Showing papers on "Polytetrahydrofuran published in 2012"

Multi-block polyurethanes via RAFT end-group switching and their characterization by advanced hyphenated techniques

Abstract: The detailed characterization of poly(styrene)-b-poly(tetrahydrofuran) (pS-b-pTHF) multiblock copolymers (17800 g mol -1≥ M n ≥ 46800 g mol -1) generated via urethane linkages is presented. The synthesis of the block copolymers is enabled via a mechanistic switch of the thiocarbonyl thio end group of a poly(styrene) to dihydroxyl terminated polymers that subsequently react with a diisocyanate terminated polytetrahydrofuran based prepolymer to form multiblock copolymer structures. The characterization of the multiblock copolymers and their substructures includes size exclusion chromatography (SEC), liquid chromatography at critical conditions (LCCC), nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy as well as matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. To obtain even further details of the polymer size and its composition, SEC with triple detection as well as newly developed SEC coupled online to IR spectroscopy was carried out. The quantification of the average block fractions via online SEC-IR (41-61 mol % pTHF) is in very good agreement with the results obtained via NMR spectroscopy (39-66 mol % pTHF). © 2012 American Chemical Society.

Micellar assemblies from amphiphilic polyurethanes for size-controlled synthesis of silver nanoparticles dispersible both in polar and nonpolar media

Abstract: A size-controlled synthesis of silver nanoparticles (AgNPs) dispersible in polar and nonpolar media was carried out in micellar assemblies from amphiphilic invertible polyurethanes (AIPUs) based on poly(ethylene glycol) as a hydrophilic constituent and polytetrahydrofuran as a hydrophobic constituent. At a low concentration, AIPUs form micelles with a hydrophilic interior and a hydrophobic exterior. As concentration increases, individual micelles self-assemble into micellar assemblies with hydrophilic interior and hydrophobic exterior domains. It was shown that these domains can be applied simultaneously as nanoreactors and colloidal stabilizers to synthesize size-controlled batches of AgNPs in a nonpolar solvent. Size control and narrow particle size distribution can be facilitated by changes in the AIPU composition, macromolecular configuration, and polymer solution concentration. Depending on the length of polymer hydrophilic and hydrophobic fragments, and fragment distribution along the macromolecule, the size of fabricated AgNPs has been changed from 6 to 14 nm. Owing to the invertible properties of polyurethanes, the synthesized silver nanoparticles can be successfully dispersed in either polar or nonpolar media, where they form stable colloidal solutions.

Multi-Block Polyurethanes via RAFT End-Group Switching and Their Characterization by Advanced Hyphenated Techniques

Abstract: The detailed characterization of poly(styrene)-b-poly(tetrahydrofuran) (pS-b-pTHF) multiblock copolymers (17800 g mol–1 ≤ Mn ≤ 46800 g mol–1) generated via urethane linkages is presented. The synthesis of the block copolymers is enabled via a mechanistic switch of the thiocarbonyl thio end group of a poly(styrene) to dihydroxyl terminated polymers that subsequently react with a diisocyanate terminated polytetrahydrofuran based prepolymer to form multiblock copolymer structures. The characterization of the multiblock copolymers and their substructures includes size exclusion chromatography (SEC), liquid chromatography at critical conditions (LCCC), nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy as well as matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. To obtain even further details of the polymer size and its composition, SEC with triple detection as well as newly developed SEC coupled online to IR spectroscopy was carried out. The quantification of the average blo...

Multi-layer plastic substrate and method for manufacturing same

Abstract: The present invention relates to a multi-layer plastic substrate having two sheets of plastic films, which are bonded together, at the center, and having a first organic or organic-inorganic hybrid layer, a gas barrier layer, and a second organic or organic-inorganic hybrid layer, which are laminated on both sides of the plastic films, wherein the first organic or organic-inorganic hybrid layer and/or the second organic or organic-inorganic layer comprise(s) a composition including at least one compound selected from the group of compounds, which is represented by chemical formula 1, and consists of an organic silane, a polycaprolactone, a polytetrahydrofuran, an epoxy, and a xylen glycol.

Ring opening polymerization of tetrahydrofuran catalysed by maghnite-H +

Abstract: The cationic ring-opening polymerization of tetrahydrofuran using maghnite-H+ is reported. Maghnite-H+, is a non-toxic solid catalyst issued from proton exchanged montmorillonite clay. Polytetrahydrofuran, also called “poly(butandiol) ether”, with acetate and hydroxyl end groups was successfully synthesized. Effects of reaction temperature, weight ratio of initiator/monomer and reaction time on the conversion of monomer and on the molecular weight are investigated. A cationic mechanism of the reaction was proposed. This chemistry can be considered as a suitable route for preparing poly(THF) as a soft segment for thermoplastic elastomers.

Energy efficient polyalkylene glycols and lubricant composition containing same

Abstract: A polyalkylene glycol comprising: a random copolymer comprising units derived from EO and units derived from PO initiated with polytetrahydrofuran; wherein the polyalkylene glycol has a pour point of less than or equal to −30° C. as measured using ASTM D97 and a traction value of less than 0.0165 at a contact pressure of 1.25 GPa, speed=2 m/s, SRR of 100% and temperature of 80° C. is provided. Also provided are lubricant compositions containing such polyalkylene glycol.

Environment-friendly raw skin preservative and preparation method thereof

Abstract: The invention discloses an environment-friendly raw skin preservative and a preparation method thereof. The preservative comprises the following component raw materials in percentage by weight: 42-61% of sodium chloride, 16-27% of polyvinyl alcohol, 16-27% of polyethylene glycol, 0.5-5% of polypropylene glycol, 0.5-5% of polytetrahydrofuran ether glycol and 0.5-2% of polyacrylamide, and the sum of weight percentages is 100%, wherein the molecular weight of polyvinyl alcohol is 25000-35000, the molecular weight of polyethylene glycol is 1000-10000, the molecular weight of polypropylene glycol is 400-2000, and the molecular weight of polytetrahydrofuran ether glycol is 600-2000. The preservative provided by the invention has small usage amount, is safe and nontoxic and can be biologically degraded, the total dissolved solids (TDS) and chloride pollution in tanning waste water can be greatly lowered, and no negative effect is produced on following tanning process.

Dynamic Mechanical Properties of Hydroxyl-terminated Polybutadiene Containing Polytetrahydrofuran as a Plasticizer

Abstract: Solid propellant is a fuel for rockets. Composite propellant is a kind of solid propellant and this propellant is produced by the following method. The first step is the mixing of the oxidizer, binder, burning rate modifier, plasticizer, metal fuel, etc. The next involves the removal of air from the mixture. The final step is casting the propellant to a rocket motor. Hydroxyl-terminated polybutadiene (HTPB) has generally been used as the binder for composite propellants. The liquid plasticizer and cross-linker are added to the propellant to improve processing properties, such as mixing viscosity, casting, and pot life, as well as to improve mechanical properties, such as strength, elongation, and modulus. Researchers have recently developed several energetic plasticizers and investigated their effects to improve the mechanical properties of cured HTPB after the addition of these plasticizers. However, the processes involved in the synthesis of energetic plasticizers are complicated, therefore it is difficult to manufacture these plasticizers industrially. Currently, these energetic plasticizers are not used for practical applications because they are expensive. Polytetrahydrofuran (PTHF) is an ingredient of rubber products that is produced in several different molecular weights. In addition, this polymer is mass-produced commercially and is inexpensive. The chemical structures of PTHF and HTPB are shown in Fig. 1. PTHF has a linear molecular structure. The repeating unit of PTHF consists of a single bond and has one oxygen atom, four carbon atoms and eight hydrogen atoms. PTHF has a OH group on one side of the molecular chain of PTHF and a hydrogen atom on the other side so that both sides of the molecular chain have a hydroxide group. Then, PTHF is a di-ol and the molecular structure of PTHF is similar to that of HTPB. The difference is that the first one has saturations while the second one has unsaturations. Because there is oxygen in the repeating unit of PTHF, Dynamic Mechanical Properties of Hydroxyl-terminated Polybutadiene Containing Polytetrahydrofuran as a Plasticizer

Characterization of the Waterborne Polyurethane/Nanosilica Composite Synthesized by Dispersing Nanosilica in Polytetrahydrofuran Glycol

Abstract: The waterborne polyurethane/nanosilica composite (PU/SiO2) was prepared by dispersing nanosilica in polytetrahydrofuran glycol (PTMG) and preformed polymer separately. The distribution of nanosilica, mechanical property, thermal performance, and the ultraviolet (UV) absorbance characteristic of PU/SiO2 were investigated by scanning electron microscope, FTIR, mechanical test, thermogravimetric analysis, and UV spectroscopy. Compared with dispersed in preformed polymer, the composite prepared by dispersing nanosilica in PTMG could lead to better soluability, mechanic performance, thermostability, water resistance, and stronger UV absorbance.

Poly (p-dioxanone)/polytetrahydrofuran multi-block copolyether ester with shape memory function and preparation method thereof

Abstract: The invention discloses poly (p-dioxanone)/polytetrahydrofuran multi-block copolyether ester with shape memory function. The repetitive structure of the copolyether ester is shown in the specification, the intrinsic viscosity is 0.54-3.5dl/g, the shape fixed rate Rf is 82.6-100% and the shape recovery rate Rr is 84.9-100%. The invention also discloses a preparation method of the multi-block copolyether ester. The multi-block copolyether ester provided by the invention simultaneously has the advantages of shape memory function, controlled thermal transition temperature, controlled molecular weight, biodegradability, etc and has wide application prospect. The preparation method provided by the invention is simple, convenient and mature and has easily controlled process.

Preparation method for hydroxyl terminated polyethylene glycol-polytetrahydrofuran triblock copolyether

Abstract: The invention discloses a preparation method for hydroxyl terminated polyethylene glycol-polytetrahydrofuran triblock copolyether. The method comprises the following steps: dissolving dry polytetrahydrofuran glycol in a solvent, adding an alkali metal hydride, allowing polytetrahydrofuran glycol and the alkali metal hydride to react at a temperature of from room temperature to 150 DEG C for more than 1 h to produce polytetrahydrofuran glycol alkoxide, placing the polytetrahydrofuran glycol alkoxide into an autoclave, adding oxirane, initiating oxirane to carry out anionic ring-opening polymerization, and carrying out polymerization at a temperature of from room temperature to 150 DEG C for 1 to 120 h so as to prepare hydroxyl terminated polyethylene glycol-polytetrahydrofuran-polyethylene glycol ABA type block copolyether. The method provided in the invention is stable and controllable; prepared hydroxyl terminated triblock copolyether has a high purity, a definite structure and narrow molecular weight distribution.

Polyurethane resin and synthesis method thereof

Abstract: The invention relates to a polyurethane resin, aiming at providing a polyurethane resin used for synthetic leather, and the polyurethane resin used for the synthetic leather simultaneously has the characteristics of high brightness and glossiness as well as excellent cold-resistant flexibility so as to meet the market demand of the northern cold areas. The invention has another purpose of providing a preparation method of the polyurethane resin. The invention provides the technical scheme that the polyurethane resin is characterized by being prepared by raw materials by weight percent: 15-35%of polytetrahydrofuran ether glycol, 3-5% of tripropylene glycol, 30-60% of dimethyl fomamide, 10-30% of 4, 4-diphenylmethane diisocyanate, 2-5% of isocyanate sealing agent, 2-4% of polyether amine and 2-5% of isoflurane ketone diamine.

Method for preparing hydroxyl-terminated polytetrahydrofuran polypropylene oxide block copolyether

Abstract: The invention relates to a method for preparing copolyether, in particular to a method for preparing hydroxyl-terminated polytetrahydrofuran polypropylene oxide block copolyether. The defects of complex process, high requirements on the raw materials, low molecular weight of the copolyether and the like in the existing method for preparing the copolyether by utilizing tetrahydrofuran and propylene oxide are overcome. The method for preparing the hydroxyl-terminated polytetrahydrofuran polypropylene oxide block copolyether is characterized in that the hydroxyl-terminated polytetrahydrofuran polypropylene oxide block copolyether is obtained through polymerization reaction by taking polytetrahydrofuran and polypropylene glycol (polypropylene oxide) as the raw materials under the super acid catalytic action of concentrated sulfuric acid and under the rection condition of a temperature of 120 DEG C to 130 DEG C. The method disclosed by the invention is very suitable for mass production. The experiment of carrying out polymerization in a 10L kettle shows that the larger the amount of a reaction system is, the smaller the temperature fluctuation of the reaction system is, so that the method is easy to control; and the larger the amount of the reaction system is, the lower the risk that the copolyether is oxidized is, so that the prepared copolyether has high quality and is colorless and transparent.

Aliphatic hydroxyamino polyether and preparation method thereof

Abstract: The invention belongs to the field of organic synthesis technology, and provides an aliphatic hydroxyamino polyether and a preparation method thereof. The hydroxyamino polyether is polyoxypropylene ether or polytetrahydrofuran glycol terminated by a secondary amino group and containing two secondary hydroxyl groups. The hydroxyamino polyether is prepared by the following steps: adding epichlorohydrin and a catalyst into the raw material of polyether polyol, heating and adding dropwisely an alkali solution, removing salts and alkaline materials by water washing to obtain a glycidyl ether intermediate, adding unit primary amine, performing heating reaction, and finally removing superfluous unit primary amine under vacuum condition so as to obtain the product. An interstitial kettle-type reactor is adopted by the method of the invention to synthesize hydroxyamino polyether by polyether polyol glycidyl ether and unit primary amine, and the method has the advantages of low investment cost,simple process, simple reaction, manageable waste water, no pollution, etc. The material obtained by applying the reaction of hydroxyamino polyether and isocyanate to spray polyurea elastomer has comparable performance such as elongation and mechanical strength to current widely-used products, but has superior performance such as the adhesion to substrate materials and the leveling property than current products.

Fabric coating slurry prepared by modified environment-friendly polyurethane

Abstract: The invention discloses a fabric coating slurry prepared by modified environment-friendly polyurethane. The slurry comprises by mass: 150-200 parts of environment-friendly modified polyurethane, 11-13 parts of a fracturing thickening agent SX and 9-11 parts of a printing fixation cross-linking agent SE. The environment-friendly modified polyurethane is prepared by polymerization of the following reagents: polytetrahydrofuran glycol; isophorone diisocyanate (IPDI); a T12 catalyst; dimethylol propionic acid; methyl acrylate; 1.4-butylene glycol; hexylenediamine; a KOH solution; and deionized water. Therefore, the fabric coating slurry of the invention has the advantages of high breaking elongation rate, good moisture and air permeability, as well as environmental protection.

Study of the Main Influence Factors on Compression Set of PTMG Based Polyurethane Elastomer

Abstract: The present study described the effect of the different synthetic methods, hard segment types, chain extension coefficient and the starting NCO/OH molar ratio on the compression set and the other properties of castable polyurethanes based on polytetrahydrofuran glycol (PTMG).The result showed that the system of PTMG/TDI/MOCA prepared by a quasi-prepolymer method and with the starting molar ratio of TDI to PTMG of 6:1 exhibits lower compression set.

Novel leather layer material

Abstract: The invention discloses a novel leather layer material which comprises diphenylmethane diisocyanate (MDI), polytetrahydrofuran diol (PTMG), polyoxyethylene diol (PEG) and other raw materials. The novel leather layer material is characterized in that the material comprises the following components by weight: 18-25% of PTMG, 18-25% of PEG, 2-7% of MDI, 20-28% of dimethyl formamide (DMF), and 22-30% of methyl ethyl ketone (MEK). The novel leather layer material disclosed by the invention has the characteristics of dry method surface layer, good moisture and water resistance, good moisture permeability, super softness and good handfeel, and can be widely used for clothing leather, shoe leather and waterproof cloth.

Preparation method for high-stress high-resilience polyurethane fiber

Abstract: The invention discloses a preparation method for a high-stress high-resilience polyurethane fiber The preparation method is characterized by comprising the steps of (1) prepolymerization, (2) polymerization and (3) spinning In the prepolymerization step, diphenylmethane-4, 4'-diisocyanate and polytetrahydrofuran are mixed and stirred according to the mole ratio of 18:1-22:1, reacted by being warmed and then cooled to obtain a prepolymerization product; in the polymerization step, the prepolymerization product prepared in step (1) is dissolved by an aprotic polar solvent and then transported into a polymerization reaction kettle, the temperature of the transported prepolymerization product is 35-40 DEG C, the prepolymerization product is cooled to 8-10 DEG C, and then a chain extender is added to carry out polymerization reaction to generate a spandex spinning solution with the molecular weight of 20000-300000; and in the spinning step, the spandex spinning solution obtained in step (2) is prepared into the high-stress high-resilience polyurethane fiber in a solution spinning method The polyurethane fiber prepared in the method disclosed by the invention has two characteristics of high stress and high resilience at the same time

Polycaprolactone/polytetrahydrofuran supramolecular polymer blends: mechanical and thermal properties

Abstract: Iranian Journal of Polymer Science and Technology Vol. 25, No. 2, 151-163 June July 2012 ISSN: 1016-3255 Online ISSN: 2008-0883 polytetrahydrofuran,

Rosin polyether ester elastomer and preparation method thereof

Abstract: The invention provides a rosin polyether ester elastomer, which comprises modified rosin, divalent alcohol and cross linker, wherein the modified rosin is a compound expressed by a formula I; the divalent alcohol is polyethylene glycol, polytetrahydrofuran diol or polycaprolactone diol; the mole ratio of the modified rosin, the divalent alcohol to the cross linker is 1: 1-1.5: 0.5-1; and the degradability of the rosin polyether ester elastomer is 12 to 45 percent. The rosin with ternary ring phenanthrene frame structure is used as a raw material, and the ternary ring phenanthrene frame structure is a steroidal structure, has high rigidity and can be matched with a benzene ring; and the rosin is used as the raw material, the modified rosin is reacted together with the divalent alcohol and the cross linker to prepare the netlike rosin polyether ester elastomer, the elastomer is innocuous and degradable, and the raw materials are regenerative and have the simulated performance as the aromatic polyether ester elastomer. The invention also provides a preparation method for the rosin polyether ester elastomer.

Synthesis and Characterization of Novel Thermal Stability Poly (ester-imide-ether) with Excellent Lower Temperature Elastic Recovery

Abstract: A new poly(ester-imide-ether) (PEIE) was prepared by melt polymerization from 1,4-butanediol(BD), polytetrahydrofuran diol (PTMG) and a novel imide dicarboxylic acid monomer which was synthesized from 3,3',4,4'-biphenyltetracarboxylic di-anhydride(BPDA) and glycine acid(GLY). The structure, thermal behaviour and elastic recovery of polymer were characterized by FT-IR. thermogravimetric analysis (TGA), differential scanning calorimetry thermograms (DSC) and laboratory stretching machine. The results showed this polymer has excellent thermal stability, 5 % weight loss temperature was at 354°C. Meanwhile, the DSC curve showed that glass-transition temperature and crystallization temperature of the polymer were at -30 °C and 160 °C, respectively. The excellent elastic recovery was still displayed at low temperature.

Method to produce copolymers of tetrahydrofuran and epoxidised natural oils

Abstract: The invention relates to a method to produce polytetrahydrofuran (PTHF) copolymer from plant oil by copolymerizing epoxidized oil; preferably from natural sources like animal oils and more preferably from plants oils; with tetrahydrofuran (THF), in the presence of boron trifluoride-diethylether complex or tetrafluoroboric acid to yield the desired copolymer with specific properties. The properties of the produced PTHF copolymer depends on the (i) type of epoxidized oil used as co-monomer (ii) mole ratio between epoxidized oil and THF (iii) amount of catalyst (iv) reaction temperature (v) reaction time. The produced PTHF copolymers were then used as raw material for the production of polyurethane and polyurea.

Formulation of dedicated urethane resin for waterproof coating

Abstract: The invention discloses a formulation of dedicated urethane resin for a waterproof coating. The formulation comprises the following ingredients: polytetrahydrofuran, diphenylmethane-4,4'-diisocyanate, 1,4-butanediol and accessory ingredients, wherein the accessory ingredients comprise anti-oxidant, ultraviolet light absorbers and photo-stabilizers. The urethane resin that is prepared by adopting the formulation achieves better water resisting property.

Method for preparing modified environment-friendly polyurethane

Abstract: The invention discloses a method for preparing modified environment-friendly polyurethane. The method comprises the following steps of: (1) preparing a pre-polymer: adding polytetrahydrofuran glycol into a reaction container under the protection of nitrogen, after increasing the temperature to 75-80 DEG C, adding IPDI (Isophorone Diisocyanate) and T12 catalyst to react for 2 h, then adding dimethylolpropionic acid to react 30 min, adding methyl acrylate to react for 1 h, and obtaining the pre-polymer; and (2) extending a chain: adding a chain extension agent, namely 1.4-butanediol into the pre-polymer obtained in the step (1) to react for 1 h, decreasing the extended pre-polymer to 30 DEG C, adding KOH (Potassium Hydroxide) solution under stirring at high speed till the pH value is 7-8, after dispersing for 20 min, adding hexamethylenediamine, continuously stirring and reacting for 20 min, and adding deionized water under the action of high shear force to prepare aqueous polyurethane emulsion. Therefore, the polyurethane disclosed by the invention is high in breakage extension rate and good in moisture-penetrability and air permeability; simultaneously, the polyurethane is environmental-friendly.