Molecular complexes of l-phenylalanine with substituted 1,4-benzoquinones in aqueous medium: spectral and theoretical investigations

Preparation of Octadecyl Amine Grafted over Waste Rubber Powder (ODA-WRP) and Properties of Its Incorporation in SBS-Modified Asphalt

Through a covalent grafting reaction, octadecyl amine (ODA) was grafted on the surface of waste rubber powder (WRP) to obtain an ODA-WRP modifier, which was in turn compounded with a styrene-butadiene-styrene block copolymer (SBS) to prepare ODA-WRP/SBS-modified asphalt. The three major indicators (i.e., dynamic shear rheometer (DSR), multi-stress creep recovery (MSCR), and separation tests) showed that 1-ODA-WRP effectively improved the complex shear modulus (G*), elastic Modulus (G'), and loss modulus (G″) by 36.47%, 40.57%, and 34.77% (64 °C and 10 Hz), respectively, as compared to pristine SBS-modified asphalt. Fluorescence microscopy (FM) results concluded that the enhancement in mechanical properties was accredited to the better compatibility of various components in asphalt and establishment of network structure between ODA-WRP and SBS in ODA-WRP/SBS-modified asphalt. Fourier infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) analyses confirmed the successful synthesis of ODA-WRP. This study could be of great help in synthesizing ODA-WRP asphalt modified with SBS for highways and construction applications.

Charge transfer complexes between 2-, 3- and 4-aminopyridines and some π-acceptors in the gas phase and in chloroform: DFT calculations

This work reports density functional theory (DFT) calculations on the molecular structures, electronic distribution, and UV-Vis and IR spectroscopy analysis of charge transfer complexes between aminopyridines (APYs), namely 2-APY, 3-APY and 4-APY, as electron-donors and some [Formula: see text]-electron-acceptors, namely chloranil (CHL), tetracyanoethylene (TCNE) and picryl chloride (PC), formed in the gas phase at the B3LYP/6-31[Formula: see text]G(d,p) method/basis set, and in chloroform at the same method/basis set using PCM as solvation model. Good correspondence was generally obtained between the calculated parameters and the experimental ones.