To Thermogravimetric Analysis Research Articles

Synthesis of Sulfonated Phenylsilsesquioxanes Guided by Machine Learning.

Sulfonated octaphenylsilsesquioxane (SPOSS) has garnered significant interest due to its unique structural properties of containing the -SO3H group and its wide range of applications. This study introduces a novel approach to the synthesis of SPOSS, leveraging machine learning algorithms to explore new recipes and achieve higher -SO3H functionality. The focus was on synthesizing SPOSS with 2, 4, 6, and 8-SO3H functional groups on the phenyl group, marked as SPOSS-2, SPOSS-4, SPOSS-6, and SPOSS-8, respectively. The successful synthesis of SPOSS-8 was achieved by 5 training outputs based on the recipes of 21 sets of low-functionality (<4) SPOSS. The structure of SPOSS was confirmed using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and time-of-flight mass spectrometry (MALDI-TOF MS). Machine learning analysis revealed that K2SO4 is an important additive to improve the functionality of SPOSS. A synthetic mechanism was proposed and validated that K2SO4 participated in the reaction to generate sulfur trioxide (SO3), a sulfonating agent with high reactivity. SPOSS shows thermal stability superior to octaphenylsilsesquioxane (OPS) according to thermogravimetric analysis (TGA) and TG-FTIR.

Physicochemical and antioxidant properties of pectin fractions extracted from lemon (Citrus Eureka) peels

Pectin, a natural polysaccharide, holds versatile applications in food and pharmaceuticals. However, there is a need for further exploration into extracting novel functional fractions and characterizing them thoroughly. In this study, a sequential extraction approach was used to obtain three distinct lemon pectin (LP) fractions from lemon peels (Citrus Eureka): LP extracted with sodium acetate (LP-SA), LP extracted with ethylenediaminetetraacetic acid (LP-EDTA), and LP extracted with sodium carbonate and sodium borohydride (LP-SS). Comprehensive analysis revealed low methyl-esterification in all fractions. LP-SA and LP-SS displayed characteristics of rhamnogalacturonan-I type pectin, while LP-EDTA mainly consisted of homogalacturonan pectin. Notably, LP-SA formed self-aggregated particles with rough surfaces, LP-EDTA showed interlocking linear structures with smooth planes, and LP-SS exhibited branch chain structures with smooth surfaces. Bioactivity analysis indicated that LP-SA had significant apparent viscosity and ABTS radical scavenging activity, while both LP-EDTA and LP-SS showed excellent thermal stability according to thermogravimetric analysis (TGA). Furthermore, LP-SS exhibited remarkable gel-forming ability and significant hydroxyl free radicals scavenging activity. In conclusion, this study presents a novel method for extracting various lemon pectin fractions with unique structural and bioactive properties, contributing insights for advanced applications in the food and pharmaceutical sectors.

Immobilized transition metal (II) bis–imine chelate on ZnO@TiO2 nanoparticles as sufficient catalysts for alcohol oxidation and for α,β‐cinnamic acid decarboxylative bromination

Based on the strong coordination ability of substituted imines towards transition metals of different oxidation states, the coordination of the HL imine ligand with the Cu2+ ion to form the Cu–bis–imine complex was achieved in 2:1 molar ratios. Their structures were confirmed with various spectroscopic tools. Heterogeneously, CuL2 was successfully appended on ZnO@TiO2 nanoparticles, as the less harmful materials, within the deprotonated p‐hydroxy chain of the bonded ligand in CuL2. The surface and internal structural morphologies of ZnO@TiO2@CuL2 were analyzed using X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), high‐resolution transmission electron microscopy (HRTEM), energy‐dispersive X‐ray spectroscopy (EDS), and infrared (IR) spectroscopy, in addition to thermogravimetric analysis (TGA). The catalytic behavior of both catalysts, CuL2 (the homogeneous catalyst) and ZnO@TiO2@CuL2 (the heterogeneous catalyst), was examined in the benzyl alcohol redox protocols using H2O2 for their optimization. α,β‐Cinnamic acid decarboxylative bromination in the presence of potassium bromide and H2O2 in water was studied with both catalysts, in which (2‐bromovinyl)benzene was the chemoselective product. Both Cu catalysts displayed appreciable catalytic effectiveness for the oxidation protocols and the decarboxylative bromination reactions. CuL2 recorded less required time for optimization than that of the heterogeneous catalyst. The catalytic effectiveness of CuL2 was less promoted than that of ZnO@TiO2@CuL2. Despite the less performance in yield of benzaldehyde for the oxidation protocols with ZnO@TiO2@CuL2, ZnO@TiO2@CuL2 had more recycling than its homogeneous counterpart, with seven to three times, respectively.

Potentiality of PLA 3D printed macro-structured feed spacers with a rational and facile layout for improved MD desalination performance

Membrane performance, regarding water flux and water recovery during membrane distillation (MD), is crucial during desalination. In this study, the membrane performance was improved using 3D-printed macro-structured feed spacers. Typically, 3D-printed feed spacers offer maximum flexibility for designing favorable geometrical transformations. The role of 3D-printed spacers in enhancing the permeate flux and recovery in direct contact membrane distillation (DCMD) has been thoroughly investigated. A comparative assessment was performed for various designs of 3D printed feed spacers with varying hydraulic diameters and filament thicknesses. An economical, biocompatible, and highly robust 3D-printed membrane spacer was developed using polylactic acid (PLA), which has a high elastic modulus. PLA is a biodegradable and environmentally friendly material. The thermal stability of PLA materials is advantageous for temperature-driven MD processes. PLA filaments were subjected to thermogravimetric analysis (TGA) for evaluating thermal stability. It provides structural support for the membranes and enhances mass movement through the membrane surface. In addition, these 3D-printed membrane spacers employing PLA have proven superior to conventional layouts in performance. These 3D-printed feed spacers were rationally designed to create a high flow disruption, which can lead to increased turbulence, thereby increasing the permeate flux. The overall results suggest that the 3D printed spacers can be ranked like TR˃DI ≈ SQ ˃ CR in terms of water flux. Eventually, the presence of 3D-printed spacers may prevent the external foulant layer onto the surface of membrane. Thus, the 3D printed spacers were ranked as TR˃DI ≈ CR≈ SQ for fouling mitigation ability. Furthermore, the used PVDF membrane with 3D printed spacers indicates lower hydrophobicity reduction, 11–14%. Therefore, this paper illustrates a facile approach to designing 3D-printed feed spacers that exhibit increased membrane performance in MD operation.

Modified Gallic Acids as Both Reactive Flame Retardants and Cross‐Linkers for the Fabrication of Flame‐Retardant Polyurethane Elastomers

AbstractPolyurethane elastomers (PUEs) serve a vital role in our daily life and various industrial applications, but their flammability has been proven to be a significant drawback. In this work, we have successfully fabricated two modified gallic acids (GAP and GAN) by simple esterification, both of which are effective flame retardants and cross‐linkers for PUEs. According to thermogravimetric analysis (TGA) and limiting oxygen index (LOI) tests, the introduction of GAP and GAN conspicuously improves the char yield (4.9~5.8 wt.%) and LOI value of PUEs (33~35 %). The cone calorimetry tests suggest that the peak heat release rate (PHRR) and total heat release (THR) of PUE decrease significantly, while the fire performance index (FPI) value increase after GAP or GAN modification. Both GAP and GAN enhance the density and strength of carbon residues, and inhibit the generation of combustible volatile gas during the combustion process, thereby improving the fire safety of PUEs. In addition, both GAP and GAN contain multiple benzene rings and hydrogen bonding, which can improve the cross‐linking density of PUEs to enhance their mechanical properties (the elongation at break: 844~951 %; tensile strength: 6.37~8.13 MPa).

Developing Filament Extruder and Characterization of Recycled High-Density Polyethylene for 3D Printing Filament Material

With the rise of additive manufacturing, the demand for 3D printing feedstock has increased exponentially and its sustainability is critical in the future. Many scholars are now concerned about how 3D printing filaments should be reproduced from recycled plastic. This study aimed to develop a filament extruder machine and investigate the potential of using recycled high-density polyethylene (HDPE), one of the most commonly used and recyclable thermoplastic, for 3D printing filament material. Desktop sized filament extruder machine was built, and a smooth and round-shaped 1.75±0.01mm diameter recycled HDPE filament was produced. Its mechanical, thermal, chemical, and physical properties were characterized by conducting various tests and validation test was conducted by comparing its properties with its virgin counterpart. The ultimate tensile strength of the recycled HDPE filament was obtained 19.02±0.35MPa, which is comparable to the ultimate tensile strength of virgin HDPE, making it a viable 3D printing feedstock for rapid prototyping. According to Thermogravimetric analysis (TGA), the recycled HDPE filament offers significant thermal stability with an onset degradation temperature of 430℃ and a full degradation temperature of 520℃. Its Fourier Transform Infrared (FTIR) spectrum shows the same functional groups as virgin HDPE polymer. The recycled HDPE filament has also excellent water-rejecting capability. In general, the study revealed a promising result for the use of recycled HDPE plastic as a more sustainable and environmentally friendly source material for 3D printing filament. To increase the potential and market competitiveness of recycled filaments, further investigation is required to optimize the filament extrusion and 3D printing process parameters, improve the mechanical properties, and overall development methods for both the recycled HDPE filament and 3D printed products.

Synthesis and application properties of polyaniline‐amino‐carbon nanotube antistatic agents

AbstractEmulsion polymerization was used to create composites of polyaniline‐amino‐carbon nanotubes (PANI‐A‐CNT). Fourier transform infrared spectroscopy (FT‐IR) was used to examine the chemical bonding properties of PANI and carbon nanotubes in composite materials. Transmission electron microscopy (TEM) was used to confirm that the PANI layer on the core‐shell structure of PANI‐A‐CNT material was nanoscale in size. In order to assess the impact of various carbon nanotube contents on the electrostatic and mechanical properties of the composites, pristine carbon nanotube/ABS (p‐CNT/ABS) and PANI‐A‐CNT/ABS composites were prepared. The mass fractions of PANI and CNT in PANI‐A‐CNT were 93.7 and 6.3 wt%, respectively, according to thermogravimetric analysis (TGA); hence, 4 wt% of PANI‐A‐CNT included 0.3 wt% CNT and 3.7 wt% PANI. The surface resistance test revealed that the PANI‐A‐CNT/ABS composite with 4 wt% PANI‐A‐CNT has a surface resistance of 108 Ω, which is one time less than the surface resistance of the p‐CNT/ABS composite with 4 wt% p‐CNT. Moreover, PANI‐A‐CNT/ABS composite (0–4 wt% PANI‐A‐CNT) has stronger tensile and impact properties than p‐CNT/ABS composite (0–4 wt% p‐CNT), expanding the range of applications for ABS resin.

Non-supported bimetallic catalysts of Fe and Co for methane decomposition into H2 and a mixture of graphene nanosheets and carbon nanotubes

Herein, non-supported pure and mixed cobalt and iron oxide catalysts were synthesized from nitrate precursors using a simple, environmentally friendly preparation method in which water was the sole solvent. The prepared catalysts were then used to decompose methane into hydrogen and carbon (graphene nanosheets and carbon nanotubes). The fresh and spent catalysts were characterized by employing X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy-energy dispersive X-ray analysis (SEM/EDX), transmission electron microscopy (TEM) and N2 adsorption-desorption techniques. In addition, the spent catalysts were subjected to thermo-gravimetric analysis (TGA) in order to measure the quantity of carbon deposits on the spent catalysts. The results indicated that the carbon deposited over these catalysts is a mixture of graphene nanosheets and carbon nanotubes (CNT). The results indicated that the mixed oxide catalysts exhibit higher catalytic activity than the pure oxides and that Fe: Co atomic ratio represents the key factor in the catalytic activity of these mixed oxides. After 420 min under the reaction feed, the 50Fe + 50Co catalyst shows the highest catalytic activity towards methane conversion of about 52.6% compared to 41.6% and 31.8% for 75Fe + 25Co and 25Fe + 75Co catalysts, respectively.

Production and Characterization of Polymer Blends and Assessment of Biodegradation

Polyhydroxybutyrate (PHB), a microbial polyester well known for its high glass transition and melting temperatures, is found in the intracellular granule within microbes. Herein, we have attempted to synthesize PHB along with xyloglucan (XG) as a copolymer to lower glass transition and melting temperature. Fourier transform infrared spectroscopic (FTIR) and Scanning Electron Microscopic (SEM) analyses were used to investigate the characteristics of blend films. We found that the addition of XG resulted in increased moisture absorption of the blend films. XG-PHB blend of ratio 80 : 20 showed the highest tensile strength and was subjected to thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. The results revealed that the XG-PHB blend has a lower melting point (121.3°C) and lesser crystalline degree (17.26%) than PHB. TGA results showed that blend film was more thermally stable than PHB. An effort to understand and analyze microorganisms that can produce and biodegrade copolymers such as PHB-XG is the main effort of this study which unfolds “new hope” in the field of biodegradable alternatives to plastics.

Lactate dehydrogenase encapsulated in a metal-organic framework: A novel stable and reusable biocatalyst for the synthesis of D-phenyllactic acid

In this study, we synthesized a novel biocatalyst by encapsulating lactate dehydrogenase (LDH) in the metal-organic framework ZIF-90 by one-pot embedding. It showed strong biological activity for efficient synthesis of D-phenyllactic acid (D-PLA). The morphology and structure of LDH@ZIF-90 was systematically characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, confocal laser scanning microscopy (CLSM) and gas sorption. According to thermogravimetric analysis (TGA), the enzyme loading of the biocatalyst was 3 %. The Michaelis–Menten constant (Km) and maximal reaction rate (Vmax) of LDH@ZIF-90 were similar to those of free LDH, which proved that ZIF-90 had good biocompatibility to encapsulate LDH. At the same time, LDH@ZIF-90 exhibited enhanced tolerance to temperature, pH and organic solvents, and its reusability was greatly improved with 68 % of initial enzyme activity remaining after 7 rounds of recylcing. Overall, LDH encapsulated in ZIF-90 may be an economically competitive and environmentally friendly novel biocatalyst for the synthesis of D-PLA.

Kinetics of alkaline delignification of hemp and determination of lignin content by thermogravimetry

Raw hemp (Cannabis sativa L.) was subjected to alkaline delignification with the application of NaOH ranging from [0.125M] to [1M] for times from 5 to 480 min. Lignin contents of the original and delignified samples were determined. The samples were subjected to thermogravimetric analysis (TGA) under a N2 atmosphere with temperatures ramped from 25 to 600 °C at 10 °C min-1. Lignosulfonates samples of low, medium and high molecular weight were subjected to the same TGA and showed that lignin decomposed over the entire temperature range. The contributions of lignin to the mass loss during thermal decomposition of hemp and kinetics of lignin content and the most relevant TGA results were determined. Regression models estimating the lignin content of the fibers based on TGA results were formulated. These models allow for the prediction of mean lignin content within ± 0.1% (based on dry weight of pulp) in the central range of the experimental field.

Facile Preparation of Cellulose Fiber Reinforced Polypropylene Using Hybrid Filler Method.

Dried hybrid fillers comprised of silica/CNF were successfully synthesized in ethanol/water mixed solvents at room temperature without the usage of any precursor. The as-prepared fillers were incorporated with polypropylene (PP) as a polymer matrix through a twin-screw extruder. From surface morphology analysis, the agglomeration of the silica/CNF hybrid fillers was prevented in the PP matrix and they exhibited moderate transparency, around 17.9% and 44.6% T at 660 nm. Further, the chemical structures of the polymer composites were identified by Fourier transform infrared (FT-IR) analysis. According to thermogravimetric analysis (TGA), the insertion of silica as a co-filler to the PP matrix resulted in an increase in its degradation onset temperature and also thermal stability. In addition, the mechanical properties of the PP composites also increased after the blending process with the hybrid fillers. Overall, sample PP-SS/CNF exhibited the highest tensile strength, which was 36.8 MPa, or around 73.55% compared to the pristine PP. The improvements in tensile strength were attributed to good dispersion and enhanced efficiency of the stress transfer mechanism between the silica and the cellulose within the PP matrix. However, elongation of the sample was reduced sharply due to the stiffening effect of the filler.

Synthesis and characterization of mesoporous silica-g-poly(hydroxyethylmethacrylate) nanohybrid particles as a drug delivery system

Hybrid nanoparticles (MSiO2/TMSPMA-g-PHEMA) based on poly(hydroxyethylmethacrylate) (PHEMA) grafted onto mesoporous silica particles (MSiO2) were prepared using “grafting from” approach by free radical polymerization. According to thermogravimetric analysis (TGA), the amount of grafted PHEMA increased as a function of the quantity of monomer feed. The hybrid nanoparticles were uniformly shaped as ellipsoids with a mean size diameter of 74 nm. Textural characterization and transmission electron microscopy (TEM) demonstrated that the morphology and structural framework of the materials were maintained. The grafted PHEMA favored that MSiO2/TMSPMA-g-PHEMA system could be well dispersed in an aqueous solution, showing pH dependence. The hybrid nanoparticles were capable to load 5FU with a maximum efficiency of 36.6% ± 5.4%. The drug release rate of (MSiO2/TMSPMA-g-PHEMA)/5FU was pH dependent and reached up to 86 ± 2.58% after 4 h at pH 7.4, much higher than at pH 2, which was only 46 ± 3.20% in 3.5 h. In vitro cytotoxicity test showed that hybrid MSiO2 were cytotoxic against U87 glioblastoma cells, indicating that the dosage-dependent effect of the hybrid delivery system was more effective than free 5FU. These results suggested that the MSiO2/TMSPMA-g-PHEMA is a potential system to be used as drug carrier for cancer therapy.

Pyrolysis and combustion characterisation of HDPE/APP composites via molecular dynamics and CFD simulations

Understanding and characterisation of the pyrolysis and burning behaviour of flame retardant (FR) polymers are essential towards optimising the end-product in terms of flammability, charring, toxicity and smoke reduction. This study proposes a modelling framework to study the combustion behaviour, pyrolysis kinetics and FR mechanisms of FR treated polymer composites. This numerical framework has utilised reactive molecular dynamics (MD-ReaxFF) simulations to characterise the pyrolysis kinetics, char formation and residues fragments of High-density polyethylene (HDPE) and Ammonium polyphosphate filled HDPE (HDPE/APP) composites. Through MD characterisation of the polymer breaking process, thermal degradation behaviours are described by reactions rates in Arrhenius form and subsequently imported into the computational fluid dynamics (CFD) models. The modelling framework has well-predicted the heat release rate (HRR) profiles, ignition time and combustion duration of the HDPE and HDPE/APP composites, where average relative errors less than 15% were achieved compared to thermogravimetric analysis (TGA) and cone calorimeter tests. The proposed numerical framework demonstrated the capability to capture the burning behaviour and flammability of FR treated polymer composites and identify the pyrolysis kinetics and FR mechanisms offered by the APP additives, such as dehydration and char formation.

Evaluation of Thermal Properties of Composites Prepared from Pistachio Shell Particles Treated Chemically and Polypropylene.

The purpose of the present work was to prepare polypropylene (PP) matrix composited filled with chemically treated pistachio shell particles (PTx), and evaluate their effect on the composites’ thermal properties. PP-PTx composites were formulated in different PTx content (from 2 to 10 phr) in a mixing chamber, using the melt-mixing process. The PTx were chemically treated using a NaOH solution and infrared spectroscopy (FTIR). According to thermogravimetric analysis (TGA), the treatment of pistachio shell particles resulted in the remotion of lignin and hemicellulose. The thermal stability was evaluated by means of TGA, where the presence of PTx in composites showed a positive effect compared with PP pristine. Thermal properties such as crystallization temperature (Tc), crystallization enthalpy (∆Hc), melting temperature (Tm) and crystallinity were determinate by means differential scanning calorimetry (DSC); these results suggest that the PTx had a nucleation effect on the PP matrix, increasing their crystallinity. Dynamic mechanical analysis (DMA) showed that stiffness of the composites increase compared with that PP pristine, as well as the storage modulus, and the best results were found at a PTx concentration of 4 phr. At higher concentrations, the positive effect decreased; however, they were better than the reference PP.

A Study of Thermal Decomposition and Kinetic Evaluation of Boron Blended Flash Powder Composition

Abstract Herein, the thermal characteristics of flash powders of different combinations of potassium nitrate, sulfur, aluminum, and boron are reported. From the literature, it is identified that boron implements lack of sensitiveness to flash powder mixture, which promotes safety during the manufacturing process. But the thermal behavior of the boron blended compositions remains a mystery. Hence, various combinations of flash powder compositions are prepared by keeping the % of KNO3 and % of S constant, and gradually 23% of aluminum is reduced (23% to 0) by increasing the quantity of boron (0% to 23%) in 19 trials and are subjected to thermogravimetric analysis (TGA)/differential scanning calorimetric (DSC) analysis individually. The TGA and the DSC analysis reveals that the 65.65% replacement of aluminum with boron mixture shows predominant characteristics which is suitable for fireworks. Also, the reaction kinetics and the critical ignition temperature are calculated for the optimum composition. The performance of the fireworks product is checked with varying quantities to meet out the optimum quality.

Conductive Compartmented Capsules Encapsulating a Bitumen Rejuvenator

This paper explores the potential use of conductive alginate capsules encapsulating a bitumen rejuvenator as a new extrinsic self-healing asphalt method. The capsules combine two existing self-healing asphalt technologies: (1) rejuvenator encapsulation and (2) induction heating to create a self-healing system that will provide rapid and effective asphalt pavement repair. The work presents a proof of concept for the encapsulation process, which involves embedding the capsules into the bitumen mortar mixture and the survival rate of the capsules in the asphalt mixture. A drip capsule production process was adopted and scaled up to the production of 20l wet capsules at rate of 0.22 l/min. To prove the effectiveness and its ability to survive asphalt production process, the capsules were prepared and subjected to thermogravimetric analysis (TGA) and uniaxial compression Test (UCT). The test results demonstrated that the capsules had suitable thermal characteristics and mechanical strength to survive the asphalt mixing and compaction process. Scanning electron microscopy (SEM) was employed to investigate physiological properties, such as rejuvenator (oil) and iron particle distribution, within the capsules. The electrical resistance tests proved that the capsules were capable of conducting electrical current. The capsules were also tested for their conductive properties in order to determine whether they are capable of conducting and distributing the heat once subjected to induction heating. The results showed that capsules containing higher amounts of iron (alginate/iron powder in a ratio of 20:80 by weight) can efficiently conduct and distribute heat. To prove its success as an asphalt healing system, conductive alginate capsules encapsulating a bitumen rejuvenator were embedded in a bitumen mortar mix. The samples where then subjected to local damaging and healing events, and the degree of healing was quantified. The research findings indicate that conductive alginate capsules encapsulating a bitumen rejuvenator present a promising new approach for the development of an extrinsic self-healing asphalt pavement systems.

Thermal and electrical properties enhancement of a nanocomposite of industrial silicone rubber filled with reduced graphene oxide

In this work, a nanocomposite was developed by in-situ polymerization using industrial-grade diatom-containing silicone rubber (SR) as the matrix and reduced graphene oxide (RGO) as filler. The Concentration of RGO, was very low, varying from 0 to 1 wt%. In these nanocomposites, diatoms as well as RGO flakes of sizes smaller than 20 µm were dispersed homogeneously within the SR. According to thermogravimetric analysis (TGA), the thermal stability of the composite is improved by increasing the decomposition temperature of SR from 497 °C to 546 °C at 0.8 wt% of RGO. A TGA signal between 620 °C and 670 °C is identified as due to C-C bonds thermal breaking, whose integrated intensity increases in proportion to the concentration of RGO and can be used to determine the concentration of RGO in similar composite systems. When 1.0 wt% of RGO is added thermal conductivity increases by 47.5% and the electrical resistivity decreases four orders of magnitude, respect to SR values. The SR/RGO nanocomposite is flexible and represents a good candidate for applications in the development of sensors and biomedical applications. The use of industrial-grade SR reduces production costs of composites in comparison to those prepared with more expensive analytical grade rubbers.

Preparation and Characterization of New Sol-Gel Hybrid Inulin-TEOS Adsorbent.

A new biopolymer–silica hybrid material consisting of inulin and tetraethoxysilane (TEOS) for use as an adsorbent was successfully synthesized via the sol–gel method in acidic conditions. The hydrolysis and condensation processes were attained in water/ethanol solution. Three molar ratios of inulin:TEOS (1:1, 1:2, and 2:1) were prepared and dried at various temperatures (50, 60, and 70 °C). The optimized molar ratio of 2:1 with a drying temperature of 70 °C was found to obtain the best morphology and characteristics for absorbent properties. Fourier transform infrared spectroscopy (FTIR) analysis showed a strong interaction between inulin and TEOS, which was also observed using energy dispersive X-ray spectroscopy (EDX). Field emission scanning electron microscopy (FESEM) images revealed the presence of nanoparticles on the rough surface of the hybrid sol–gel. X-ray diffractometer (XRD) analysis showed the amorphous state of the silica network where the inulin existed as an anhydrous crystalline phase. Brunauer–Emmet–Teller (BET) analysis confirmed that the composite was mesoporous, with 17.69 m2/g surface area and 34.06 Å pore size. According to thermogravimetric analysis (TGA) results, the hybrid inulin-TEOS adsorbent was thermally stable under a temperature of 200 °C.

Unravelling the para- and ortho-benzene substituent effect on the glass transition of renewable wholly (hetero-)aromatic polyesters bearing 2,5-furandicarboxylic moieties

High-glass transition thermoplastic polymers have dawned much attention in recent years due to their typical stiffness, enhanced thermal properties, and more importantly the emerging need to replace commercial fossil-based products by more sustainable alternatives, derived from renewable resources. In this regard we engineer here for the first time the design of wholly (hetero-)aromatic polyesters based on a key-platform chemical-2,5-furandicarboxylic acid (FDCA) and commercially-available catechol, or hydroquinone, whose structures were characterized by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR). Both polymers had a high glass transition (Tg up to 167 °C) detected by differential scanning calorimetry (DSC) and has excellent thermal stability according to thermogravimetric analysis (TGA). The para- and ortho- substitution in hydroquinone and catechol, respectively, affected crystallinity, which was typically higher for poly(1,4-phenylene-2,5-furandicarboxylate) (PHQF) favouring a stiffer and close packing structure. Also, the thermal properties were higher for PHQF.