Bioplastics are emerging as most promising materials to replace oil based thermoplastics particularly in packaging. Bioplastics can mitigate and address concerns about the negative role of plastics in the environment creating pollution and depleting resources hence bioplastics can enable an innovative approach toward addressing these issues. However, manufacturing of bioplastic is still costly and their mechanical and thermal properties require extensive development. Therefore there has been substantial interest to improve processing and properties of bioplastics to diminish the environmental impacts caused by continuous use of synthetic polymers of petroleum origin. In this research, Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV and Polybutylene succinate (PBS) composites and blends were developed to improve the properties of PHBV as the matrix polymer and hence produce a novel formulation for product development. Three approaches were studied in this work:  The effect of talcum powder as a nucleating agent and reinforcing filler.  The effect of oligomer chain extenders on miscibility, crystallinity, thermal and thermomechanical, mechanical and morphological properties of PHBV/PBS blends.  The effect of acrylic core-shell impact modifier on crystallinity, thermal and thermomechanical, mechanical and morphological properties of PHBV were also evaluated. All the above scientific approaches have been studied. It was noticed that talc can change the sluggish crystallinity of PHBV. Talc enhances nucleation of PHBV in the composites which leads to a faster crystallization rate. The heat distortion temperature, crystallinity and the modulus of PHBV/talc composite were also increased. In the presence of the chain extender (CE) the miscibility conditions of PHBV/PBS blends were changed. The results were supported by calculation of the activation energies. The elongation at break and tensile strength of PHBV/PBS/Chain extender blends increased indicating miscibility change. The possible reaction mechanism between PHBV, PBS and CE are proposed and the results supported by using FTIR. Immiscibility results of the PHBV/PBS blends are supported by SEM images. Addition of the impact modifier to PHBV reduced the crystallization rate and prolonged crystallization time. It has been found that the shell of impact modifier (PMMA) is partially miscible with PHBV. The absorbed impact energy is improved by the impact modifier but the improvement was not as satisfactory as results noted for PLA. The SEM images showed the average fine dispersion of different sized particles inside the matrix.

Neste trabalho foi estudado o processo de tenacificação do poli(ácido lático), PLA, através da produção de blenda com terpolímero randômico (etileno/éster acrílico/glicidil metacrilato), EMA-GMA, como modificador de impacto. Três composições foram estudadas, 90/10, 80/20 e 70/30% em massa, as misturas foram homogeneizadas em extrusora dupla-rosca (melt blending) e corpos de prova foram moldados por injeção. A avaliação do comportamento mecânico e da eficiência da tenacificação foi realizada através de ensaios mecânicos de tração (ATSM D638), resistência ao impacto Izod com entalhe (ASTM D256), flexão (ASTM D790) e dureza Shore D (ASTM 2240). A presença de umidade e a temperatura de degradação foram avaliadas por análise termogravimétrica (TGA), as temperaturas de transição vítrea (Tg), fusão cristalina (Tm) e grau de cristalinidade foram avaliadas por calorimetria exploratória diferencial (DSC) e a morfologia foi analisada por meio de micrografias obtidas por microscopia eletrônica de varredura (MEV). Os resultados dos ensaios mecânicos idicaram que todas as blendas possuem valores de tenacidade superiores ao do PLA. Entretanto, as blendas apresentaram como efeito colateral queda em módulo (obtidos por ensaios de resistência a tração e flexão), resistência a tração no ponto de escoamento e dureza, em função do aumento da concentração de EMA-GMA no PLA. Na composição com 20% de EMA-GMA a distribuição da dispersa ao longo da fase matriz está mais homogênea, e a composição com 30% de EMA-GMA resultou em um material super tenaz (com valores de resistência ao impacto Izod com entalhe acima de 500J/m). / In this work poly(lactic acid), PLA, was toughened by addition a thermoplastic elastomer, the random terpolymer (ethylene / acrylic ester / glycidyl methacrylate), EMA-GMA. Three= compositions were prepared: with concentrations of 10, 20 and 30 wt% of EMA-GMA into PLA. The blends were prepared in a twin-screw extruder and molded by injection molding. The samples were systematically characterized by tensile strength, notched Izod impact strength, flexural properties and Shore hardness (using Shore D scale). The presence of moisture and the degradation temperature of PLA were evaluated by thermogravimetric analysis (TGA), the glass transition temperature (Tg), crystalline melting (Tm) and crystallinity index of PLA and of the blend were evaluated by differential scanning calorimetry (DSC) and the blend morphology was analyzed by scanning electron microscopy (SEM). The results showed that all blends presented a dramatic increase in their toughness, when compared to PLA. However, the moduli (obtained by tensile and flexural tests), tensile strength at yield, and hardness decreased when the dispersed phase content increased. In the 80/20 PLA/EMA-GMA blend, the dispersed phase is more homogeneously dispersed within the matrix, and the composition with 30 wt% of EMA-GMA resulted in a super tough material (notched Izod impact strength exceeding 500 J/m).

PA 66 nanocomposites and PA 66 blends were prepared using Cloisite 15A, Cloisite 25A and Cloisite 30B as organoclays and Lotader 2210 (E-BA-MAH), Lotader AX8840 (E-GMA) and Lotader AX8900 (E-MA-GMA) as impact modifiers. The effects of the composition, types of the components and the addition order of the nanocomposites on the morphology, mechanical, flow and thermal properties were investigated. Melt compounding step was carried out twice in a co-rotating twin-screw extruder. This was called as All-S mixing sequence when all the components were melt mixed, simultaneously. The concentration of the elastomer was determined as 5 wt% and the organoclay as 2 wt% to minimize agglomeration of the organoclay and decrease in the mechanical properties. The components which exhibited the best mechanical results and organoclay delamination in All-S mixing sequences were compounded by using different addition orders. Substantial increases were not observed in the tensile, impact, flexural and hardness test results of the nanocomposites compared to the polymer matrix that was twice extruded. Addition order of the components affected the properties of the nanocomposites and dispersion of the elastomeric domains and the organoclay. The best mechanical test results were obtained for All-S mixing sequence of (PA 66-15A-2210). The degree of organoclay dispersion is better in Cloisite 15A and Cloisite 25A containing nanocomposites than the ones which have Cloisite 30B. Low melt flow index values aided dispersion of the organoclay whereas the slight changes in the crystallinity did not significantly contribute to the changes in the mechanical properties of the nanocomposites or the blends.

Polystyrene, PS, is a preferable polymer in industry, but, its brittle characteristic restricts its utilization. The aim of this study is to improve the impact strength of PS by the help of elastomeric materials SEBS-g-MA and E-BA-GMA. In order to prevent the reduction in the tensile strength of the materials, three different types of organic montmorillonites, MMT, (Cloisite&reg / 30B, 25A and 15A) were used as fillers. Nanocomposite preparation was performed in a co-rotating twin screw extruder. Initially elastomer and organoclay contents were kept at 5wt% and 1-2wt% respectively. Well dispersed silicate layers were obtained for the nanocomposite containing SEBS-g-MA and Cloisite&reg / 25A owing to the high viscosity of SEBS-g-MA and the solubility of polystyrene end block of SEBS with PS matrix. Owing to higher hydrophobicity of Cloisite&reg / 15A a better dispersion was expected compared to Cloisite&reg / 25A, but, it was concluded that two long aliphatic tails of Cloisite&reg / 15A limited the access of polymer chains to the clay surface. The desired impact strength values could not be achieved by using 5wt% elastomeric materials / therefore, it was decided to increase the SEBS-g-MA content up to 15, 20, 30 and 40wt%. With increasing elastomer content, increasing average elastomer domain size was obtained. Also, it was observed that with the addition of organoclay, the elastomeric domain size increases since the clay particles reside in the elastomer phase and at the interphase between elastomer and PS. The mechanical test results showed that the nanocomposites containing 15 and 20wt% SEBS-g-MA have the optimum average domain size that results in better impact strength values without deteriorating tensile properties.

Neste trabalho foi estudado o processo de tenacificação do poli(ácido lático), PLA, através da produção de blenda com terpolímero randômico (etileno/éster acrílico/glicidil metacrilato), EMA-GMA, como modificador de impacto. Três composições foram estudadas, 90/10, 80/20 e 70/30% em massa, as misturas foram homogeneizadas em extrusora dupla-rosca (melt blending) e corpos de prova foram moldados por injeção. A avaliação do comportamento mecânico e da eficiência da tenacificação foi realizada através de ensaios mecânicos de tração (ATSM D638), resistência ao impacto Izod com entalhe (ASTM D256), flexão (ASTM D790) e dureza Shore D (ASTM 2240). A presença de umidade e a temperatura de degradação foram avaliadas por análise termogravimétrica (TGA), as temperaturas de transição vítrea (Tg), fusão cristalina (Tm) e grau de cristalinidade foram avaliadas por calorimetria exploratória diferencial (DSC) e a morfologia foi analisada por meio de micrografias obtidas por microscopia eletrônica de varredura (MEV). Os resultados dos ensaios mecânicos idicaram que todas as blendas possuem valores de tenacidade superiores ao do PLA. Entretanto, as blendas apresentaram como efeito colateral queda em módulo (obtidos por ensaios de resistência a tração e flexão), resistência a tração no ponto de escoamento e dureza, em função do aumento da concentração de EMA-GMA no PLA. Na composição com 20% de EMA-GMA a distribuição da dispersa ao longo da fase matriz está mais homogênea, e a composição com 30% de EMA-GMA resultou em um material super tenaz (com valores de resistência ao impacto Izod com entalhe acima de 500J/m). / In this work poly(lactic acid), PLA, was toughened by addition a thermoplastic elastomer, the random terpolymer (ethylene / acrylic ester / glycidyl methacrylate), EMA-GMA. Three= compositions were prepared: with concentrations of 10, 20 and 30 wt% of EMA-GMA into PLA. The blends were prepared in a twin-screw extruder and molded by injection molding. The samples were systematically characterized by tensile strength, notched Izod impact strength, flexural properties and Shore hardness (using Shore D scale). The presence of moisture and the degradation temperature of PLA were evaluated by thermogravimetric analysis (TGA), the glass transition temperature (Tg), crystalline melting (Tm) and crystallinity index of PLA and of the blend were evaluated by differential scanning calorimetry (DSC) and the blend morphology was analyzed by scanning electron microscopy (SEM). The results showed that all blends presented a dramatic increase in their toughness, when compared to PLA. However, the moduli (obtained by tensile and flexural tests), tensile strength at yield, and hardness decreased when the dispersed phase content increased. In the 80/20 PLA/EMA-GMA blend, the dispersed phase is more homogeneously dispersed within the matrix, and the composition with 30 wt% of EMA-GMA resulted in a super tough material (notched Izod impact strength exceeding 500 J/m).

Antimony trioxide (Sb203) and halogenated additives are used together in flameretarded formulations due to their synergistic retardant properties. A study has been made to determine the effects of adding different grades of Sb203 (dSD particle sizes 0.11 um, 0.52um and 1.31 um) into ABS polymer either alone or with commercial brominated materials (BTBPE, TBBA, DBDPO) and an experimental bromine grade (sDBDPO). The Sb20 3 was added at 4wt% loadings and the bromines at 20wt% loadings. The results consider the influence of the additives on processing, mechanical, morphological and flame retardant properties. All compounds were produced using a twin-screw co-rotating extruder and then an injection moulder was used to mould notched impact (falling weight testing), flexural, LOI and UL-94 flame test bars. Samples of all the compounded formulations were titrated to determine Sb20 3 and Br contents. Fracture surface, morphology, size and dispersion analysis was carried out using both SEM and TEM equipment. Osmium tetroxide (OS04) staining was used to determine relative locations of filler particles and polybutadiene phase. Additions of the different antimony trioxide grades showed that the 0.52um and 1.31 um grades lowered impact energy absorption (-25 to -30%) when added at 4wt% loading. The use of a sub-micron size grade (0.1 um) did not significantly lower impact properties (-3%) and had similarly small effects on the flexural modulus and flexural strength. Additions of the brominated materials had much greater effects causing large reductions in impact properties (-20 to :70%). The presence of the bromines generally increased flexural modulus and lowered flexural strength with the exception of TB BA, which increased both modulus and strength. Compounds containing both 1.31 um Sb203 and bromines suffered a further reduction in impact energies, with the bromine properties dominating. Using the 0.1 um Sb20 3 grade again improved impact and flexural properties compared to the 1.31 um grade. The 0.1 um grade resulted in improvements in fire resistance as measured by the UL-94 properties when used with all bromine grades.