Influence of grape marc extract on tuning the intermolecular interactions in the high‐density polyethylene

Abstract

Intermolecular interactions and molecular dynamics in thin films of highdensity polyethylene (HDPE) containing a high loading of Grape Marc Extract (GME) were analyzed by solid-state NMR. Optical microscopy (OM), Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) studies were used to corroborate the findings. The OM and SEM images and 1 H-13 C RAMP CP/MAS (ramped amplitude cross-polarization/magic-angle spinning) spectra of HDPE, HDPE-GME, and GME confirmed the incorporation of the GME into the HDPE structure. The results were compared to those for an unfilled HDPE film. The influence of GME on enhancing the amorphous nature of HDPE, altering the crystalline melting behavior and possible intermolecular interactions were evident from the DSC and FTIR. The NMR spin-diffusion and T 1 (1 H), T 2 (1 H), T 1ρ *(13 C), T 1ρ (1 H) relaxation and variable contact time experiments revealed the interactions and dynamics at the sub-micron level.

Characterization and utilization of apple peel and grape branches extract constituents as green restraints for aluminum dissolution

“…The alkanes presence is con rmed via stretching band at 2943 cm − 1 that changed to 2956 cm − 1 after EP. The absorption peak at 1226 cm − 1 proves the esters and ethers presence that changed to 1234 cm − 1 after EP [ 25].…”

Negatively Charged Poly(acrylic acid) Side Chains Grafted onto Poly(3-hexylthiophene): Impact on the Structural Order and Molecular Dynamics

“…The longitudinal spin−lattice relaxation (time constant T 1 ( 13 C)) is generally driven by the fluctuations of the heteronuclear dipolar interactions of carbons with directly bonded protons, a chemical shift anisotropy interaction and the molecular motion (particularly in the case of quaternary carbons) on the time scale of the inverse Larmor frequency in the MHz region (∼75 MHz for the 13 C in our case). 42,44,45 The variable-temperature measurements of T 1 values offer differentiation between structural units with correlation times either below or above the value determined by the inverse Larmor frequency. Unlike proton relaxation, carbon spin− lattice relaxation is not affected by spin diffusion.…”

“…Unlike proton relaxation, carbon spin− lattice relaxation is not affected by spin diffusion. 44,45 The spin diffusion process is carried out by the energy-conserving flipflop effect, which occurs between two abundant static dipolar coupled nuclear spins. This process can average various proton T 1 components within a domain size of ca.…”

“…The T 1ρ rotating-frame relaxation data can provide information about local reorientational motion (dynamical fluctuations) in the mid-kHz motional regime. 44 T 1ρ ( 13 C), T 1 ( 13 C), and T CH (a cross-polarization time constant) can be attributed to the changes in carbons at site-specific positions. 44 On the other hand, the T 1ρ ( 1 H) does not represent a sitespecific parameter.…”

“…44 T 1ρ ( 13 C), T 1 ( 13 C), and T CH (a cross-polarization time constant) can be attributed to the changes in carbons at site-specific positions. 44 On the other hand, the T 1ρ ( 1 H) does not represent a sitespecific parameter. This is because T 1ρ ( 1 H) components within specific domains of ca.…”