Polytetrahydrofuran Research Articles

폴리테트라메틸렌 에테르 글리콜과 폴리카보네이트 디올로부터 합성한 수분산 폴리우레탄 필름의 가수분해에 의한 특성 변화

폴리테트라메틸렌 에테르 글리콜과 폴리카보네이트 디올로부터 합성한 수분산 폴리우레탄 필름의 가수분해에 의한 특성 변화

Superficial physicochemical properties of polyurethane biomaterials as osteogenic regulators in human mesenchymal stem cells fates

All of the cells’ interactions are done through their surfaces. Evaluation of surface physicochemical scaffolds along with other factors is important and determines the fate of stem cells. In this work, biodegradable and biocompatible polyester/polyether based polyurethanes (PUs) were synthesized by polycaprolactone diol (PCL) and poly (tetra methylene ether) glycol (PTMEG) as the soft segment. To assess better the impact of surface parameters such as stiffness and roughness effects on osteogenic differentiation of the human mesenchymal stem cell (hMSC), the dimension effect of substrates was eliminated and two-dimensional membranes were produced by synthesized polyurethane. Surface and bulk properties of prepared 2D membranes such as surface chemistry, roughness, stiffness and tensile behavior were evaluated by Attenuated total reflectance Fourier transform infrared (ATR-FTIR), atomic force microscopy (AFM) and tensile behavior. The prepared 2D PU films had suitable hydrophilicity, biodegradability, water absorption, surface roughness and bulk strength. The hMSCs showed greater osteogenesis expression in PU substrates with more roughness and stiffness than others. The results demonstrated that surface parameters along with other differentiation cues have a synergistic effect on stem cells fates.

Synthesis and characterization of polyurethane/bentonite nanoclay based nanocomposites using different diisocyanates: relation between mechanical and thermal properties

Polyurethanes (PUs) and polyurethane nanocomposites (PUNC) with bentonite nanoclay were prepared by the reaction of toluene-2,4-diisocyanate (TDI), dimeryl diisocyanate (DDI) and isophorone diisocyanate (IPDI) with two different polymers: hydroxyl terminated polybutadiene (HTPB) and polytetramethylene ether glycol (PTMEG), and the chains were further extended with 1,4-butanediol (1,4-BDO) to get final PUs and PUNCs. PUNCs were prepared by dispersing within the polymers a commercial and a synthesized bentonite nanoclay by mechanical dispersion. Mechanical properties showed that the addition of a small amount of nanoclay resulted in a significant increase in tensile strength and reduction in elongation at break (maximum increase of 2.3 and 5-times reduction, respectively, for a HTPB-TDI-BDO PUNCs). Thermal analysis revealed that the addition of nanoclays improved the thermal stability and increased decomposition temperature of PUNCs. We concluded that there is a positive correlation between mechanical and thermal properties as a result of nanoclay addition.

Evaluation of Stability of Amylose Inclusion Complexes Depending on Guest Polymers and Their Application to Supramolecular Polymeric Materials.

This paper describes the evaluation of the stability of amylose–polymer inclusion complexes under solution state in dimethyl sulfoxide (DMSO) depending on guest polymers. The three complexes were prepared by the vine-twining polymerization method using polytetrahydrofuran (PTHF), poly(ε-caprolactone) (PCL), and poly(l-lactide) (PLLA) as guest polymers. The stability investigation was conducted at desired temperatures (25, 30, 40, 60 °C) in DMSO solutions of the complexes. Consequently, the amylose–PTHF inclusion complex was dissociated at 25 °C, while the other complexes were stable under the same conditions. When the temperatures were elevated, the amylose–PCL and amylose–PLLA complexes were dissociated at 40 and 60 °C, respectively. We also found that amylose inclusion supramolecular polymers which were prepared by the vine-twining polymerization using primer-guest conjugates formed films by the acetylation of amylose segments. The film from acetylated amylose–PLLA supramolecular polymer had higher storage modulus than that from acetylated amylose–PTHF supramolecular polymer, as a function of temperature.

Effects of the NCO/OH molar ratio and the silica contained on the properties of waterborne polyurethane resins

Waterborne polyurethane resins (WPUs) were synthesized with polytetramethylene ether glycol (PTMG), dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), triethylamine (TEA) and ethylenediamine (EDA) as the raw materials of polyol, internal emulsifier, isocyanate, neutralizer and chain extender, respectively. The NCO/OH molar ratios used for the pre-polymerization were set as 1.6/1, 1.8/1 and 2.0/1. Furthermore, tetraethoxysilane (TEOS) was added to the WPUs to prepare the WPU/silica organic-inorganic hybrids by the sol-gel process. The characteristics of WPUs prepared with different NCO/OH molar ratios, and the properties of WPU and WPU/silica films were investigated. The results show that WPUs prepared with higher NCO/OH molar ratios have suspensions with lower viscosity, smaller average particle size and smaller average molecular weight, and lead the films to have more urea and amide structure, better solvent resistance, higher tensile strength, modulus and break energy, lower molecular chain activity, and smaller damping peak height, but weaker thermal resistance. The network structure of silica can limit the activity of the soft-segment, increase the stiffness of the hard-segment and enhance the thermal resistance of WPUs films.

High elasticity and corresponding microstructure origin of novel long chain poly(amide-block-ether) filament fibers

A new kind of elastic filament fibers based on long chain poly(amide-block-ether) (LPAE) was successfully prepared by simple melt spinning. The LPAE elastomer was synthesized with hard blocks of long chain polyamide (LCPA) oligomers, produced by bio-fermenting monomers, and poly(tetra-methylene ether) glycol (PTMEG) soft blocks. The mechanical and thermal results demonstrated that it represented large elongation at break, low initial modulus and excellent elastic recovery, which were comparable to that of commercially used spandex within strain of 200% and superior to that of olefin-based XLA fibers. The high elasticity and reversibility arise from that the LCPA hard segments, representing semi-crystalline state at ambient temperature and generating three dimensional hydrogen bonds between adjacent chains, serve as the physical crossing linking sites, while the polyether soft segments can be deformed largely due to amorphous state and the easy conformation changes of polymer chains. However, beyond 200%, the recovery gradually drops and it origins from the strain-induced crystallization and slight crystal transition in soft and hard segments, respectively. Hence, the novel elastic filament fibers retain the merits of the segmented copolymer and LCPA like better dimensional stability, chemical and abrasion resistance, and better soft handle. With this research, LPAE elastic fiber, featuring excellent elasticity and reversibility, is confirmed to be a promising candidate to replace spandex and XLA fibers in some typical textile applications.

Thermal Decomposition Behaviors and Burning Characteristics of Ammonium Nitrate/Polytetrahydrofuran/Glycerin-based Composite Propellants Supplemented with MnO2and Fe2O3

Although a polytetrahydrofuran (PTHF) blend with added glycerin as a crosslinking modifier is an effective binder for improving the performance of a propellant, a burning catalyst is required for the combustion of the ammonium nitrate (AN)/PTHF/glycerin propellant. MnO2 and Fe2O3 are useful burning catalysts for AN-based propellants. The thermal decomposition behaviors of the AN/PTHF/glycerin propellant supplemented with MnO2 and Fe2O3 catalysts, and the catalytic effect of these catalysts on the burning characteristics was investigated in this study. The thermal decomposition behaviors of these propellants depended on the kind of catalyst used. The propellants containing MnO2 burned above 4 MPa, while those containing Fe2O3 burned above 0.5 MPa. The burning rate increased in the order, (AN/PTHF/Fe2O3)<(AN/PTHF/MnO2)<(AN/PTHF/MnO2/Fe2O3). The improvement in the ignitability and burning rate was dependent on the kind of catalyst used. The burning characteristics of the AN/PTHF/glycerin propellants were improved by the combined effect of multiple catalysts with differing catalytic mechanisms, as compared to the propellant supplemented with any single catalyst.

Independent assessment of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) sample preparation quality: Effect of sample preparation on MALDI-MS of synthetic polymers.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides detailed and in-depth information about the molecular characteristics of synthetic polymers. To obtain the most accurate results the sample preparation parameters should be chosen to suit the sample and the aim of the experiment. Because the underlying principles of MALDI are still not fully known, a priori determination of optimal sample preparation protocols is often not possible. Employing an automated sample preparation quality assessment method recently presented by us we quantified the sample preparation quality obtained using various sample preparation protocols. Six conventional matrices with and without added potassium as a cationization agent and six ionic liquid matrices (ILMs) were assessed using poly(ethylene glycol) (PEG), polytetrahydrofuran (PTHF) and poly(methyl methacrylate) (PMMA) as samples. All sample preparation protocols were scored and ranked based on predefined quality parameters and spot-to-spot repeatability. Clearly distinctive preferences were observed in matrix identity and cationization agent for PEG, PTHF and PMMA, as the addition of an excess of potassium cationization agent results in an increased score for PMMA and a contrasting matrix-dependent effect for PTHF and PEG. The addition of excess cationization agent to sample mixtures dissipates any overrepresentation of high molecular weight polymer species. Our results show reduced ionization efficiency and similar sample deposit homogeneity for all tested ILMs, compared with well-performing conventional MALDI matrices. The results published here represent a start in the unsupervised quantification of sample preparation quality for MALDI samples. This method can select the best sample preparation parameters for any synthetic polymer sample and the results can be used to formulate hypotheses on MALDI principles. Copyright © 2016 John Wiley & Sons, Ltd.

Synthesis of rotaxane cross-linked polymers with supramolecular cross-linkers based on γ-CD and PTHF macromonomers: The effect of the macromonomer structure on the polymer properties

Vinylic supramolecular cross-linkers (VSCs) consisting of γ-cyclodextrin (γ-CD) and terminal bulky macromonomers (TBMs) based on polytetrahydrofuran (PTHF) were designed, synthesized, and used to introduce rotaxane cross-linkers into vinyl polymers in order to endow the resulting rotaxane-cross-linked polymers (RCPs) with improved mechanical properties. Special attention was focused on the impact of the TBM structure on the properties of RCPs. VSCs, which formed in situ upon mixing γ-CD and the TBMs in water, were added to radical polymerization systems based on N,N-dimethylacrylamide to afford the corresponding RCPs. These RCPs were substantially tougher than covalently cross-linked polymers (CCPs), indicating a strong impact of the VSCs on the mechanical properties of the RCPs. VSCs obtained from macromonomers with longer PTHF chains afforded tougher RCPs compared to RCPs derived from TBMs with shorter PTHF chains, which highlights the importance of the flexible region of the polymer chain at the cross-linking points.

Photoisomerization of waterborne polyurethane with side-chained phenylazonaphthalene group

Novel waterborne polyurethane (WPU) with side-chained Phenylazonaphthalene group was prepared by step-growth addition polymerization between isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMG), 2, 2-dimethylol propionic acid (DMPA) and a self-made azo diol, N,N-(2-hydroxyethyl)-4-phenylazo naphthylamine (HPN), as a chain extender to partially substitute for 1, 4-butanediol (BDO). 1H nuclear magnetic resonance spectra (1H NMR), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet–Visible (UV–Vis) spectroscopy were used to research the properties of HPN and HPN-WPU. The WPU latex presented obvious trans–cis photoisomerization during UV radiation and the absorption wavelength of the HPN exhibited a blue shift after attached into polyurethane chains. It needed longer irradiated time to finish isomerization due to the emulsion aggregated states, comparing with phenylazonaphthalene monomer solution and WPU dilute solution.

Synthesis of tetraarm star block copolymer based on polytetrahydrofuran and poly(2-methyl-2-oxazoline) for gene delivery applications

New star shaped block copolymers were synthesized according to a core first strategy, with a hydrophobic polytetrahydrofuran (PTHF) central block and a poly(2-methyl-2-oxazoline) (PMeOx) external block. First, the cationic polymerization of THF was initiated from a tetrafunctional triflate ester synthesized in situ. The chain ends were functionalized by quenching the polymerization with an excess of MeOx, that allowed for the MeOx polymerization under microwave in a subsequent step. Demonstration of the expected structures was carried out at each step of the polymerization. The controlled molar mass of the star copolymers was kept below 5000gmol−1 in order to mimick the structure of the efficient poloxamines for gene transfer applications. Formulations containing various concentrations of star block copolymers were intramuscularly injected in mice. Efficient gene transfer was measured at formulations with very low concentration of copolymer compared to reference standard containing Lutrol®.

Artificial extracellular matrix for biomedical applications: biocompatible and biodegradable poly (tetramethylene ether) glycol/poly (ε-caprolactone diol)-based polyurethanes

The cells as a tissue component need to viscoelastic, biocompatible, biodegradable, and wettable extracellular matrix for their biological activity. In this study, in order to prepare biomedical polyurethane elastomers with good mechanical behavior and biodegradability, a series of novel polyester–polyether- based polyurethanes (PUs) were synthesized using a two-step bulk reaction by melting pre-polymer method, taking 1,4-Butanediol (BDO) as chain extender, hexamethylene diisocyanate as the hard segment, and poly (tetramethylene ether) glycol (PTMEG) and poly (ε-caprolactone diol) (PCL-Diol) as the soft segment without a catalyst. The soft to the hard segment ratio was kept constant in all samples. Polyurethane characteristics such as thermal and mechanical properties, wettability and water adsorption, biodegradability, and cellular behavior were changed by changing the ratio of polyether diol to polyester diol composition in the soft segment. Our present work provides a new procedure for the preparation of engineered polyurethanes in surface properties and biodegradability, which could be a good candidate for bone, cartilage, and skin tissue engineering.

Polyurethane/amino‐grafted multiwalled carbon nanotube nanocomposites: Microstructure, thermal, mechanical, and rheological properties

ABSTRACTA mixture of two different polyols, (polytetramethylene ether glycol and polydimethylsiloxane), were employed to synthesize a new structure of polyurethane (PU) with methylene diphenyl diisocyanate (MDI) and 1,4‐butanediol as chain extender. PU nanocomposites containing variable amount (0.3, 0.5, 1, and 3 wt %) of amino‐grafted multiwalled carbon nanotubes (NH2‐MWNT) were prepared via in situ polymerization. The dispersion of NH2‐MWNT into polymer matrix was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FT‐IR) confirmed the urethane‐urea chemical bonding between the PU chains and the NH2‐MWNT. Thermal stabilities of the nanocomposites were examined with thermogravimetric analysis (TGA) and the results indicated a remarkable improvement with increasing NH2‐MWNT contents. The results of dynamic mechanical thermal analysis (DMTA) including storage modulus (E′) and glass transition temperature (Tg), as well as tensile properties demonstrated that the yield strength, strain‐at‐break, and young modulus were enhanced by increasing NH2‐MWNT content. Rheological behavior including complex viscosity and storage and loss moduli of the PU nanocomposites improved with increasing NH2‐MWNT loading, as well. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44411.

Synthesis and application of hyperbranched poly(urethane‐urea) finishing agent with amino groups

ABSTRACTThe isocyanate‐terminated linear polyurethane prepolymer (LPPU) was successfully synthesized via step‐by‐step polymerization, with isophorone disocyanate (IPDI) and polytetramethylene ether glycol (PTMG, Mn = 2000 g/mol) used as raw materials, dibutyltin dilaurate (DBTDL) as the catalyst, 1,4‐butanediol (BDO) as the chain extender and anhydrous ethanol (EtOH) as the blocking agent. Then the hyperbranched poly (urethane‐urea) (HBPU) containing amino groups was synthesized by grafting LPPU on amino‐terminated hyperbranched polymers (NH2‐HBP). The molecular structure of LPPU and HBPU were characterized by means of FT‐IR and 1H‐NMR. It was founded that LPPU and HBPU were successfully synthesized as anticipated. The thermal stability and crystalline morphology of LPPU and HBPU were characterized and analyzed by TG and XRD. Additionally, it was also found that, after addition of 10% HBPU, the water absorption rate, water vapor transmission rate, and water vapor permeability increased markedly by 162.02%, 400.00%, 260.00%, respectively. The tensile strength of membrane decreased by 24.57% and the elongation at break increased by 26.92%. Compared with the leather finished by commercial PU finishing agent, the leather finished by HBPU presented better properties. The water vapor permeability of the leather finished by increased by 13.0%, and the dry‐ and wet‐rub resistances and the physical and mechanical performances were excellent. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44139.

Polyurethane makers prepare for a phaseout

It’s a scenario common in the chemical industry: A chemical is ideal for a certain use, but it is being shunned or banned outright because of environmental and health concerns. The insecticide dichlorodiphenyltrichloroethane, or DDT, is perhaps the most famous example. Polychlorinated biphenyl (PCB) coolants and chlorofluorocarbon (CFC) refrigerants also come to mind. Compared with these iconic chemicals, the polyurethane curative 4,4´-methylenebis 2-chloroaniline, also known as MOCA or MbOCA, is much more obscure. But it is no less useful in its own orbit of polyurethane elastomers. And the ban it faces in Europe because of toxicity fears is leading to a scramble for replacements. For decades, MOCA has been the standard curative for toluene diisocyanate (TDI)-based polyurethane elastomers. To make them, chemical companies react TDI with a polyol, commonly polytetramethylene ether glycol (PTMEG), yielding what is called a prepolymer. Companies that fashion finished elastomeric parts mix the prepolymer with MOCA.

스피커용 댐퍼에 사용되는 폴리우레탄/에폭시 하이브리드 수지의 합성

As a coating material for loudspeaker dampers, resilient polyurethane/epoxy hybrid resins were synthesized to replace conventional phenol resin and examined the physical properties, which are not only environmentally friendly but also not harmful to human. Five types of polyurethane resins were synthesized in the step-shot method using methylene diisocyanate, three polyols such as poly tetramethylene ether glycol(PTMEG, MW:2000), poly(1,4-buthylene adipate(PBAP, MW:2000), and poly carbonatediol(PCD, MW:2000), and three chain extenders such as ethylene glycol(EG), neopentyl glycol(NPG), and 1,4-buthandiol(1,4-BD). The five types of synthesized polyurethane resins and commercially available bisphenol A type epoxy resin were blended in weight ratios of 90:10, 70:30, and 50:50 to synthesize 15 types of polyurethane/epoxy hybrid resins. Among the polyurethane resins, the one that was synthesized using PCD and 1,4-BD showed excellent tensile strength, 100% modulus, low extension, and relatively high viscosity. Polyurethane/epoxy hybrid resins with higher epoxy resin contents showed better thermal properties and water resistance while those with higher polyurethane contents showed higher flexibility. The polyurethane/epoxy hybrid resin made by blending the polyurethane based on PCD and 1,4-BD with a bisphenol A type epoxy resin in a weight ratio of 70:30 was identified to be the most suitable to be used in speaker dampers.

Synthesis and Shape Memory Property of a MDI Based Liquid Crystalline Polyurethane

Liquid crystalline polyurethanes (LCPU) were prepared from 4,4’-methylenediphenyl diisocyanate (MDI), 1,6-hexanediol (HDO), 2,2-dimethylol propionic acid (DMPA) and polytetramethylene ether glycol (PTMG). The experiments synthesized three liquid crystalline polyurethane films with different soft/hard segment ratio. Chemical and structural characterization of the polyurethanes were investigated by Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, differential scanning calorimeter and polarized microscopy respectively. Swelling rate and shape memory property were tested. The results indicated that the polyurethane with 62% soft segment and large group of carboxyl displayed excellent swelling and shape memory properties, and the shape recovery rate reached 100%. It was found that the crystallinity, thermal stability decreased and the temperature flexibility, water absorption and shape recovery rate increased with the increase of polytetramethylene ether glycol.

Preparation and Characterization of UV Cured Optical Films Containing a Fluorene Compound

In this study, the high refractive coating films applicable for optical materials were produced. the conversion and the photo curing behaviors were examined through FTIR-ATR and photo-DSC, and thermal and mechanical properties of cured films were examined by using DMA and UTM, and pencil hardness, refractive index and optical transmittance of film were measured. Urethane metacrylate oligomer was synthesized by mixing bisphenoxyethanolfluorene (BPEF), polycaprolactone diol (PCL), and polytetramethylene ether glycol (PTMeG) in varying ratios. Also, as the results of mixing ethylene glycol phenyl ether acrylate (PHEA) and trimethylolpropanetriacrylate (TMPTA) in varying ratios, the more time UV irradiated, the higher conversion and the heat of enthalpy (ΔH) and the initial curing rate increased with increasing TMPTA content up to 70%. Also, as the trifunctional monomer increased, the storage modulus and Tg increased, and the stress increased while the strain decreased to reach its maximum value. Also, as the BPEF ratio increased, the maximum value of stress increased while the strain decreased, the refractive index and pencil hardness increased, and light transmittance was all over 80%.

Synthesis and Photochromism Properties of Anionic Waterborne Polyurethane Containing Azobenzene Chromophores

A series of novel waterborne polyurethane dispersions (HPB-WPU) possessing the property of photochromism was prepared from isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMG), and 2, 2-dimethylol propionic acid (DMPA) using a self-made azo diol, N, N-bis-(2-hydroxy-ethyl)-4-phenylazo-aniline (HPB), as a chain extender to partially substitute for 1, 4-butanediol (BDO). The molecular structures of HPB and HPB-WPU were confirmed using Fourier-transform infrared spectroscopy. The photochromism of HPB and HPB-WPU was evaluated using ultraviolet visible (UV-Vis) absorption spectroscopy during the test. The results indicated that when the dispersion was placed under UV irradiation, the color and absorption intensity both changed. The UV-Vis absorption showed a blue shift effect of about 33 nm when HPB was blocked into polyurethane chains. The azo chromophore became permanently fixed into the molecule, and the dispersions remained stable for a long time because of the covalent bonding with polyurethane chains during synthesis. There were no precipitates or any other changes after they had been allowed to remain at room temperature for half a year. The synthesized HPB-WPU was also investigated using differential scanning calorimetric analysis, particle size analysis, and water resistance analysis. It was observed that HPB could improve the thermostability, emulsion stability and water-resistant property of the waterborne polyurethane.

Reactively dispersed olefins in polyurethanes: A new class of polymer/polymer composite

Maleic anhydride grafted polyethylenes (MAH-g-PE) can be reacted with polyols to create fine phase dispersions in polyurethanes. Desirable blends can only be realized when the anhydrides are in the dehydrated state prior to reaction. The reaction of anhydride with hydroxyls can occur with the polyol prior to addition of isocyanate and chain extender to make the polyurethane, or with an already formed polyurethane heated up above its reversion temperature when hydroxyl functionality becomes available. Phase dispersion kinetics are a function of MAH-g-PE molecular weight and percentage grafted maleic anhydride along the chain, but also on viscosity matching of the forming polyurethane and the MAH-g-PE during the blending operation which maximizes shear stress between the phases. The final result is not strongly dependent on the preparation path. Thermoplastic polyurethane elastomers (TPUs) based on polypropylene oxide and polyethylenoxide/polypropylene oxide triblock copolymer soft segments are compared to industry standard TPUs prepared from polytetramethylene ether glycol (PTMEG) and polycaprolactone (PCL) soft segments. The control TPUs prepared from polypropylene oxide and the polyether triblock are inferior to those of PTMEG and PCL. However; when the polypropylene oxide and the triblock soft segments are prepared with 20% substitution of MAH-g-PE, the creep, thermal and solvent resistance of these elastomers exceeds those of the industry standards, and the tensile properties are comparable. Additionally, TPUs from PTMEG and PCL with added MAH-g-PE can also have their properties improved. The property improvements are a function of improved hard segment phase separation from the soft segment, and the creation of polyester crosslinks between the MAH-g-PE and the polyurethane.