Poly Tetramethylene Glycol Research Articles

Mechanical, thermal, and ultraviolet resistance properties of poly(ether–ester)/cerium oxide (CeO2) composite fibers

Poly(ether–ester)/cerium oxide (CeO2) composites with CeO2 nanoparticles of 0, 1, 2, 3, 4, and 5 wt% were prepared from dimethyl terephthalate, 1,4-butanediol, polytetramethylene glycol, and CeO2 nanoparticles by traditional melt polymerization. The Fourier transform infrared, scanning electron microscopy, thermal gravimetric analysis, tensile strength, thermal stability, aging resistance, ultraviolet resistance, and low-temperature elastic recovery of these composites were characterized. The results indicated that introduction of CeO2 nanoparticles into poly(ether–ester) can enhance the mechanical, thermal, low-temperature elastic recovery properties and ultraviolet resistance of traditional poly(ether–ester). In particular, the incorporation of 2 wt% CeO2 nanoparticles endowed poly(ether–ester) with the best performance in mechanical and low-temperature elastic recovery properties.

Structural and transport properties of polydimethylsiloxane based polyurethane/silica particles mixed matrix membranes for gas separation

Mixed matrix membranes of synthesized polyurethane (PU) based on toluene diisocyanate (TDI), polydimethylsiloxane (PDMS) and polytetramethylene glycol (PTMG) with polyvinyl alcohol based polar silica particles were prepared by solution casting technique. The homogeneity and thermal properties of the prepared PDMS-PU/silica membranes were characterized using scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The SEM micrographs confirmed the distribution of silica particles in the polymer matrix without agglomerations. Gas permeation properties of membranes with different silica contents were studied for pure CO2, CH4, O2, He and N2 gases. The obtained results indicated the permeability of the condensable and polar CO2 gas was enhanced whereas permeability of other gases decreased upon increasing the silica content of the mixed matrix membranes. The permeability of CO2 and its selectivity over N2 was increased from 68.4 Barrer and 22 in pure PDMS-PU to 96.7 Barrer and 64.4 in the mixed matrix membranes containing 10 wt% of the silica particles.

High transition temperature shape memory polymers (SMPs) by telechelic oligomer approach

This work describes the synthesis and comparative shape memory properties of cross-linked networks derived from epoxy and cyanate ester monomers containing polyether oligomers as reactive shape memory segments. The hydroxy telechelic oligomers viz. polyethyleneglycol (PEG), polypropyleneglycol (PPG), and polytetramethyleneglycol (PTG) are reacted with epoxy–cyanate ester matrix resulting in shape memory polymers with high transition temperatures. The soft oligomer segments act as flexible linker unit which interconnect oxazolidone, isocyanurate and triazine ring structures in the cross-linked polymer. The resultant cyclomatrix SMPs exhibit high transition temperatures 132, 178 and 161°C respectively for PEG, PPG and PTG integrated SMPs. The Eg/Er ratios are increased in the order PEG<PTG<PPG. The PTG and PPG based SMPs show shape retention of 99% and shape recovery of >98% with recovery time <100s. All the SMPs display good thermal stabilities (both inert and oxidative) above 275°C.

Polyamide4(PA4)-Polyurethane(PU)-PA4 삼블록 공중합체의 제조 및 특성

Polyamide4 (PA4)-polyurethane (PU)-PA4 triblock copolymers were synthesized by isocynated (NCO)-terminated PU prepared from 4,4'-diphenyl methane diisocyante (MDI) and polytetramethylene glycol (PTMG) as an initiator and potassium pyrrolidonate (P-py) as a catalyst for anionic ring opening polymerization of 2-pyrrolidone. Subsequently copolymer was controlled to contain different or same molecular weight of PA4 hard block with same or different molecular weight of PU soft block in order to investigate the effects of those differences on various properties of triblock copolymers as a thermoplastic elastomer. As the results shown in typical properties of block copolymeric elastomers, the mechanical strength and melting point (Tm) of the copolymers increased with an increase in molecular weight of PA4 block while the elongation at break increased with an increase in that of PU block.

Dyeing properties of mixture of ultrafine nylon and polyurethane with different types of dye

The dyeing and color fastness properties of levelling type acid dye, milling type acid dye, metal complex dye and reactive dye on ultrafine nylon, polyurethane fiber/film and their mixtures were investigated. Ultrafine nylon was dyed well with four types of dye at pH 3-6, but levelling type acid dye showed low washing fastness. Amine-rich polyurethane fiber exhibited enhanced dyeability due to amino groups which acted as dyeing sites, compared to regular polyurethane fiber. In simultaneous dyeing with milling type acid dye and metal complex dye, amine-rich polyurethane fiber absorbed more dye molecules than ultrafine nylon, the color difference between two fibers were apparent. Polyurethane-impregnated ultrafine nylon was also prepared and its build-up properties were determined. It was found that polyurethane whose soft segment was composed of polytetramethylene glycol (PTMG) and polypropylene glycol (PPG) showed improved dyeing property and subsequently high color strength.

Synthesis and properties of segmented polyurethanes with triptycene units in the hard segment

Segmented polyurethanes based on polytetramethylene glycol (PTMG) of 1000 g/mol were synthesized using a two-step polymerization procedure. Various hard segments were obtained using hexamethylene diisocyanate (HDI) or 4,4′-methylenebis(phenyl isocyanate) (MDI) as the diisocyanates and hydroquinone bis(2-hydroxyethyl)ether (HQEE) or triptycene-1,4-hydroquinone bis(2-hydroxyethyl)ether (TD) as the chain extenders. The effect of rigidity and bulkiness of the hard segments on morphology, thermal and mechanical properties were studied. Fourier transform infrared (FTIR) suggested that hydrogen bonding interactions were weakened in the presence of the bulky triptycene-containing hard segments. Variable temperature FTIR demonstrated that hydrogen bonds completely dissociate at around 170 °C for polyurethanes chain extended by HQEE compared to around 110 °C for their TD analogs. Polyurethanes from MDI and TD displayed microphase mixing behavior based on atomic force microscopy (AFM) and small angle X-ray scattering (SAXS). When HDI was used as the diisocyanate in the TD chain extended polyurethane, enhanced microphase separation was observed with comparable mechanical properties to those of the MDI analogs with HQEE.

Effect of polyol structure on the properties of the resultant magnetic polyurethane elastomer nanocomposites

In this study, two types of magnetic polyurethane (PU) elastomer nanocomposites using polycaprolactone (PCL) and polytetramethylene glycol (PTMG) as polyols were synthesized by incorporating thiodiglycolic acid surface modified Fe3O4 nanoparticles (TSM‐Fe3O4) into PU matrices through in situ polymerization method. TSM‐Fe3O4 nanoparticles were prepared using in situ coprecipitation method in alkali media and were characterized by X‐ray diffraction, Fourier Transform Infrared Spectrophotometer, Transmission Electron Microscopy, and Vibrating Sample Magnetometer. The effects of PCL and PTMG polyols on the properties of the resultant PUs were studied. The morphology and dispersion of the nanoparticles in the magnetic nanocomposites were studied by Scanning Electron Microscope. It was observed that dispersion of nanoparticles in PTMG‐based magnetic nanocomposite was better than PCL‐based magnetic nanocomposite. Furthermore, the effect of polyol structure on thermal and mechanical properties of nanocomposite was investigated by Thermogravimetric Analysis and Dynamic Mechanical Thermal Analysis. A decrease in the thermal stability of magnetic nanocomposites was found compared to pure PUs. Furthermore, DMTA results showed that increase in glass transition temperature of PTMG‐based magnetic nanocomposite is higher than PCL‐based magnetic nanocomposite, which is attributed to better dispersion of TSM‐Fe3O4 nanoparticles in PTMG‐based PU matrix. Additionally, magnetic nanocomposites exhibited a lower level of hydrophilicity compared to pure PUs. These observations were attributed to the hydrophobic behavior of TSM‐Fe3O4 nanoparticles. Moreover, study of fibroblast cells interaction with magnetic nanocomposites showed that the products can be a good candidate for biomedical application. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Effects of the Phase Behavior of the Diluent Mixture on the Microstructure of Polyethylene Membranes Formed by Thermally Induced Phase Separation Process

To understand the effects of the phase behavior of the diluent mixture on the microstructure of polyethylene (PE) membranes, PE membranes were prepared from PE blends with various diluent mixtures including dioctyl phthalate (DOP)/polytetramethylene glycol (PTMG), soybean oil (SBO)/PTMG, and liquid paraffin (LP)/PTMG via a thermally induced phase separation (TIPS) process. The DOP/PTMG mixtures were always miscible, while the SBO/PTMG and LP/PTMG mixtures exhibited upper critical solution temperature (UCST)-type phase behavior. The PE/diluent-mixture blends showed UCST-type phase behavior, and their phase separation temperatures increased with increasing PTMG content in the diluent mixture. Just above the PE crystallization temperature, the PE-rich phase formed from the PE//(LP/PTMG) blend contained a larger amount of diluent than that formed from the PE//(DOP/PTMG) or PE//(SBO/TMPG) blends. The number of pores formed from the PE//(DOP/PTMG) or PE//(SBO/TMPG) blends by liquid–liquid phase separation was much greater than that formed from the PE//(LP/PTMG) blend. As a result, the porosities of PE membranes fabricated using the DOP/PTMG or SBO/PTMG mixtures were higher than those fabricated using the LP/TMPG mixtures.

In situ synthesis of thermoplastic polyurethane/graphene nanoplatelets conductive composite by ball milling

Thermoplastic polyurethane/graphene nanoplatelets conductive composite was in situ synthesised by ball milling at room temperature, using polytetramethylene glycol as soft segment, 4-methyl-m-phenylene diisocyanate as hard segment, 1,4-butanediol as chain-extending agents, graphene nanoplatelets as conductive filler. Carbon black was used as contrast conductive filler, stir was used as contrast method. The mechanisms and influence of different ball milling time to exfoliate layered graphene nanoplatelets and compound with thermoplastic polyurethane resin were studied. The morphology, electrical, mechanical and thermal properties of thermoplastic polyurethane/graphene nanoplatelets composite were investigated too. It showed that ball milling was an effective method to prepare thermoplastic polyurethane/graphene nanoplatelets conductive composite of low loading level by avoiding aggregation of graphene nanoplatelets. The percolation threshold effect of thermoplastic polyurethane/graphene nanoplatelets composite by ball milling 6 h occurred at the content around 2 wt% of the graphene nanoplatelets, which was much lower than 6 wt% of that prepared by stir. Besides, thermoplastic polyurethane/graphene nanoplatelets composite showed much better conductive and mechanical properties than thermoplastic polyurethane/carbon black composite.

Influence of Diisocyanates on Dynamic Mechanical Properties of Castable Polyurethane Elastomers

A series of castable polyurethane elastomers, based on polytetramethylene glycol as soft segments and toluene diisocyanate, 4, 4’-diphenylmethane diisocyanate, P-phenylene diisocyanate as diisocyanates respectively, were synthesized. The dynamic mechanical analysis method was utilized to determine tan delta property (tanδ). Also the influence of diisocyanates on the dynamic mechanical properties of castable polyurethane elastomers was analyzed. It can be concluded that the P-phenylene diisocyanate system elastomers have the most excellent dynamic mechanical properties.

Synthesis and Characterization of Shape‐Memory Polyurethane–Polybenzoxazine Compounds

AbstractThe study investigates the scope for significant enhancements in shape‐memory properties in blends of thermoplastic polyurethanes (PUs) and polybenzoxazine (PB). PB was expected to serve as a second fixed phase in addition to hard segment of PU. The shape‐memory compounds were prepared in three steps. First, benzoxazine monomer was dissolved in urethane prepolymer synthesized from 4,4′‐methylenebis (phenyl isocyanate) (MDI) and poly (tetramethylene) glycol (PTMG). Second, the prepolymer was chain extended with 1,4‐butanediol (BD) without curing of benzoxazine. Third, the benzoxazine was polymerized into PB by thermal curing at 180 °C for 3 h. A compound with 17 wt% PB exhibited a recovery stress (RS) of 13 MPa and strain recovery (SR) of 93% compared with RS of 6.8 MPa and SR of 72% for PU.magnified image

Compatible compositions based on aqueous polyurethane dispersions and sodium alginate

A series of aqueous polyurethane dispersions were synthesized by the reaction of polytetramethylene glycol and isophorone diisocyanate, extended with dimethylol propionic acid. Their chemical structures were characterized using FTIR, 1H NMR, and 13C NMR, and thermal properties were determined by DMTA. Then, a number of aqueous polyurethane dispersions–sodium alginate (PUD/SA) compositions were prepared by addition of sodium alginate solution with different concentrations into the aqueous polyurethane dispersion. Characterization of chemical structure and thermal properties of these blends were performed by FTIR, EDX and DMTA, respectively. The morphology of the alginate in polyurethane matrix was studied by SEM. The hydrophilicity of the prepared samples decreases by increasing the content of sodium alginate in blends. These observations were attributed to the increase of hydrophilicity of the blends as a consequence of addition of hydrophilic carboxylate, hydroxyl and ether functional groups of the alginate to them.

Fullerene containing polyurethane nanocomposites for microwave applications

AbstractNovel flexible polyurethane (PU) composite films containing nano‐barium hexaferrite (BaF) and nano‐barium titanate (BT) have been synthesized and characterized. The PU nanocomposites were synthesized from fullerenol and prepolymer of hexamethylene diisocyante and polytetramethylene glycol by adding 1–3% each of BaF (high permeability) and BT (high permittivity). The incorporation of the nanopowders was confirmed by X‐ray diffraction (XRD), transmission electron microscopy, and energy dispersive X‐ray diffraction (EDX). Study of thermal properties by thermogravimetric analysis and dynamic mechanical analysis revealed enhanced thermal stability of the nanocomposites. Study of mechanical properties showed that the tensile strength had increased remarkably in the nanocomposites. The electromagnetic‐absorbing properties were studied by measuring the complex permeability and permittivity in the frequency range of 8.2 to 12.4 GHz. The good reflection loss of the nanocomposites at such low filler content suggests its potential applicability as a radar absorber. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Thermal stability of copolymer derived from l-lactic acid and poly(tetramethylene) glycol through direct polycondensation

The thermogravimetric analysis (TG) of triblock copolymers (PLAG) based on poly(l-lactic acid) (PLLA) and poly(tetramethylene) glycol (PTMEG) segments with different PTMEG content and catalyst concentration was conducted. The thermal degradation behaviors of copolymers were determined by thermogravimetric analysis and the results are also confirmed by hydrogen nuclear magnetic resonance spectrometry (1H NMR). The thermal stability of PLA-based copolymer is improved with decreasing use level of Sn catalyst and short-chain molecules with hydroxyl and carboxyl end group also have a significant effect on the thermal degradation of chain-extended products of copolymer (PLAE). PLAE-10 with 0.5 wt% catalyst shows two main decomposition kinetic mechanisms. On the other hand, PLAE-10 with 0.05 wt% catalyst mainly undergoes Sn-catalyzed selective depolymerisation. Moreover, the PTMEG segments in PLAEs seem to increase the mobility of the Sn salt moiety in PLAEs and the activation energy (E a) decreases with increasing the PTMEG content in PLAEs.

Synthesis and Properties of Novel Multiblock Thermoplastic Elastomers - Poly(ester-imide-ether) - Based on Pyromellitic Dianhydride, Glycine, 1,4-Butanediol and Polytetramethylene Glycol

A series of multiblock thermoplastic ploy(ester imide ether)s elastomers derived from polytetramethylene glycol of molecule weight is 1000 (PTMG1000), 1,4-butanediol (BD), and a new imide diacid monomer were synthesized of Pyromellitic dianhydride (PMDA) and glycine (GLY). was synthesized by two-step melting polycondensation method. Their chemical structures were studied by 1H-NMR spectroscopy as well as their thermal properties of the copolymers were investigated from differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), respectively. Otherwise, the solubility of these polymers was characterized by various organic solvents. The effects of the hard/soft segment content on the thermal properties and soluble behavior were investigated. The result demonstrated that these copolymers had better thermal properties (Tm: 225~280°C and T5% : 350~353°C) than those of conventional thermoplastic elastomers due to the introduction of imide bond. At the same time, the polymers have good solubility.

Novel metallomesogenic polyurethanes: Synthesis, characterization and properties

A series of tetradentate Schiff base metallomesogenic diols were synthesized from two simple dihydroxy benzenes. The metallomesogenic diol was constructed from three ring containing mesogen linked through ester and azomethine with terminal hydroxy group. This upon complexation with copper(II) formed metallomesogenic diol with varying terminal chain length. A series of metallomesogenic polyurethanes were synthesized using these metallomesogenic diols as chain extenders for the prepolymers based on polytetramethylene glycol (PTMG) of varying molecular weight (Mn=650, 2000) and 2,4-toluene diisocyanate (TDI), or 4,4′-methylene bis(phenyl isocyanate) (MDI). The molar ratio of metallomesogenic diol and PTMG were varied in the polyurethane to find their role in liquid crystalline and mechanical properties. Extensive characterization of all metallomesogenic compounds and intermediates were carried out by FT-IR, 1H and 13C NMR, EPR, VSM, Mass (EI and FAB) and UV–visible spectroscopy. Hot stage polarizing microscope and differential scanning calorimetry were used to ensure the phase characteristics such as nature of phase, melting and clearing temperatures and phase range. The appearance of enantiotropic smectic A phases indicated high molecular polarizability of the core due to the metal ion.

Synthesis of Segmented Block Copolymers Based on Polyamide-1010 and Polytetramethylene Glycol

Segmented block copolymers (PA1010-b-PEG) based on α,ω-dicarboxy-polyamide-1010 (PA1010dC, = 1000, 2000, 3000 and 5000) and α,ω-dihydroxy-polytetramethylene glycol (PEG, = 1000, 2000) were synthesized by melt condensation. Various block copolyamides with different block lengths of the hard and soft segments were obtained, and their composition and block lengths were determined via FT-IR and 1H-NMR.

Effect of Block Molecular Weight on the Mechanical Properties of PA1010-&lt;i&gt;b&lt;/i&gt;-PEG Segmented Block Copolymers

The mechanical properties were investigated of a series of PA-PEG thermalplastic elastomer based on PA1010 and polytetramethylene glycol (PEG) with varying hard and soft segment content. Dynamic mechanical measurements of these polymers have carried out over a wide range of temperatures. The block copolymers exhibit three peaks, designated as α, β and γ in the tanδ-temperature curve. The α transition shifts to higher temperature with increasing hard block molecular weight. However, at a constant hard molecular weight, the α transition shifts to higher temperature and the damping increases on increasing the soft segment molecular weight. DMA results show that the block copolymers exhibit a microphase separation structure and both soft and hard segments were found to be crystallizable. The degree of phase separation increases with increasing hard block molecular weight.

Changes in microporous structure of polyethylene membrane fabricated from PE/PTMG/paraffin ternary mixtures

Abstract Polyethylene (PE) membranes containing controlled pore sizes and porosities were fabricated using a polytetramethylene glycol (PTMG) mixture with paraffin as a novel diluent via a thermally induced phase separation (TIPS) process. PTMG could not be used as a diluent alone regardless of its molecular weight because it does not form a single phase mixture with PE over the entire temperature range. However, PTMG and paraffin mixtures, which exhibited upper critical solution temperature (UCST) type phase behavior, formed miscible blends with PE at elevated temperatures. The phase separation temperature of the PE//(paraffin/PTMG) ternary mixture increased with increasing PTMG content in the diluent mixture when PE content was fixed. At a fixed blend composition, the phase separation temperature of the PTMG/paraffin mixture increased as the molecular weight of the PTMG decreased, while that of the PE//(paraffin/PTMG) ternary mixture increased with increasing PTMG molecular weight. The observed phase behavior was attributed to the intermolecular association behavior of PTMG. The phase separation temperature in the PE//(paraffin/PTMG) ternary blend could be increased up to the evaporation temperature of paraffin by controlling the PTMG content or its molecular weight. As a consequence, a PE membrane containing controlled pores and porosities was able to be fabricated using a diluent mixture containing PTMG and paraffin.

Synthesis and characterization of calcium-containing polyurethane using calcium lactate as a chain extender

In this study, a calcium-containing monomer, namely calcium lactate, was used for the synthesis of calcium-containing polyurethane for use in biomedical applications. Ether-based polyurethane was prepared using poly(oxytetramethylene)glycol, hexamethylene diisocyanate and calcium lactate. The prepared polymer was characterized by FTIR spectroscopy, which confirmed the presence of ionic linkages in the main chain. The thermal behavior, mechanical properties and viscosity of the polymer were studied, and the properties were compared with those of a control polyurethane sample without any metal. Because of ionic clustering in calcium lactate-incorporated ionic polyurethane, the mechanical properties and storage modulus were enhanced compared with those of nonionic polyurethane. The prepared calcium-containing polyurethane was evaluated for its blood compatibility. An evaluation of blood–material interactions revealed that the material is blood compatible and that the polymer does not induce any hemolysis. Segmented polyurethane prepared using a novel chain extender, calcium lactate along with polytetramethylene glycol and hexamethylene diisocyanate. The properties of the synthesized polyurethane compared with that of polyurethane without any calcium. The prepared polymer has high glass transition temperature and storage modulus, and has improved mechanical properties. In vitro hemocompatibility evaluation reveals that the material is blood compatible and does not induce any hemolysis to blood.