the same extent or protein absorbing water from the atmosphere during milling because of its hygroscopic nature. There is an insignificant difference in moisture content after conditioning and subsequent freeze drying. There is no effect on the decomposition behaviour and thermal stability of Novatein within the range of processing water and extrusion temperature used as there was an insignificant difference observed in the TGA thermograms after freeze drying and milling.
•	WAXS, crystallinity of the tested formulation ranged from 15% to 27% where most were within the range of 19% and 22% which fell within the reported crystallinity range of Novatein from previous study demonstrating that the range obtained was the appropriate range for NTP therefore no change in crystallinity was observed.
The optimal processing temperature and formulation was achieved using 35pphBM water and extrusion die temperature of 150 °C (experiment 8). It showed ease of processing, having good mechanical properties. Before conditioning it had tensile strength of 5.35MPa, Young’s modulus of 253MPa, strain at break of 0.34mm/mm, toughness of 1.61Mpa and after conditioning it had tensile strength of 17.49MPa, Young’s modulus of 1101MPa, strain at break of 0.02mm/mm and toughness of 0.18MPa. Thermal property showed no significant difference therefore there is no change in thermal property of Novatein with this optimal processing temperature and formulation.

text: The Effect of Moisture Content and Extrusion Temperature on the Processing, Thermal and Mechanical Properties of Novatein® The recent effect of petroleum based synthetic plastic on economy and environment has led to ever increasing study of renewable natural polymers such as proteins. Novatein Thermoplastic (NTP) is a protein based thermoplastic processed from bloodmeal. Bloodmeal is a by-product of the animal slaughter house and it is widely sold and used as low cost fertilizer and animal feed. It contains 90% dry weight of protein and it can biodegrade under suitable conditions making it a better alternative to petroleum based synthetic plastics. The objective of this thesis was to investigate the effect of processing water and extrusion temperature on the processing, thermal and mechanical properties of urea free NTP to optimize processing temperature and formulation for this material.
Literature revealed that extrusion processing of protein applies considerable amount of heat and shear into protein material to form polymer melt requiring sufficient chain mobility which could be achieved through the lowering of the glass transition temperature (Tg) of protein with the addition of water and other additives. Also literature revealed that optimization of material properties of protein thermoplastic is highly dependent on extrusion processing parameters such as extrusion temperature, initial moisture content (processing water), torque, pressure, screw-speed and specific mechanical energy (SME).
Four formulations of Novatein were processed using bloodmeal powder with Sodium Sulfite (SS), Sodium Dodecyl Sulfate (SDS), Tri ethylene glycol (TEG) and varying Water content at 30, 35, 40 and 45pphBM. The resultant thermoplastic was extruded using varying die temperatures of 120 °C, 130 °C, 140 °C and 150 °C. Test pieces were produced using injection moulding and conditioned for 7days
The effect of processing water and extrusion temperature was characterized by
•	Extrusion Processing, processing water between 30 to 35pphBM produced consolidated material because of protein chain unravelling and above this water content, material produced was mostly not consolidated due to irregularities in measured torque and pressure as a result of inconsistent feed-rate which is caused by excessive plasticization of the material.
•	Moisture Content, after conditioning assumed water content measured at oven drying ranged between 4% to 15% with 9 out of the 16 experiments falling within the accepted narrower range of 8% to 11%. The remaining 7, all experiment in formulation 4 had higher moisture content than the acceptable range and all experiment extruded at die temperature of 150 °C had lower moisture content than the acceptable range.
•	Mechanical properties, water was shown to be critical for processing as it    acted as plasticizer lowering the glass transition temperature (Tg) and denaturing temperature of the protein material. During conditioning moisture was lost resulting to a brittle material because of the new interaction between the protein chains after conditioning. There was no clear trend when considering the effect of extrusion die temperatures used on the mechanical properties of Novatein.
•	DMA, increasing processing water decreased Tg while increasing temperature, the 9 experiment with the acceptable range, at 30pphBM showed increase in Tg and at 35 and 40pphBM no increase was observed, the 7 experiments outside the acceptable narrower range showed no significant difference in Tg within their range. There was an insignificant difference in Tg when considering the effect of added water and processing temperature therefore the difference is as a result of water remaining in the sample when they were tested.
•	TGA, showed varying residual moisture content as after freeze drying and milling the mass loss observed varied between 3% to 17% for all experiments which could be as a result of samples not freeze dried to the same extent or protein absorbing water from the atmosphere during milling because of its hygroscopic nature. There is an insignificant difference in moisture content after conditioning and subsequent freeze drying. There is no effect on the decomposition behaviour and thermal stability of Novatein within the range of processing water and extrusion temperature used as there was an insignificant difference observed in the TGA thermograms after freeze drying and milling.
•	WAXS, crystallinity of the tested formulation ranged from 15% to 27% where most were within the range of 19% and 22% which fell within the reported crystallinity range of Novatein from previous study demonstrating that the range obtained was the appropriate range for NTP therefore no change in crystallinity was observed.
The optimal processing temperature and formulation was achieved using 35pphBM water and extrusion die temperature of 150 °C (experiment 8). It showed ease of processing, having good mechanical properties. Before conditioning it had tensile strength of 5.35MPa, Young’s modulus of 253MPa, strain at break of 0.34mm/mm, toughness of 1.61Mpa and after conditioning it had tensile strength of 17.49MPa, Young’s modulus of 1101MPa, strain at break of 0.02mm/mm and toughness of 0.18MPa. Thermal property showed no significant difference therefore there is no change in thermal property of Novatein with this optimal processing temperature and formulation.

year: 2015

title: Practice Makes the Difference: The Effect of Rate-Building and Rate-Controlled Practice on Retention

authors: McGregor, Susan Jennifer

subjects: Pecision Teaching

abstract: Six home-schooled students and one adult participant each initially practiced to accuracy two decks of five previously unknown multiplication facts. The decks were yoked for practice and reinforcement. Once accurate performance was achieved, overpractice was undertaken using custom computer software that allowed either fast (free-operant) or rate controlled responding. Rate-building practice, to an established fluency performance standard, was used with one deck while practice with the other deck was rate-controlled.  The number of times a fact was practiced was the same for both methods. Response rate and accuracy was assessed after training to accuracy, at the end of overpractice and after 4  and 8-weeks of no practice. The assessment at the end of rate-building confirmed that rate building resulted in fast and accurate responding. It also confirmed that, for the rate controlled facts, response rates did not meet the fluency performance standard. However, the 4- and 8-week retention assessments showed no consistent differences in accuracy or response rate between the rate-controlled and rate built decks. After 8 weeks without practice, performance on the rate-built deck was not significantly different to that prior to rate building. These results suggest that practice to fluency does not lead to superior retention when compared to the same amount of rate-controlled practice. The results also indicate that when a skill is practiced to fluency, a period without practice leads to deterioration, to pre-rate-building levels, of accuracy and response rate. This study highlights the need for research examining the role of maintenance in the effectiveness of fluency based learning like Precision Teaching.

text: Practice Makes the Difference: The Effect of Rate-Building and Rate-Controlled Practice on Retention Six home-schooled students and one adult participant each initially practiced to accuracy two decks of five previously unknown multiplication facts. The decks were yoked for practice and reinforcement. Once accurate performance was achieved, overpractice was undertaken using custom computer software that allowed either fast (free-operant) or rate controlled responding. Rate-building practice, to an established fluency performance standard, was used with one deck while practice with the other deck was rate-controlled.  The number of times a fact was practiced was the same for both methods. Response rate and accuracy was assessed after training to accuracy, at the end of overpractice and after 4  and 8-weeks of no practice. The assessment at the end of rate-building confirmed that rate building resulted in fast and accurate responding. It also confirmed that, for the rate controlled facts, response rates did not meet the fluency performance standard. However, the 4- and 8-week retention assessments showed no consistent differences in accuracy or response rate between the rate-controlled and rate built decks. After 8 weeks without practice, performance on the rate-built deck was not significantly different to that prior to rate building. These results suggest that practice to fluency does not lead to superior retention when compared to the same amount of rate-controlled practice. The results also indicate that when a skill is practiced to fluency, a period without practice leads to deterioration, to pre-rate-building levels, of accuracy and response rate. This study highlights the need for research examining the role of maintenance in the effectiveness of fluency based learning like Precision Teaching.

year: 2006

title: An evaluation of the Raukawa Health Services Kaumatua Mirimiri Programme

authors: Gregg, Lisa

subjects: Maori

abstract: The Kaumatua Mirimiri Programme was funded as a Service to Improve Access project under a contract which ran from 1st September 2004 to 30th June 2005. Its aim was to provide a “culturally based treatment and recovery programme to restore the health and independence” of people aged 40 years and over (Pinnacle Group Ltd, 2004a, p.1). However, as the service specification in the contract made clear, the programme was not designed be exclusive: it has attracted younger as well as older people, non-Māori as well as Māori, and people seeking help for a wide range of ailments and pain.

text: An evaluation of the Raukawa Health Services Kaumatua Mirimiri Programme The Kaumatua Mirimiri Programme was funded as a Service to Improve Access project under a contract which ran from 1st September 2004 to 30th June 2005. Its aim was to provide a “culturally based treatment and recovery programme to restore the health and independence” of people aged 40 years and over (Pinnacle Group Ltd, 2004a, p.1). However, as the service specification in the contract made clear, the programme was not designed be exclusive: it has attracted younger as well as older people, non-Māori as well as Māori, and people seeking help for a wide range of ailments and pain.

year: 2006-03