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Solid alkali KF/MgO catalysts were prepared using the impregnation method by combining alkali metal compounds with oxides, which performed the transesterification of isosorbide (IS) with dimethyl carbonate (DMC) into dicarboxymethyl isosorbide (DC). Characterization of the catalysts was conducted through X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and N2 adsorption–desorption analysis. The catalytic performance of KF/MgO was examined under diverse KF loading and calcination temperature conditions. The characterization of catalyst identified that the creation of innovative active components K2MgF4 and K2CO3 were produced at a calcination temperature of 500 ℃ and a KF loading amount of 40%. The catalyst of 40-KF/MgO-500 demonstrated the most effective, favourable activity and selectivity. Through the optimization of transesterification process conditions, it was discovered that the yield of DC was at its highest under the optimal reaction conditions of n(DMC)/n(IS) = 6.5, catalyst dosage of 0.21 wt% (relative to IS mass), transesterification temperature of 120 °C, and reaction time of 6 h. [ABSTRACT FROM AUTHOR]

The effects of triethyl citrate (TEC) on the viscoelastic properties of a copolycarbonate comprising isosorbide and 1,4-cyclohexanedimethanol (ISB-PC) were studied in both the molten and solid states. TEC acted as an antiplasticizer for ISB-PC and increased its modulus in the glassy state, as demonstrated in blends comprising 5 and 10 wt% TEC. Because antiplasticization reduces the free volume fraction, the water content of the copolycarbonate films, which is known to affect various properties, decreased following the addition of TEC. Furthermore, TEC greatly decreased the zero-shear viscosity. The experimental values were much lower than those predicted by the Berry–Fox formula. In other words, a small amount of TEC greatly enhances the flowability of ISB-PC. [ABSTRACT FROM AUTHOR]

Isosorbide, a bicyclic C6 diol, has considerable value as a precursor for the production of bio-derived polymers. Current production of isosorbide from sorbitol utilizes homogeneous acid, commonly H2SO4, creating harmful waste and complicating separation. Thus, a heterogeneous acid catalyst capable of producing isosorbide from sorbitol in high yield under mild conditions would be desirable. Reported here is a quantitative investigation of the liquid-phase dehydration of neat sorbitol over sulfated zirconia (SZ) solid acid catalysts produced via sol-gel synthesis. The catalyst preparation allows for precise surface area control (morphology) and tunable catalytic activity. The S/Zr ratio (0.1-2.0) and calcination temperature (425-625 °C) were varied to evaluate their effects on morphology, acidity, and reaction kinetics and, as a result, to optimize the catalytic system for this transformation. With the optimal SZ catalyst, complete conversion of sorbitol occurred in

The replacement of polymers derived from petrochemical resources has been a prominent area of focus in recent decades. Polymers used in engineering materials must exhibit mechanical strength and stiffness while maintaining performance through a broad temperature range. Most of the polyesters used as engineering materials are based on terephthalic acid (TPA) and its derivatives, which provide necessary rigidity to molecular chains due to an aromatic ring. Bio-based alternatives for TPA-based polyesters that are gaining popularity are the polyesters derived from 2,5-furandicarboxylic acid (FDCA). To broaden applicational possibilities, one effective way to achieve specific properties in targeted applications is to adjust the composition and structure of polymers using advanced polymer chemistry techniques. The incorporation of rigid diols such as isosorbide, 1,4-cyclohexanedimethanol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO) should result in a greater stiffness of the molecular chains. This review extensively explores the effect of incorporating rigid diols on material properties through a review of research articles as well as patents. Moreover, this review mainly focuses on the polyesters and copolyesters synthesized via two-step melt polycondensation and its alterations due to the industrial importance of this method. Innovative synthesis strategies and the resulting material properties are presented. [ABSTRACT FROM AUTHOR]

Using the abundant and cost‐effective oleic acid and isosorbide with excellent properties as raw materials, the plasticizers of isosorbide di‐oleate (IDO) and isosorbide di‐epoxidized oleate (IDEO) with good plasticizing effect, low cost and green safety were synthesized by esterification and epoxidation reaction. The molecular structure of the synthesized plasticizers was characterized by FT‐IR and 1H NMR. The PVC shows better flexibility when IDEO or IDO plasticizer is used than commercial DOP. In particular, IDEO‐40 has 34% higher tensile strength and 17% higher elongation at break than DOP‐40. The introduction of epoxy groups on the carbon–carbon double bond of fatty acids meets the high thermal stability of plasticized film. The residual amount of IDEO‐40 is 7.01%, and at a high temperature of 180 °C, it can maintain high heat resistance for more than 220 min and transmittance of over 86%. Moreover, IDEO demonstrates excellent resistance to migration and volatilization. However, PVC films plasticized with IDO display reduced mechanical properties, cold resistance, and resistance to volatilization and migration due to the presence of non‐rotating carbon–carbon double bonds. The results indicate that these bio‐based plasticizers hold promise for practical applications in PVC products, offering improved environmental sustainability and performance characteristics. [ABSTRACT FROM AUTHOR]

In recent years, non‐traditional intrinsic luminescence (NTIL) materials containing only ester groups in their molecules have been emerging and received extensive attention and research. Nevertheless, the existing NTIL materials still have the problems of low molecular weight and insufficient mechanical properties, which limit their further application. Isosorbide is a kind of bio‐based rigid diol monomer which is mainly used to improve the heat resistance and mechanical properties of materials all along. Besides, the ring‐opening reaction under acidic conditions makes isosorbide‐based materials exhibit some new functionalities. In this paper, a series of isosorbide‐based copolyesters with high molecular weight are synthesized by a simple and economical two‐step melt polycondensation method. It is found that, on the basis of improving the thermal and mechanical properties of the materials, copolyesters also exhibit fluorescence emission in the visible region at the excitation wavelength of 350 nm. And the fluorescence emission wavelength can be adjusted from 400 to 480. This study broadens the functional application of the isosorbide‐based materials and effectively enriches fluorescence mechanism of NTIL. [ABSTRACT FROM AUTHOR]

An unsymmetrical PCN palladium pincer complex 2-{(E)-{{(R)-1-[(1R,5S,6R)-3,3-dimethyl-2,4,7-trioxabicyclo[3.3.0]octan-6-yl]ethyl}imino}methyl}-6-{[(diphenylphosphino)oxy] phenyl}palladium(II) chloride based on an iminophosphinite ligand bearing two fused five-membered cycles, one of which containing a THF ring, was prepared in an eight-reaction sequence from a sustainable and enantiopure starting material, isosorbide, in a 20% overall yield. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effects of different hydroxy-terminated silicones on the properties of polycarbonate-silicone copolymers (ICS-PC) by introducing flexible and hydrophobic silicone into isosorbide-based polycarbonate through melt transesterification- polycondensation method. Through compatibility and transesterification experiments, it is confirmed that the alcohol-hydroxyl polydimethylsiloxane (a-PDMS) has higher reactivity and silicone conversion than the phenol-hydroxyl polydimethylsiloxane (p-PDMS), but the conversion does not exceed 81%. Polyether-modified silicone (PEMS) exhibits better compatibility and higher reactivity, thus resulting in higher conversion that can reach 86%. Effects of the type and content of silicone on the glass transition temperature (Tg), optical transparency, saturated water absorption, and mechanical strength of ICS-PCs were also discussed. It is found that p-PDMS has higher Tg, hydrophobicity, and mechanical strength with similar silicone content, but the total transmittance does not exceed 60%. In contrast, the PEMS system exhibits better optical transparency due to its improved compatibility with the PC matrix, with a total transmittance of up to 73%, Tg exceeding 150 °C while maintaining excellent flexibility and hydrophobicity. These results are helpful to further improve the comprehensive properties of bio-based polycarbonates. [ABSTRACT FROM AUTHOR]

Diglycidil ether of isosorbide (DGEISO), a potential biobased substitute for petro-based epoxy resin, such as to diglycidil ether of bisphenol A (DGEBA), was synthesized with a classic epoxidation route using isosorbide, epichlorohydrin, and sodium hydroxide. Fourier-transform infrared spectroscopy (FTIR) an inexpensive and fast technique, was used to monitor the DGEISO synthesis by the conversion of epoxy groups, reaching a constant absorption index after 2.5 h of the reaction. Differential scanning calorimetry (DSC) scans displayed that DGEISO epoxy curing temperature with methyltetrahydrophtalic anhydride (MTHPA) is similar to diglycidil ether of bisphenol A (DGEBA) (~ 135 °C) in the whole range of the heating rates evaluated in this work (2.5–20 °C/min). The curing kinetics of both DGEISO/MTHPA and DGEBA/MTHPA were evaluated using the Friedman, Vyazovkin, and Ozawa model, whereas the first two models described the kinetics parameters with errors lower than 3%. Despite subtle differences in the investigated systems' different thermal properties, the similar curing behavior could be beneficial, suggesting the DGEISO resin could be a competitive replacement for epoxy resins. [ABSTRACT FROM AUTHOR]

Unsaturated polyester resins, one of the most important thermosets, are invariably produced from oil-based monomers. Their application is limited in areas where high thermal stability is required due to their low Tg. Besides, these resins contain 30–40% hazardous styrene as a reactive solvent. Therefore, developing bio-based solventless unsaturated polyester resin with medium to high thermomechanical properties compared to petrochemical-based counterparts is important. In order to achieve this, a series of branched bio-based unsaturated polyester resins were synthesized using bulk polymerization method in two steps. In the first step, four different intermediates were prepared by reacting glycerol (as a core molecule) with either isosorbide (diol), 1,3-propanediol (diol), 2,5-furandicarboxylic acid (saturated diacid), or adipic acid (saturated diacid). In the second step, the branched intermediate was end capped with methacrylic anhydride to introduce reactive sites for cross-linking on the branch ends. The chemical structure of the resins was characterized by 13C-NMR. FT-IR confirmed the polycondensation reaction in the first step and the end functionalization of the resins with methacrylic anhydride in the second step. The effect of 2,5-furandicarboxylic acid and isosorbide on thermomechanical and thermal properties was investigated using dynamic mechanical analysis, differential scanning calorimetry, and thermo-gravimetric analysis. Results indicated that 2,5-furandicarboxylic acid based resins had superior thermomechanical properties compared to a commercial reference unsaturated polyester resin, making them promising resins for high-temperature composite applications. For example, the resin based on 2,5-furandicarboxylic acid and isosorbide and the resin based on 2,5-furandicarboxylic acid and 1,3-propanediol gave glass transition temperatures of 173 °C and 148 °C, respectively. Although the synthesized 2,5-furandicarboxylic acid based resins had higher viscosity (22.7 Pas) than conventional unsaturated polyester (0.4–0.5 Pas) at room temperature, preheated resins can be used for making high-temperature-tolerance fiber-reinforced composite. [ABSTRACT FROM AUTHOR]

5(S)-((3aR,4R,6aR)-2,2-Dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)-2-phenyl-4,5-dihydrooxazole was synthesized from isosorbide in a three-step sequence, with an overall yield of 46%. The first reaction step involves a single regioselective ring-opening reaction of isosorbide with Me3SiI in the presence of acetone followed by an intramolecular nucleophilic substitution to transform the iodoalcohol into its corresponding epoxide. The last reaction allows the formation of the oxazoline ring directly from the epoxide with benzonitrile in the presence of BF3·Et2O. [ABSTRACT FROM AUTHOR]

Background and Objective: Extracorporeal shockwave lithotripsy (ESWL) is mong the the low-risk treatment methods of treating kidney stones. Specialists are looking for ways to remove small stones caused by ESWL in patients as soon as possible. The present study aimed to determine the effect of isosorbide on the duration of renal pelvis excretion after ESWL. Materials and Methods: In this clinical trial, 176 patients with renal pelvis < 20 mm, who were referred to the ESWL Department of Moradi Hospital, Rafsanjan, Iran, in 2019, were examined. After lithotripsy, the patients were randomly assigned into two intervention groups of receivers of isosorbide 20 mg tablets every 12 hours for two weeks and placebo control for two weeks. The collected data was analyzed using Mann-Whitney and Kruskal-Wallis statistical tests. Results: The success of ESWL was 78.2% in the isosorbide group and 77.5% in the placebo group (P=0.919). The average duration of stone excretion in the isosorbide group was 4.21 ± 1.05 days, and the placebo group was 4.79 ± 1.16 (P=0.001). In the isosorbide group, the duration of stone excretion in patients with stone size 16-20 mm was less than 16 mm (P=0.011). The average duration of stone excretion in patients 36-55 years old (P=0.021) and patients with right-sided stones (P=0.008) in the isosorbide group was less than the placebo group. Conclusion: Isosorbide, accompanied by other treatments, reduced the duration of stone excretion after ESWL. Moreover, although Isosorbide can be used to improve the management of patients with kidney stones, more studies are needed to confirm this finding.

Using CO2-derived dimethyl carbonate (DMC) instead of diphenyl carbonate (DPC) as a carbonyl source for synthesizing bio-based polycarbonates is a green and cost-effective route. However, the synthesis of high-performance polycarbonates via the DMC route remains challenging due to the poor reactivity and selectivity of DMC compared to DPC. Herein, we designed a series of highly active protic ionic liquid (PIL) catalysts for the synthesis of poly(isosorbide carbonate) (PIC) from DMC with ISB. The influences of the structures of anion and cation on the catalytic activity of PILs were systematically studied. Compared with the reported aprotic IL catalysts, the unique reactive hydrogen of the cation in PILs could form a strong hydrogen bond interaction with the carbonyl group of DMC, resulting in higher reactivity of the carbonyl carbon of DMC. Moreover, the nucleophilicity of the anion could be easily tuned by adjusting the pKa value, which effectively realized the balance of the reactivity difference between exo-OH and endo-OH in ISB. Among them, [DBUH][Im] showed the highest catalytic activity, and the weight-average molecular weight (Mw) and glass transition temperature of PIC reached 55,700 g/mol and 160 °C, respectively. Combined with NMR analyses and DFT calculations, the mechanism that exhibited the synergetic catalytic effect of anion-cation for the polymerization of DMC and ISB was presented.

Development of biobased aliphatic polyesters with better mechanical (tensile) properties in film has attracted considerable attention. This report presents the synthesis of soluble network biobased aliphatic polyesters by acyclic diene metathesis (ADMET) polymerization of bis(undec-10-enyl)isosorbide diester [M1, dianhydro-D-glucityl bis(undec-10-enoate)] in the presence of a tri-arm crosslinker [CL, glycerol tris(undec-10-enoate)] using a ruthenium–carbene catalyst, and subsequent olefin hydrogenation using RhCl(PPh3)3. The resultant polymers, after hydrogenation (expressed as HCP1) and prepared in the presence of 1.0 mol% CL, showed better tensile properties than the linear polymer (HP1) with similar molecular weight [tensile strength (elongation at break): 20.8 MPa (282%) in HP1 vs. 35.4 MPa (572%) in HCP1]. It turned out that the polymer films prepared by the addition of CL during the polymerization (expressed as a 2-step approach) showed better tensile properties. The resultant polymer film also shows better tensile properties than the conventional polyolefins such as linear high density polyethylene, polypropylene, and low density polyethylene. [ABSTRACT FROM AUTHOR]

The rising concern of environmental issues from the non-degradable conventional polymers is triggering the development of sustainable and renewable polymers. Thermoplastic starch (TPS) has been known to have huge potential to substitute conventional synthetic polymers. A thermoplastic starch was prepared using a non-food bitter cassava starch with isosorbide as plasticizer. To improve the dispersion and interfacial affinity of thermoplastic starch and boost the compatibility between starch and isosorbide, citric acid (CA) was used as an additive. The influence of citric acid to the TPS was then investigated. The result shows that citric acid improved tensile strength from 8.68 MPa to 11.98 MPa. The addition of citric acid at a concentration of 1 – 10 wt % can increase glass transition temperature (Tg) from 48.81°C to 63.89°C and storage modulus at 25°C from 1.20 GPa to 3.47 GPa. Two degradation temperatures (Td) were detected which are Td1onset value was decrease from 83.32°C down to 79.78°C while Td2onset value was decrease from 275.29°C down to 247.17°C and Td2max from 311.12°C to 295.06°C. [ABSTRACT FROM AUTHOR]

In this study, double dehydration of sorbitol into isosorbide using commercial sulfonic acid resin as a catalyst was carried out under vacuum conditions generated by water ejection. To improve the efficiency and selectivity of the process, optimum reaction conditions prescribed by temperature, catalyst loading, and reaction time were investigated using the Box-Behnken design (BBD) together with Response Surface Methodology (RSM). The results showed that using the water ejection system could increase reaction activity. Statistically, all the reaction parameters were found to significantly affect the double dehydration reaction response, including sorbitol conversion, 1,4-sorbitant yield, and isosorbide yield. Furthermore, accurate predictive equations for all the reaction responses displayed R2 > 95 %, with no significant errors observed. The optimized conditions resulted in the complete conversion of sorbitol with 6.42 % 1,4-sorbitant yield and 67.55 % isosorbide yield. The equations yielded predicted values of the responses with minor variances being lower than 1 % when compared with the experimental values. However, the efficiency of the catalyst decreased steadily over recycling cycle due to reduced active sites and textural properties, likely caused by structural collapse and by-product accumulation. This work contributes to biomass valorization by optimizing the effective process for the production of isosorbide via commercial catalysts under vacuum conditions.

5(S)-((3aR,4R,6aR)-2,2-Dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)-2-phenyl-4,5-dihydrooxazole was synthesized from isosorbide in a three-step sequence, with an overall yield of 46%. The first reaction step involves a single regioselective ring-opening reaction of isosorbide with Me3SiI in the presence of acetone followed by an intramolecular nucleophilic substitution to transform the iodoalcohol into its corresponding epoxide. The last reaction allows the formation of the oxazoline ring directly from the epoxide with benzonitrile in the presence of BF3·Et2O.

An unsymmetrical PCN palladium pincer complex 2-{(E)-{{(R)-1-[(1R,5S,6R)-3,3-dimethyl-2,4,7-trioxabicyclo[3.3.0]octan-6-yl]ethyl}imino}methyl}-6-{[(diphenylphosphino)oxy] phenyl}palladium(II) chloride based on an iminophosphinite ligand bearing two fused five-membered cycles, one of which containing a THF ring, was prepared in an eight-reaction sequence from a sustainable and enantiopure starting material, isosorbide, in a 20% overall yield.

To enhance the degradation rate of poly (butylene adipate-co-terephthalate) (PBAT) in the natural environment and to investigate the effect of modified monomers on the molding and structure of copolyester fibers, a series of isosorbide modified PBAT (PBIAT) tetrapolyesters were synthesized and monofilaments were prepared by solid-state drawing in this work. The experimental results revealed that the introduction of isosorbide formed a partial block structure in the molecular chain, and that a significant improvement in the properties of heat resistance and degradability of the copolyester was observed with the introduction of isosorbide. In the research of fiber forming and structure-property relationship by isosorbide, it was found that although the monofilament orientation process was affected by the V-shape structure of isosorbide, the change of the crystal structure under stress was similar to that of polybutylene terephthalate (PBT). The PBIAT monofilaments showed a decrease in the strength at break affected by the introduction of isosorbide but they still met the requirements for textile applications.

Plasticizers are widely used in poly(vinyl chloride) (PVC), polylactic acid (PLA), thermoplastic starch (TPS), and other modified powder materials to enhance the flowability, flexibility, and processability of macromolecules. Because of the reprotoxicity of phthalates in animals and humans, certain phthalates have recently been banned in the United States and Europe. Biobased plasticizers from green biomass–derived renewable resources with low toxicity are expected to be a substitute for phthalates. Among a variety of newly developed biobased monomers, cardanol, and isosorbide are the two most promising materials because of their unique structural features. This review summarizes the research progress of cardanol‐ and isosorbide‐based plasticizers with synergistic effects of plasticization, thermal stabilization, and anti‐migration. By summarizing and analyzing the relationship between molecular structure of plasticizer and plasticizing performance, this review can provide theoretical guidance for future research on the design of isosorbide‐ and cardanol‐based plasticizers. Highlights: Biobased plasticizers with low toxicity are expected to replace certain phthalates.The plasticizing effect of single biobased plasticizer is not good.Biobased plasticizer with synergistic effects is required.There exists the trade‐off effect between the molecular weight and the compatibility.Epoxidized isosorbide ester can be used as a heat stabilizer. [ABSTRACT FROM AUTHOR]

Environmental issues are becoming more and more prominent, and bio‐based polymers are essential to alleviate environmental degradation by replacing traditional polymers. With this context, a new family of functional isosorbide‐based polyesters and polyamides with high glass transition temperature are prepared via Passerini‐Three component polymerization (P‐3CP). To optimize the P‐3CP conditions, the influence of the polymerization solvent, temperature, feed ratio on the molar mass of final polymers are investigated. The higher molar mass (up to 10100 g/mol) and yield (>70 %) are achieved under very mild conditions (30 °C, standard atmosphere). Functional side groups, such as alkenyl, alkynyl and methyl ester, were introduced into polymer structure via P‐3CP by using functional isocyanides. The obtained polyesters and polyamides are characterized by nuclear magnetic resonance (NMR) and infrared (IR) spectroscopies, differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). All polymers are thermal stable and amorphous with variable glass transition temperatures (Tg). The obtained polyester has Tg up to 87.5 °C, while the Tg of polyamides (ISPA‐2) is detected to be 97.5 °C depending on the amide bonds in the polymer backbone and the benzene ring side groups. The cytotoxicity is investigated by the CCK‐8 assay against mBMSC cells to confirm the biological safety. Overall, this novel strategy provides an efficient approach to produce functional isosorbide‐based polyesters and polyamides, which are promising prospect for being applied to biodegradable materials. [ABSTRACT FROM AUTHOR]

Herein, we present a facile synthetic process for producing biomass‐derived isosorbide (ISB) dioxides using dimethyl dioxirane (DMDO) as an efficient oxidizing agent, which was generated in situ from acetone and KHSO5. To achieve high conversion and product yield, the KHSO5 concentration, KHSO5 flow rate, and reaction temperature were optimized. Under the optimal conditions, rapid and efficient epoxidation using the in situ‐generated DMDO was observed under ultrasonication, yielding the desired product within 35 min at 0 °C. This study offers a convenient and efficient method for generating biomass‐derived ISB building blocks, which have significant potential for the fabrication of bioplastics. [ABSTRACT FROM AUTHOR]

Isosorbide can be used as a third monomer in the synthesis of aliphatic polyesters, and its V-shaped bridging ring structure can effectively improve the rigidity of the copolyester molecular chain. In this work, a series of degradable polyester materials were prepared by modifying polybutylene succinate and using isosorbide as the third monomer. The degradation tests in this paper were implemented through the hydrolysis of copolyesters in distilled water, degradation in natural water and degradation tests in simulated natural environments. The results showed that PBS and its copolyesters can degrade under natural conditions, and the introduction of isosorbide can accelerate the degradation of copolyesters, which could effectively reduce pollutants in nature. [ABSTRACT FROM AUTHOR]

Isosorbide, an environmentally friendly and renewable substance, finds extensive application in diverse fields, such as a bisphenol A substitute, polymers, functional materials, organic solvents, fuels, and pharmaceuticals. Despite its increasing interest and widespread usage, there remains a notable absence of available reports regarding its absorption, distribution, metabolism, and excretion (ADME) properties. This study endeavors to investigate the ADME characteristics of isosorbide in rats. Isosorbide levels in biological samples were quantified based on the analytical method using gas chromatography-mass spectrometry (GC-MS). Following administration, isosorbide exhibited rapid absorption and elimination, with a bioavailability of 96.1%. The metabolic stability assay indicated that isosorbide remained stable during metabolism. The majority of absorbed isosorbide was promptly excreted, with urinary excretion as the primary route. This study furnishes valuable insights into the ADME of isosorbide, contributing to its safety assessment and fostering its continued application across various domains.

The replacement of polymers derived from petrochemical resources has been a prominent area of focus in recent decades. Polymers used in engineering materials must exhibit mechanical strength and stiffness while maintaining performance through a broad temperature range. Most of the polyesters used as engineering materials are based on terephthalic acid (TPA) and its derivatives, which provide necessary rigidity to molecular chains due to an aromatic ring. Bio-based alternatives for TPA-based polyesters that are gaining popularity are the polyesters derived from 2,5-furandicarboxylic acid (FDCA). To broaden applicational possibilities, one effective way to achieve specific properties in targeted applications is to adjust the composition and structure of polymers using advanced polymer chemistry techniques. The incorporation of rigid diols such as isosorbide, 1,4-cyclohexanedimethanol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO) should result in a greater stiffness of the molecular chains. This review extensively explores the effect of incorporating rigid diols on material properties through a review of research articles as well as patents. Moreover, this review mainly focuses on the polyesters and copolyesters synthesized via two-step melt polycondensation and its alterations due to the industrial importance of this method. Innovative synthesis strategies and the resulting material properties are presented.

This study aims to investigate the effects of different hydroxy-terminated silicones on the properties of polycarbonate-silicone copolymers (ICS-PC) by introducing flexible and hydrophobic silicone into isosorbide-based polycarbonate through melt transesterification- polycondensation method. Through compatibility and transesterification experiments, it is confirmed that the alcohol-hydroxyl polydimethylsiloxane (a-PDMS) has higher reactivity and silicone conversion than the phenol-hydroxyl polydimethylsiloxane (p-PDMS), but the conversion does not exceed 81%. Polyether-modified silicone (PEMS) exhibits better compatibility and higher reactivity, thus resulting in higher conversion that can reach 86%. Effects of the type and content of silicone on the glass transition temperature (Tg), optical transparency, saturated water absorption, and mechanical strength of ICS-PCs were also discussed. It is found that p-PDMS has higher Tg, hydrophobicity, and mechanical strength with similar silicone content, but the total transmittance does not exceed 60%. In contrast, the PEMS system exhibits better optical transparency due to its improved compatibility with the PC matrix, with a total transmittance of up to 73%, Tg exceeding 150 °C while maintaining excellent flexibility and hydrophobicity. These results are helpful to further improve the comprehensive properties of bio-based polycarbonates.

Viscoelastic properties of copolycarbonate materials comprising isosorbide (ISB) and cyclohexanedimethanol (CHDM) were studied as a function of the ISB content. In the glassy state, β dispersion was clearly detected in the dynamic mechanical spectra. The tensile storage modulus E′ at room temperature increased with the ISB content, and the glass transition temperature Tg, i.e., peak temperature of α dispersion, increased with the ISB content. It was found from oscillatory shear modulus that the rubbery plateau modulus GN0 decreased with the ISB content. The entanglement molecular weights Me were found to be 2330–3640, which were slightly higher than that of bisphenol-A polycarbonate and much lower than those of poly(methyl methacrylate) and polystyrene. The onset shear stress of shark-skin failure at capillary extrusion was evaluated and found to increase with the ISB content. [ABSTRACT FROM AUTHOR]

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Bio-based cross-linkers can fulfill the role of enhancing additives in bio-sourced curable materials that do not compare with artificial resin precursors. Isosorbide dimethacrylate (ISDMMA) synthesized from isosorbide (ISD) can serve as a cross-linker from renewable sources. Isosorbide is a bicyclic carbon molecule produced by the reaction modification of sorbitol and the optimal conditions of this reaction were studied in this work. The reaction temperature of 130 °C and 1% w/w amount of para-toluenesulfonic acid (p-TSA) were determined as optimal and resulted in a yield of 81.9%. Isosorbide dimethacrylate was synthesized via nucleophilic substitution with methacrylic anhydride (MAA) with the conversion of 94.1% of anhydride. Formed ISD and ISDMMA were characterized via multiple verification methods (FT-IR, MS, 1H NMR, and XRD). Differential scanning calorimetry (DSC) proved the curability of ISDMMA (activation energy Ea of 146.2 kJ/mol) and the heat-resistant index of ISDMMA (Ts reaching value of 168.9) was determined using thermogravimetric analysis (TGA). Characterized ISDMMA was added to the precursor mixture containing methacrylated alkyl 3-hydroxybutyrates (methyl ester M3HBMMA and ethyl ester E3HBMMA), and the mixtures were cured via photo-initiation. The amount of ISDMMA cross-linker increased all measured parameters obtained via dynamic mechanical analysis (DMA), such as storage modulus (E') and glass transition temperature (Tg), and the calculated cross-linking densities (νe). Therefore, the enhancement influence of bio-based ISDMMA on resins from renewable sources was confirmed. [ABSTRACT FROM AUTHOR]

Bioderived polycarbonate (ISB-PC) was synthesized via transesterification and polycondensation of isosorbide (ISB) and diphenyl carbonate (DPC) using lithium acetoacetone as a catalyst. The resulting ISB-PC exhibited high glass transition temperatures similar to bisphenol A polycarbonate (BPA-PC) and was thermally stable up to 350 ℃. The incorporation of isosorbitol into the polymer chain imparted an improved mechanical property of ISB-PC, such as a higher bending and tensile modulus and higher elongation at break. ISB-PC can be readily cast into transparent films with a tensile strength of 73.3 MPa and a tensile modulus of 534 MPa. ISB-PC displayed high UV transmittance and possessed blue fluorescence under UV irradiation. At the same time, ISB-PC also has strong anti-yellowing ability. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) synthesis based on poly(ethylene glycol) (PEG) with isosorbide (ISO) and pentamethylene diisocyanate (PDI), named (ISOPUs) was carried out targeting PUs from renewable sources. The cross‐linked ISOPUs were produced and the details of the curing kinetics were determined via Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). DSC scans displayed exotherms between 100 and 200°C, related to cross‐linking. ISO addition accelerated the curing and the maximum curing rate (Cmax), with 91°C and 0.2964 min−1 for the compound with 70% ISO. FTIR spectra confirmed the interaction between OH (ISO/PEG) and NCO (PDI) groups, with total NCO consumption (band at 2267 cm−1). Through the thermogravimetric analyses (TGA), the PU/70% ISO presented weight loss at 146°C due to the degradation of ISO. ISOPUs displayed a decreased activation energy (Ea) during curing over a range of 100 to 42 kJ/mol for 0 < α < 5%, as demonstrated using the Friedman model, and higher thermal stability as evidenced through TG analyses. Curing and degradation kinetics were modeled using Friedman (FR), Kissinger‐Akahira‐Sunose (KAS), and Ozawa‐Flynn‐Wall (OFW). Overall, ISO accelerated the curing rate and increased the degradation Ea, suggesting high thermal stability for PUs with intermediate ISO contents, that is, 30%–50%. [ABSTRACT FROM AUTHOR]