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Your search keyword '"Rodriguez‐Uribe, Arturo"' showing total 42 results
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42 results on '"Rodriguez‐Uribe, Arturo"'

24. Studies on curing kinetics of polyphenylene sulfide: An insight into effects of curing temperature and time on structure and thermo‐mechanical behavior.

Author

Chen, Guowei, Rodriguez‐Uribe, Arturo, Wu, Feng, Mohanty, Amar K., and Misra, Manjusri

Subjects
POLYPHENYLENE sulfide, INJECTION molding, CURING, TEMPERATURE effect, GLASS transition temperature, MELT spinning, CHAIN scission, BENZENEDICARBONITRILE
Abstract

Polyphenylene sulfide (PPS) is a type of thermoplastic that has high thermal and mechanical performances and extensive applications. Before processing, pre‐curing is required to improve its processability and mechanical properties. Here, effects of curing temperature (245 and 260°C) and time (10, 30, 60, and 120 min) on structure and thermal‐mechanical behavior of PPS were studied through melt flow index (MFI), rheology, Fourier‐transform infrared spectroscopy, and thermal‐mechanical characterizations. The MFI was decreased from ~700 g/10 min to less than 100 g/10 min (315°C/5.0 kg) after 60 min of curing at two different temperatures, greatly improving the processability of PPS in melt extrusion and injection molding processes. The functional groups remained unchanged after curing, due to the main reactions of chain extension and scission that occurred. For the PPS cured both at 245 and 260°C, the samples cured for 10 min displayed the highest degree of crystallinity and heat deflection temperature but had the lowest glass transition temperatures. The coefficient of linear expansion of PPS cured at 260°C showed anisotropy on flow and normal directions, which greatly differed from the PPS cured at 245°C. This study promotes an improved understanding of the curing process for solid PPS. [ABSTRACT FROM AUTHOR]

Published
2022
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34. Impact of renewable carbon on the properties of composites made by using three types of polymers having different polarity.

Author

Rodriguez‐Uribe, Arturo, Snowdon, Michael R., Abdelwahab, Mohamed A., Codou, Amandine, Misra, Manjusri, and Mohanty, Amar K.

Subjects
POLYLACTIC acid, CARBON composites, INTERMOLECULAR forces, POLYMERS, CARBON-black, POLYAMIDES
Abstract

Pine wood derived biocarbon (BioC) is investigated as a renewable alternative to carbon black (CB) for plastics and composites applications. Three different polymers with different polarity were used to prepare the composites: polypropylene (PP), polylactic acid (PLA), and polyamide 6 (PA6). Comparatively, CB had a nodule size of ~300 nm and surface area of 8 m2/g, whereas BioC showed an average particle size of ~950 nm and surface area of ~260 m2/g, respectively. CB, in the composites, was found in large aggregations in the flow direction (FD), while BioC particles showed a better dispersion. Aggregation of CB affected mostly the mechanical strength of the composites. Furthermore, it was found that the overall performance of composites was influenced more by the polarity of the phases, rather than the particle size or the surface area of the fillers. Even when the polarity of the particles had an expected trend (PA6 > PLA > PP with BioC > CB), the work of cohesion obtained for the composites was PA6‐BioC > PP‐BioC > PLA‐BioC, showing, in particular, that the chain‐to‐chain intermolecular forces in neat PLA are stronger as compared to those developed by the particle‐matrix interactions. [ABSTRACT FROM AUTHOR]

Published
2021
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42. Mechanical, Chemical, and Physical Properties of Wood and Perennial Grass Biochars for Possible Composite Application.

Author

Behazin, Ehsan, Ogunsona, Emmanuel, Rodriguez-Uribe, Arturo, Mohanty, Amar K., Misra, Manjusri, and Anyia, Anthony O.

Subjects
LUMBER industry, MISCANTHUS, WOOD chips, BIOCHAR, COMPOSITE applications (Computer science), MECHANICAL behavior of materials, PYROLYSIS
Abstract

Miscanthus, switchgrass, and softwood chip biochars, produced by slow pyrolysis, were characterized to evaluate their properties in light of potential alternative and novel applications. This work investigated specific physical and chemical properties of biochars that have not been previously reported. Atomic force microscopy (AFM), moisture absorption, and electrical and thermal analysis were conducted to demonstrate the mechanical, physical, and chemical properties of biochars. In addition, elemental analysis, specific surface area, Fourier transform infrared in the attenuated total reflectance (FTIR-ATR), and X-ray diffraction were performed. The state-of-art quantitative nano-mechanical measurement yielded a modulus of elasticity of approximately 10 GPa for the wood chip biochar, while the grass-based samples exhibited a comparatively lower modulus of approximately 5 GPa. In addition, the pore blocking phenomenon by water molecules was identified as a cause for atypical behavior of the biochars' moisture absorptions, resulting in wood chip biochar having the lowest equilibrium moisture content of 6.2 wt.%. Results from electrical and thermal conductivity measurements demonstrated relatively lower values in comparison to carbonized biomass. [ABSTRACT FROM AUTHOR]

Published
2016
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