resumo
Over the recent years, bitumen modification with polymers, acids, or mineral fillers has gained relevance to adjust its performance properties. This work reports the use of polyphosphoric acid (PPA) for the modification of formulated bitumen. With this objective, an in-depth literature review on PPA modification was firstly performed. Subsequently, five individual refinery components were selected for the preparation of bitumen blends, namely, as phaltic residue, vacuum residue, and three lube oils extracts. Seven binary/ternary bitumen blends were prepared and then treated with PPA. Afterwards, the five components and the unmodified and PPA-modified bitumen were characterized by standard methods (penetration, softening point, and penetration index), SARA analysis, elemental analysis, and P-31 and H-1 nuclear magnetic resonance (NMR) spectroscopy. The results evidenced higher asphaltenes and lower saturates/resins contents in PPA-modified bitumen. The NMR data suggest that the paraffinic chains became longer, the content of condensed aromatics increased, more substituted aromatic structures appeared, and alpha-hydrogen in aromatic structures diminished. These findings disclosed the improved consistency and oxidation stability of PPA-modified bitumen blends.
palavras-chave
TEMPERATURE PERFORMANCE; (PPA)-MODIFIED BITUMEN; CHEMICAL-COMPOSITION; PROPOSED MECHANISMS; COMMERCIAL WAXES; MODIFIED ASPHALT; MODEL COMPOUNDS; PPA ADDITION; SPECTROSCOPY; FRACTIONS
categoria
Chemistry; Engineering
autores
Varanda, C; Portugal, I; Ribeiro, J; Silva, AMS; Silva, CM
nossos autores
Carlos Manuel Silva
Professor associado
Catarina Varanda
Estudante de doutoramento
Inês Portugal
Professor Auxiliaragradecimentos
This work was developed within the scope of the projects CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013) and UI QOPNA (Ref. FCT UID/QUI/00062/2013), financed by national funds through the FCT/MEC and when appropriate cofinanced by FEDER under the PT2020 Partnership Agreement and the Portuguese National NMR Network (RNRMN). Catarina Varanda also thanks the FCT for a doctoral grant (SFRH/BDE/51420/2011).