Properties Of Copolyesters Research Articles

Synthesis and properties of high performance biobased liquid crystal copolyesters toward load-bearing bone repair application

In order to acquire satisfactory load-bearing bone substitute, a series of high performance biobased liquid crystal copolyesters derived from 4-hydroxybenzoic acid (HBA), phloretic acid (HPPA), vanillic acid (VA) and lactic acid (LA) were designed and prepared via “one-pot” melt polymerization method in this work. The structure and properties of the copolyesters were fully investigated by experimental measurements and molecular simulation. The copolyesters showed relative low melting temperatures (176–229 °C) and controllable crystallinity (15.3–36.5%), due to the increased molecular chain mobility caused by LA units and the multi-component copolymerization effect. Broad temperature range of nematic liquid crystal phase, good thermal stability as well as shear shinning and viscous melt flow behavior were observed for the copolyesters, indicating they had excellent melt processing ability. As compared with polyetheretherketone (PEEK) materials, the copolyesters exhibited better mechanical properties and hydrophilicity, which of the tensile strength and water contact angle were in range of 95 to 175 MPa and 72.5 to 84.8°, respectively, ascribing to the combination effect of its liquid crystal nature and chemical structure. In addition, the cytotoxicity test showed the copolyesters have good biocompatibility. It is shown that the unique combination of potential biodegradability, excellent mechanical properties, hydrophilicity and biocompatibility of the copolyesters make them prospective and suitable for application in load-bearing bone repair area.

Synthesis and properties of high performance aromatic thermotropic liquid crystal copolyesters based on naphthalene ring structure

In order to obtain thermotropic liquid crystal polymers (TLCP) with excellent comprehensive performance, naphthalene monomers (amount exceeding 50 mol%) of 6-hydroxy-2-naphthoic acid (HNA) and 2,6-naphthalene dicarboxylic acid (NDA) were used to prepare wholly aromatic TLCP with strong molecular interaction via “one-pot” melt polymerization method in this work. The structure and properties of the copolyesters were fully investigated by experimental measurements and molecular simulation. The simulation results indicated that the naphthalene TLCPs had less chain mobility and stronger molecular interactions, and resulted in a linear rigid chain conformation, endowing the copolyesters with superior properties. As compared with the control copolyester M without naphthalene units, the resulted copolyesters had higher glass transition and melting temperature, higher melt tension, better thermal stability and fiber mechanical property. Overall, the rigidity, molecular interaction and properties of the obtained copolyesters could be efficiently improved after incorporation of the naphthalene units, which is beneficial for its processing and application.

Kilogram-Scale Production of Sustainable PCF Copolyesters Based on Novel Cyclic Diol THFDM Derived from 5-Hydroxymethylfurfural: Trade-Off between the THFDM Structure and Various Properties of Copolyesters

Kilogram-Scale Production of Sustainable PCF Copolyesters Based on Novel Cyclic Diol THFDM Derived from 5-Hydroxymethylfurfural: Trade-Off between the THFDM Structure and Various Properties of Copolyesters

The Synthesis and Properties of Halogencontaining Copolycarbonates

The main properties of copolycarbonates on the basis of bisphenols of 1,1-dichloro-2,2-di (4-hydroxy-phenyl) ethylene (S-2), 1,1-dichloro-2,2-di (3,5-dibromo-4-hydroxy-phenyl) ethylene (TB-S-2) and dichlorformiate 4,4'-isopropylidenediphenol are synthesized and studied. Regularities of synthesis of copolymers are determined by method of acceptor and catalytic polyfunctional condensation. The interconnection between their composition, structure and properties is also established. It was shown that copolycarbonates exhibited a high softening point and high heat and flame resistance. The existence of the raw material base for the production of the initial monomers, the improved service properties of copolyesters based on them, and the high technological effectiveness of the proposed synthesis method enabled the copolycarbonates to be regarded as industrially promising polymeric materials.

ДОСЛІДЖЕННЯ АМФІФІЛЬНИХ ВЛАСТИВОСТЕЙ КОПОЛІЕСТЕРІВ З ХРОМОФОРНИМИ ГРУПАМИ В СИСТЕМІ ВОДА-ОКТАНОЛ

ДОСЛІДЖЕННЯ АМФІФІЛЬНИХ ВЛАСТИВОСТЕЙ КОПОЛІЕСТЕРІВ З ХРОМОФОРНИМИ ГРУПАМИ В СИСТЕМІ ВОДА-ОКТАНОЛ

Effects of Alkyl Chain Length of Aliphatic Dicarboxylic Ester on Degradation Properties of Aliphatic-Aromatic Water-Soluble Copolyesters for Warp Sizing

In order to study the effects of alkyl chain length of aliphatic dicarboxylic ester (ADE) monomers on enzymatic and hydrolytic degradation properties of aliphatic-aromatic water-soluble copolyesters for warp sizing, dimethyl terephthalate, dimethyl isophthalate-5-sulfonic sodium, and ADE monomers with various alkyl chain lengths were copolymerized through a two-step method, i.e. transesterification and polycondensation. The enzymatic and hydrolytic degradation properties of the copolyesters were studied in terms of reduction rates of molecular weight, glass transition temperatures, and surface morphology after being cultivated for 24-96 h. It was found that, enzymatic degradation of the copolyesters strongly depended on alkyl chain length of ADE monomers. After being enzymatically degraded for 96 h, reduction rate of molecular weight of the copolyester using dimethyl malonate as ADE monomers could reach 22.2 %. Meanwhile, the hydrolytic degradation of the copolyesters was not directly related to the alkyl chain length.

Synthesis and characterization of bio-based poly(butylene succinate-co-10-hydroxydecanoate)

Aliphatic poly(butylene succinate-co-10-hydroxydecanoate)s (PBHs) with various compositions were synthesized from 1,4-butanediol, succinic acid, and 10-hydroxydecanoic acid (HDA) by esterification and polycondensation with tetrabutyl titanate as catalyst. Gel permeation chromatography and proton nuclear magnetic resonance analysis indicate that the molecular weight of PBHs is in the range of 24,947–45,921 g/mol with a relatively narrow polydispersity index at 1.76–2.09. The influence of block length on the properties of copolyesters was investigated. With the increase of HDA unit content, melting point, crystallization temperature, and tensile modulus of PBHs decrease, while the thermal stability and toughness enhanced significantly. In addition, PBHs keep relatively stable in phosphate buffer solution (pH = 7.4) and HCl solution (0.1 mol/L), but 22% weight was lost after 30 days in NaOH solution (0.1 mol/L). Furthermore, the degradation rate of PBHs in NaOH solution (0.1 mol/L) accelerates monotonically with increasing HDA content.

Poly(ethylene terephthalate) copolyesters and fibers modified with NPG and SIPE for improved hydrophilicity and dyeability

A series of Poly(ethylene terephthalate) (PET)-based copolyesters containing sodium-5-sulfo-bis-(hydroxyethyl)-isophthalate (SIPE) and 22-dimethyl-13-propanediol (NPG) were successfully synthesized. The results showed that the actual molar ratio of comonomers was consistent with the relative feed ratio, and the thermal properties of copolyester were greatly dependent on the amount of NPG. Meanwhile, the modified PET fibers were prepared via traditional melting-spinning and the effects of NPG amounts and draw ratio on the crystallinity, orientation, and mechanical property of the fibers were also investigated. Furthermore, the hydrophilic property and dyeability of the fibers were explored. The results showed that compared with the pure PET fibers, the resultant fibers exhibited improved hydrophilicity and dyeability, which also were controllable by tuning the amount of NPG and in turn provided the modified PET fibers with more potential application in various fields.

Thermoplastic elastomers derived from bio‐based monomers

ABSTRACTSeries of copolyesters based on poly(propylene succinate) (PPS) and poly(butylene succinate) (PBS), which can be produced from biological feedstock, and postconsumer poly(ethylene terephthalate) (PET) were synthesized with the aim of developing sustainable materials, which combine the mechanical properties of high performance elastomers with those of flexible plastics. The aliphatic polyesters were synthesized by the catalyzed two‐step transesterification reaction of dimethyl succinate, 1,3‐propanediol, and 1,4‐butanediol followed by melt reaction with PET in bulk. The content of PET segments in the polymer chains was varied from about 10 to 100 wt % per 100 wt % PPS or PBS. The effect of the introduction of the PET segments on the structure, thermal, physical, and mechanical properties was investigated. The composition and structure of these aliphatic/aromatic copolyesters were determined by NMR spectroscopy. The thermal properties were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The level of crystallinity was studied by means of DSC and wide‐angle X‐ray scattering. A depression of melting temperature and a reduction of crystallinity of copolyesters with increasing content of PET segments were observed. Consequently, the tensile modulus and strength of copolyesters decreased, and the elongation at break increased with PET content in the range of 10−50 wt %. Thus, depending on PET content, the properties of copolyesters can be tuned ranging from semicrystalline polymers possessing good tensile modulus (380 MPa) and strength (24 MPa) to nearly amorphous polymer of high elongation (∼800%), and therefore they may find applications in thermoplastics as well as elastomers or impact modifiers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39815.

SYNTHESIS OF LIQUID CRYSTALLINE COPOLYESTERS WITH T-SHAPED TWO-DIMENSIONAL MESOGENIC UNIT AND CROWN ETHER CYCLE

A novel series of liquid crystalline copolyesters with T-shaped two-dimensional mesogenic unit and crown ether cycle of cis-4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6 was prepared via solution condensation polymerization from 4,4′-(α,ω-hexanedioyloxy)dibenzoyl dichloride (M1), 2-(4′-ethoxyphenyl)hydroquinone (M2) and cis-4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6 (M3). The molecular weights of copolyesters are not high, and the intrinsic viscosity [η] of copolyesters ranges from 0.29–0.43. The monomers' structures were identified by elemental analysis, IR, UV, 1 H-NMR, MS, etc. All the copolyesters are yellowish powders and insoluble in THF and CHCl3 at room temperature except CP-9. The properties of copolyesters were investigated by using GPC, [η], DSC, TG, WAXD and POM. It was found that all the copolyesters entered into liquid crystalline phase when they were heated to above their melting temperature (Tm). The threaded texture and schlieren texture of nematic phase can be observed on POM. Their...

Synthesis and Properties of Thermotropic Liquid Crystalline Copolyesters Containing p‐Hydroxyphenylacetic Acid and m‐Hydroxybenzoic Acid Units

A series of copolyesters based on p‐acetoxybenzoic acid (p‐ABA), m‐acetoxybenzoic acid (m‐ABA), and p‐acetoxyphenylacetic acid (p‐APAA) were prepared by a modified melt polycondensation reaction. The effect of linear p‐ABA structure, kink m‐ABA and flexible p‐APAA moiety on the properties of copolyesters were systematically investigated. The copolyesters were characterized by DSC, thermogravimetric analysis, 1H‐NMR, polarized optical microscopy, X‐ray diffraction, and intrinsic viscosity measurements. The copolyesters exhibited nematic liquid‐crystalline phases in a broad temperature range of about 110°C, when the content of linear p‐ABA units was over 55 mol%. DSC analysis of the anisotropic copolyesters revealed broad and weak endotherms associated with the nematic phases, and the melting temperatures were found to be in the processable region. The degree of crystallinity, thermal decomposition temperatures, crystal‐to‐nematic and nematic‐to‐isotropic transitions depend on the type of monomer units, and these transitions increased as the content of the rigid‐linear p‐ABA units increased, or as the content of the flexible/kink p‐APAA/m‐ABA units decreased.

Synthesis and Physico‐chemical Properties of Copolyesters of 1,1′‐bis(3‐Methyl‐4‐hydroxy Phenyl)cyclohexane with 2,2′‐bis(4‐Hydroxy Phenyl)propane with Terephthaloyl Chloride

Copolyesters of varying compositions have been synthesized by interfacial polycondensation technique by using H2O‒CHCl3 as an interphase, alkali as an acid acceptor and cetyl trimethyl ammonium bromide–sodium lauryl sulfate as mixed emulsifiers at 0°C for 4 h. Copolymers are characterized by IR and NMR spectral data, viscosity and density (1.2465–1.2403 g/cm3) by a floatation method. Copolymers possess excellent solubility in common solvents and chemical resistance against water, acids, alkalis, and salt. They possess moderate to good tensile strength (9.3–61.8 N/mm2), excellent volume resistivity (1.2 × 1015–1.1 × 1017 Ωcm), electric strength (29.6–50.0 kV/mm), and dielectric constant (1.51–2.03). They are thermally stable up to about 303–307°C in an N2 atmosphere and possess high T g (176–190°C). DTA endo/exothermic transition(s) supported either decomposition or formation of new product(s).

Phase Behavior and Thermal Properties for Binary Blends of Bacterial Poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)s with Narrow‐Comonomer‐Unit Compositional Distribution

AbstractThe miscibility and the effect of compositional distribution on physical properties were investigated for binary blends of biosynthesized poly(3‐hydroxybutyrate) [P(3HB)] and comonomer compositionally fractionated poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)s [P(3HB‐co‐3HH)] with narrow compositional distribution. Biosynthesized P(3HB‐co‐3HH) samples were compositionally fractionated using solvent (chloroform)/nonsolvent (n‐heptane) mixtures. The binary blends of fractionated P(3HB‐co‐3HH)s with different 3HH unit content were prepared by casting from solution in chloroform. The miscibility and the thermal properties of these blends were analyzed by differential scanning calorimetry (DSC). It was found that the two components are miscible in the amorphous phase when the difference in 3HH unit content between the two component polymers of these blends is less than 20 mol‐%, subsequently they are immiscible when the difference is larger than 30 mol‐%. By comparing the thermal properties of the binary blends of fractions, with those for the fractions themselves, and with those for the bacterially as‐produced unfractionated copolyesters, the effects of compositional distribution on the properties of copolyesters were discussed.Glass transition temperatures of blends PHB/H10, H10/H20, and PHB/H20 versus total 3HH unit content in the blends. The solid lines are the best fits of the experimental results of the P(3HB‐co‐3HH) fractions with narrow compositional distribution.magnified imageGlass transition temperatures of blends PHB/H10, H10/H20, and PHB/H20 versus total 3HH unit content in the blends. The solid lines are the best fits of the experimental results of the P(3HB‐co‐3HH) fractions with narrow compositional distribution.

Synthesis and characterization of copolyester sizing agents

The effect of main chain structure of anion-containing copolyesters on the properties of copolyester sizing agents was investigated. The copolyesters were prepared by conventional two step polymerization technique from DMT, DMI, DMS, EG, and DEG. The copolyesters synthesized were characterized by atomic absorption spectroscopy,1H-NMR Spectroscopy, GC, FTIR Spectroscopy, and DSC. The solubility decreased as the DMT content increased. The copolyesters having DMT:DMI=1:1 showed the minimum viscosity. The effect of EG content on the solution stability was not clear and the samples having high DMI content showed better solution stability. The water resistance was best when only DMI and EG were used, while it was worst when DMT:DMI was 1:0.

Syntheses and properties of thermotropic copolyesters of p-hydroxybenzoic acid

Two series of thermotropic copolyesters of p-hydroxybenzoic acid (HBA) were synthesized by direct thermal polycondensation. One comprised aromatic copolyesters from HBA, terephthalic acid, bis(4-hydroxyphenyl) ketone (BHP) and resorcinol. The other comprised semi-aromatic copolyesters from HBA, terephthalic acid, BHP and α,ω-diols with carbon atom number of 4, 6, 8, 10. The properties of the two series were characterized by polarized light microscopy, differential scanning calorimetry and wide angle X-ray diffraction. Most of the resulting copolyesters could form a nematic phase over a wide temperature range above their melting points. The effects of variation in composition and monomer structure on the properties of copolyesters were discussed.

Synthesis of hydrolytically degradable aromatic polyesters with lactide moieties

A synthetic route to higher molecular weight processable polyesters with bisphenol A terephthalate/isophthalate moieties and lactide moieties which are of potential interest for tissue engineering is described. The combination of aliphatic and aromatic moieties is a promising concept for processable polyesters with potential sites for physiological degradation and improved mechanical properties. The molecular structure of the copolyesters prepared by melt condensation via an acid chloride route and incorporation of the lactide moieties by transesterification of an oligo dl-lactide was confirmed by infrared, 1H and 13C nuclear magnetic resonance spectroscopy as well as gel permeation chromatography. The thermal and mechanical properties of copolyesters with different amounts of lactide moieties are reported and correlated with their composition. The reaction mechanism by transesterification was proved by a model reaction with a physical blend of the components and the hydrolytical behavior of the copolyesters under physiological conditions has been investigated. © 1997 John Wiley & Sons, Ltd.

Synthesis and properties of copolyesters having an ordered comonomer sequence: copolyesters prepared from naphthylene bis(4-hydroxybenzoate)s and α,ω-bis(4-carboxyphenoxy)alkanes

A series of sequentially ordered copolyesters were prepared from isomeric naphthylene bis(4-hydroxybenzoate)s (NBHBs) and α,ω-bis(4-carboxyphenoxy)alkanes (BCPAs) with varying length of α,ω-alkylene units. All of the copolyesters were composed of naphthalenediol (NAPH), BCPA and p-hydroxybenzoic acid (POB) (1:1:2 molar ratio). The polymer chains were made up of POBNAPHPOBBCPA segments. The naphthalene units were derived from 1,5-, 1,6-, 2,6- and 2,7-naphthalenediols. The BCPAs employed were 1,4-butane, 1,5-pentane and 1,10-decane derivatives. The melting points and crystallizability of these copolyesters were found to be much higher than those of the corresponding random copolyesters having the same overall compositions. All of the polymers, with the exception of the polyester derived from 2,7-naphthalenediol and 1,5-pentane spacers, formed nematic phases in melts. The ordered sequence copolyesters were found to undergo a rapid sequence randomization at temperatures higher than their melting points. A model compound of a copolyester, 2,7-naphthylene bis[4-(4-n-butoxybenzoyloxy)-benzoate], was also synthesized and its thermal behaviour and liquid crystal properties were studied.

Liquid crystalline properties of copolyester having dimethoxyphenylene groups.

Liquid crystalline properties of copolyester having dimethoxyphenylene groups.

Synthesis and properties of copolyesters having an ordered monomer sequence. A series of poly(oxynaphthyleneoxycarbonyl-1,4-phenylene-oxyterephthaloyl-4-oxy-1,4-phenylenecarbonyls)

Preparation par polycondensation en presence de SOCl 2 des bis-hydroxy-4 benzoate de naphtalenediol-1,5, -1,6, -2,6 ou -2,7 avec l'acide terephtalique. Les polymeres obtenus ont des Tg, des Tm et des cristallisabilites tres superieures a celles des copolymeres statistiques de meme composition acide terephtalique/naphtalenediol/acid p-hydroxybenzoique 1/1/2. Augmentation de la masse moleculaire, de Tm et de la cristallinite par recuit

Melt flow and fiber properties of copolyesters

AbstractThe effect of modifying monomer [sodium 3,5‐di(carbonethoxy)benzene sulfonate] contents range from 1.5 to 4.5 mol % on the melt flow and fiber properties of copolyesters (COPET) dyeable with basic dyes was investigated. An Instron capillary rheometer was used to obtain data over shear rates ranging from 10 to 104 s−1 at 265, 275, and 285°C. The COPET's flow properties as a function of temperature, inherent viscosity, melting point, and modifying monomer content were determined. The drawn fibers annealed in oil and air at 80, 110, 130, 150, 175, and 200°C were studied by means of measurements of shrinkage ratio, crystallinity, birefringence, long period, sonic rate, and static state flexibility of molecular chain. All these showed that the large side group, SO3Na in COPET molecular chains causes an increase in chain rigidity and melt viscosity, and a decrease in crystallinity and orientation.