Poly Oxytetramethylene Glycol Research Articles

Influence of fullerene content on the properties of polyurethane resins: A study of rheology and thermal characteristics

The effect of different contents of fullerene on the properties of polyurethane resins (PUs), including rheology and thermal properties, was investigated. Polyurethane resins were prepared through polyaddition reactions using different isocyanate monomers such as isophorone diisocyanate (IPDI), methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), and different polyols, such as poly(oxytetramethylene) glycol (PTMG), the triol trade name FA-703, and polypropylene glycols (PPG), at an NCO/OH ratio 0.94 and a temperature of 100 °C. IR spectroscopy was used to control the polymerization of PUs through the shifting of NCO peaks. The results showed that the rheology and thermal properties of the prepared PU resins depend on the type of isocyanates and fullerene used. Based on the type of isocyanates, the PU resin prepared by MDI has the highest viscosity and thermal stability compared to the other isocyanates investigated. On the other hand, the PU resins prepared by IPDI mixed with fullerene had the highest viscosity and thermal stability. However, the initial decomposition temperature (T onset) of the PUs decreased with the addition of fullerene without affecting the maximum decomposition temperature (PDTmax) of the PU resin.

The strengthening mechanism of mechanical performance for polyurethanes with micro-content crosslinkers

Chemical crosslinking is one widely used method to endow polyurethane (PU) with desirable properties. However, the introduction of crosslinkers in PU elastomers can often lead to the destruction of phase separation, resulting in weakened mechanical properties. Herein, a series of PUs with micro-content crosslinker were synthesized from poly(oxytetramethylene) glycol (PTMG), diphenylmethane-4,4′-diisocyanate (MDI), and chain extender of butane-1,4-diol (BDO) containing varied amounts of glycerol. The phase separation of PUs decreases with increased glycerol content, while the tensile strength increases. To elucidate this enhancement in mechanical properties, morphology investigation with capability of direct observation of components distribution is employed. An increased thickness of interphase between the domain of hard segment (HS) and soft segment (SS) is observed, which indicates that more HS is moved to the interphase upon the introduction of glycerol. The results of electron energy loss spectroscopy (EELS) further disclosed that glycerol formed aggregations located at the interphase. These aggregations increase the crosslinking density of the interphase, which strengthens HS domains and prevents them from being destroyed under tension, thereby increasing the tensile strength. It is the first time of disclosing distribution feature of micro-content crosslinker of PU as well its strengthening mechanism in tensile strength, which could assist in developing PU with desirable mechanical properties.

Effects of low temperatures and high strain rates on the tensile properties of polyurethane polymers for adhesives

ABSTRACT The mechanical properties of polyurethane compounds were experimentally investigated by changing the composition of their components. Polyol components (polyoxypropylene glycol: PPG, polyoxytetramethylene glycol: PTMG, and polycarbonatediol: PCD) were mixed with monomeric methylene diphenyl diisocyanate to synthesize polyurethane pre-polymer, mixed with chain extenders (1,4’-butanediol: 1,4’-BD or dimethylthiotoluene diamine: DMTDA), and cured, to prepare four types of polyurethane resins. Tensile tests were conducted using a mechanical testing machine with a strain rate of approximately 0.3 s−1 and a hydraulic high-speed tensile testing machine with a strain rate of approximately 500 s−1. The temperature was controlled to be −40°C, −10°C, or 25°C. When PTMG was used as the polyol, the stress-strain relationship was less sensitive to temperatures and loading rates, and the material properties exhibited a relatively good balance between elongation and strength. Additionally, the use of 1,4’-BD as a chain extender resulted in higher elongation and lower strength than the use of DMTDA. Conversely, the stress-strain relationship was dramatically altered by the test conditions when PPG and PCD were used as the polyol and embrittlement under a combination of low temperature and high strain rate was confirmed. Furthermore, there were certain compositional combinations that exhibit necking at low temperatures.

Effect of NCO/OH ratio on the physico-mechanical properties of polyurethane-polyurea hybrid spray coatings

Polyurethane- polyurea hybrid spray coating was prepared by two steps polymerization. In the first step, polyurethane prepolymers (PUs) were prepared by polyaddition reaction based on 4,4-methylene diphebyl dissocyanate (4,4 MDI), poly(oxytetramethylene) glycol (PTMG), polyoxypropylene glycol (PPG), and triol (trade name FA-703) with different NCO/OH molar ratios. IR spectroscopy and acid-base titration were used to check the NCO content of the prepolymers. In the second step, polyurethane-polyurea hybrid resin was prepared by mixing the polyurethane prepolymer (PU) with polyoxypropylenediamine (POPA) at constant molar ratio (1: 1). The effect of NCO/OH ratios on physico-mechanical properties of the polyurethane-polyurea hybrid coating films was studied including viscosity, tensile strength, elongation at break, tear strength, contact angle and adhesion. The results obtained showed that tensile strength, contact angle and hardness increased, while viscosity, elongation, adhesion and tear strength decreased with increasing NCO/OH molar ratio.

Robust Stretchable Thermoplastic Polyurethanes with Long Soft Segments and Steric Semisymmetric Hard Segments

Thermoplastic polyurethane (TPU) elastomers based on polyoxytetramethylene glycol (PTMG) with 2000 g·mol–1 as soft segments (SSs) and isocyanates as well as their reaction with butanediol as hard segments (HSs) were synthesized. The three-dimensional supramolecular networks were constructed in TPU by the formation of physical HSs-rich domains via microphase separation, hydrogen bonding, and microcrystallization, which are dominated by the chemical structure of HSs. The robust stretchable TPU with an excellent tensile strength of 32 MPa and elongation of 1378% at break could be successfully prepared, and no crystallization happened to keep the elasticity even at a low temperature (−90 °C) when the steric semisymmetric bis(4-isocyanatocyclohexyl)methane (HMDI) was introduced into HSs-rich domains. The crystallinity and ordered hydrogen bonding content decreased in HSs-rich domains with increases in steric hindrance and asymmetry of diisocyanates. A new approach was developed to construct the high-performanc...

Preparation of waterborne polyurethane-silica nanocomposites by a click chemistry method

A series of waterborne polyurethane-silica (WPUS) crosslinked hybrid dispersions were prepared based on polyoxytetramethylene glycol (PTMG) and isophorone diisocyanate (IPDI) as the raw materials, with 2-hydroxyethyl methacrylate (HEMA) and pentaerythritol triacrylate (PETA) as grafting reagents and (3-mercaptopropyl)triethoxysilane (MPTES) as the coupling agent. SiO2 nanoparticles that functioned as a nanofiller were introduced by a novel click chemistry method. Crosslinked networks were constructed in the WPUS, with SiO2 acting as the crosslinks. The effects of the amount of SiO2 on the properties of the WPUS nanocomposites were investigated. It was found that WPUS films exhibited admirable thermal properties due to their crosslinked structure. Contact angle tests and water absorption rate measurement results demonstrated the hydrophobicity of WPUS films are obviously enhanced, because of the migration and crosslinked of highly hydrophobic silicon which has lower surface energy during the film formation. Meanwhile, SiO2 as a crosslinker and reinforcing filler, which affects the mechanical tensile in this system, the tensile strength of the WPUS increased from 10.45 MPa to 24.10 MPa with increased amounts of SiO2. The performances of the WPUS composite material top the most, when the amount of SiO2 is 2.5 wt%.

Polypropylene Glycol-Polyoxytetramethylene Glycol Multiblock Copolymers with High Molecular Weight: Synthesis, Characterization, and Silanization.

The high crystallization at room temperature and high cost of polyoxytetramethylene glycol (PTMG) have become obstacles to its application. To overcome these problems, a segment of PTMG can be incorporated into a block copolymer. In this work, polypropylene (PPO) glycol-polyoxytetramethylene (PPO-PTMG) multiblock copolymers were designed and synthesized through a chain extension between hydroxyl (OH)-terminated PPO and PTMG oligomers. The chain extenders, feed ratios of the catalyst/chain extender/OH groups, reaction temperature, and time were optimized several times to obtain a PPO-PTMG with low crystallization and high molecular weight. Multiblock copolymers with low crystallization and high average molecular weight (Mn = 1.0–1.4 × 104 Dalton) were harvested using m-phthaloyl chloride as the chain extender. The OH-terminated PPO-PTMG multiblock copolymer with high Mn and a functionality near two was further siliconized by 3-isocyanatopropyltrimethoxysilane to synthesize a novel silyl-terminated polyether. This polyether has an appropriate vulcanizing property and potential applications in sealants/adhesive fields.

A study on recyclable waterborne polyurethane process with a photo and thermal hybrid treatment system

Development of a novel recycling process of waterborne polyurethane (WBPU) with a poly(oxytetramethylene)glycol (PTMG) soft segment was performed using characteristics of nitroxyl radical (TEMPO) dormant bond. A TiO2/hindered amine light stabilizer (HALS) combination produced the dormant bond in a 24 h UV irradiated WBPU. The WBPU extraction rate was 66% with a water-ethanol solvent, and its bond was found to contain a PTMG sequence by Py-GC/MS measurement. The binary blend of extracted WBPU and PTMG was immiscible and converted to miscible one by thermal treatment at 120 °C for 0.5 h in nitrogen. The WBPU was partially graft-polymerized onto the PTMG by the treatment and worked as a compatibilizer. The change to miscibility showed that the blend was recyclable as PTMG material.

Antibacterial and Biocompatible Cross-Linked Waterborne Polyurethanes Containing Gemini Quaternary Ammonium Salts.

A cross-linked waterborne polyurethane (CPTMGPU) with long-term stability was developed from poly(ethylene glycol) (PEG), polyoxytetramethylene glycol (PTMG), isophorone diisocyanate (IPDI), l-lysine, and its derivative diamine consisting of gemini quaternary ammonium salt (GQAS), using ethylene glycol diglycidyl ether (EGDE) as a cross-linker. Weight loss test, X-ray photoelectron spectroscopy (XPS) measurements, and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) were performed to prove the surface structure and stability of these CPTMGPU films. Furthermore, the GQAS-bearing CPTMGPUs show repeatable contact-active antibacterial efficacy against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria and do not show any inhibition effect against fibroblasts in vitro. After subcutaneous implantation in rats, the CPTMGPU films manifest good biocompatibility in vivo, despite the presence of a typical foreign body reaction toward surrounding tissues and mild systematic inflammation reaction that could be eliminated after a short implantation period, as demonstrated by histology and immunohistochemistry combined with interleukin (IL)-1β, IL-4, IL-6, IL-10, and TNF-α analysis though enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qRT-PCR). Therefore, these cross-linked waterborne polyurethanes hold great promise for antibacterial applications in vivo.

Preparation and characterization of a new class of poly(ether‐block‐amide)s via solvent free reactive processing

Novel poly(ether‐co‐amide) block copolymers (PEA) with polyamide‐6 as hard segments and different polyether (polyoxytetramethylene glycol [PTMG]/polyethylene glycol [PEG]) as soft segments were prepared via reactive processing. The chemical structure, crystalline properties, mechanical properties, water resistance, and thermal stability of as‐prepared PEAs were extensively studied by Fourier transform infrared spectroscopy, X‐ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, tensile testing, water contact angle, water absorption, and thermal gravity analysis. Fourier transform infrared spectroscopy confirmed the chemical structure and composition of PEAs. The X‐ray diffraction and differential scanning calorimetry showed that PEAs consist of obvious crystalline polyamide‐6 hard segments and that the crystalline structure of PEG will be significantly changed with the addition of PTMG. Dynamic mechanical analysis and tensile testing showed that the obtained PEAs exhibit classical elastomeric rubber plateau and tensile behavior. Meanwhile, the introduction of PTMG will improve the mechanical properties of PEAs. PEA with PEG as soft segments exhibited extremely surface hydrophilicity and high water absorption of 127%; the increasing of PTMG content in soft segments will reduce the surface hydrophilicity and improve the water resistance. In addition, the obtained PEAs exhibited good thermal stability, which will meet requirement of multiple processing.

Influence of the soft segment nature on the thermomechanical behavior of shape memory polyurethanes

Shape‐memory polyurethanes (SMPUs) represent a highly interesting class of materials due to their applications in different sectors such as biomedical, textile, and aerospace. Moreover, it is possible to synthesize a variety of polyurethanes with different molecular architectures just choosing properly the chemical structure of their components. In this work, it is described the influence of the soft segment on the thermomechanical properties and shape memory behavior of shape memory polyurethanes. The synthesis, based on two‐step polymerization, was prepared by two different soft segments: poly(oxytetramethylene) glycol (PTMG) or poly(ethylene glycol) (PEG). Depending on the molecular architecture achieved, the materials present different properties that were studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Furthermore, the shape memory response of thermally activated SMPUs is determined qualitative and quantitatively by visually monitoring the shape recovery process and by thermomechanical analysis (TMA), respectively. All developed compositions have shown good shape memory behavior, with recovery ratios higher than 99.8%. POLYM. ENG. SCI., 58:238–244, 2018. © 2017 Society of Plastics Engineers

Antibacterial polyurethane materials with silver and copper nanoparticles

New biologically active polyurethanes with silver and copper nanoparticles in their composition were prepared by saturation of liquid polyether (the initial component for polyurethane synthesis) with nanoparticles (Ag, Cu), followed by synthesis of polyurethane. The results of these studies allow consideration of these materials as medical suppliers with antibacterial properties. The main problem of their creation is uniform distribution of the metal nanoparticles inside the polymer matrix without changing the physico-chemical properties of the latter. Obtaining of metal nanoparticles’ colloid in a liquid polyoxytetramethylene glycol, MM 1000 was carried out by electron beam evaporation technology and vacuum deposition. This method allowed creating, on the basis of obtained colloids, the metal-containing polyurethane materials with targeted properties and structure that are determined by diisocyanates and chain extenders nature. Biological study has shown that polyurethanes containing Cu and Ag nanoparticles possess bactericidal/bacteriostatic effect against bacteria, fungi and yeast-like fungi. Polymer samples did not exhibit toxicity to the tissue culture cells and there were no biodegradation products observed in the culture medium. Resulting biologically active metal-containing polyurethane materials can be processed into products for medical purposes (implants, drug delivery systems, antimicrobial coatings for biomedical devices and antimicrobial packaging) by standard methods of polyurethane processing, since the presence of metal nanoparticles in their composition does not affect the physical properties of the polymer.

The effect of TDI, PTMG and DMPA on the physico-mechanical properties of polyurethane dispersion containing aromatic isocyanate

The present paper relates to environment-friendly polyurethane dispersion having a high solids content of polyurethane polymer based on aromatic isocyanate. A series of water dispersion polyurethanes (PUDs) were prepared by polyaddition reaction using toluene diisocyanate (TDI), poly(oxytetramethylene) glycol (PTMG), and dimethylolpropionic acid (DMPA). Physico-mechanical properties of PUDs were studied by average particle size, viscosity, contact angle, tensile strength and elongation. IR spectroscopy was used to check the end of polymerization reaction and characterization of polymer. Results revealed that tensile strength, tear strength, hardness, contact angle and viscosity increase with increase of the amount of TDI, PTMG and DMPA in the PUDs. Elongation at break and average particle size decrease with increase of TDI, PTMG and DMPA. The increase of physico-mechanical properties are attributable to the increase of free NCO content and hard segment in the prepolymer of high content of TDI, PTMG and DMPA.

Development of polyurethane dispersion based on aromatic isocyanat: influence of NCO/OH ratio on physico-mechanical properties of PUD

Aqueous polyurethane dispersions (PUDs) were prepared by the prepolymer mixing technique solventfree using aromatic isocyanat[toluene diisocyanate (TDI)], poly(oxytetramethylene) glycol (PTMG), dimethylol propionic acid (DMPA). The properties of both the dispersion’s and casting polymer films were characterized byparticle size analyzer, viscosity and tensile tester. IR spectroscopy was used to check the end of polymerization reaction and characterization of polymer. The effect of NCO/OH molar ratio on the physico-mechanical properties of the polyurethanes was studied. Results showed that tensile strength, contact angle and average particle size increase with increase of NCO/OH molar ratios. Elongation at break and viscosity decrease with increase of NCO/OH molar ratios.

Synthesis and antibacterial characterization of waterborne polyurethanes with gemini quaternary ammonium salt

To obtain an aqueous polymer system with good antibacterial properties, a series of gemini waterborne polyurethanes (GWPU) were designed and synthesized using isophorone diisocyanate, polyoxytetramethylene glycol, poly(ethylene glycol), L-lysine and a novel L-lysine-derivatized diamine containing gemini quaternary ammonium salt (EG12) without any other organic agent involved in the whole synthetic process. EG12 was first synthesized and characterized with proton nuclear magnetic resonance spectra and mass spectra. The antibacterial activities of EG12 and GWPU were evaluated by quantifying the minimal inhibitory concentration. The results indicated that the gemini quaternary ammonium chain extender EG12 and GWPU showed excellent antibacterial activity against a broad spectrum of gram-positive and gram-negative bacteria. This work provides a new and facile approach to prepare novel antibacterial materials, which could be applied as coatings in various fields to prevent microbial contamination.

Synthesis, structure and fungal resistance of sulfadiazine-based polyurethane ureas

In this study, polyether-urethane prepolymers were chain-extended with sulfadiazine and additional crosslinkers to produce polymers resistant to fungi which maintain good mechanical properties. The linear polyurethane ureas with varying stoichiometric ratio were obtained by chain extension with sulfadiazine moieties. The polyurethane prepolymers were synthesized using poly(oxytetramethylene) glycol (PTMG) and 1,6-hexanediisocyanate. The sulfadiazine based-polyurethanes were characterized by FTIR spectroscopy, thermal-mechanical properties and surface properties. The effects of fungal exposure of polymers were also investigated. Atomic force microscopy images showed that the surface morphologies are dependent on the hard segment structure. Results indicate that the incorporation of sulfadiazine into the polyurethane main structure improved fungal resistance.

Effects of TDI and FA-703 on physico-mechanical properties of polyurethane dispersion

A series of water dispersion polyurethanes dispersions (PUDs) were prepared by polyaddition reaction using isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), poly(oxytetramethylene) glycol (PTMG), dimethylol propionic acid (DMPA), and triol (trade name FA-703). Various formulations were designed to investigate the effects of process variables such as TDI and FA-703 on the physico-mechanical properties of PUD. IR spectroscopy was used to check the end of polymerization reaction and characterization of polymer. Evolution of the particle size distribution, contact angle, Tg, molecular weight, viscosity, and mechanical properties of the emulsion-cast films were significantly affected by variable content of TDI and FA-703. Average particle size of the prepared polyurethane emulsions and contact angle decrease with increase of content of FA-703 and TDI. Molecular weight, Tg, tensile strength, tear strength, hardness, viscosity and elongation at break increase with increase of content of FA-703 and TDI. The increase of molecular weight, tensile strength, tear strength and elongation at break properties are interpreted in terms of increasing hard segments, chain flexibility, and phase separation in high content of FA-703 and TDI-based polyurethane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Control of Mechanical Properties of Thermoplastic Polyurethane Elastomers by Restriction of Crystallization of Soft Segment.

Mechanical properties of thermoplastic polyurethane elastomers based on either polyether or polycarbonate (PC)-glycols, 4,4’-dipheylmethane diisocyanate (1,1’-methylenebis(4-isocyanatobenzene)), 1,4-butanediol, were controlled by restriction of crystallization of polymer glycols. For the polyether glycol based-polyurethane elastomers (PUEs), poly(oxytetramethylene) glycol (PTMG), and PTMG incorporating dimethyl groups (PTG-X) and methyl side groups (PTG-L) were employed as a polymer glycol. For the PC-glycol, the randomly copolymerized PC-glycols with hexamethylene (C6) and tetramethylene (C4) units between carbonate groups with various composition ratios (C4/C6 = 0/100, 50/50, 70/30 and 90/10) were employed. The degree of microphase separation and mechanical properties of both the PUEs were investigated using differential scanning calorimetry, dynamic viscoelastic property measurements and tensile testing. Mechanical properties could be controlled by changing the molar ratio of two different monomer components.

Synthesis and Characterization of Novel Segmented Castable Polyurethanes Based on 2,4-TDI and 3,5-DMTDA

A series of three castable polyurethane elastomers were prepared from 2,4- toluene diisocyanate (TDI) and 3,5-dimethyl-thioltoluenediamine (DMTDA) chain extender, with polyethylene adipate (PEA), polyoxytetramethylene glycol (PTMG) and polycaprolactone (PCL) soft segments. The polyol molecular weight employed was 2000g/mol. The polyurethane elastomers were characterized by an electronmechanical universal testing machine, a LX-A Shore durometer and a Dynamic Mechanical analyzer (DMA). In addition, fractured surface of the polyurethane elastomers was investigated by a field emission scanning electron microscopy (FE-SEM). The test results showed PCL based elastomer exhibits the excellent tear and stress-strain properties that polyester based elastomers offer, while retaining superior resilience similar to polyether based elastomers. The static and dynamic properties of PCL based elastomer were more suitable for dynamic applications. SEM micrographs of all polyurethane samples indicated the existing of microphase separation structure. Particles of the dispersed phase formed by hard phase and crystalline part of the soft phase grow bigger with increasing crystallinity of the soft segments. The hard domains are irregular shapes and with size of a few micrometers.

Synthesis and properties of elastic polyurethane‐imide

AbstractA new synthesis route for elastic polyurethane‐imides (EPUIs) has been established by a method involving the use of urea. Various EPUIs were synthesized from polyurethane‐urea, which was prepared from 4,4′‐diphenylmethane diisocyanate (MDI), polyoxytetramethylene glycol (PTMG) and 4,4′‐diphenylmethanediamine (MDA), and pyromellitic dianhydride in N‐methyl‐2‐pyrrolidone (NMP). Flexible films were cast from these solutions that had different inherent viscosities. Imidization of the EPUI films was completed at 200°C for 4 h in vacuo. The EPUIs were determined by FTIR, 1H NMR, and 13C NMR spectra. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010