Search

Fire retardants, although can impart fire-safety in polymeric composites, are detrimental to the mechanical properties. Biochar can be used, in conjunction with fire retardants, to create a balance between fire-safety and mechanical performance. It is possible to thermally dope fire retardants into the pores of biochar to make it functionalised. Thus, the current work is intended in identifying a composite having the combination of the most desirable fire retardant, bioplastic, and a suitable processing method. A comparison was made between two fire retardants (lanosol and ammonium polyphosphate), bioplastics (wheat gluten and polyamide 11), and composite processing methods (compression and injection moulding). It was found that wheat gluten containing ammonium polyphosphate-doped biochar made by compression moulding had the best fire-safety properties with the lowest peak heat release rate (186 kW/m2), the highest fire performance index (0.6 m2s/kW), and the lowest fire growth index (1.6 kW/ms) with acceptable mechanical properties compared to the corresponding neat bioplastic. Thus, for gluten-based polymers, the use of ammonium polyphosphate thermally doped into biochar processed by compression moulding is recommended to both simultaneously improve fire-safety and conserve the mechanical strength of the resulting biocomposites. Validerad;2023;Nivå 2;2023-06-13 (hanlid)

The use of environmentally friendly materials such as bio-sourced plastics is being driven by increased awareness of environmental issues caused by synthetic plastics. However, bio-sourced plastics have poor fire behaviour that limits their application. The addition of a flame retardant to these plastics is one effective way to increase the fire resistance property; however, the flame retardant should not interfere with the mechanical performance of the plastic. Most flame retardants act as stress concentration points, reducing tensile strength. Hence, to create a balance between tensile strength and fire resistance, biochar (to conserve strength) and lanosol (to improve fire resistance) were added to wheat gluten bioplastic in various ratios and the optimal ratio was identified. Wheat gluten composites were fabricated using compression moulding at four different concentrations of lanosol (2, 4, 6, and 8 wt.%) and biochar (2, 4, 6, and 8 wt.%). From the test results, the composite with 4 wt.% lanosol and 6 wt.% biochar exhibited a good balance between the mechanical and fire properties; it conserved the strength and improved the fire properties (39 % reduction in peak heat release rate).

The physical properties of biocarbon vary widely with the biomass used, and the temperature and duration of pyrolysis. This study identifies the effects of feedstock characteristics and pyrolysis conditions on the production of biocarbon and the corresponding properties for industrial applications. For coffee chaff and soy hulls, ash content and carbon content increased with pyrolysis temperature and duration. Ash content increased thermal conductivity and specific heat, and decreased electrical conductivity. Change in surface area with pyrolysis conditions was dependent on type of feedstock. Increased surface area corresponded with increased thermal and electrical conductivity. Increased carbon content corresponded with increased graphitization and thermal stability and decreased surface functionality. Properties of soy hull biocarbons were found to be similar to the properties of other biocarbons with industrial applications such as incorporation into polymer composites.

"Article ID 463790"

The rarity of orbito-cranial gun shot injury in both war and civilian practice has been reported. In a large series of 351 missile head injuries in the Vietnam war, orbital penetration was noted in 0.6% cases only. Review of literature shows that orbital injury was ipsilateral to the cerebral injury in most reported cases. We have previously reported a rare case of left parieto-occipital lobe injury due to gun shot wound of the contralateral (right) orbit. The case reported here sustained a bullet injury to the left frontal bone but the missile was located below the contralateral (right) optic canal. The rarity of the case prompted this report.

A case of atypical Wilson disease is being reported. Possible mechanism of the process, diagnostic features and CT appearance of brain is described. Early detection and therapy with copper chelating agents result in neurologic and performance improvement of patients.

Three-dimensional (3D) printing technologies have captured the attention of academia and industry for their ability to fabricate functional and complex geometry components. Unlike traditional manufacturing methods, 3D printing can produce complex designs that contain moving parts without the need of a mold or production chain. Fused deposition modelling is one of the most used 3D printing techniques due to its versatility and ability to combine polymers with fillers. In the present research, recycled materials recovered from the ocean and agroindustry waste product (soy hulls) were transformed through extrusion processing to obtain filaments for 3D printing. Filaments of polyethylene and polypropylene, as well as soy hulls, were mixed to make 3D printed products. Furthermore, thermomechanical, and rheological properties of composites were studied. 3D printing parameters were optimized to achieve defect-free printing samples. (i) Ontario Ministry of Economic Development, Job Creation and Trade ORFRE09-078 (ii) Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), University of Guelph, Bioeconomy Industrial Uses Research Program Theme Project (iii) Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grants Project No # 400320 for their financial support. 2022-08-31

The annual world production of plastics is around 300 million tons. From the production, almost 60% corresponds to polyolefins with a major production of polyethylene (60%) and polypropylene (40%). Plastic recycling, to make sustainable materials, is considered one of the biggest initiatives towards the greener environment and socio-economic development. This research was aimed to investigate the effect of the blend of recycled bale wrap linear low-density polyethylene (rLLDPE) and polypropylene (PP) (PP/rLLDPE 50:50 matrix), which was further reinforced with 25 wt.% agave fiber prepared by injection-molded technique. Different ratios of combined maleic anhydride grafted PP/PE (MAPP and MAPE) were used (1-3 wt.%), and further compared with the synthesized compatibilizer made from MAPP/rLLDPE; in terms of mechanical and thermo-mechanical properties of the biocomposites. Incorporating the compatibilizer into the composite improved the interfacial adhesion between hydrophobic matrix and hydrophilic agave fiber; which further increased the mechanical properties and heat deflection temperature of the composite. Scanning electron microscopy showed enhanced compatibility and adhesion between the matrix and the fiber by inclusion of 2 wt.% compatibilizer. Moreover, Fourier transform infrared spectroscopy (FTIR) analysis showed that the compatibilizer improved the interaction between the fiber and the matrix. The optimal compatibilizer content in the biocomposite was found to be 2 wt.% of the matrix. The synthesized compatibilizer blended composite showed improved mechanical properties than the industrial one which indicates the potential application of this composite (around 62% recycled material) in the manufacturing packaging materials and commodity products. (i) the Ontario Research Fund, Research Excellence Program; Round 7 (ORF-RE07) from the Ontario Ministry of Research, Innovation and Science (MRIS) (Project Nos. 052644 and 052665); (ii) the Agriculture and Agri-Food Canada (AAFC) and Competitive Green Technologies, Canada through AgSci Cluster Program (Project No. 054712); (iii) the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph – Bioeconomy for Industrial Uses Research Program (Project #030177); and (iv) the Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grants (Project #400320) 2021-12-17

This thesis involves an investigation on developing biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) based blends, and biocomposites. PHBV is derived from various agricultural carbon sources and was extruded with plasticized cellulose acetate (pCA), to develop a sustainable and biodegradable PHBV/pCA blend. PHBV/pCA blends were found to be immiscible and had reduced mechanical performance and flexibility compared to the individual components. Miscanthus fibre and distillers dried grains with solubles (DDGS) biocomposites of PHBV were developed to ascertain the effect on marine biodegradability. Under ASTM D7991-15, PHBV/Misc (75/25) and PHBV/DDGS (75/25) biocomposites increased the biodegradation rate of PHBV by 24 and 40% respectively. Marine biodegradation of PHBV/DDGS (75/25) composite exceeded cellulose and is 100% marine biodegradable in 260 days, attributed to the presence of cellulosic material and protein promoting microbial growth in DDGS. PHBV/Misc (85/15) and (75/25) had increased tensile/flexural moduli by 55 and 100%, and impact strength of 100%, relative to PHBV. Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grants (Project # 400320); the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) – University of Guelph, the Bioeconomy Industrial Uses Research Program Theme (Project # 030054, 030177, 030255 and 030361); OMAFRA-University of Guelph Gryphon’s Leading to the Accelerated Adoption of Innovative Research (LAAIR) Program (Project # 298635); and the Ontario Research Fund, Research Excellence Program; Round-9 (ORF-RE09) from the Ontario Ministry of Economic Development, Job Creation and Trade, Canada (Project #053970 and # 054345). FedDev Ontario; Ontario Ministry of Agriculture, Food, and Rural affairs (OMAFRA); Canada Foundation for Innovation (CFI); Federal Post-Secondary Institutions Strategic Investment Fund (SIF); and matching funds from the province of Ontario, Bank of Montreal (BMO) and numerous University of Guelph's Alumni. 2021-04-14

Considering a circular economy approach to materials development, this thesis investigates the development of novel and sustainable materials for injection molding and extrusion three-dimensional (3D) printing practices. The objectives, goals and hypotheses are discussed in chapter one. Chapter two combines a comprehensive and critical literature surveys on the benefits of high-performance engineering thermoplastics for 3D printing applications and the use of sustainable fillers like biocarbon in composites applications as well as the implications and challenges with oceanic plastics. The third chapter focuses on the physicochemical and morphological analyzes of biocarbon derived from peanut hulls and their use in biobased engineering thermoplastics, poly(trimethylene terephthalate) for biocomposite application. Following this work, the fourth chapter combines recycled fish net, virgin polymer and compatibilizing agents in melt extrusion. Blends were used in a Taguchi L9 experimental design for large scale extrusion 3D printing. Valorization of waste products from both biomass and recycled polymer has led to the fabrication of novel, renewable and sustainable polymeric materials for 3D printing and injection molding purposes which aligns with the circular economic approach for sustainable products design and fabrication. For the study pertaining to fabrication of sustainable biocomposites from peanut hull biocarbon and poly(trimethylene terephthalate: I am very grateful for the support of i) Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph – Bioeconomy for Industrial Uses Research Program Theme (Project # 030332); ii) Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grants Project # 400320 and 401111; iii) the Ontario Research Fund, Research Excellence Program; Round-7 (ORF-RE07) from the Ontario Ministry of Research, Innovation and Science (MRIS) (Project # 052644 and 052665). A special thanks to in-kind support of Picard Foods Partnership (795 Old Hwy 24, Waterford, Ontario). For all work completed with extrusion 3D printing, I am also very thankful for the financial support from: (i) Ontario Ministry of Economic Development, Job Creation and Trade ORF-RE09-078 (Project # 053970); (ii) the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), University of Guelph, Bioeconomy Industrial Uses Research Program Theme (Project # 030252 and 030485); and the (iii) Natural Sciences and Engineering Research Council (NSERC) Canada Discovery Grants Project #400320. My research has also benefited from the facility funding to the Bioproducts Discovery and Development Centre supported by FedDev Ontario; Ontario Ministry of Agriculture, Food, and Rural affairs (OMAFRA); Canada Foundation for Innovation (CFI); Federal Post-Secondary Institutions Strategic Investment Fund (SIF); and matching funds from the province of Ontario, Bank of Montreal (BMO) and numerous University of Guelph's Alumni. 2022-08-06

The use of biomass as a feedstock to produce biofuels, biochemicals and bioproducts is becoming more common as growth in the biorefinery sector continues. The bioeconomy seeks to optimize all products in a manufacturing process such as the biobased carbon produced during pyrolysis. Currently biocarbon lacks valuable applications, restricting its potential in the bioeconomy. By using this material in the production of biocomposites, the project targeted the biobased carbon for higher-value and more novel applications. Poly(lactic acid) (PLA), is being investigated as a component of polymeric matrices for the biocomposites as it is the most prominent biobased and biodegradable thermoplastic polymer in use today. According to recent literature, biocarbon filler can act as a reinforcement within the polymer matrix enhancing performance. By developing this suitable composite system which has a high degree of biobased content or is readily compostable and performs similarly in relation to current commodity plastics, there are advantages of creating more environmentally friendly materials. To evaluate this hypothesis, multiple trials with variation in the blend and filler morphology and interfacial interactions were examined. Several other tests looked at the effect of hybrid fillers or compatibilization with multiple polymer constituents to determine the differences according to mechanical, thermal and morphological properties. Additional studies with engineering plastics including poly(ethylene terephthalate) (PET), and poly(trimethylene terephthalate) (PTT), and ways in which to enhance toughening and increase sustainable content through recycled addition and biobased material was examined. Characterization of the biocomposites was conducted with the aid of optical microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy for interfacial analysis, while tensile, flexural and impact strength was measured following ASTM standards. Thermal characteristics of the biocomposites was tested using other equipment such as differential scanning calorimetry, dynamic mechanical analysis and thermogravimetric analysis machines. The focus of the project was to ascertain suitable biocomposite options and formulations that have a balanced performance viable for industrial use in various applications. This in turn can assist biofuel companies in using the biobased carbon more readily and increase the knowledge discovery. FedDev Ontario; Ontario Ministry of Agriculture, Food and Rural Affairs; Canada Foundation for Innovation; Federal Post-Secondary Institutions Strategic Investment Fund; Province of Ontario; University of Guelph Alumni; Competitive Green Technologies 2020-11-19

This thesis aims to explore ways of improving the social, economic and environmental sustainability of biobased fibers. Specifically, the first paper aimed to lower the cost of bacterial nanocellulose (BNC) production by recycling bacteria via subcultures and determining the maximum number of viable subcultures that could be inoculated. It was found that the bacteria Komagateibacter xylinus was viable (gcellulose / Lgrowth media) for a maximum of four subcultures with a 1:25 000 v/v transfer ratio. Recycling cultures of cellulose-producing bacteria makes BNC more cost competitive as a polymer. The streamlined steps to process bacterial nanocellulose (BNC) as reinforcement for poly(lactic acid) (PLA) was proposed. This straightforward process uses less steps as compared to the traditional process. The X-ray diffraction (XRD) revealed that sodium carbonate may be acting as a compatibilizer in the BNC/PLA films aiding the dispersion of BNC in the PLA matrix. The mechanical properties and water vapor transmission rate (WVTR) of the BNC/PLA were improved as compared to neat PLA film and CNF/PLA composites. More work needs to be done throughout society to make the bioeconomy a reality.

Engineered thermoplastic blends were fabricated using PA6 and poly (butylene terephthalate) (PBT) and, upon optimization, they were reinforced with biocarbon and other conventional fillers. A twin-screw extruder and injection molder were used to produce the blends compatibilized blends, and biocomposites. Analyses of the materials were completed through mechanical and thermal tests while the viscoelastic behaviour was investigated via dynamic mechanical analysis. Fourier transform infrared spectroscopy and nuclear magnetic resonance was also performed to understand the effect of blending PBT with PA6. Following optimization of the PA6 and PBT blends, a maleic anhydride grafted polyamide 11 compatibilizer was designed in order to increase the compatibility. Comparison of thermo-oxidative aging on a new emerging and sustainable filler was carried out against fillers used in the automotive industry. The thermal degradation of the different fillers was investigated under accelerated heat aging for 1000 h at 140 °C. The composite’s performances, before and after heat aging, were evaluated using mechanical and thermal tests. We gratefully acknowledge the financial support of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/ University of Guelph - Bioeconomy for Industrial Research Program Theme Project # 030176; and the Natural Sciences and Engineering Research Council (NSERC), Canada−Discovery Grants Project # 401111. and the Ontario Ministry of Research, Innovation and Science (MRIS) Ontario Research Fund, Research Excellence Program Round-7 (ORF-RE07) (Project # 052644 and 052665) to carry out this research work. Special thanks to Competitive Green technologies from Leamington Ontario, Canada for the pyrolyzed biocarbon samples used in this research.

Biobased polymeric materials, obtained from renewable biomass resources, are seen as a platform which could enable the transition to a more environmentally sustainable economy, by gradually replacing fossil based counterparts. In this context, this thesis investigated the synthesis and usage of a biobased polymeric material, poly(glycerol succinate) (PGS) and its copolyesters, in thermoplastic blend materials synthesis and processing. Upgrading glycerol usage by its value added application in synthesis of materials as proposed in this thesis work is considered as a key step towards enabling oleaginous biomass biorefinery sustainable growth. To compensate for the low stiffness and high toughness of the synthesized polyesters, industrially relevant melt blending techniques were used and the synthesized poly(glycerol succinate) polyesters were melt blended with commercially available biobased thermoplastics poly(lactic acid) (PLA) and poly(butylene succinate) (PBS). The melt blending of these three polymeric materials allowed to achieve thermoplastic blend materials displaying tensile properties and notched Izod impact resistance comparable to petroleum based poly(propylene) and its copolymers. In a first section, synthesis conditions for the polycondensation of glycerol and succinic acid were screened, aiming to produce a toughness increase in PLA by melt blending with PGS. Incorporation of maleic anhydride as comonomer for the synthesis was employed as a tool for the reactive extrusion of PLA and poly(glycerol succinate-co-maleate) (PGSMA) in presence of free radical initiators, which favored the toughening of PLA by addition of PGSMA. In a second section, the reactive extrusion of PLA and PGSMA was investigated and the role of the grafting and crosslinking reactions occurring in the extrusion process was studied. In a third section, the incorporation of PBS to the blend system was evaluated. The addition of PBS allowed for the creation of biobased ternary blend materials with notched Izod impact resistance higher than 100 J/m, while maintaining tensile strength and modulus on the range of 20 – 30 MPa and 1 – 1.9 GPa, respectively. Linear regression models constructed accurately predicted a range of blend compositions were tensile properties and notched Izod impact resistance of the biobased PGSMA/PLA/PBS blend formulated was comparable to petroleum based poly(propylene) and its copolymers. Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)-Chile; Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) – University of Guelph Bioeconomy-industrial uses research program; OMAFRA New Directions Research Program; OMAFRA Gryphon LAAIR Program; Ministry of Economic Development and Innovation (MEDI), Ontario Research Fund - Research Excellence Round 7 program; Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grants; NSERC – Collaborative Research and Development (CRD).

Bio-composites were fabricated using biocarbon to reinforce engineering thermoplastics like polyamide 6 and 6, 10. Twin screw extrusion and injection molding were selected as the fabrication method since it is the most likely and commonly used for commercialization. Analysis of the bio-composites was done through tensile, flexural and impact tests for the mechanical properties. The heat deflection temperatures, glass transition temperatures and thermal stability were performed to demonstrate the thermal properties of the bio-composites. Rheological analysis was also performed to understand the effect of biocarbons on the polyamide. Well dispersed biocarbon particles with good adhesion with the polyamide were noticed after extrusion and injection molding processes. The most significant improvements of the mechanical test performed were the tensile and flexural strengths and moduli of the bio-composite when compared to the neat polyamide. Depending on the biocarbon used, the mechanical behaviors were observed to be different. Using functionalized biocarbons at a biocarbon loading of 20 wt. %, the tensile and flexural strengths were improved by 21 and 31.5 % respectively. However, the impact strength was reduced by 32 %. When un-functionalized biocarbon was used, the reverse was the case; the impact strength was insignificantly different from that of the neat polyamide while the improvements in tensile and flexural strengths were 0 and 21.9 % respectively. The effects of biocarbon on other properties of polyamide were also characterized and results showed that biocarbon acts as an anti-nucleating agent in polyamides and thereby reduces its crystallinity. Fabrication of polyamide bio-composites with up to 40 wt. % biocarbon is possible without any significant thermal degradation effects to the samples. Unlike natural fibers, biocarbons can reduce the water uptake of polyamides. A durability test shows that it has better overall mechanical property retention up to 50 % than talc reinforced polyamide composites. Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) – University of Guelph Product Development and Enhancement through Value Chains Research Theme (Project # 200399), the Natural Sciences and Engineering Research Council of Canada (NSERC) (Project # 401111) and Ontario Research Fund, Research Excellence Program; Round-7 (ORF-RE07) from the Ontario Ministry of Research and Innovation (MRI), currently known as the Ontario Ministry of Research, Innovation and Science (MRIS) (Project # 052644 and # 052665). FedDev Ontario (Project # 050993) and Canada Foundation for Innovation (CFI) (Project # 460214), Bank of Montreal (BMO)

This thesis is an investigation to enhance the efforts of advancing the CO2 based polymer technology and addresses the issue of carbon emission. The target of this study was to utilize poly(propylene carbonate) (PPC), to develop sustainable biopolymer blends and biocomposites for various applications. This thesis is divided into 3 studies: (1) biopolymer blends of PPC with poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), (2) switchgrass surface modification via alkali and bleach treatments, (3) biocomposites from the chosen biopolymer blend and untreated and treated switchgrass. Incorporating PHBV into PPC was capable of improving thermal and mechanical performance with the added bonus of improving the dimensional stability of the material. Surface modification of switchgrass increased the cellulose content and enhanced the surface roughness of the fiber showing promising results for use in composite applications. Enhancement of the mechanical properties for the chosen blend was observed upon the addition of untreated and treated switchgrass into the system.

Use of synthetic plastics derived from petroleum is challenged due to extremely well-known issues of greenhouse gas (GHG) emissions causing climate change. Bioplastics are emerging as a new paradigm, focusing on renewability and sustainability. Replacing the fossil carbon present in plastics and products with renewable carbon allow to reduce the carbon footprint and GHG emissions. Polylactic acid (PLA) is one of the widely studied renewable resource based bioplastic with huge potential to be on a par with synthetic plastics. However, common commercial grades of neat PLA is yet to gain a strong commercial standpoint in applications other than cold food packaging due to its poor toughness and low heat resistance. This thesis demonstrated feasible routes to fabricate PLA based blends and biocomposites with desirable morphology and crystallinity for durable applications. Two promising directions were considered; one based on PLA as a major phase and the other based on PLA as a minor phase. A three step approach was followed while pursuing both research directions. First, binary blends were studied to have a fundamental understanding regarding how the properties of the blends change by varying the blend ratio. Next, a suitable compatibilizer containing a reactive functional group was added to the optimum binary blend to achieve better properties through a reactive extrusion technique. The developed ternary blends showed improvement in toughness depending on the type of functionalized terpolymer. In the third and final step, fabrication of biocomposites and the effect of addition of different fillers, additives, and processing strategies were investigated in an aim to increase the crystallinity and heat resistance. Through a combination of univariate and statistical optimizations, biocomposites containing PLA either as a major or minor phase, having a stiffness-toughness balance and a higher heat resistance were developed. Successful property improvements obtained in the developed materials has so far been unattainable for injection molded PLA biocomposites. Polymer and additive combinations investigated in this thesis are novel. Property attainment elaborated here enriches the existing body of literature concerning PLA based durable materials. (1) the Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA)- University of Guelph Bioeconomy-Industrial Uses Theme (Project # 200245, 200358, 200425); (2) the Ontario Research Fund, Research Excellence Program; Round-7 (ORF-RE07) from the Ontario Ministry of Research and Innovation (MRI), currently known as the Ontario Ministry of Research, Innovation and Science (MRIS) (Project # 052644 and # 052665); (3) the Natural Sciences and Engineering Research Council (NSERC) Canada Discovery Grants (Project # 401111); and the NSERC Network of Centres of Excellence (NCE) AUTO21 Program (Project # 460372 and 460373).

Non-biodegradable polymers, polymer blends and composites are known to persist in the environment over a long time. The use of certain biodegradable polymers is limited as they often fail to match some of the non-biodegradable counterpart perfromances. Blends of biodegradable polymers and composites with complementary attributes can provide materials that strike a balance between cost and performance. This research was focused on the fabrication and performance evaluation of biodegradable polymer blends and composites, as potential alternatives to non-biodegradable polymeric materials. Industrially viable melt processing techniques like extrusion and injection molding were adopted to fabricate and evaluate the structure-property-relationship of biodegradable polymer blends and composites. In this research work, two different types of commercially available biodegradable polyesters, namely poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) were used to fabricate binary blends and composites. Melt blending these two polymers yielded synergistic properties, which are not present in the respective polymers. The optimal PBS/PBAT blend was selected based on its overall performance and it was used as the standard biocomposite matrix. Miscanthus is a purpose grown energy crop and has not been explored much for polymer composite applications. This fiber was used as reinforcing agents in the PBS, PBAT and blend of PBS/PBAT matrix to compare the effects of matrix properties upon the performance of the resulting composites. One important aspect of this study was reactive compatibilization to improve the interfacial adhesion between the miscanthus fibers and polymer matrix. Maleic anhydride grafted polyesters were synthesized as a compatibilizer, which was used to improve the compatibility with the miscanthus fibers and polymer matrices. The improved fiber-to-polymer matrix adhesion exhibited in better mechanical performances of the resulting composites compared to that of uncompatibilized counterparts. The influence of major processing parameters such as processing temperature, screw speed, fiber length, and holding pressure on the mechanical performance were statistically analyzed by factorial design of experiment. The impact strength of the PBS/PBAT/miscanthus fiber composites was significantly dependent on the fiber length. The durability of the biodegradable polymer (PBS, PBAT and PBS/PBAT blend) was investigated after being exposed to elevated temperature (50oC) and humidity (90%) for 30 days. It was found that the mechanical properties of the samples were heavily affected under the selected environmental conditions and exposure time. An optimum biocomposite formulation was successfully extruded and injection molded for continuous prototype manufacturing in pilot-scale production facilities.

In order to develop bioplastic alternative to conventional petro-based flexible packaging, this study focused on the fabrication and evaluation of a bio-based and biodegradable cast film. The material chosen for the matrix of film is a blend of poly(lactic acid) (PLA) and poly(propylene carbonate) (PPC). The effect of a chain extender at different loading levels on the mechanical, thermal and barrier properties of the films were investigated. With the chain extender, the compatibility and interfacial adhesion between the two polymer phases significantly improved. It is hypothesized that a PLA-chain extender-PPC copolymer is being formed during the reactive extrusion process, which was revealed by characterization studies. The elongation at break of the film with optimal amount of chain extender showed dramatic increase by more than 2000%. Differential Scanning Calorimetry (DSC) studies demonstrated that chain extender hindered the crystallization of the film which explained the decrease in both water and oxygen barrier. the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) – University of Guelph’s Bioeconomy for Industrial Uses Research Theme (Project #200369) and Natural Sciences and Engineering Research Council (NSERC) Canada Discovery grant (Project #400322)

Mechanical performance improvement of brittle bioplastic polylactic acid (PLA) was investigated through the use of a novel processing method: co-injection moulding. Co-injection moulding produces layered products with distinct core and skin phases. PLA toughening was attempted via encapsulation in a polycaprolactone (PCL) skin. Select co-injection operating parameters were assessed regarding their ability to influence product morphology. Injection speeds and skin melt temperature were observed to have negative effects on core content and advancement, while core ratio had a positive influence. These results were used to develop samples with up to 60% biobased PLA content. Comparable PLA/PCL blend samples were produced for mechanical testing. Co-injection products had better tensile strength and stiffness compared to similar blends, but the layered structure was less adept at resisting flexural stress. Impact resistance improved with co-injection compared to neat PLA. Co-injection was identified as a functional bioplastics processing method which results in unique mechanical behaviour. Natural Sciences and Engineering Research Council (NSERC), (Canada) through the Discovery Grants Program (PI: Mohanty); Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA); Canada Foundation for Innovation (CFI) - Leaders Opportunity Fund (LOF)

Biodegradable polymers, such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL), have been shown to be effective in solving many end of life issues with certain current commodity plastics. Lignin has received attention in biomaterials and chemical applications due to its favorable polyphenolic structure and large quantity of available functional groups. Blends of bioplastic and lignin have been prepared through extrusion and injection molding. These processing techniques have been adopted to manufacture test samples for performance evaluations. Effects of lignin content as well as bioplastics in blend formulations have been studied for their tensile, flexural, impact, and thermomechanical properties. Through rheological studies, the processing aspects of the blend systems in presence of ENR were evaluated. The morphologies of select formulations were studied through scanning electron microscopy. In order to improve the impact performance of the blends, the effects of several concentrations of epoxidized natural rubber (ENR) on the resulting blend were studied. National Sciences and Engineering Research Council Lignoworks Strategic Network

In recent years, the expansion of the corn ethanol industry has generated surplus amounts of solid coproducts mainly in the form of dried distillers’ grains with solubles (DDGS). In order to help economic viability and sustainability of the industry, research is being conducted to find new, more profitable applications for this coproduct besides its traditional usage as animal feed. In the present project, the capabilities of DDGS are evaluated for using as a filler and/or reinforcement in producing green biocomposites with a number of bioplastics. The bioplastics used here are partially originated from renewable resources with end-life biodegradability in compost conditions. The focus of this research is to design and engineer material formulations with balanced performance. Extrusion and injection molding techniques have been employed to produce the biocomposites and the performance of the produced materials was evaluated through several mechanical, thermomechanical and physical properties. The discussions are augmented with thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results are conclusive in that DDGS is a better filler for polymeric biocomposites when it undergoes a water treatment before processing with polymer melts. The treated DDGS shows a thermal degradation rate four times less than as-received DDGS at 180 °C, the processing temperature of the composite materials. The DDGS biocomposites are produced with a range of biodegradable plastics and the effect of a polymeric isocyanate compatibilizer is evaluated. The compatibilizer improves the interfacial adhesion between DDGS particles and the polymeric matrix, as evidenced by SEM, and thus, enhances the strength and modulus; however, reduces the impact strength. A high-impact DDGS biocomposite is produced using a combination of compatibilizer and lubricant as additives. The optimization of the material’s formulation is approached statistically based on a full factorial design of experiment (DOE) for additive amounts, followed by a response surface methodology (RSM) for mechanical and physical properties. With this approach, biocomposites of DDGS and bioplastics are successfully designed which exhibit acceptable performance such as tensile strength of more than 20 MPa, flexural modulus of more than 1 GPa, impact strength of more than 100 J/m and melt flow index of more than 5 g/10min.

Various commodity plastics used today are based on fossil fuels. Most of these plastics are non-biodegradable and will persist in the environment over a long time. The bioplastics from renewable resources have the potential to support a greener economy. The two of such renewably resourced bioplastics are poly (hydroxyl butyrate-co-valerate), PHBV and poly (butylene succinate), PBS. We have used petro-based PBS in our study, but renewable resource based PBS is expected to be available on a commercial scale in a very near future. These two bioplastics are both biodegradable. These two bioplastics are both biodegradable. In our study we have used PBS from petroleum resource but PHBV is a brittle bioplastic with a high modulus value and a low elongation at break while PBS is a low modulus bioplastic with a high elongation at break. Complementary properties can be obtained by blending PHBV and PBS. The direct melt blends showed poor mechanical properties due to limited interaction between PHBV and PBS phases. This research focuses on increasing the interaction between PHBV and PBS blends by using compatibilizers. The compatibilizers used in this thesis were dicumyl peroxide, DCP and trimethylolpropane triacrylate, TMPTA. Use of an in situ compatibilization method was done for the melt mixing of PHBV and PBS yielding blends with improved characteristics. The investigations were performed at three different ratios of PHBV and PBS blends. The increase in the compatibility between the two phases was demonstrated through various thermal, thermo-mechanical, rheological and morphological means. The increase in elongation at break was used as a primary marker for compatibilization. The optimization of DCP and TMPTA was carried out, which showed the enhanced interaction between PHBV and PBS phases, with the successful stress transfer from PHBV phase to the PBS phase resulting in increase in elongation at break. Inward shifts in tan delta peak on addition of DCP and TMPTA to the blends also showed increase in compatibility between the two phases. The interfacial adhesion between a brittle and ductile polymer, PHBV and PBS respectively was increased by using DCP and TMPTA. This opened gateways to various novel applications of PHBV and PBS blends via in situ reactive extrusion process. The Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA) for their financial support via New directions research program (SR9235). We would also like to thank Canadian Foundation for Innovation (CFI) and Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA) for their equipment supports.

This study involves the fabrication and performance evaluation of injection molded biomass based biocomposites. The matrix material chosen for this study was a preblend of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly (butylene adipate-co-terephthalate) (PBAT). In the first part of the study, the effect of incorporation of switchgrass at loading levels of 20 to 40 wt% was investigated. The hydrophobic-hydrophilic disparity between the matrix and fiber was solved by the addition of compatibilizer, poly diphenylmethane diisocyanate (pMDI). Loading levels of pMDI at 0.5, 0.75 and 1 parts per hundred (phr) were investigated. (PHBV-PBAT) matrix with 30 wt% switchgrass compatibilized by 0.75 phr pMDI resulted in the highest tensile properties and heat deflection temperature. In a second part, the potential of various biomass fibers including agricultural residues like soy stalk, corn stalk, wheat straw and other perennial grasses like miscanthus were explored as reinforcing filler for (PHBV-PBAT) at 30 wt% fiber loading. All the composites using different fiber types exhibited improved modulus performance and showed significant increase in heat deflection temperature (HDT). This study has revealed prospects for hybrid composite fabrication to further enhance the performance of the composites. Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), New Directions Research Program (SR9211) and OMAFRA Highly Qualified Personal (HQP) Scholarship program

Soy meal, a coproduct of the soy oil-based biodiesel industry, has up to 50 wt% protein content. The main aim of this work was to develop value-added application for soy meal by blending with biopolymers. The chosen biopolymers were poly(butylenes adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA). This study is divided into two parts: the first part explained the plasticization of soy meal and modification of soy meal by denaturation. Characterization by Fourier transform infrared (FTIR) spectroscopy confirmed that the soy meal was plasticized and denatured. This part also discussed the fabrication, testing and characterization of blends of PBAT/soy meal (SM), PBAT/plasticized soy meal (PSM) and PBAT/modified plasticized soy meal (mPSM). The elongation at break of the bioblend was found to increase after plasticization of soy meal, and improved furthermore after denaturation while the tensile strength remained the same. Scanning electron microscope (SEM) images showed that the blends PBAT/mPSM had smoother surfaces and better internal structures than the other two. The second part of the study investigated the properties of mPSM blended with PBAT and PLA at varying ratios. The results revealed that with an increase in PLA content, the tensile strength improved, but the elongation of the blend reduced. No phase separations between PBAT and PLA were observed in the SEM pictures of the ternary blends, indicating limited miscibility between PBAT and PLA. Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA) (Project Title: “New Value-Added Biomaterials from Waste Streams of Biodiesel Industries and Polylactides (PLA)”; Project NO.: SR9223 TF#049549), Hannam Soybean Utilization Fund (HSUF)

Commercial cultivation of switchgrass in Ontario is limited mainly due to inadequate market opportunities. However, recent developments in bioproducts identify switchgrass as a promising biomass crop for bioenergy and biomaterials applications. At present assessment of environmental impact of growing switchgrass in Ontario is lacking. Therefore, this study was conducted to evaluate the energy use and environmental impacts of switchgrass biomass production in Ontario through life cycle assessment. Cradle to farm gate life cycle assessment was conducted following the ISO 14040/14044 guidelines. Life cycle inventory data were collected from farmers, experts and available literature. Life cycle impact assessment was conducted for energy use and environmental impact using the SimaPro software. Life cycle processes related to fertilization, harvesting and soil N emission were identified as major hot spots for energy and environmental impacts. Improving efficiency of energy, inputs and biomass yield will reduce the environmental burden associated with growing switchgrass in Ontario. OMAFRA- UofG Highly Qualified schlorship programme and OMAFRA- UofG Partnership bioeconomy industrial uses reaserch theme project funding.

Processing parameters such as extrusion screw rotation and cooling were analyzed in this research with blends of plasticized soy protein Isolate (PSPI) and poly(butylene succinate) (PBS). The goal was to develop more efficient ways of processing soy protein based bioplastics in standardized equipment so that they can be utilized to their full potential when processed on a large scale. The study was divided into two parts: (1) Analyzing extrusion processing's counter-rotation (CTR) and co-rotation (CR) blending techniques and determining which allowed for enhanced destructurization and mixing of the two materials; (2) Understanding how soy protein and biopolymer based films respond to slow (air) and fast (water) cooling techniques using DSM micro-compound extrusion and compression film processing (CFP). Overall, CTR extrusion provided enhanced interfacial adhesion, tensile elongation (~40% higher for PSPI-CTR material & -55% higher for PBS: PSPI-CTR (70:30) blends) and prolonged onset (Tonset) and end (T end) thermal degradation temperatures (CTR blend ~10°C > CR blends). The second studied demonstrated that the slowly cooled nature of the DSM films (~30C/min) showed higher percent crystallinity and storage modulus for both CTR and CR processed blends, compared to their CFP (fast cooling) counterparts. The tensile strain for the DSM film was also 9.9% higher than those of the CPF counterpart.

Soy fibre and soybean oil were utilized to produce a bio-composite targeted as a substitute for conventional petroleum-based materials. The study was divided into two parts; the first was the development of a bio-epoxy that consisted of conventional epoxy, epoxidized soybean oil, and two types of functionalized POSS. The second part of the study involved blending of the bio-epoxy with titanate treated soy fibre. Combined incorporation of epoxide and amine functionalized POSS in the bio-epoxy matrix resulted in a 29% impact strength improvement compared to the petroleum-based epoxy. Incorporation of the epoxide functionalized POSS resulted in improvements in tensile strength by 8%, tensile modulus by 2%, and an increase in the glass transition temperature by 4% compared to the petroleum-based epoxy and epoxidized soybean oil hybrid. The coupling of titanate to soy fibre in comparison to the soy fibre without titanate treatment resulted in an impact strength improvement of 37%. Furthermore, the coupling of titanate increased the tensile strength and tensile modulus by 24% and 22% respectively, and reduced the water absorption by 70%.