Experimental Study of the Impact of Trace Amounts of Acetylene and Methylacetylene on the Synthesis, Mechanical and Thermal Properties of Polypropylene

Hernández‐Fernández, Joaquín; Vivas‐Reyes, Ricardo; Toloza, Carlos A.T.

doi:10.3390/ijms232012148

Cited by 19 publications

(21 citation statements)

References 39 publications

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“…This result is because furan acted as an inhibitor of the reaction since it reacted with the active center of titanium, preventing the propylene from polymerizing in the vibrant center of titanium. It should be noted that the inhibitory behavior of impurities on the productivity of the Ziegler–Natta catalyst has been previously reported [ 1 , 3 , 12 , 35 , 36 , 37 , 38 , 39 , 40 ], showing that the presence of impurities such as H 2 S, oxygenated compounds, and thiol, among others, affects the efficiency in the production of polypropylene on an industrial scale.…”

Section: Resultsmentioning

confidence: 94%

Furan as Impurity in Green Ethylene and Its Effects on the Productivity of Random Ethylene–Propylene Copolymer Synthesis and Its Thermal and Mechanical Properties

2023

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The presence of impurities such as H2S, thiols, ketones, and permanent gases in propylene of fossil origin and their use in the polypropylene production process affect the efficiency of the synthesis and the mechanical properties of the polymer and generate millions of losses worldwide. This creates an urgent need to know the families of inhibitors and their concentration levels. This article uses ethylene green to synthesize an ethylene–propylene copolymer. It describes the impact of trace impurities of furan in ethylene green and how this furan influences the loss of properties such as thermal and mechanical properties of the random copolymer. For the development of the investigation, 12 runs were carried out, each in triplicate. The results show an evident influence of furan on the productivity of the Ziegler–Natta catalyst (ZN); productivity losses of 10, 20, and 41% were obtained for the copolymers synthesized with ethylene rich in 6, 12, and 25 ppm of furan, respectively. PP0 (without furan) did not present losses. Likewise, as the concentration of furan increased, it was observed that the melt flow index (MFI), thermal (TGA), and mechanical properties (tensile, bending, and impact) decreased significantly. Therefore, it can be affirmed that furan should be a substance to be controlled in the purification processes of green ethylene.

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Section: Resultsmentioning

confidence: 94%

Furan as Impurity in Green Ethylene and Its Effects on the Productivity of Random Ethylene–Propylene Copolymer Synthesis and Its Thermal and Mechanical Properties

2023

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“…A suspension of TEAL/heptane pre-catalyst was prepared [35]. Hydrogen (30 g/h) and propylene (1.2 MT/h) were added [9][10][11][12]35]. The mixture was heated to 71 • C and stirred at 510 rpm at 27 bar.…”

Section: Polymerization Procedures For Propylenementioning

confidence: 99%

“…Some doublers generate essential changes in the stereospecificity of the catalyst by the selective inhibition of non-stereospecific sites [5][6][7][8]. The selective poisoning of the catalyst minimizes the number of available active centers and changes in the propagation rate of the polymer [9][10][11][12][13][14]. The reaction mechanisms that make it possible to explain the previously indicated interactions have not been fully elucidated and are still the subject of due debate [4].…”

Section: Introductionmentioning

confidence: 99%

Parts per Million of Propanol and Arsine as Responsible for the Poisoning of the Propylene Polymerization Reaction

Hernández-Fernández,

González-Cuello,

Ortega-Toro

2023

Polymers

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Polypropylene synthesis is a critical process in the plastics industry, where control of catalytic activity is essential to ensure the quality and performance of the final product. In this study, the effect of two inhibitors, propanol and arsine, on the properties of synthesized polypropylene was investigated. Experiments were conducted using a conventional catalyst to polymerize propylene, and different concentrations of propanol and arsine were incorporated into the process. The results revealed that the addition of propanol led to a significant decrease in the Melt Flow Index (MFI) of the resulting polypropylene. The reduction in the MFI was most notable at a concentration of 62.33 ppm propanol, suggesting that propanol acts as an effective inhibitor by slowing down the polymerization rate and thus reducing the fluidity of the molten polypropylene. On the other hand, introducing arsine as an inhibitor increased the MFI of polypropylene. The maximum increase in the MFI was observed at a concentration of 0.035 ppm arsine. This suggests that small amounts of arsine affect the MFI and Mw of the produced PP. Regarding the catalyst productivity, it was found that as the concentration of propanol in the sample increased (approximately seven ppm), there was a decrease in productivity from 45 TM/kg to 44 TM/kg. Starting from 10 ppm, productivity continued to decline, reaching its lowest point at 52 ppm, with only 35 MT/kg. In the case of arsine, changes in catalyst productivity were observed at lower concentrations than with propanol. Starting from about 0.006 ppm, productivity decreased, reaching 39 MT/kg at a concentration of 0.024 ppm and further decreasing to 36 TM/kg with 0.0036 ppm. Computational analysis supported the experimental findings, indicating that arsine adsorbs more stably to the catalyst with an energy of −60.8 Kcal/mol, compared to propanol (−46.17 Kcal/mol) and isobutyl (−33.13 Kcal/mol). Analyses of HOMO and LUMO orbitals, as well as reactivity descriptors, such as electronegativity, chemical potential, and nucleophilicity, shed light on the potential interactions and chemical reactions involving inhibitors. Generated maps of molecular electrostatic potential (MEP) illustrated the charge distribution within the studied molecules, further contributing to the understanding of their reactivity. The computational results supported the experimental findings and provided additional information on the molecular interactions between the inhibitors and the catalyst, shedding light on the possible modes of inhibition. Solubles in xylene values indicate that both propanol and arsine affect the polymer’s morphology, which may have significant implications for its properties and final applications.

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“…Microplastics have been identified in different countries and by different techniques. In Cartagena, Colombia, there is a whole industrial zone where a considerable number of plastic-producing plants (petrochemical plants) are located that can contribute to the presence of microplastics and pollutants in the environment and which can affect the health of the surrounding inhabitants [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. To identify how they can be dispersed and which would be the populations or sites most affected by MPs, it is necessary to identify and obtain the morphological parameters of the particles.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the Morphological and Chemical Profile of Different Families of Microplastics in Samples of Breathable Air

2023

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Microplastic (MP) contamination has become a problem of great interest to the community at large. The detection of these particles in different ecosystems and foods has been the subject of study. However, the focus of these investigations has been on the identification and quantification of PM by DSC and Pyr-GC/MS and not on how they are transported to reach the air we breathe. In this study, the values of morphological parameters for plastic particles in a range between 1 and 2000 µm, present in the breathable air of 20 neighborhoods in the city of Cartagena, Colombia, were obtained to determine the characteristics that make these particles airborne. The values of parameters were obtained, such as roundness, sphericity, curvature, and the convexity of the particle, as well as its compactness and size, which influence its transport through the air and its ability to be ingested and inhaled. The data obtained in this study allows for simulations and the analysis of the behavior of microplastics once in the environment to predict future settlements. The DSC showed us the melting temperatures of PP, PE, PET, and PS, the Pyr-GC/MS showed the fragmentation patterns, and the presence of these MPs in the samples was confirmed.

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Experimental Study of the Impact of Trace Amounts of Acetylene and Methylacetylene on the Synthesis, Mechanical and Thermal Properties of Polypropylene

Cited by 19 publications

References 39 publications

Furan as Impurity in Green Ethylene and Its Effects on the Productivity of Random Ethylene–Propylene Copolymer Synthesis and Its Thermal and Mechanical Properties

Furan as Impurity in Green Ethylene and Its Effects on the Productivity of Random Ethylene–Propylene Copolymer Synthesis and Its Thermal and Mechanical Properties

Parts per Million of Propanol and Arsine as Responsible for the Poisoning of the Propylene Polymerization Reaction

Characterization of the Morphological and Chemical Profile of Different Families of Microplastics in Samples of Breathable Air

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