Polyol Content Research Articles

Polyurethanes Made with Blends of Polycarbonates with Different Molecular Weights Showing Adequate Mechanical and Adhesion Properties and Fast Self-Healing at Room Temperature

Dynamic non-covalent interactions between polycarbonate soft segments have been proposed for explaining the intrinsic self-healing of polyurethanes synthesized with polycarbonate polyols (PUs) at 20 °C. However, these self-healing PUs showed insufficient mechanical properties, and their adhesion properties have not been explored yet. Different PUs with self-healing at 20 °C, acceptable mechanical properties, and high shear strengths (similar to the highest ones reported in the literature) were synthesized by using blends of polycarbonate polyols of molecular weights 1000 and 2000 Da (CD1000 + CD2000). Their structural, thermal, rheological, mechanical, and adhesion (single lap-shear tests) properties were assessed. PUs with higher CD1000 polyol contents exhibited shorter self-healing times and dominant viscous properties due to the higher amount of free carbonate groups, significant carbonate–carbonate interactions, and low micro-phase separation. As the CD2000 polyol content in the PUs increased, slower kinetics and longer self-healing times and higher mechanical and adhesion properties were obtained due to a dominant rheological elastic behavior, soft segments with higher crystallinities, and greater micro-phase separation. All PUs synthesized with CD1000 + CD2000 blends exhibited a mixed phase due to interactions between polycarbonate soft segments of different lengths which favored the self-healing and mobility of the polymer chains, resulting in increased mechanical properties.

A facile strategy for synthesizing isosorbide-based polyurethane structural adhesives and core–shell rubber

A structural adhesive series of biomass-based polyurethane (Biomass-PU) is synthesized using polypropylene glycol (PPG2000), isosorbide-based polyol (RPO300) as polyols, isophorone diisocyanate (IPDI) as an isocyanate and 4-tert-butylphenol (BP) as a capping agent. Three different equivalent ratios of PPG2000/RPO300, 9/1 (Biomass-PU1), 7/3 (Biomass-PU2), and 1/1 (Biomass-PU3), are evaluated to determine the effect of isosorbide-based polyol content on the properties and the optimizing formulation of biomass-PU structure adhesive. The 9/1 ratio of PPG2000/RPO300 substantially leads to the improvement of impact strength by up to 35 MPa, and the PPG2000/RPO300 = 9/1 ratio exhibits better thermal properties and impact strength than those of other ratios. To achieve more compatibility between biomass-PU structure adhesive and core–shell rubber (CSR) toughener, novel CSRs are successfully synthesized using acryl-PU as a shell and biomass-based PU as a core. The chemical structure of biomass-PU structure adhesives is analyzed through FT-IR Spectroscopy and NCO% titration. Thermal properties are evaluated using TGA and DSC analysis. Their molecular weights are measured by GPC. Also, the core–shell rubber (CSR) with a polyurethane shell is prepared to reinforce the impact strength of Biomass-PU structure adhesive.

Plasma Levels of Polyols Erythritol, Mannitol, and Sorbitol and Incident Coronary Heart Disease Among Women.

Erythritol, a sugar alcohol (polyol), has recently been linked to the risks of major adverse cardiovascular events. We investigated whether plasma erythritol and other polyols (mannitol/sorbitol) were associated with the risk of incident coronary heart disease (CHD). This prospective nested case-control study included 762 incident cases of CHD and 762 controls from the Nurses' Health Study. Plasma concentrations of polyols were measured at baseline (1989-90 or 2000-02). Associations of erythritol with cardiometabolic risk factors were also analyzed in the Women's Lifestyle Validation Study (n=728; blood collected in 2010-12). Higher erythritol levels were related to more adverse cardiometabolic risk factor status. The relative risk (RR) for CHD per 1-SD increment was 1.15 [95% CI: 1.04, 1.28] for erythritol and 1.16 [1.05, 1.28] for mannitol/sorbitol, after adjusting for diet quality, lifestyles, and adiposity. Compared with women in the lowest quartile, those in the highest quartile (Q4) of erythritol had a RR 1.55 [1.13, 2.14] for CHD. The RR in Q4 of erythritol was 1.61 [1.15, 2.24; p=0.006] when hypertension and dyslipidemia were further added to the model; the RR was 1.21 [0.86, 1.70] after adjustment for diabetes. For mannitol/sorbitol, the RR in the Q4 was 1.42 [1.05, 1.91; p=0.022] for CHD in the multivariable-adjusted model including diabetes. Higher plasma erythritol and mannitol/sorbitol were related to elevated risks of CHD even after adjustment for diet, lifestyles, adiposity, and other risk factors. The unfavorable association of mannitol/sorbitol, but not erythritol, with CHD risk remained significant independently of diabetes/hyperglycemia.

QbD Approach in Cosmetic Cleansers Research: The Development of a Moisturizing Cleansing Foam Focusing on Thickener, Surfactants, and Polyols Content.

Cleansing products, particularly innovative cosmetic foams, must efficiently remove impurities with minimal impact on the skin barrier and have a favorable sensory profile. The choice of product ingredients is crucial to ensure the optimal characteristics. The current study aims to provide a comprehensive framework for understanding the variability in the characteristics of a cleansing foam to achieve desired properties. The novelty of this study lies in the combination of ingredients for their potential synergistic and complementary effects in cleansing dry skin, as well as the application of Quality by Design (QbD) elements to develop and optimize the formulation of cleansing foam. The effects of varying the concentration of mild surfactants, polyols, and gel-forming agents on the properties of the gels and of the generated foams were studied. Significant influences of the formulation factors were observed: an increased ratio of xanthan gum positively impacted the texture properties of the gel, whereas higher concentrations of surfactants had a negative impact on these parameters. Additionally, increasing the polyols ratio was found to negatively influence the foaming property and stability of the foam. The study established an optimal formulation of a cleansing foam with a ratio of 0.45% xanthan gum, 26.19% surfactants and 2.16% polyols to be used for dry skin hygiene.

Assessment of heating rate and mixing ratio on the synergistic effects of co-pyrolysis of pine sawdust and high-density polyethylene

The co-pyrolysis of biomass and plastics presents a promising approach for generating hydrocarbon fuels and high-value chemicals while addressing environmental pollution concerns. This study investigates the pyrolysis process by examining mixtures of pine sawdust (PS) and high-density polyethylene (HDPE) with varying mass proportions and heating rates using analytical methods including thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) coupled analysis, pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) and kinetic analysis. The study highlights the impact of heating rate on product distribution, with significant changes observed when the biomass ratio is at 30 %. Moreover, the addition of high-density polyethylene leads to an increase in polyol content in the liquid product. Analysis of product types reveals that plastics act as “hydrogen donors,” supplying hydrogen to biomass during co-pyrolysis, thus reducing oxygen chemicals. Results from the kinetic analysis show that the activation energy for co-pyrolysis is lower than individual pyrolysis, also indicating a synergistic effect. Overall, this research provides insights into the synergistic benefits of co-pyrolysis and establishes a theoretical foundation for advancing co-pyrolysis technology.

Phase behaviour and thermodynamics of triton X-100 + metformin hydrochloride mixture: influences of several polyols and polymer media

The applications of surfactants and drugs in a wide variety of fields such as pharmaceuticals, food industry, textile, fabrics, etc. are increasing significantly. Herein, we investigated the clouding behavior and thermodynamics of triton X-100 (TX-100) and metformin hydrochloride (MNH) drug mixture in the effect of several polyols and polyethylene glycol (PEG) polymer. The phase separation behavior of the mixture of TX-100 + MNH has been deduced with the help of the cloud point technique. The cloud point (CP) values for the TX-100 and drug mixtures were documented in a decreased and increased manner with the augmentation of the concentration of polyol and PEG respectively. With the subsequent enhancement of polyol and PEG content, the CP values were recorded in the following order: C P H 2 O + PEG > C P H 2 O + fructose > C P H 2 O + glucose > C P H 2 O + galactose > C P H 2 O + maltose . The standard enthalpy change ( Δ H c o ) and entropy change ( Δ S c o ), of TX-100 + MNH mixture in aq. polyols solutions were documented as negative; the negative values reduce in magnitudes with the polyols contents and become positive at the highest polyol content while opposite trend was obtained in presence of PEG. The presence of electrostatic and hydrophobic interactions among TX-100/MNH/polyols/polymer has been recommended as the interaction forces.

Effects of polyols at low concentration on the release of sweet aroma compounds in model soda beverages

This study investigated the effect of polyols erythritol, d-mannitol, and maltitol on the volatility of aroma compounds γ-butyrolactone, 3-methyl-1-butanol, and 2-phenylethanol in aqueous solution. Headspace solid-phase microextraction/gas chromatography and diffusion-ordered nuclear magnetic resonance techniques were used to obtain information on aroma–food matrix interaction. Results demonstrated that adding polyols at final low concentrations of 5% or 10% (w/w) to an aqueous solution of 2-phenylethanol reduced the release of vapor-phase aromas, except in the case of 3-methyl-1-butanol, which was not affected by the presence of polyols in the liquid matrix. Polyols also reduced the diffusion coefficients of all three aroma compounds, probably due to friction between the molecules. At low polyol concentrations, aroma compound volatility and diffusion coefficient values were altered compared to those of aromas released from pure water. This observation is related to the physicochemical properties of the aroma compounds. These insights may help guide the use of the combination of aroma compounds and polyols in the formulation of sugar-free and reduced-sugar beverages. Chemical compoundsγ-butyrolactone (PubChem CID: 7302), 3-methyl-1-butanol (PubChem CID: 31260), 2-phenylethanol (PubChem CID: 6054), erythritol (PubChem CID: 222285), d-mannitol (PubChem CID: 6251), maltitol (PubChem CID: 493591).

Dehydrated mycelia (Cordyceps militaris, Grifola frondosa, Hericium erinaceus and Laricifomes officinalis) as Novel Foods: A comprehensive NMR study

Several medicinal mushrooms have been approved as European Novel Foods or have the potential to become Novel Foods. However, their chemical characterization is limited, being mainly focused on specific compounds.Here, the dehydrated mycelia (isolated from sporophores collected in Italy) of Grifola frondosa, Hericium erinaceus, recently defined as Novel Foods, and Cordyceps militaris and Laricifomes officinalis, with potential Novel Food use, were analyzed by NMR methodology to define their metabolite and nutritional profile. Amino acids and derivatives, sugars and polyols, organic acids, fatty acids, lipid polar moieties, nitrogen-containing compounds were identified and quantified in hydroalcoholic and organic extracts.C. militaris showed a high amount of glutamate, citrate and mannitol, also involved in mushroom taste, being the only species presenting tri-unsaturated fatty acids. L. officinalis was characterized by the highest amount of TAA and EAA, and the lowest sugars and polyols content. G. frondosa and H. erinaceus were characterized by high amounts of trehalose (13–14 % of dried weight).Each dehydrated mycelia potentially represents an innovative food matrix alone, for culinary, nutritional and nutraceutical needs, or mixed together to obtain new products. Moreover, these mycelia can be of interest as sources of isolated bioactive compounds for supplements with particular nutritional functions.

FODMAP Content Like-by-like Comparison in Spanish Gluten-free and Gluten-containing Cereal-based Products

Gluten-free foods (GF) availability on supermarket shelves is growing and it is expected to continue expanding in the years ahead. These foods have been linked to a lower content of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), molecules that trigger gastrointestinal symptoms in sensitive persons. In this study, the FODMAP content of 25 cereal-based GF foods in Spain (breakfast cereals, pasta, bread, biscuits, bakery products, and dough and puff pastry) and 25 gluten-containing equivalents (GC) available in the same supermarket were analysed and compared. Lactose, fructose, glucose, sorbitol, mannitol, raffinose, stachyose and fructans were quantified. In a like-by-like analysis, GF foods were found to generally contain fewer FODMAPs than their GC counterparts. The ingredients used in the manufacture of GF cereal-based foods may contribute to this fact. When the individually wrapped size was considered, the proportion of samples classified as high-FODMAPs in GC and GF foods showed a trend towards fewer samples in the GF. However, not all the GF samples were low-FODMAP. Altogether, our findings provide essential information for FODMAP content databases of GF products in Spain.

Organic tracers in fine and coarse aerosols at an urban Mediterranean site: contribution of biomass burning and biogenic emissions.

The concentrations of anhydrosugars (levoglucosan, mannosan, and galactosan), polyols (inositol, xylitol, sorbitol, and mannitol), and glucose were measured in PM1 and PM10 samples collected during 1 year at a traffic site in the city of Elche (southeastern Spain). Levoglucosan, mannosan, and galactosan were mainly found in the PM1 fraction since they are mainly emitted from biomass burning (BB). Likewise, inositol, xylitol, and sorbitol were primarily distributed in the fine mode, suggesting a non-negligible contribution from anthropogenic sources (specifically BB) to the levels of these compounds. This was supported by their seasonal variations, with higher concentrations during winter, and their correlations with levoglucosan concentrations. The average contributions of biomass burning and biogenic sources to OC and PM levels were calculated using levoglucosan and mannitol, respectively, as tracers. On average, BB accounted for 12% and 16% of the OC in PM1 and PM10, while the estimated contribution of fungal spores to OC and PM10 levels was 1.2 and 0.8%, respectively. The results of the present study suggest that, at least in the study area, most sugar alcohols are not appropriate tracers of biogenic emissions.

The impact of 48 h high carbohydrate diets with high and low FODMAP content on gastrointestinal status and symptoms in response to endurance exercise, and subsequent endurance performance.

This study investigated the effects of a high carbohydrate diet, with varied fermentable oligo-, di-, and mono-saccharide and polyol (FODMAP) content, before endurance exercise on gastrointestinal integrity, motility, and symptoms; and subsequent exercise performance. Twelve endurance athletes were provided with a 48 h high carbohydrate (mean±SD: 12.1±1.8 g kg day-1) diet on two separate occasions, composed of high (54.8±10.5 g day-1) and low FODMAP (3.0±0.2 g day-1) content. Thereafter, participants completed a 2 h steady-state running exercise at 60% of (22.9±1.2 °C, 46.4±7.9% RH), followed by a 1 h distance performance test. Pre-exercise and every 20 min during steady-state exercise, 100 mL maltodextrin (10%w/v) solution was consumed. A 150 mL lactulose (20 g) solution was consumed 30 min into the distance performance test to determine orocecal transit time (OCTT) during exercise. Blood was collected pre- and post exercise to determine gastrointestinal integrity biomarkers (i.e., I-FABP, sCD14, and CRP). Breath hydrogen (H2) and gastrointestinal symptoms (GIS) were determined pre-exercise, every 15 min, during and throughout recovery. No differences in gastrointestinal integrity biomarkers, OCTT, or distance completed were observed between trials. Pre-exercise total-GIS (1.3±2.9vs. 4.3±4.4), gut discomfort (9.9±8.1vs. 15.8±9.0), and upper-GIS (2.8±2.6vs. 5.7±4.8) during exercise were less severe on high carbohydrate low FODMAP (HC-LFOD) versus high carbohydrate high FODMAP (HC-HFOD) (p<0.05). Gut discomfort (3.4±4.4vs. 0.2±0.6) and total-GIS (4.9±6.8vs. 0.2±0.6) were higher during recovery on HC-LFOD versus HC-HFOD (p<0.05). The FODMAP content of a 48 h high carbohydrate diet does not impact gastrointestinal integrity or motility in response to endurance exercise. However, a high FODMAP content exacerbates GIS before and during exercise, but this does not impact performance outcomes.

Содержание свободных жирных кислот и углеводов в подземных органах элеутерококка колючего (Eleutherococcus senticosus (Rupr. et Maxim.) Maxim.)

Objective: determination of the qualitative and quantitative content of free fatty acids and free carbohydrates in various samples of Eleutherococcus raw materials collected in the Russian Far East. Materials and methods. The samples used for the study were rhizomes and roots of Eleutherococcus collected in the Primorsky and Khabarovsk Territories, Amur and Jewish Autonomous Regions. The composition of the constituents was studied by gas chromatography-mass spectrometry (GC-MS). Results. In the samples analysed, 3 polyols (sugar alcohols), 6 sugars and 5 fatty acids were identified. The group of polyols identified includes arabitol, mannitol and inositol. From the group of fatty acids, palmitic, margaric, stearic, linoleic and oleic acids were identified. The carbohydrate group includes fructose, allose, glucose, cellobiose, sucrose and raffinose. The quantitative content was evaluated for each compound. In the fatty acid complex, the highest content was found for linoleic acid (1.15 mg/g). The dominant components of the carbohydrate complex were found to be sucrose and glucose with respective contents of 9.29 mg/g and 12.53 mg/g. The average content of total polyols was 1.29 mg/g, fatty acids - 2.01 mg/g and free carbohydrates - 29.51 mg/g. Significant variability was observed in the quantitative content not only of individual substances, but also in the sum of substances of different groups. The coefficients of variability of the content of individual substances ranged from 47 to 199%, and the amounts of fatty acids, polyols and free carbohydrates from 61 to 62%. Conclusion. Thus, presence of 3 polyols, 6 sugars and 5 fatty acids was detected. A quantitative assessment of their content and statistical processing of the data obtained were carried out. It has been shown that the quantitative content of the compounds in the samples studied is characterized by a significant variability.

Characterization and Application of Rice Straw-Based Polyurethane Foam Blocks for Soil Erosion Control

Soil erosion, a global problem, degrades land quality and increases pollution and sedimentation in bodies of water. This study propounds a new material to mitigate soil erosion using rice straw-based polyurethane foam (RSPF) blocks as a potential replacement for commercially available expanded polystyrene (EPS) foam in slope stabilization. RSPF was synthesized via a conventional one-shot foaming method with 15% rice straw-based polyol content. The RSPF blocks have an average density of 43.29 kg/m3, average compressive strength of 184.55 kPa, closed cell content of 88.4%, and water absorption capacity of 262% that can effectively reduce water runoff. These properties are comparable to EPS foams according to ASTM D6817, except for the high absorption capacity of RSPF. This added feature allows the foam to act as topsoil protection by reducing runoff. In slope stabilization and topsoil protection applications, the effectiveness of the RSPF blocks in reducing soil loss was tested in both simulated and natural rainfall events with different land slope degrees, rain intensities, and soil covers. Results show that the use of RSPF in the simulated setup with a heavy rain intensity of 80 mm/h reduced the soil loss by 61.5%, 22.7%, and 4.3% in 5°, 10°, and 20° of land slope, respectively. There was also a higher degree of soil loss reduction when the RSPF block was coupled with a natural vegetation soil cover by 79.6%, 70%, and 19.3% in 5°, 10°, and 20° land slopes, respectively. Moreover, in the natural rainfall events in an open field with a land slope of 20°, the recorded soil loss reduction reached 93.6–98.8% at an average rainfall intensity of 16.26 mm/h. Additionally, the relationship between soil loss and land slope was investigated to produce a best fit model that predicts the soil loss up to a 20° land slope. An interesting observation was made wherein the erosion rate increased using linear regression modeling in the simulated setup for bare soil (BS), soil with vegetation (SV), soil with RSPF (SF), and soil with RSPF and vegetation (FV), with high coefficient of determination (R2) values between 0.92 and 0.99. These findings suggest that the RSPF block is a promising alternative and sustainable material for EPS foams in mitigating soil erosion, especially under heavy rainfall conditions.

Lipid composition of plasma membranes of rooster sperm (Gallus gallus domesticus) and its dynamics during cryopreservation

The structural features of the plasma membranes of avian sperm make them more sensitive, compared to those of mammals, to low-temperature stress. The qualitative and quantitative composition of membrane lipids can become a determining factor in the development of new effective compositions of cryoprotective media. The purpose of the study was to determine the lipid composition of the plasma membranes of native rooster sperm, the content of carbohydrates and polyols in their cytosol, as well as dynamic changes in the membrane lipidome and cytosol composition under the influence of the cryopreservation protocol, depending on the composition of the cryoprotective medium. The studies were carried out on Rhode Island roosters (n=10), the total and progressive sperm motility and membrane damage were determined. Semen freezing and thawing was carried out using fast protocols. To determine the lipid composition of the plasma membranes of sperm and the composition of their cytosol, a chromatographic analysis method was used. The following were identified in the membranes of native spermatozoa: phospholipids, glycolyllipids and neutral lipids, represented by phosphatidylethalamine, phosphatidylserine, phosphatidylcholine, sphingomyelin and sterol. A change in the ratio between membrane lipids of the inner and outer layers of the plasma membrane of rooster spermatozoa under the influence of the cryopreservation protocol was shown. In native spermftozoa this ratio was 41.2% and 39.4%, respectively, in thawed sperm when using the LCM-control medium – 38.3% and 47.2%, respectively, when using the LCM-T20 medium - 40.7% and 44.5%, respectively. There was a significant decrease, more than 3 times, in the total amount of carbohydrates (fructose, glucose, trehalose) and polyols (glycerol, mannitol, inositol) in the cytosol of frozen/thawed spermatozoa when using the cryoprotective medium LCM-control compared with the values of the native spermatozoa - 0 .1145 mg/ml and 0.0360 mg/ml, respectively. When using the LCM-T20 medium, the change was insignificant and the delta was 5.2%. The effectiveness of using cryoprotective medium LCM-T20 containing trehalose has been proven to maintain the lipid membrane architecture of rooster spermatozoa, the carbohydratepolyol composition of their cytosol and, as a consequence, the morphofunctional usefulness of gametes during the freezing/thawing process.

Changes in kinetic parameters and cytological characteristics of rooster spermatozoa under the influence of technological factors

The problems of fertility reducing of rooster semen in the cycle «native sperm-equilibration-short-term and long-term storage (cryopreservation)» are urgent. The purpose of this study was to determine the effect of different methods of preparation (centrifugation or filtration) of rooster semen on its quality characteristics, depending on the method of removing possible pollutions; to evaluate the change in the composition of the cytosol of spermatozoa of native sperm under the influence of dilution and during short-term storage. Materials and methods. Semen of roosters (n=22) of the Russian white breed was used. Experiment 1: semen was divided into 3 aliquots: I - diluted with synthetic cryoprotective medium LCM in a ratio of 1:1, II - filtered semen diluted with medium (membrane pore diameter 0.2 μm), III - centrifuged (at 3000 rpm in for 10 minutes). Native and frozen/thawed sperm were evaluated in terms of damage to spermatozoa membranes, chromatin, and acrosomes. The composition of carbohydrates and polyols of native spermatozoa was assessed under the influence of dilution and after storage (3 h). The advantage of filtration as a method of technological preparation of semen compared to centrifugation in terms of progressive motility (with rectilinear-translational movement) of sperm (41.0 % versus 27.0 %) and chromatin damage (43.4 % versus 66.4 %) has been shown. The same advantage was observed in frozen/thawed sperm filtered before freezing in terms of progressive motility (25.5 % vs. 5.5 %) and chromatin damage - 16.5 % vs. 33.6 %, respectively. Semen filtration, as a method of technological processing of rooster semen, can be an effective additional step in the preparation of semen for artificial insemination and/or short-term storage. The main component in the composition of the cytosol of native spermatozoa, according to the content of carbohydrates and polyols, was inositol - 73.7 % of ∑ carbohydrates and polyols. The level of inositol decreased during storage by 6.5 times (from 0.030 mg/ml to 0.007 mg/ml). The data obtained let us suppose the role of inositol as the main antioxidant in the cytosol of spermatozoa. Technological factors of storing rooster semen in various modes (short-term at a temperature of 5ºC and long-term at a temperature of -196ºC) have a significant impact on the ratio of sperm cytosol components (carbohydrates and polyols). A significant, 2.5-fold decrease in the relative content of inositol in the cytosol of frozen/thawed spermatozoa, compared with the indicators of native semen, allows us to recommend the introduction of the antioxidant inositol into the composition of cryoprotective media for rooster semen.

Wettability, adhesive performance and structural evolution of an environment-friendly modified silicate binder for foundry moulding and coremaking

For the manufacturing of sand cores, silicate inorganic binders have emerged as promising green casting binder materials; however, their adhesive performance requires further improvement. In this study, to evaluate the impact of using water-soluble polyols, i.e. polyethylene glycol (PEG) and xylitol, to modify silicate adhesives, the effect of the content and type of water-soluble polyol on the colloidal stability, wettability and adhesive performance of a silicate binder were investigated. The structural evolution of the modified silicate binder and the polysilicate bondswere studied using characterisation techniques including infrared spectroscopy and 29Si nuclear magnetic resonance (NMR) spectroscopy. Results revealed that PEG 400 and PEG 600 increased the size of polysilicate particles in the solution, resulting in flocculation of the silicate binders and easy precipitation or separation in a short period of time. However, PEG 200 and xylitol exerted little effect on the stability of the silicate solution. Moreover, 0.25 wt% PEG 200 reduced the surface tension of the solution from 78.93 to 54.15 mN/m and the equilibrium contact angle from 45.0° to 34.6°. The polyol promoted the dehydration and condensation of silicic acid gel to form a more stable three-dimensional network structure, improving the bonding strength of casting sand cores prepared using the silicate binder and silica sand from 2.42 to 3.02 MPa. This study not only unveils the role of PEG in improving the wettability and bonding behaviour but also provides an example of the rational use of environment-friendly water-soluble polyols to enhance the performance of green inorganic adhesive materials.

Soybean-Based Polyol as a Substitute of Fossil-Based Polyol on the Synthesis of Thermoplastic Polyurethanes: The Effect of Its Content on Morphological and Physicochemical Properties.

Thermoplastic polyurethanes (TPUs) are remarkably versatile polymers due to the wide range of raw materials available for their synthesis, resulting in physicochemical characteristics that can be tailored according to the specific requirements of their final applications. In this study, a renewable bio-based polyol obtained from soybean oil is used for the synthesis of TPU via reactive extrusion, and the influence of the bio-based polyol on the multi-phase structure and properties of the TPU is studied. As raw materials, 4,4'-diphenylmethane (MDI), 1,4-butanediol, a fossil-based polyester polyol, and a bio-based polyol are used. The fossil-based to soybean-based polyol ratios studied are 100/0, 99/1, 95/5, 90/10, 80/20, and 50/50% by weight, respectively. The TPUs were characterized by size exclusion chromatography (SEC), gel content analysis, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), dynamic mechanical analysis (DMA), and contact angle measurements. The results reveal that incorporating the renewable polyol enhances the compatibility between the rigid and flexible segments of the TPU. However, due to its high functionality, the addition of soybean-based polyol can promote cross-linking. This phenomenon reduces the density of hydrogen bonds within the material, also reducing polarity and restricting macromolecular mobility, as corroborated by higher glass transition temperature (Tg) values. Remarkably, the addition of small amounts of the bio-based polyol (up to 5 wt.% of the total polyol content) results in high-molecular-weight TPUs with lower polarity, combined with suitable processability and mechanical properties, thus broadening the range of applications and improving their sustainability.

The utilization of glycerol and xylitol in bio-based vitrimer-like elastomer: Toward more environmentally friendly recyclable and thermally healable crosslinked rubber

Eco-friendly rubbers developed from renewable materials and using covalent adaptive networks (CANs) are a family of sustainable materials that has recently attracted enormous interest from both industry and academia. In this study, vitrimer-like elastomers based on epoxidized natural rubber (ENR) were synthesized by cross-linking with dimer fatty acid (DFA). The addition of a small amount of bio-based polyol, namely the sugar alcohol glycerol (GLY) or xylitol (XYL), into the elastomeric vitrimer significantly enhanced its physical and viscoelastic properties. The glycerol-containing vitrimer tended to have reduced maximum torque, modulus, and crosslink density, while the opposite trend was found when xylitol was loaded in ENR50 vitrimer. Therefore, the mechanical and thermal properties of ENR50 vitrimer, as well as H-bond formation, can be manipulated by incorporating different types and concentrations of bio-based polyols. Importantly, a β-hydroxy ester formed in ENR50 can undergo an exchange reaction between the ester and hydroxyl group, a so-called dynamic exchange transesterification reaction, enabling thermo-healing and recycling. The formation of a denser network in polyol-treated ENR50 vitrimer may suppress the mobility of chain segments, affecting speeds of exchange reaction and stress relaxation. The ENR50 vitrimer with sugar alcohols shows several remarkable features in its mechanical performance and dynamic properties and points to an alternative for achieving green production, circular economy, and environmentally friendly processes.

Elevated CO2 increases biomass of Sorghum bicolor green prop roots under drought conditions via soluble sugar accumulation and photosynthetic activity.

Elevated [CO2 ] (E[CO2 ]) mitigates agricultural losses of C4 plants under drought. Although several studies have described the molecular responses of the C4 plant species Sorghum bicolor during drought exposure, few have reported the combined effects of drought and E[CO2 ] (E[CO2 ]/D) on the roots. A previous study showed that, among plant organs, green prop roots (GPRs) under E[CO2 ]/D presented the second highest increase in biomass after leaves compared with ambient [CO2 ]/D. GPRs are photosynthetically active and sensitive to drought. To understand which mechanisms are involved in the increase in biomass of GPRs, we performed transcriptome analyses of GPRs under E[CO2 ]/D. Whole-transcriptome analysis revealed several pathways altered under E[CO2 ]/D, among which photosynthesis was strongly affected. We also used previous metabolome data to support our transcriptome data. Activities associated with photosynthesis and central metabolism increased, as seen by the upregulation of photosynthesis-related genes, a rise in glucose and polyol contents, and increased contents of chlorophyll a and carotenoids. Protein-protein interaction networks revealed that proliferation, biogenesis, and homeostasis categories were enriched and contained mainly upregulated genes. The findings suggest that the previously reported increase in GPR biomass of plants grown under E[CO2 ]/D is mainly attributed to glucose and polyol accumulation, as well as photosynthesis activity and carbon provided by respiratory CO2 refixation. Our findings reveal that an intriguing and complex metabolic process occurs in GPRs under E[CO2 ]/D, showing the crucial role of these organs in plant drought /tolerance.

Thermoset polyurethanes from biobased and recycled components

In this work, a recycled bis(2-hydroxyethyl) terephthalate (BHET) monomer, obtained by glycolysis of marine polyethylene terephthalate (PET) litter, and a biobased polyol derived from castor oil were used for the synthesis of thermoset polyurethanes (PUs). BHET was obtained in a closed reactor at 220 °C and a short reaction time of 30 min. Different PUs were synthesized, varying the BHET content, ranging from 0 to 21 wt% and varying the polyol content, obtaining a renewable carbon content between 23 and 43%. The PUs synthesized in this work, in which at least 40% of their components are renewable and recycled, showed an interesting combination of thermal, thermo-mechanical and mechanical properties. In addition, a preliminary chemical recycling study of the synthesized PUs was performed to evaluate their recyclability, wrapping the whole process within the circular economy. The obtained glycolyzed product was a single-phase viscous liquid consisting on polyol-rich and BHET-rich fractions, with contents in the range of those employed in the synthesis of PUs.