Alicyclic Diols Research Articles

2,5-Tetrahydrofurandimethanol as a sustainable comonomer for modification of polyethylene terephthalate: Liter-level pilot test and non-isothermal crystallization kinetics

2,5-tetrahydrofurandimethanol (THFDM), which is an alicyclic diol in products of 5-hydroxymethylfurfural (HMF), is a sustainable monomer to protect environment for replacing the role of isophthalic acid (IPA) and 1,4-cyclohexanedimethanol (CHDM) which were optimized polyethylene terephthalate (PET) performance. By direct esterification method, poly (ethylene-co-tetrahydrofurandimethanol terephthalate) (PETT) was synthesized in 2.5 L reactor. The results showed that the contents of THFDM in copolyester were less than that feeding ratio attributed to its lower reaction reactivity. The color of PETT slightly turned yellow. PETT performed broader processing temperature window, while Tg maintained in good range because of the cyclic structure of THFDM. Especially, the cold crystallization occured in PETT but not in PET after finishing melt crystallization. Otherwise, the thermal stability and crystal structure of PETT remained the same as PET. The crystallization activity of PETT became significantly lower than PET. What proved THFDM was effective in reducing PET crystallinity was that crystallization kinetics using Jeziorny theory and the trend of activation energy of melt crystallization which was calculated by Friedman method. And PETT-2 fibre had comparable mechanical property to PET fibre. In the advancement of green chemistry, THFDM has added a choice of cyclic bio-based comonomers.

Kilogram-scale preparation of sustainable PETG modified with a biobased cyclic diol derived from 5-hydroxymethylfurfural: From synthesis to properties

• Kilogram-scale novel PETT copolyesters were successfully synthesized in 5L reactor. • The cyclic structure and ether group of THFDM reach a balance to the influence on T g . • Kwei’s equation evaluated the T g of copolyesters better than other theories. • The introduction of THFDM provides better processability and hydrophilicity. • PETT copolyester with outstanding properties is an ideal candidate in replacing PETG. Poly(ethylene terephthalate-co-cyclohexanedimethanol terephthalate) (PETG) which could perform good mechanical and transparency properties have been commercialized for decades. While, such good properties presented only when the copolyesters is unable to crystallize for a narrow window of compositions. Moreover, considering the unsustainability of 1,4-cyclohexanedimethanol (CHDM) which was mainly obtained from fossil resources, incorporating novel biobased monomer into poly(ethylene terephthalate) (PET) to obtain the excellent properties have arisen researchers’ attentions. Novel biobased 2.5-tetrahydrofurandimethanol (THFDM), an alicyclic diol containing similar structure with CHDM, was successfully introduced into PET and obtained a series of copolyesters with outstanding tunable properties. The process was conducted in 5L stainless steel reactor, which maintained the stability of properties of samples and provided the prospect of being large scale production. The cyclic structure and ether group contained by THFDM reached a balance to the influence on the T g of copolyesters, resulting only slight change of T g (ranging from 76.1 °C to 69.4 °C). Three equations, namely Fox’s, Gordon–Taylor’s and Kwei’s equations, were employed to evaluate the T g of copolyesters. According to the statistics analysis, the value calculated by Kwei’s equation performed the best fitting the experimental results comparing to the other two theories, due to the peculiar dielectric properties. The (co)polymers performed as amorphous materials with excellent transparency at room temperature. As expected, the introduction of highly electronegative ether-oxygen atoms increased the hydrophilicity. It was worthy noting that the rheology property determining the processability was significantly influenced by the polarity which could be adjusted by the content of THFDM. As for the mechanical property, the yield strength increased form 52.7 MPa (PET) to 63.6 MPa (poly(tetrahydrofurandimethanol terephthalate), PTT), while the elongation at break decreased from 205.0% (PET) to 43.3% (PTT) in consistent with the decrease tendency of impact strength (200.6–78.0 J/m). Overall, the PETTs copolyesters performed outstanding transparency, comparable T g , broader processing window and better mechanical properties comparing with PETG, and it could be potentially used in sheet material, high-performance shrink film, bottle and profile markets. Therefore, the PETT copolyesters is an ideal candidate in replacing PETG to realize the concept of “carbon neutral” and “sustainable development”.

Random and Multiblock PBS Copolyesters Based on a Rigid Diol Derived from Naturally Occurring Camphor: Influence of Chemical Microstructure on Thermal and Mechanical Properties

(1R,3S)-1,2,2-trimethylcyclopentane-1,3-dimethanol (TCDM) is a rigid alicyclic diol prepared by oxidation and subsequent reduction of naturally occurring camphor. To improve the low glass transition temperature (Tg), slow degradation rate, and brittleness of poly(butylene succinate) (PBS), two series of PBS copolyesters based on TCDM were synthesized using two different methods. Random copolymerization (RC) of a mixture of TCDM, 1,4-butanediol (BDO), and 1,4-succinic acid (SA) afforded random PBS copolyesters, while reactive blending (RB) of pure PBS and PTS (homopolyester based on TCDM and SA) afforded PBS copolyesters with blocklike chemical microstructures. For both series, the insertion of TCDM units resulted in elevated thermal stability and higher Tg values compared to those of neat PBS. The RB-prepared copolyesters displayed higher melting points, a higher degree of crystallinity, and higher mechanical properties with respect to those of their random counterparts obtained by RC. The incorporation of TCDM units enhanced the hydrolytic degradation rates for both series, which is more pronounced for the RC-prepared copolyesters. Overall, this work confirmed the effectiveness of the RB technology in preparing high-performance biopolymers such as improving the sustainability of raw materials, achieving high Tg values, and promoting the mechanical strength and biodegradability as well.

Fluorination of some highly functionalized cycloalkanes: chemoselectivity and substrate dependence.

A study exploring the chemical behavior of some dihydroxylated β-amino ester stereo- and regioisomers, derived from unsaturated cyclic β-amino acids is described. The nucleophilic fluorinations involving hydroxy–fluorine exchange of some highly functionalized alicyclic diol derivatives have been carried out in view of selective fluorination, investigating substrate dependence, neighboring group assistance and chemodifferentiation.

Random Copolycarbonates Based on a Renewable Bicyclic Diol Derived from Citric Acid

To address the poor thermal stability of isohexides while at the same time retain rigidity, we developed a novel bicyclic diol octahydro-2,5-pentalenediol (OPD) from naturally occurring citric acid in this study. Owing to the bicyclic skeleton composed of two fused cyclopentane rings, OPD is supposed to have perfect rigidity but higher thermal stability compared to isohexides. Herein, OPD was first converted to octahydro-2,5-pentalenediol bis(methyl carbonate) (OPBMC) by reacting with dimethyl carbonate. The absolute stereochemistry of OPBMC was investigated by 2D 1H NMR and 13C NMR as well as single crystal X-ray diffraction. By polymerization of OPBMC with several aliphatic diols [1,8-octanediol (A8), 1,10-decanediol (A10), and 1,12-dodeacnediol (A12)] and alicyclic diols [1,4-cyclohexanedimethanol (CHDM), 1,2,2-trimethylcyclopentane-1,3-dimethanol (TCDM), and octahydro-2,5-pentalenediol (OPD)], a series of bio-based copolycarbonates (co-PCs) with intriguing properties were synthesized. NMR spectra reve...

Effect of alicyclic monomers on thermal properties of transparent biodegradable polyesters

Amorphous biodegradable copolyesters have been synthesized using various alicyclic monomers, including 1,4-cyclohexanedimethanol (CHDM), 1,4-cyclohexanediol (CHDO), isosorbide (1,4:3,6-dianhidro-D-sorbitol) (IS), and 1,4-cyclohexane dicaboxylic acid (CHDA), to enhance the thermal properties of polyesters. We have studied the effect of alicyclic monomers on the thermal properties, especially, on the glass transition temperature (Tg) of the amorphous copolyesters. On incorporating alicyclic diol monomers into poly(ethylene succinate-co-terephthalate) (PEST), Tg of amorphous copolyesters was greatly increased. As the rigidity of alicyclic monomers increases, the effect becomes more significant. By comparing copolyesters synthesized with the same molar ratio of alicyclic monomers in the feed, we found that the molar ratio of IS in the copolyester product was much smaller than those of CHDM and CHDO. Nonetheless, IS induced the largest Tg enhancement in copolyesters even though a much smaller molar ratio of IS was incorporated in the product compared to CHDM and CHDO. To study the effects of alicyclic diacid monomers, copolyesters containing CHDA were synthesized. As in the case of alicyclic diols, CHDA was found to be very effective in enhancing the thermal properties. Among these copolyesters produced, PEI30ST synthesized with 30 mol% of succinic acid (SA) and 70 mol% of dimethyl terephthalate (DMT) as diacid and 30 mol% of IS as diol exhibited the highest Tg of 74.2 °C. And poly(ethylene-co-CHDM succinate-co-terephthalate) (PEC30ST70) and poly(ethylene-co-IS succinate-co-terephthalate) (PEI30ST70) exhibited high optical transmittance and were confirmed to be biodegradable, exhibiting about 50% and 40% biodegradability, respectively, after 50 days in a biodegradability test under compost conditions. Hence, these novel transparent biodegradable polyesters could be highly useful in flexible packaging applications requiring transparency.

Investigation on synthesis and properties of isosorbide based bis-GMA analogue

The aim of this work was to synthesize and investigate properties of a novel dimethacrylic monomer based on bioderived alicyclic diol—isosorbide. Its potential as a possible substitute of 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane (BISGMA), widely used in dental restorative materials and suspected for toxicity was assessed. The novel monomer was obtained in a three-step synthesis. First, isosorbide was etherified by a Williamson nucleophilic substitution and subsequently oxidized to isosorbide diglycidyl ether (ISDGE). A triphenyl phosphine catalyzed addition of methacrylic acid to ISDGE resulted in 2,5-bis(2-hydroxy-3-methacryloyloxypropoxy)- 1,4:3,6-dianhydro-sorbitol (ISDGMA). The monomer obtained was photopolymerized using camphorquinone/2-(dimethylamino)ethyl methacrylate initiating system. Next, compositions with triethylene glycol dimethacrylate (TEGDMA) were prepared and polymerized. Double bond conversion, polymerization shrinkage and water sorption of resulting polymers were determined. Selected mechanical (flexular strength and modulus, Brinell hardness) and thermomechanical (DMA analysis) properties were also investigated. BISGMA based materials were prepared as reference for comparison of particular properties.

ChemInform Abstract: Organotin Halides as Catalytic Precursors in Dehydration Processes. Part 1. Acetalizations and Transacetalizations of Alicyclic Diols and Polyols

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Synthesis and examination of antimicrobial properties of aminomethylated derivatives C6–C7 of alicyclic diols

Synthesis of C6–C7 alicyclic diols was studied by a catalytic oxidation of cyclohexene, norbornene and their methyl derivatives in the presence of heterogenized molybdenum-containing catalysts. By a triple condensation of the diols with formaldehyde and secondary amines a synthesis of their aminomethylated derivatives with various substituents at nitrogen atom was examined. Antimicrobial properties of the synthesized amino alcohols in M-10 oil as additives with fungicidal and bactericidal activities were studied.

Otrzymywanie 1,4-cykloheksanodimetanolu wwyniku uwodornienia tereftalanu dimetylowego i jego zastosowanie jako substratu wsyntezie poliestrow

A review concerning the preparation of alicyclic diol 1,4-cyclohexanedimethanol (CHDM), being the substrate for the polyesters' syntheses, is presented. CHDM synthesis consists of two-stage hydrogenation of dimethyl terephthalate [equation (1) and (2)]. Dimethyl 1,4-cyclohexanedicarboxylate (CHDKM) is an intermediate product in the process. General conditions of both stages of the process were given (catalyst, temperature, pressure) and technological solutions (Fig. 1) were discussed in detail. Polyesters and copolyesters produced with use of CHDM were characterized and their useful advantages (high melting point, significant crystallinity, good thermal stability and mechanical strength) were stressed. Most important directions of applications have been presented.

Alternative hydrogen bonding modes employed by a helical tubuland diol host molecule

The racemic alicyclic diol 3 yields different types of hydrogen bonded inclusion structures depending on the recrystallisation solvent used. Non-protic guests are enclosed within parallel tubes through formation of the helical tubuland structure in chiral space group P3121 (or P3221). This arrangement contains the molecules of 3 surrounding threefold screw axes. Racemic hydrogen bonded 1 ∶ 1 co-crystalline adducts are formed in space group P21/c on crystallisation of 3 from mono-functional alcohols or carboxylic acids. In these, the alcohol molecules contribute one hydroxy group to an intermolecular pseudo-threefold screw arrangement with a ⋯O–H⋯O–H⋯O–H⋯ hydrogen bonded repeat unit, while the carboxylic acid groups participate in the closely-related ⋯O–H⋯OC(R)–O–H⋯O–H⋯ repeat unit. The carboxylic acid functionality thus behaves like an extended alcohol hydroxy group in these compounds. In contrast, crystallisation of 3 from ethane-1,2-diol yields a novel 4 ∶ 3 network compound in space group P. This material assembles using hydroxy group hydrogen bonded ladders and (O–H)6 cycles. The X-ray structures of these various materials are described and compared in crystal engineering terms.

05/01853 Evaluation on thermal explosion induced byslightly exothermic interface reaction: Yu, M.-H. et al. Journal of Hazardous Materials, 2004, 113, (1–3), 165–174

We have found that several aliphatic and alicyclic diols induce melanogenesis in cultured S91 mouse melanoma cells and normal human epidermal melanocytes (NHEM). In addition, these compounds induce melanogenesis when applied to guinea pig skin, with transfer of melanin to keratinocytes and formation of “supranuclear caps,” as occurs in naturally pigmented skin. The relative order of potency of some of these diols in NHEM is 5-norbornene-2,2-dimethanol bg 3,3-dimethyl-1,2-butanediol bg cis-1,2-cyclopentanediol bg 2,3-dimethyl-2,3-butanediol bg 1,2-propanediol. Following treatment with these diols or 3-isobutyl-1-methylxanthine, melanin and tyrosinase activity are increased within S91 cells and NHEM; however, for cultured NHEM, the largest increases of melanin and tyrosinase occur in an extracellular particulate fraction, shown by electron microscopy to consist almost entirely of stage III and IV melanosomes. These results indicate that cultured NHEM treated with diols export melanosomes in a fashion that is commensurate with natural melanogenic processes. In contrast, S91 mouse melanoma cells exhibit aberrant melanosomal trafficking, in accordance with the known defect in myosin-V mediated melanosomal transport. Both S91 cells and NHEM exhibit morphologic changes and growth arrest indicative of differentiation following treatment with diols. The diols described in this report are candidates for use as cosmeceutical tanning agents.

ChemInform Abstract: Fine-Control of Helical Tubuland Inclusion Properties Through the Pendant Group Approach.

Abstract The helical tubulands are a family of alicyclic diols which crystallise in chiral space group P3121 and whose lattices can contain guest molecules enclosed within parallel tubes. New examples can be designed following a series of rules based on molecular structure and symmetry. In order to probe the latter requirement, and also to increase host–guest interactions, the behaviour of 2,5,8-trimethyltricyclo[5.3.1.13,9]dodecane-syn-2,syn-8-diol 4 was investigated using X-ray methods. Although molecules of 4 have no C2 symmetry they still form the helical tubuland lattice on crystallisation. In the pure apohost 4 their symmetry-breaking C5 methyl groups protrude into the tube volumes where they randomly adopt one of two equivalent orientations. Although the pendant methyl groups reduce the volume available for guest inclusion, they create irregular tube wall surfaces and interact more effectively with guest molecules. The helical tubulate inclusion compounds of 4 with diisopropyl ketone, benzene, toluene, and o-xylene show significant local methyl group ordering around a given guest molecule which performs a crucial templating role in formation of the product. In all cases, however, crystallographic C2 symmetry results in the solid through overall disorder of these diol orientations. Hence this, rather than strict molecular symmetry, is the true symmetry requirement of the P3121 helical tubuland lattice.

Fine-control of Helical Tubuland Inclusion Properties through the Pendant Group Approach

The helical tubulands are a family of alicyclic diols which crystallise in chiral space group P3121 and whose lattices can contain guest molecules enclosed within parallel tubes. New examples can be designed following a series of rules based on molecular structure and symmetry. In order to probe the latter requirement, and also to increase host–guest interactions, the behaviour of 2,5,8-trimethyltricyclo[5.3.1.13,9]dodecane-syn-2,syn-8-diol 4 was investigated using X-ray methods. Although molecules of 4 have no C2 symmetry they still form the helical tubuland lattice on crystallisation. In the pure apohost 4 their symmetry-breaking C5 methyl groups protrude into the tube volumes where they randomly adopt one of two equivalent orientations. Although the pendant methyl groups reduce the volume available for guest inclusion, they create irregular tube wall surfaces and interact more effectively with guest molecules. The helical tubulate inclusion compounds of 4 with diisopropyl ketone, benzene, toluene, and o-xylene show significant local methyl group ordering around a given guest molecule which performs a crucial templating role in formation of the product. In all cases, however, crystallographic C2 symmetry results in the solid through overall disorder of these diol orientations. Hence this, rather than strict molecular symmetry, is the true symmetry requirement of the P3121 helical tubuland lattice.

Aliphatic and Alicyclic Diols Induce Melanogenesis in Cultured Cells and Guinea Pig Skin

We have found that several aliphatic and alicyclic diols induce melanogenesis in cultured S91 mouse melanoma cells and normal human epidermal melanocytes (NHEM). In addition, these compounds induce melanogenesis when applied to guinea pig skin, with transfer of melanin to keratinocytes and formation of "supranuclear caps," as occurs in naturally pigmented skin. The relative order of potency of some of these diols in NHEM is 5-norbornene-2,2-dimethanol > 3,3-dimethyl-1,2-butanediol > cis-1,2-cyclopentanediol > 2,3-dimethyl-2,3-butanediol > 1,2-propanediol. Following treatment with these diols or 3-isobutyl-1-methylxanthine, melanin and tyrosinase activity are increased within S91 cells and NHEM; however, for cultured NHEM, the largest increases of melanin and tyrosinase occur in an extracellular particulate fraction, shown by electron microscopy to consist almost entirely of stage III and IV melanosomes. These results indicate that cultured NHEM treated with diols export melanosomes in a fashion that is commensurate with natural melanogenic processes. In contrast, S91 mouse melanoma cells exhibit aberrant melanosomal trafficking, in accordance with the known defect in myosin-V mediated melanosomal transport. Both S91 cells and NHEM exhibit morphologic changes and growth arrest indicative of differentiation following treatment with diols. The diols described in this report are candidates for use as cosmeceutical tanning agents.

Enantiomeric Self-Resolution through Dimethylsulfoxide Complexation

The alicyclic diol 2 is known to adopt five different types of crystallattice: the pure solid, cocrystalline compounds with water or certainphenols, and two different types of lattice inclusion system (helicaltubulates and ellipsoidal clathrates). Self-resolution only occurs onforming the helical tubulate inclusion compounds. Its close analogue2,7-bis(trifluoromethyl)tricyclo[4.3.1.13,8]un-decane-syn-2,syn-7-diol 4 was synthesised to examine the influence ofreplacing CH3- by CF3-groups. It no longer formslattice inclusion compounds but does form a cocrystalline solid withdimethyl sulfoxide (DMSO). Crystal structures of 4[C13H16O2F6,P21/c, a 7.8636(6), b 13.1020(7), c 25.319(2) A, β101.526(4)°, Z 8, R 0.044] and (4)V_2.VD/MSO[(C13H16O2F6)2⋅C2H6SO,P212121, a 7.249(1), b 16.064(3),c 25.347(4) A, Z 4, R 0.033] were determined. In solid diol 4 themolecules are linked through (–-O–-H)4 rings toproduce layers of chirally pure enantiomers but the net crystal structure,which comprises layers of alternating handedness, is achiral. In contrast,complexation of 4 with DMSO by means of two -–O-–H.O=Shydrogen bonds induces complete enantiomeric self-resolution.

ChemInform Abstract: Helical Host Lattices Formed by Alicyclic Diols

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Poly(alkylene carbonate)s by the carbonate interchange reaction of aliphatic diols with dimethyl carbonate: synthesis and characterization

Poly(alkylene carbonate)s have been synthesized by the melt-phase interchange reaction of aliphatic diols with dimethyl carbonate. Aliphatic polycarbonates with inherent viscosities of 0.3 to 0.8 dlg−1 have been obtained. Polycarbonates derived from alicyclic diols show a Tg below room temperature and a Tm in the range 50–60°C. However, the polycarbonate derived from a cyclic diol, namely 1,4-bis(hydroxymethyl)-cyclohexane, shows a Tg of + 35°C and a Tm of + 97°C, the highest yet reported for this class of polymers.

Poly(alkylene carbonate)s by the carbonate interchange reaction of aliphatic diols with dimethyl carbonate: synthesis and characterization

Poly(alkylene carbonate)s have been synthesized by the melt-phase interchange reaction of aliphatic diols with dimethyl carbonate. Aliphatic polycarbonates with inherent viscosities of 0.3 to 0.8 dlg −1 have been obtained. Polycarbonates derived from alicyclic diols show a T g below room temperature and a T m in the range 50–60°C. However, the polycarbonate derived from a cyclic diol, namely 1,4-bis(hydroxymethyl)-cyclohexane, shows a T g of + 35°C and a T m of + 97°C, the highest yet reported for this class of polymers.

ChemInform Abstract: Syntheses and Crystal Structures of Four Alicyclic Diols Which Crystallize in Different Lattices Involving Helical Extensions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.