Mistura polipropileno/poliestireno: um exemplo da relação processamento-estrutura-propriedade no ensino de polímeros

Oliveira, Ricardo Vinícius Bof de; Ferreira, Creusa Iara; Peixoto, Luciano de Jesus Ferreira; Bianchi, Otávio; Silva, Patrícia Alves da; Demori, Renan; Silva, Rodrigo Pinheiro da; Veronese, Vinicius Bassanesi

doi:10.1590/s0104-14282013005000001

Cited by 12 publications

(8 citation statements)

References 11 publications

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“…The voids that appear in the micrograph are a result of the separation of the blend components when the impact force is applied, an indication of a weak interphase interaction40,41 .A similar behavior was reported by Pachekoski et al42 , who examined PHB/PP mixtures after processing. Other studies report the immiscibility of polymer blends of morphologies similar to the one found in this research40,[43][44][45] .It can be observed that the size of the PHB phase increases with the number of reprocessing cycles, which is more visible in the seventh cycle (Figure4d). These results are thought to indicate that the intense shear causes the coalescence of the PHB phase in the blend.Figure5shows the micrographs of the reprocessed nanocomposite.…”

supporting

confidence: 84%

Effect of Reprocessing Cycles on the Morphology and Mechanical Properties of a Poly(Propylene)/Poly(Hydroxybutyrate) Blend and its Nanocomposite

Oliveira

Silva

et al. 2021

Mat. Res.

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The use of polymer blends and composites based on fossil-based and bio-based polymers has become an important environmentally protective alternative for common use and disposable plastics applications such as packaging, bottles and trays. The disposal of these more degradable products, however, may also harm the environment and, therefore, recycling these systems becomes relevant. Recycling involves reprocessing which can significantly change the morphology and properties of polymeric products. Therefore, this study deals with the effects of reprocessing cycles on the properties and morphology of blends and nanocomposites based on fossil and bio-based polymers. The systems investigated were: a) neat polypropylene (PP), b) a polypropylene/poly(3-hydroxybutyrate) (PP/PHB) blend and c) PP/PHB/organoclay nanocomposite compatibilized with polypropylene-g-maleic anhydride (PP-g-MA) and erucamide. These materials were submitted to up to seven extrusion cycles in a single screw extruder operating at 60 rpm. Samples were taken after the first, third, fifth and seventh extrusion cycles and their tensile properties and morphology were determined. Scanning electron microscopy indicated that two phases were observed in the blend which showed spherical PHB domains. The addition of clay, PP-g-MA and erucamide improved the adhesion between the nanocomposites components. X-ray diffraction analysis showed that crystallinity tended to increase with the number of reprocessing cycles for all systems investigated up to the fifth cycle and then tended to decrease. A 10% crystallinity increase was observed for neat PP in the fifth cycle. In general, the tensile properties of all systems decreased with reprocessing and the highest losses were observed for the PP/PHB blend after seven processing cycles with 50% and 37% decreases in stress at break and elastic modulus, respectively. Impact strength of the PP matrix and of the PP/PHB blend tended to decrease with reprocessing, except for the nanocomposite which showed a slight increase especially after the seventh processing cycle in which an 18% increase in impact strength was observed.

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supporting

confidence: 84%

Effect of Reprocessing Cycles on the Morphology and Mechanical Properties of a Poly(Propylene)/Poly(Hydroxybutyrate) Blend and its Nanocomposite

Oliveira

Silva

et al. 2021

Mat. Res.

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“…PP H103 and R BB have higher T c , which may be associated to smaller polymer chains. PP H103 has higher MFR (40 g/10 min), this fact may improve crystallization (nucleation and growth), as already reported by Oliveira et al (2012) 21 . In addition, the presence of impurities can contribute to a higher crystallization rates, they may act as activation centers for new crystals 22 .…”

Section: Differential Scanning Calorimetry (Dsc)supporting

confidence: 69%

Properties and Morphology of Polypropylene/Big Bags Compounds

et al. 2019

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In this work, compounds based on two grades of polypropylene (PP), i.e., PP H503 or PP H103 with residues of Big bag fabrics (R BB ) were processed in a corrotational twin screw extruder with R BB content ranging from 10% to 50% of the weight. Then, their thermal properties were investigated through Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG); mechanical by tensile and impact; thermomechanic by heat deflection temperature (HDT); and their morphology by Scanning Electron Microscopy (SEM). With the aim to add maximum R BB content without considerable damage to the properties of neat PPs, it was observed that addition of 10%, 30% and 50% of R BB did not significantly interfere in the PP matrices, being the compound PP + 30% R BB which one presented more successful properties, leading to reused compounds with higher performance and lower costs at same time.

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“…PP presented a single thermal decomposition step, with weight loss in the range from 290 to 430 C, similarly to the reported in the literature. [73] EPDM-MA is thermally more stable than PP, since the initial degradation was around 430 C. PA6 displayed higher thermal stability than PP, with a single degradation step in the range from 415 to 490 C; however, PA6 showed a subtle decline in TG plot between 80 and 170 C, due to moisture loss, and in this case, it is a physical event. Similar behavior was verified by Anjos et al [74] in PA6/PE blends compatibilized with PE-g-MA.…”

Section: Thermogravimetrymentioning

confidence: 92%

Reactive processing of PA6/EPDM‐MA blends as modifier for application and development of high‐performance polypropylene

Luna

Siqueira

Ferreira

et al. 2021

Vinyl Additive Technology

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In this work, PA6/EPDM-MA was added as an impact modifier for highperformance polypropylene (PP) production. PA6/EPDM-MA compounds were processed in an internal mixer, aiming at chemical reaction between maleic anhydride of EPDM-MA and the amine terminal groups of PA6. Afterward, PP/(PA6/EPDM-MA) blends were processed by extrusion and injection molding. Rheological properties were evaluated using torque rheometry; additionally, Fourier transform infrared spectroscopy, Molau test, impact and tensile strengths, Shore D hardness, thermal deflection temperature, X-ray diffraction, differential scanning calorimetry, thermogravimetry, water absorption, contact angle, and scanning electron microscopy tests were performed in injected specimens. PP/(PA6/EPDM-MA) with 70/(15/15)% displayed quite high increase in impact and elongation at break, with gains of 850% and 265%, compared to neat PP. There were no drastic losses in tensile strength, elastic modulus, and Shore D hardness, due to PA6 addition. A significant increase was seen in the thermal stability of PP/(PA6/EPDM-MA), corroborating the increase in structural stability seen in HDT. SEM images showed high interfacial adhesion between PP and PA6/EPDM-MA corroborating higher mechanical properties.Summing up, PA6/EPDM-MA premix acted as an efficient impact modifier for PP. Acquired data show that P6/EPDM-MA system was effective in developing high-performance PP with potential for application in the automotive and electronics industries.high-performance blends, PP/(PA6/EPDM-MA), reactive processing | INTRODUCTIONPolypropylene (PP) is one of the most common industrially applied polymers, mainly due to its low cost, low density, good thermal properties, excellent processability, and reasonable mechanical properties. [1][2][3] However, PP displays low impact strength, which limits its higher performance applications [4] ; hence, PP must be toughened to expand the range of its properties. [5] Toughness is a quite useful parameter that determines whether a given

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Mistura polipropileno/poliestireno: um exemplo da relação processamento-estrutura-propriedade no ensino de polímeros

Cited by 12 publications

References 11 publications

Effect of Reprocessing Cycles on the Morphology and Mechanical Properties of a Poly(Propylene)/Poly(Hydroxybutyrate) Blend and its Nanocomposite

Effect of Reprocessing Cycles on the Morphology and Mechanical Properties of a Poly(Propylene)/Poly(Hydroxybutyrate) Blend and its Nanocomposite

Properties and Morphology of Polypropylene/Big Bags Compounds

Reactive processing of PA6/EPDM‐MA blends as modifier for application and development of high‐performance polypropylene

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