Supermolecular structure and nucleation ability of polylactide-based composites with silica/lignin hybrid fillers

Abstract

In this paper, amorphous silica Syloid 244 and kraft lignin were mechanically coupled. Four hybrid materials containing silica and lignin in ratios 1:1, 2:1, 5:1 and 20:1 were prepared. As reference samples for hybrid fillers pristine silica and lignin were used. Particle size determination and microscopic observations were applied to determine dispersive and morphological properties of hybrid fillers. Fourier transform infrared spectroscopy confirmed the effective preparation of silica/lignin hybrid materials. The parameters of porous structure of examined hybrid filler were determined using the multipoint Brunauer-Emmett-Teller method and Barrett-Joyner-Halenda algorithm. Composite samples of polylactide (PLA) containing 2.5 % (w/w) of hybrid filler were extruded. Optical microscopy, wide-angle X-ray scattering and differential scanning calorimetry were applied to specify the supermolecular structure of functional PLA/hybrid composites and analyze the crystallization parameters as well as the phase transformation in PLA matrix. Silica/lignin hybrid material was found to be a filler capable of an effective crystal nucleation. The nucleating ability of silica/lignin hybrid filler in PLA matrix is related to porous properties of filler and its composition.

Activation of Magnesium Lignosulfonate and Kraft Lignin: Influence on the Properties of Phenolic Resin-Based Composites for Potential Applications in Abrasive Materials

“…The observed values are in accordance with literature data [45,46]. Most of the bands are characteristic for the phenylpropanoid units present in the lignin structure, especially the most common guaiacyl unit [47].…”

Functional MgO–Lignin Hybrids and Their Application as Fillers for Polypropylene Composites

“…Moreover, this biopolymer is distinguished from other products by properties such as biodegradability, antioxidant and antibacterial activity [10,11], good chemical reactivity [12], affinity to inorganic oxides [13,14] or possible sorption of harmful compounds from the environment due to the diversity of functional groups in the lignin structure [15,16]. These properties allow the use of lignin in the preparation of functional hybrid materials with applications as fillers for polymer composites [14,[17][18][19] or effective sorbents of environmentally harmful metal ions [15,16]. It is worth emphasizing that lignin is a renewable raw material, i.e., it corresponds well Molecules 2020, 25 with global environmental trends.…”

“…However, a significant disadvantage of lignin is its limited thermal stability. At temperatures above~200 • C this biopolymer is gradually decomposed, which ultimately results in its degradation [14,[17][18][19]. Therefore, it seems important to combine lignin with inorganic compounds, including highly thermally stable MgO [20,21].…”

Calorimetric and spectroscopic investigations of interactions between cucurbituril Q7 and gemcitabine in aqueous solutions

“…In the future, we are going to use the calorimetric titration technique to study the thermodynamic of the cucurbiturilgemcitabine complexes (1) in an aqueous medium of hydrochloric acid, as well as (2) in formic buffer at different pH values and electrolyte concentrations, which should enable to study the influence of more complex environment to the interactions between cationic species and cucurbituril Q7. We also plan to use the technique of mass spectrometry to examine the stoichiometry of complexes in the mixtures containing an excess of gemcitabine or cucurbituril.…”

“…Thermal analysis enables to study interactions occurring inside supermolecular structures built from macromolecules (hosts) and ions/small molecules (guest ligands) [1][2][3][4][5][6]. Many research centers have carried out studies on the use of cucurbiturils as transporters of toxic medicines [7], including oncological drugs [8][9][10][11].…”