Caracterização de compósitos obtidos a partir de polímero biodegradável e casca de arroz utilizando duas técnicas de processamento

Azevedo, Joyce Batista; Barbosa, Josiane Dantas Viana; Carvalho, Laura H.; Canedo, Eduardo L.

doi:10.1590/s1517-707620160002.0037

Cited by 9 publications

(7 citation statements)

References 15 publications

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“…Moreover,

E_{0} = \int_{t_{1}}^{t_{2}} (||, J ((), t) - J_{0} ((), t)) italicdt

𝐸 0 indicates the total energy released during the exothermic crystallization event and, at the same time, the terms t 1 and t 2 represent the initial and ending times of an event. Regarding the melting and crystallization rate ( c ), [ 43 ] the mathematical equation is given by:

c ((), t) = \frac{dx}{dt} = \frac{|J (t) - J_{0} (t)|}{E_{0}}

…”

Section: Methodsmentioning

confidence: 99%

Biopolyethylene/Morinda citrifolia cellulosic biocomposites: The impact of chemical crosslinking and PE‐g‐MA compatibilizer

et al. 2021

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The development of new ecological materials to promote sustainability is being encouraged. Crosslinked biopolyethylene (BioPE)/noni flour (Morinda citrifolia) biocomposites were prepared using maleic anhydride-grafted polyethylene (PE-g-MA) and dicumyl peroxide (DCP). The biocomposites were processed in an internal mixer and injection molded. Torque rheometry, Izod impact strength, tensile strength, heat deflection temperature (HDT), differential scanning calorimetry (DSC), thermogravimetry (TG), and scanning electron microscopy (SEM) properties were investigated. Torque rheometry curves suggest that the biocomposites did crosslink due to the DCP attack on the BioPE chain. The BioPE/noni flour/PE-g-MA formulation with 0.5% and 1% DCP produced a higher level of crosslinking. As a result, the mechanical properties (impact strength, elastic modulus, and tensile strength) were improved. SEM showed fractured noni flour particles in the BioPE matrix with the formation of a tubular structure. The HDT increased, suggesting that the biocomposites exhibit enhanced thermomechanical strength. Furthermore, the biocomposites thermal properties obtained by DSC underwent few modifications. The TG results showed that the crosslinked biocomposites have better thermal stability than the noncrosslinked biocomposites. The crosslinking process of BioPE/noni flour biocomposites with the PE-g-MA/DCP hybrid is an effective way to improve the performance of these materials.

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“…Moreover,

E_{0} = \int_{t_{1}}^{t_{2}} (||, J ((), t) - J_{0} ((), t)) italicdt

c ((), t) = \frac{dx}{dt} = \frac{|J (t) - J_{0} (t)|}{E_{0}}

…”

Section: Methodsmentioning

confidence: 99%

Biopolyethylene/Morinda citrifolia cellulosic biocomposites: The impact of chemical crosslinking and PE‐g‐MA compatibilizer

et al. 2021

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“…E 0 indicates the total energy released during the exothermic crystallization event and, at the same time, the terms t 1 and t 2 represent the initial and ending times of an event. Regarding the melting and crystallization rate (c) [38], the mathematical equation is given by Equation 5…”

Section: Composites Characterizationmentioning

confidence: 99%

Effect of kaolin waste annealing on the structural and thermal behavior of poly(ε−caprolactone)

Filho

Luna

Silva

et al. 2022

Momento

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The heat treatment effect on kaolin waste from mining was evaluated on the structural and thermal behavior of poly(ε-caprolactone) (PCL). The PCL/KW (kaolin waste) and PCL/HTKW (heat-treated kaolin waste) composites were processed in an internal mixer and subsequently characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The kaolin waste showed kaolinite and quartz in its composition, while the heat treatment at 1200°C modified it to mullite, quartz and silica-rich amorphous phase. By XRD, there was an increase in the intensity of the peak 2θ = 23.9° of the PCL/KW composites compared to neat PCL. In contrast, PCL/HTKW composites tended to reduce the intensity of the peak 2θ = 23.9°, especially at 5% HTKW. The crystalline melting temperature and the degree of crystallinity of PCL/KW and PCL/HTKW composites were practically unchanged, compared to PCL. However, the crystallization process was more effective with the kaolin waste (KW) without heat treatment, indicating that the HTKW amorphous phase inhibited crystallization. The PCL/KW development promoted an increase in crystallization temperature, relative crystallinity, and crystallization rate, surpassing PCL and the PCL/HTKW system. In view of this, kaolin waste has the potential to accelerate the PCL crystallization process, contributing to add value to a material that would otherwise be discarded and minimizing environmental impacts.

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“…It converts the appropriate raw material into a given product with semi-continuous production in which the material is forced through a matrix, thus acquiring a predetermined shape under controlled conditions. Different authors [34][35][36][37] have used this method to produce composites with satisfactory properties, but the literature does not provide comparisons for material properties using other production methods.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Surface and micromechanical analysis of polyurethane plates with hydroxyapatite for bone structure

et al. 2022

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To analyze the surface topography and mechanical properties of a polyurethane derived from castor oil reinforced with hydroxyapatite (PU-HA) for bone fixation. The surface analysis was performed by Scanning Electron Microscopy (SEM) and the mechanical properties by Vickers microhardness and tensile tests. The SEM images showed that the PU surface presented important characteristics for materials intended for bone fixation, such as an irregular and porous surface. The analysis showed a surface with alternating areas with depressions and elevations of approximately 80±100 µm, presence of pores of 12 µm in size. The microhardness analysis showed values of 0.42±1.01 HV for PU-HA plates, lower in relation to the poly lactic-co-glycolic acid (PLGA) plate (control group). The elastic modulus and ultimate tensile strength of 317.4 MPa, and 35.57 MPa for PLGA sample, 1.187 MPa, and 0.29 MPa for PU-HA sample. The PU produced showed good surface properties, however demands better mechanical properties.

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Caracterização de compósitos obtidos a partir de polímero biodegradável e casca de arroz utilizando duas técnicas de processamento

Cited by 9 publications

References 15 publications

Biopolyethylene/Morinda citrifolia cellulosic biocomposites: The impact of chemical crosslinking and PE‐g‐MA compatibilizer

Biopolyethylene/Morinda citrifolia cellulosic biocomposites: The impact of chemical crosslinking and PE‐g‐MA compatibilizer

Effect of kaolin waste annealing on the structural and thermal behavior of poly(ε−caprolactone)

Surface and micromechanical analysis of polyurethane plates with hydroxyapatite for bone structure

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