Sustainable Chemical Engineering

Morphological, Thermal, Physicomechanical and Optical Properties of Crosslinked Poly (Ester-Urethane-Acrylate): Effect of Added Methyl Methacrylate

Shyam Dev Maurya — 2024-04-11

Poly (ester-urethane-acrylate) (PEUA) macromonomer was prepared by reacting two moles of isophorone diisocyanate (IPDI) with one mole of bis (1,4-butanediol ortho-phthalate) (BPE), followed by end-capping with two moles of 2-hydroxyethyl methacrylate (HEMA) in the presence of dibutyltin dilaurate (DBTDL) catalyst. Thereafter, different ratios of methyl-methacrylate (MMA) were added to the PEUA macromonomer to prepare crosslinked PEUA/MMA sheets. Fourier transform infrared spectrometry (FTIR), ultraviolet-visible spectrophotometry (UV-vis) and differential scanning calorimetry (DSC) techniques were employed to investigate the structure, optical transparency and thermal properties of the crosslinked sheets. The effect of MMA on the polymerization shrinkage and abrasive wear properties of PEUA and their copolymers were also studied. The polymerization shrinkage study showed that PEUA copolymer containing 40 wt% MMA had a more rigid microstructure with improved volume shrinkage and abrasive wear properties as compared with the other compositions of PEUA copolymers with MMA loadings of 80, 60 and 20%. The improvement was attributed to the better miscibility and compatibility of 40 wt% MMA with the PEUA as revealed by DSC, heat deflection temperature (HDT) and scanning electron microscope (SEM) studies.

Enhancing the Cu (II) Removal in Water Using Functional Hybrid Membranes

Noelle C. Zanini — 2024-04-16

This work developed hybrid EIPS/NIPS membranes of poly (butylene adipate-co-terephthalate) (PBAT) with nanocurcumin (NC) and/or Cloisite 20A (C20A). The dispersed phases were characterized by dynamic light scattering (DLS), ζ potential, X-ray diffractometry (XRD), scanning electron microscopy (SEM), and fourier-transform infrared spectroscopy (FTIR), while XRD, SEM, FTIR, mechanical properties, contact angle, and copper sorption evaluated the composite membranes. DLS analysis indicated that the dispersed phases present a nanometric size distribution; ζ potential measurements showed low electrostatic stability, explaining the agglomeration effects observed. Pure PBAT membranes presented macro-pores throughout their structure, which showed a slight size reduction with the inclusion of NC and C20A. The membrane’s mechanical performance was affected by the presence of the pores that functioned as stress-concentrating defects, and the inclusion of the dispersed phases increased the elastic modulus and tensile strength, especially for PBAT/0.5% C20A with values 18.7 and 8.9% higher than those of pure PBAT, respectively. Hybrid EIPS/NIPS membranes showed a hydrophilic nature with all the contact angle measurements lower than 90°. The sorption tests using a high-concentration copper solution (1,000 mg/L) showed a removal of around 25%. These results highlighted the development of new eco-friendly membranes using NC and C20A as dispersed phases with the potential to remove toxic elements from water.

Computational Approach for Architecture, Tailoring, and Advancements in Perfluorinated Compounds: Synthesis, Characterization, and Future Directions in Fire Suppression Technology

Rajiv Kumar — 2024-04-24

The demand for effective fire extinguishants has spurred investigation into novel perfluorinated molecules due to their exceptional properties, including high thermal stability, low toxicity, and eco-friendliness. This study presents a computational framework for designing and tailoring perfluorinated compounds as potential alternatives to traditional extinguishing agents. The research centers on elucidating the synthesis, molecular architecture, and characterization of these compounds to enhance their fire suppression capabilities while mitigating environmental impact. By employing computational methods, molecular modeling, and advanced spectroscopic techniques, the structural intricacies and potential applications of perfluorinated compounds in fire suppression are investigated. Additionally, future research directions aimed at addressing challenges and advancing the development of environmentally sustainable fire extinguishants are discussed. This manuscript contributes to the ongoing efforts to replace conventional extinguishing agents with safer and more environmentally friendly alternatives.