Diol Type Research Articles

Investigation of the impacts of several diols on the phase behavior and physico-chemical quantities associated with the Triton X-100 and antidiabetic drug mixture

Drug-surfactant interaction phenomena have received popularity in the pharmaceutical industry and technological sectors from the view point of wider applications. Herein, we aimed to investigate the clouding behavior and various thermodynamic properties of Triton X-100 (TX-100) and metformin hydrochloride drug (MNH; an antidiabetic drug) mixture in the attendance of diols followed by the cloud point measurement technique. The dosage form of metformin hydrochloride drug controls the glucose level in the blood. The different types of diols, i.e., ethylene glycol (EG), 1,2-propylene glycol (1,2-PrG), 2,3-butanediol (2,3-BD), and 1,5-pentanediol (1,5-PD) were uniformly used in this inspection. The effect of diols, with the variation of their concentrations on the clouding behavior of TX-100 + MNH mixture having fixed content of TX-100 (92.7 mmol kg−1) and MNH drug (2 mmol kg−1), were examined. The most enhanced CP value was experienced in the aqueous 1,5-PD medium, whereas the lowest CP value was observed in the aqueous EG medium. The CP values were recorded for the working system under the effect of changing concentrations of diols, which were observed to follow the sequential order: CPH2O+1,5−PD>CPH2O+2,3−BD>CPH2O+1,2−PrG>CPH2O+EG. The clouding progression of the working system was realized to be nonspontaneous as concluded from the positive free energy change (ΔGco) values. The positive and negative values of enthalpy (ΔHco) and entropy (ΔSco) change were documented, respectively, at the low and high concentrations of diols. The hydrophobic interactions amongst different components are predominant at the low concentrations of diols, whereas the electrostatic interactions are leading factors at the high concentrations of diols. Enthalpy-entropy compensation parameters were computed and interpreted with proper perceptive. The outcomes of this observation may be effective and helpful in the various industrial sectors, especially in the drug carrier system in the pharmaceutical arena.

Hydrolytic degradation and in vitro studies of poly(alkylene citrate)-based polyesters modified with glutathione

Materials currently used for vascular grafts are characterized by limited biocompatibility. Especially challenging is obtaining the degradable graft to regenerate a patient's native tissue. Poly(alkylene citrates) (PACs) are promising for soft tissue engineering applications; however, their degradation must follow a specific profile and must not result in the formation of any substances cytotoxic to the human body. The aim of this study was to evaluate the processes that occur throughout the hydrolytic degradation of PACs with a 2:3 M ratio of citric acid and diol, additionally modified with an antioxidant compound: glutathione (GSH). The samples were tested after various time intervals of incubation in an aqueous environment (up to 3 months), taking into account the influence of the type of diol used (1,6-hexanediol or 1,8-octanediol), the time of polymer cross-linking (4 or 10 days) and the presence of a different amount of GSH (0.4 or 0.8 wt%). Structural changes in the samples were monitored by means of swelling capacity, mass changes, hardness tests, mass spectrometry, and UV spectrofluorimetry. After 3 months of degradation, a higher weight loss was observed for the samples based on 1,6-hexanediol (>20 wt%) than those based on 1,8-octanediol (6–16 wt%). Based on the values obtained, the approximate time of 80% of the mass loss was calculated, which was higher for samples cross-linked for 10 days than 4 days. The samples based on 1,8-octanediol degraded slower than those of 1,6-hexanediol, but their degradation pattern was more linear and the amount of heavy ions present in the supernatant was negligible. In vitro studies on L929 fibroblasts did not show a cytotoxic effect of the materials tested. The study proved that GSH does not cause significant changes in the degradation profiles, sufficiently providing the fluorescence properties of the materials. Furthermore, any drastic changes in the material for up to 3 weeks followed by progressive degradation may support the tissue before the regeneration process begins.

Effects of (20 R)-Panaxadiol on NAFLD using non‑targeted metabolomics in stool

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome characterized by hepatocyte steatosis and adipose accumulation with the main lesion in the hepatic lobule, but without a history of excessive alcohol consumption. NAFLD ranges from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), and may further accumulate fibrosis leading to cirrhosis. Many studies have found that ginseng can treat NAFLD. (20 R)-Panaxadiol (PD) is a panax ginseng diol type compound, has been proved that can treat the obesity. This study wants to investigate the effect of PD on non-alcoholic liver disease. We used 20 ob/ob mice and 10 C57BL/6 J mice. C57BL/6 J mice as CONTROL group, ob/ob mice were divided into model group and PD group. In PD group, ob/ob mice were treated with PD for eight weeks(10 mg/kg, the CON and OB group was given the same amount of sodium carboxymethyl cellulose), detected the weight, food intake and serum index, observed the HE staining of liver and intestine, performed the 16 S rRNA and untargeted metabolomics analysis used mice feces, and verify the results by detect the expression of TNF-α, MDA and SOD. In vivo results, PD can improve abnormal glucose and lipid metabolism and liver function. In 16 S rRNA result, we found beneficial bacteria Muribaculaceae and Lactobacillus increased; in untargeted metabolomics analysis, inflammatory metabolites prostaglandin (PG) and lipopolysaccharide (LPS) decreased, antioxidant metabolites FAD and lipoic acid increased. Then, we proceeded the association analysis of gut microbiota and metabolites, the result showed gut microbiota have strongly associated with anti-inflammatory and antioxidant metabolites. In addition, PD improves intestinal wall integrity. Meanwhile, the expression of TNF-α、MDA and SOD were detected, it was verified that PD has the effect of antioxidant and anti-inflammation. Our study showed that PD, as an active ingredient of ginseng, can play an anti-inflammatory and antioxidant role by improving intestinal metabolites, thereby preventing and treating non-alcoholic fatty liver disease to a certain extent.

Bio-Degradable Polyesters with Rigid Cyclic Diester from Camphor and Tartaric Acid.

Despite their excellent, useful, and stable properties, thermoplastics are constantly subject to environmental risks because of their low degradability under thermal, chemical, and mechanical stresses. To overcome the aforementioned issues, we hereby introduce an eco-friendly camphor (Ct) cyclic diester. The Ct diester is designed as a monomer, including a ketal group from the Ct, and shows high thermal stability via a rigid spiro-ring and a bridged bicyclic structure. A series of polyester was synthesized using the Ct diester, including various types of diols and dimethyl terephthalate. PETxCty copolyesters showed appropriate thermal stability up to 414 °C and a high glass transition temperature. This thermal behavior led to amorphous regions as the Ct diester content increased. Regarding the proportion of the Ct diester in the polyester, it was sensitive to hydrolysis and contributed to the degradation of the polyester in acid buffer conditions.Graphical

(20R)-Panaxadiol as a Natural Active Component with Anti-Obesity Effects on ob/ob Mice via Modulating the Gut Microbiota.

Obesity is an important cause of diseases such as type 2 diabetes, non-alcoholic fatty liver and atherosclerosis. The use of ingredients extracted from traditional Chinese medicine for weight loss is now receiving more and more attention. Ginseng has been recorded since ancient times for the treatment of diabetes. The (20R)-Panaxadiol (PD) belongs to the ginseng diol type compounds, which are moderately bioavailable and may remain in the intestinal tract for a longer period of time. This study investigated the potential positive effect of PD in ob/ob mice and evaluated its effect against obesity. The ob/ob mice were administered PD for ten weeks. Our study showed that PD could improve obesity, glucose tolerance disorder, as well as gut dysbiosis. Panaxadiol decreased ob/ob mice’s Firmicutes/Bacteroidetes (F/B). Furthermore, 16S rRNA gene sequencing of the fecal microbiota suggested that PD changed the composition of the gut microbiota in ob/ob mice and modulated specific bacteria such as lactobacillus, prevotellace and so on. Moreover, PD improved the intestinal wall integrity. In conclusion, our results suggest that (20R)-Panaxadiol, as an active ingredient of the traditional Chinese medicinal herb ginseng, may improve obesity to some extent via improving gut microbiota

Study on the mechanism of enlarged spherulite diameter for aliphatic polyester ionomers

Aliphatic polyesters with repeated chemical cycle performance are the promising candidate to eliminate environment pollution evoked by the petroleum-based plastics. The incorporation of ionic group can improve the strength, thermal resistance and melt viscosity of polyesters and promote them to utilize at high performance film or foam. Interestingly, these semi-crystalline ionomers achieve significant enlarged spherulite diameter (Du) when the content of ionic group is 0.58 mol%. To explore the unexpected phenomenon, poly(ethylene succinate) and poly(decamethylene succinate) phosphorus-containing ionomers (PESIs-K and PDSIs-K) with 0.58–1.91 mol% ionic group containing phosphorus (PCIG) were prepared by condensation polymerization of ethylene glycol (or 1, 10-decamethylene glycol), succinic acid and phosphorous ion monomers (DHPPO-K), respectively. The effects of PCIG content and types of diols on the chemical structures, thermal behavior, crystallization, and rheological behavior of samples were characterized by FTIR, NMR, DSC, POM, XRD, SAXS, DMA and rotational rheometer, respectively. Strikingly, the t1/2 of PESI1-K decreased from 7.0 to 2.9 min, while its Du increased from 103 to 171 μm. The reasons were that PESI1-K with moderate heterogeneous nucleation sites and melt viscosity guaranteed it to achieve high crystal growth rate, and enough growth time and space for each grain. Moreover, the incorporation of electrostatic interactions by ionic clusters facilitated the crystalline grains to cumulate in large spherulites without collapse. However, due to the improved flexibility, the relaxation time of PDS and its ionomers were much lower than those of PES and PESIs-K, while their self-nucleation capacity increased, which decreased the Du. Summarily, the effects of PCIG on crystallization behaviors were elaborated in detail and the improved Du mechanism of ionomers was proposed.

Influence of the composition of macromolecular diols on the rheology and water absorption of polyurethane acrylate emulsions

AbstractWaterborne modified polyurethane (PU) dispersions with different macromolecular diols as soft segments were prepared by the self‐emulsifying method, and then compounded with the acrylate monomers, the polyurethaneacrylate composite emulsion (PUA) with the core‐shell structure was prepared by emulsifier free emulsion polymerization. The effects of the type and ratio of macromolecular diols in the soft segment on the particle size and distribution, rheological properties, adhesion, water absorption and thermal properties of the PUA emulsion were studied. The results showed that the particle size of PUA decreased, and the shear resistance and heat resistance of PUA were enhanced with the addition of polypropylene glycol. According to the water absorption rate of PUA emulsion, it was found that adding poly‐1,4‐butanediol adipate glycol and poly(caprolactone) diol with more hydrophobic groups could improve the water resistance of PUA dry film, and the minimum water absorption value was 0.68%.

Highly Proton-Conducting Membranes Based on Poly(arylene ether)s with Densely Sulfonated and Partially Fluorinated Multiphenyl for Fuel Cell Applications.

Series of partially fluorinated sulfonated poly(arylene ether)s were synthesized through nucleophilic substitution polycondensation from three types of diols and superhydrophobic tetra-trifluoromethyl-substituted difluoro monomers with postsulfonation to obtain densely sulfonated ionomers. The membranes had similar ion exchange capacities of 2.92 ± 0.20 mmol g−1 and favorable mechanical properties (Young’s moduli of 1.60–1.83 GPa). The membranes exhibited considerable dimensional stability (43.1–122.3% change in area and 42.1–61.5% change in thickness at 80 °C) and oxidative stability (~55.5%). The proton conductivity of the membranes, higher (174.3–301.8 mS cm−1) than that of Nafion 211 (123.8 mS cm−1), was the percent conducting volume corresponding to the water uptake. The membranes were observed to comprise isolated to tailed ionic clusters of size 15–45 nm and 3–8 nm, respectively, in transmission electron microscopy images. A fuel cell containing one such material exhibited high single-cell performance—a maximum power density of 1.32 W cm2 and current density of >1600 mA cm−2 at 0.6 V. The results indicate that the material is a candidate for proton exchange membranes in fuel cell applications.

Functional biopolyesters based on cross-linked Poly(L-malic acid): Network engineering towards tailoring brittle-ductile transition and shape-memory performance

Crosslinking opens more possibilities of biodegradable poly (L-malic acid) (PLMA) as functional materials, and network structure is key to its mechanical states and final applications. In this work, the diols with various chain lengths, including six types of fatty diols and four types of polyethylene glycols, were used to construct networks in PLMA, aiming at establishing network structure-mechanical state-material function correlations. As the molecular weights of diols increased from 100 to 400, the samples experienced evident transition from high-strength plastic to low-loss rubber, finally to soft elastomer. The strengths and Young's moduli varied from 71 MPa to 0.6 MPa and from 2.3 GPa to 2.7 MPa, respectively, accompanied by a broad variation of glass transition temperature (Tg, 50 oC–7 oC). This brittle-ductile transition was revealed in terms of elastoplastic and dielectric relaxations, then. Using the samples with different network structures as components, the actuators with attractive capability to complete asynchronous actions were fabricated. This work proposes promising applications of cross-linked PLMA as functional or smart materials due to its easily-tuned mechanical states and Tg, together with its good antibactierial activity and shape memory effect.

Microwave-assisted chemical recycling of polylactide (PLA) by alcoholysis with various diols

A process for the chemical recycling of degradable polylactide (PLA) has been developed, to convert its disposable wastes into small-sized products for further use as value-added starting materials for specialty products. A microwave-assisted alcoholysis reaction, using diols and tetrabutyl orthotitanate (TBT) catalyst, was employed. The effects of the types of diols and PLA/diol feeding ratios on the structures and properties of the resulting alcoholized products were examined by using ethylene glycol (EG), propane-1,3-diol (PDO), and butane-1,4-diol (BDO). The PLA/diol ratios were varied from 1:1 to 4:1 wt/wt. The products were characterized by ATR-FTIR, 1H NMR, and 2D-NMR HMQC and HMBC spectroscopy. The products compost to diol-capped lactate sequences with different lengths, i.e., lactate, lactyllactate, and poly-lactate. The yield of the shortest lactate was about 65% for the LBDOT11 system, and 90% for the LEGT11 and LPDOT11 systems, when a feeding ratio of 1:1 wt/wt was employed. The yield decreased with an increase in the ratios, from 1:1 to 4:1 wt/wt. In contrast, the yields of longer lactyllactate and poly-lactate increased with an increase in the ratios. In terms of OH-endcapping efficiency, the products have two structures: (A) LA-O-(CH2)x-OH and (B) LA-O-(CH2)x-O-LA. The contents depend on diol types and the PLA/diol feeding ratio. The alcoholized products were then used as starting polyols in the preparation of lactide-based polyurethanes (PUs) by reacting with 1,6-diisocyanatohexane (HDI) and BDO chain extender. The resulting PUs exhibit promising mechanical and thermal properties. These PUs are suitable for use as either single-component materials, e.g., 3D-printing filaments and degradable adhesives, or as toughness-enhancing agents for brittle polymers, especially PLA.

Copolymerization approach of soft segment towards the adhesion improvement of polycarbonate-based thermoplastic polyurethane

ABSTRACT Thermoplastic polyurethane elastomers (TPUs) have been intensively used as hot-melt adhesives (HMAs) due to their adherence ability that can be applied on hard surfaces. To overcome their drawbacks, such as low peel strength and deformation, the performance improvement of the TPUs-HMAs has become a challenging issue. In this study, the enhancement properties of the TPUs-HMAs were achieved from the copolymerization of a soft-segment technique. Two types of polycarbonate diols (PCDs) were utilized for the TPU production as a co-diol of the soft segment. The properties and phase behaviour of the TPUs with various ratios of copolymerized soft segment were analysed. The compatibility between the different types of the PCDs is defined by the concentration of the hydrogen bonding interaction between the hard and soft phases and the dimensions of the hard domains. The homogeneous dispersion of the hard domains in the soft phase promotes better stress transfer enhancing the mechanical properties and adhesion properties. The peel strength is measured between the TPUs/stainless steel joint, in which the highest value is accomplished with the formulation of 60:40 wt% of copolymerized soft segment, which is associated with the superior mechanical strength and the optimum compatible properties of the soft segment.

Glycerol configurations of environmental GDGTs investigated using a selective sn2 ether cleavage protocol

The glycerol configurations of glycerol dialkyl glycerol tetraethers (GDGTs) in environmental samples were investigated using a selective sn2 ether cleavage protocol. Using this procedure, GDGTs with a parallel glycerol configuration afford two types of derivatives, diols and diallylethers, whereas only one kind, monoallylethers, originate from their antiparallel isomers. Isoprenoidal GDGTs from a marine sediment are shown to be predominately parallel based on the distributions of these ether cleavage products. Crenarchaeol and its so-called regioisomer both have parallel configurations with the cyclohexane ring located on the sn3,3 ether bonded tricyclic biphytanyl moiety. A Messel shale sample containing isoprenoidal GDGTs contributed mainly by methanogenic archaea has a substantial portion with the antiparallel configuration. Branched (non-isoprenoidal) GDGTs in both the Messel shale and the marine sediment are mainly antiparallel. This selective sn2 ether cleavage approach provides a potentially powerful analytical tool to investigate not only the exact molecular structures of GDGT constitutional isomers and their biosynthetic pathways but also the heterogeneous inputs of sedimentary GDGT and their isotopic signatures, if different source species synthesize GDGTs with unique glycerol configurations. Further analyses of this type will reveal the glycerol configurations of the GDGTs of a broad range of microbial cultures and environmental samples.

1,4-Dithiothreitol mediated cleavage of the acetal and ketal type of diol protecting groups

An efficient deprotection of the ketal and acetal type protecting groups has been achieved with Brønsted acid as a catalyst and 1,4-dithiothreitol as a ketal or acetal exchange reagent.

Effects of the Amount and Type of Diol Ring Openers on the Properties of Oligolactide Acrylates for UV-Curable Printing Inks

This study aimed to synthesize low viscosity oligolactide acrylates for UV-curable inks from oligolactide diols. Firstly, low molecular weight oligolactide diols were prepared by ring opening reaction of L-lactide with diols. Oligolactide acrylates were then synthesized by functionalizing the oligolactide diols with acrylic acid. In this study, three diol ring openers having short and long alkyl chain length were used to investigate the effects of the amount and type of diols on the properties of the oligolactide acrylates. The obtained oligomers were characterized, and the viscosities of oligolactide acrylates were measured. Results showed that oligolactide acrylates were successfully synthesized in all cases of ring openers, as confirmed by 1H-NMR (proton nuclear magnetic resonance spectroscopy) and FTIR (Fourier transform infrared spectroscopy). An increase in the alkyl chain length of the ring openers resulted in oligomers with lower viscosity and a decrease in Tg. Following that, the obtained oligolactide acrylates were employed for the formulation of UV-curable screen printing inks and their properties were investigated. Results showed that the inks formulated from oligomers with lower molecular weight exhibited better ink flow. Additionally, all ink films cured by UV radiation were very flexible with excellent adhesion, high impact resistance, and excellent water resistance.

High-specificity synthesis of novel monomers by remodeled alcohol hydroxylase.

BackgroundDiols are important monomers for the production of plastics and polyurethanes, which are widely used in our daily life. The medium-chain diols with one hydroxyl group at its subterminal end are able to confer more flexibility upon the synthesized materials. But unfortunately, this type of diols has not been synthesized so far. The strong need for advanced materials impelled us to develop a new strategy for the production of these novel diols. In this study, we use the remodeled P450BM3 for high-specificity production of 1,7-decanediol.ResultsThe native P450BM3 was capable of converting medium-chain alcohols into corresponding α, ω1-, α, ω2- and α, ω3-diols, with each of them accounting for about one third of the total diols, but it exhibited a little or no activity on the short-chain alcohols. Greatly improved regiospecificity of alcohol hydroxylation was obtained by laboratory evolution of P450BM3. After substitution of 12 amino acid residues (J2-F87A), the ratio of 1,7-decanediol (ω-3 hydroxylation) to total decanediols increased to 86.8 % from 34.0 %. Structure modeling and site-directed mutagenesis demonstrated that the heme end residues such as Ala78, Phe87 and Arg255 play a key role in controlling the regioselectivity of the alcohol hydroxylation, while the residues at the mouth of substrate binding site is not responsible for the regioselectivity.ConclusionsHerein we employ an engineered P450BM3 for the first time to enable the high-specificity biosynthesis of 1,7-decanediol, which is a promising monomer for the development of advanced materials. Several key amino acid residues that control the regioselectivity of alcohol hydroxylation were identified, providing some new insights into how to improve the regiospecificity of alcohol hydroxylation. This report not only provides a good strategy for the biosynthesis of 1,7-decanediol, but also gives a promising approach for the production of other useful diols.Electronic supplementary materialThe online version of this article (doi:10.1186/s12896-016-0291-8) contains supplementary material, which is available to authorized users.

Synthesis of potentially biobased copolyesters based on adipic acid and butanediols: Kinetic study between 1,4- and 2,3-butanediol and their influence on crystallization and thermal properties

Abstract Different potentially biobased copolyesters with specific macromolecular architectures are successfully synthesized from renewables diols and diacids, and characterized. The first part focuses on the study of the esterification kinetic of two equimolar systems, 1,4-butanediol (1,4-BDO)/adipic acid (AA) and 2,3-butanediol (2,3-BDO)/AA, with and without titanium isopropoxide (TTIP) as catalyst. The influence of the type of diol (primary vs. secondary hydroxyl groups) and the temperature is also investigated. The esterification rate with 2,3-BDO is slower than with 1,4-BDO leading to higher activation energy. In the second part, poly(1,4-butylene adipate) (PBA) and poly(2,3-butylene adipate) (PB’A) aliphatic polyesters and the corresponding copolyester [poly(1,4-butylene adipate-co-2,3-butylene adipate) (PBB’A)] are synthesized by transesterification in bulk using TTIP. According to our knowledge, the synthesis of PBB’A is reported here for the first time. All synthesized copolymers are characterized by NMR, SEC, FTIR, WAXS, MALDI-TOF, DSC, TGA and specific optical rotation. PBA with a mass-average molar mass around 60,000 g/mol is obtained, whereas molar mass of PB’A and PBB’A are significantly lower. The 2,3-BDO molar content in copolyesters is lower than the initial molar feed content. A linear evolution is observed between 2,3-BDO content and specific optical rotation of the polyesters allowing to use this relation as an additional method to determine PBB’A composition. PBA shows a semi-crystalline behavior, whereas PB’A is amorphous. An increase of the 2,3-BDO content in the copolyester raises the glass transition temperature and reduces the crystallinity. All polyesters exhibit a good thermal stability, exceeding 280 °C, with a maximum rate of degradation around 380 °C.

Influence of Copolyester Composition on Adhesion to Soda-Lime Glass via Molecular Dynamics Simulations.

Copolyesters are a subset of polymers that have the desirable properties of strength and clarity while retaining chemical resistance, and are thus potential candidates for enhancing the impact resistance of soda-lime glass. Adhesion between the polymer and the glass relates to the impact performance of the system, as well as the longevity of the bond between the polymer and the glass under various conditions. Modifying the types of diols and diacids present in the copolyester provides a method for fine-tuning the physical properties of the polymer. In this study, we used molecular dynamics (MD) simulations to examine the influence of the chemical composition of the polymers on adhesion of polymer film laminates to two soda-lime glass surfaces, one tin-rich and one oxygen-rich. By calculating properties such as adhesion energies and contact angles, these results provide insights into how the polymer-glass interaction is impacted by the polymer composition, temperature, and other factors such as the presence of free volume or pi stacking. These results can be used to optimize the adhesion of copolyester films to glass surfaces.

Novel Cross-Linking Mechanism with Diol Type Cross-Linkers, to Prepare PAA Microgels via Precipitation Polymerization Method

ABSTRACTThis article describes a new cross-linking mechanism for synthesizing PAA microgels by precipitation polymerization method. The post curing stage was defined, for the first time, in this study. Effect of cross-linker concentration, and the time and temperature of post curing stage on the samples properties was investigated. A new relationship between gelation rate in the post curing stage and hydroxyl content was defined. Also a new relationship between Mc, hydroxyl concentration and temperature of post curing stage was suggested too. According to rheological characterization, microgels synthesized by novel mechanism have better rheological properties than microgels synthesized by conventional mechanism.

Hydrophobic, Water-Dispersible Polyurethane: Role of Polybutadiene Diol Structure

Preparation of stable, free-standing elastic film with hydrophobic surface from water-dispersible polyurethanes (WDPUs) is a challenging task. Here, we have prepared WDPUs from polybutadiene-based diols and the resulting PU films are satisfying the requisites. Two types of diols, namely, hydroxyl-terminated polybutadiene (HTPB) and terminal-functionalized HTPB with dinitrobenzene (DNB) [HTPB-DNB], were used to make WDPUs and the effects of diol structures were investigated. The synthesized WDPUs displayed particle morphology with size in the range of ∼130–270 nm and more than 1 year storage stability. WDPUs yielded stable and free-standing films upon curing and the resulting films showed high thermal and mechanical stabilities. The contact angle of the films is in the range of ∼80–100°, attributing the hydrophobic nature of the surface. Hard segment content of the PU varied from 30 to 40% (by weight) to tune the properties of WDPUs and the resulting films.

A facile method to synthesize high‐molecular‐weight biobased polyesters from 2,5‐furandicarboxylic acid and long‐chain diols

ABSTRACTIn this study, biobased furan dicarboxylate polyesters have been prepared using 2,5‐furandicarboxylic acid (FDCA) and diols with high number of methylene groups (long‐chain diols), namely, 8, 9, 10, and 12. Because of the high boiling points of these diols, a modified procedure of the well‐known melt polycondensation was applied in this work. According to this, the dimethyl ester of FDCA (DMFD) reacted in the first transesterification stage with the corresponding diols forming bis‐hydroxy‐alkylene furan dicarboxylates (BHFD). In the second stage, the BHFD reacted with DMFD again at temperatures of 150–170 °C (for 4–5 h), and in the final stage, the temperature was raised to 210–230 °C (vacuum was applied for 2–3 h). The molecular weight of the polyesters and the content of oligomers, as was verified by gel permeation chromatography analysis, depend on the polycondensation time and temperature. The chemical structure of the polyesters was verified from 1H NMR spectroscopy. All the polymers were found to be semicrystalline, with melting temperatures from 69 to 140 °C depending on the diol used. In addition, the mechanical properties also varied with the type of diol. The higher values were observed for poly(octylene 2,5‐furanoate), whereas the lowest values were observed for poly(dodecylene 2,5‐furanoate) with the higher number of methylene groups in its repeating unit. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2617–2632