Sustainable composites of surface-modified cellulose with low–melting point polyamide

High Concentration Lignin Biocomposites with Low Melting Point Biopolyamide

“…Furthermore, the amounts of C, O, and H elements significantly changed in the surfacemodified sample, illustrating the presence of the external molecules in the lignin particles. The amount of attached ODI molecules was previously reported for cellulose [28,32]; however, since the exact structure of the lignin is not clear, it was not possible to quantify the exact percentage of the grafted ODI molecules for the surface-modified lignin particles. The TGA/DTG thermograms were used to qualitatively evaluate the attachment of the modifier molecules.…”

“…The lignin particles were modified by changing the particles' surface from hydrophobic to hydrophilic through a urethane reaction between isocyanate molecules and lignin hydroxyl groups due to the method reported in our previous work [28]. A schematic representation of this reaction is depicted in Scheme 1b.…”

“…The test was performed in low deformation (1 % strain) to guarantee that the measurements were in the linear viscoelastic range. Furthermore, the pre-load and frequency were fixed at 1 N and 1 Hz, respectively [28]. The maximum loss factor (tan δ) curve was also considered to be the glass transition temperature (T g ) of the samples.…”

“…Thus, for the first time, we developed a series of lignin biocomposites, providing an excellent stiffness-toughness balance, even at a high filler loading of 50 wt%. We employed the same chemistry previously used for compatibilization of microcrystalline cellulose with a polyamide matrix [28], a urethane reaction between n-octadecyl isocyanate (ODI) molecules and the lignin hydroxyl groups. Accordingly, we converted lignin from a relatively hydrophilic particle into a hydrophobic one and made it compatible with the polyamide matrix.…”

Synthesis of a low viscosity amphoteric polyacrylamide and its application in oilfield profile control

“…To meet the requirements of different stratum environments, many scholars have modified other polymers through chemical means. Finally, the performance of polymers changed by adding some functional groups 34–36 . He et al 37 studied an amphiphilic polymer profile control agent, which was successfully applied in a high temperature (85°C) reservoir environment.…”