Polyether Diol Research Articles

Co-enhancement of toughness and strength of room-temperature curing epoxy adhesive derived from hydroxyl-terminated polybutadiene based polyurethane resin

Incorporation of flexible chains into epoxy adhesives facilitates toughening but usually poses an opposite effect on strengthening. Herein, by combining hydroxyl-terminated polybutadiene (HTPB) with polyether diol as soft chains, epoxy-terminated polyurethane (EHTPU) is synthesized, a strategy balancing strengthening and toughening is developed. The use of polyolefin soft chains substantially contributes to sea-island phase separation for maintaining low glass transition temperature (Tg) and high strength and toughness simultaneously. Specifically, the modified epoxy adhesive has seen a significant increase in shear strength to 19.75 MPa, tensile strength to 48.25 MPa and fracture toughness to 3.63 MPa·m1/2, with increment of 914 %, 268 %, and 149 %, respectively, compared to neat epoxy. Moreover, even under low temperatures of -45 °C, the modified epoxy resin can still maintain a high shear strength, demonstrating excellent low-temperature adhesion performance. At the same time, the incorporation of EHTPU does not significantly affect the overall thermal stability of the epoxy resin, meeting the requirements for stability in practical applications. It is worth mentioning that the adhesive exhibit excellent bonding performance under different environments and substrates, indicating that this composite material has broad application prospects in various industrial fields. These findings provide valuable insights into optimizing the performance of epoxy resins by controlling the introduction of specific modifiers and offer new ideas and methods for the development of room temperature curing epoxy resin adhesives.

The addition reaction of alcohols and aromatic carbodiimides and its application to produce thermo-reversible polymer networks

The addition reaction of primary alcohols onto aromatic carbodiimides giving iso-ureas was studied in bulk at various temperatures. A side reaction at 60 °C was found to occur between carbodiimide and iso-urea yielding N,N′-substituted polyguanidine oligomers. The occurrence of this side reaction coincides with a reduced conversion of the alcohol; the carbodiimide was always fully converted to either iso-urea or polyguanidine. The formation of the polyguanidine was reversible at higher temperatures to reform iso-urea and carbodiimide. The latter reaction was complete at about 130 °C. The thermo-reversibility of the guanidine bond was utilized to produce thermo-reversible self-healing polymer networks by reaction of polyether diol and a 1.5 to 2-fold molar excess of aromatic biscarbodiimide. The materials were soft and elastic and showed a glass transition at −60 °C. The guanidine linkages in the polymers started to unzip above 60 °C as was indicated by a drop in the E-modulus, at about 130 °C sufficient guanidine crosslinks had unzipped to provide the polymer liquid-like properties. The guanidine crosslinks were reformed after cooling to ambient temperature giving back the polymer network.

New Polyether Macrocycles as Promising Antitumor Agents-Targeted Synthesis and Induction of Mitochondrial Apoptosis.

A series of previously unknown aromatic polyether macrodiolides containing a cis,cis-1,5-diene moiety in the molecule were synthesized in 47-74% yields. Macrocycle compounds were first obtained by intermolecular esterification of aromatic polyether diols with α,ω-alka-nZ,(n+4)Z-dienedioic acids mediated by N-(3-(dimethylamino)propyl)-N'-ethylcarbodiimide hydrochloride (EDC·HCl) and 4-(dimethylamino)pyridine (DMAP). For the synthesized compounds, studies of cytotoxicity on tumor (Jurkat, K562, U937), conditionally normal (HEK293) cell lines, and normal fibroblasts were carried out. CC50 was determined, and the therapeutic selectivity index of cytotoxic action (SI) in comparison with normal fibroblasts was evaluated. With the involvement of modern methods of flow cytometry for the most promising macrocycles, their effect on mitochondria and the cell cycle was investigated. It was found that a new macrocycle exhibits pronounced apoptosis-inducing activity toward Jurkat cells and can retard cell division by blocking at the G1/S checkpoint. Also, it was shown that the synthesized macrodiolides influence mitochondria due to their high ability to penetrate the mitochondrial membrane.

Preparation and properties of high molecular weight high temperature resistant carborane polyurethane adhesive

The long-term use temperature of the traditional high-temperature adhesive can only reach about 280 °C, and it cannot be used in extreme environments such as acid and alkali for a long time, which greatly limits its application in aerospace and other fields. Because of its unique three-dimensional structure, carborane has excellent thermal stability and chemical stability. Based on this, first, this article introduced carborane monomer into polyurethane structure, using indirect copolymerization method, Hydroxyl carborane derivative (m8) and conventional polyether diols were used as soft segments. By adjusting the introduction ratio of m8, a series of copolymerized carborane polyurethane (Co-CBR-PU) with controllable thermal and mechanical properties were successfully prepared. Its structure and molecular weight were characterized by FTIR and gel permeation chromatography (GPC), its surface morphology were observed by SEM. The thermal stability and mechanical properties were studied by thermogravimetric test, tensile test and rheological dynamic mechanical analysis test., and its activity, solvent resistance and hydrophobic properties were studied by finger contact method, solvent resistance test and contact Angle test. Second, the high temperature resistant carborane polyurethane adhesive (PUAS) was prepared using Co-CBR-PU as matrix and its adhesion was studied. The results show that a series of Co-CBR-PU has good high temperature resistance, mechanical properties and solvent resistance after adding carborane monomer, and its various properties were optimal when the addition amount of m8 was 15 wt%. The carborane PUAS prepared by using it as the substrate has excellent high temperature adhesion to different adhesive parts. The aim of this study is to reduce the cost of synthesis of carborane polyurethane by regulating the proportion of carborane, and then realize the industrial trial production of high temperature resistant carborane adhesive.

Synthesis of P-N-S elemental flame-retardant waterborne polyurethane and its application in polyamide fabric

A new type of flame-retardant polyether diols containing phosphorus, nitrogen, and sulfur (SPAE) was first synthesized by using phosphoryl chloride, 2-aminobenzothiazole and ethylene glycol. The SPAE as the soft segment was then utilized to prepare a series of flame-retardant waterborne polyurethanes (SPAE-WPU) through emulsion polymerization. Subsequently, SFR-WPU as a finishing agent was coated on polyamide fabric. When the content of SPAE-WPU was 18 wt%, the coated fabric exhibited a limiting oxygen index (LOI) of 28.2 %, afterflame time of 4.6 s, afterglow time of 0 s and damaged length of 11.2 cm, respectively. After 10 washes, the coated fabric retained its good flame-retardancy and anti-dripping properties. Furthermore, the flame-retardant mechanism of SPAE-WPU was investigated using various spectral analyses, which revealed that the P, N and S elements worked together to create non-combustible gas compounds, release free radicals, and promote dehydration and carbonization, leading to synergistic flame-retardant effects in both gas- and condensed-phase.

Effects of structural symmetry of introduced polyether diol on low temperature tolerance of laminated polyurethane bearings in bridges

Laminated seismic isolators are installed on highway bridges worldwide to minimize the risk of seismic collapse. In recent years, Laminated Polyurethane Bearing (LPB) has gained immense popularity in the field of large-span bridge construction due to its advantages such as ultra-high bearing capacity, low cost, and simplicity of production. However, Polyurethane (PU) elastomers of LPB undergo cold hardening, which reduces the ability of LPB to protect bridges from seismic damage in freezing regions. In this study, four kinds of polyether diols with varied chemical symmetry were added to PU consisting of PTHF, TDI, and MOCA, respectively. The introduced polyether diols include polytrimethylene ether diol (POTG) and polytetrahydrofuran (PTHF) with symmetric linear structures, and poly(oxypropylene) (PPG) and 3-methyl-tetrahydrofuran/tetrahydrofuran co-polyether diol (3MTHF) with asymmetric structures. The microscopic characterization performance tests and low-temperature mechanical experiments were conducted to investigate the effect of structural symmetry of added polyether diol on the low-temperature tolerance of LPB. Results prove that due to the significant structural irregularity of the chains, the 3MTHF-based PU exhibits the least amount of microphase separation and the lowest elastic modulus among all specimens, yielding the best low-temperature tolerance of corresponding LPB. It was further discovered that the Bouc-Wen model with proper parameters can accurately simulate the lateral response of the 3MTHF based LPB at different temperatures. Finally, the seismic responses of bridges isolated by 3MTHF based LPB were investigated and compared with those of the bridges with the conventional PTHF based LPB under near-fault earthquake loadings at low temperatures. The results shows that 3MTHF significantly enhances the horizontal flexibility of the LPB, thus improving the effectiveness of the isolation system in low-temperature environments.

A novel CO2 based UV-induced peelable adhesive for wafer dicing

Poly (propylene carbonate) diol with double-bonds on the side chains (PPCAGE) was synthesized form CO2, propylene oxide (PO), polyether diol (PPG) and allyl glycidyl ether (AGE). Then, three kinds of CO2 based polyurethane oligomers (PPCAGE-PU) (PPCAGE-PUA, PPCAGE-PUB and PPCAGE-IPDI, respectively) with different contents of double bond were prepared through the reaction of PPCAGE, isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA). The content of -NCO was adjusted by varying the ratio of -NCO terminated prepolymer and HEA. Acrylate copolymer with side double bonds and hydroxyl groups (GMA-PSA) was synthesized by the ring-opening reaction of glycidyl methacrylate (GMA) and acrylate copolymer (PSA) containing -COOH and -OH. CO2 based UV-induced peelable adhesive was prepared by mixing PPCAGE-PU, GMA-PSA, active diluent and photoinitiator. The structure of PPCAGE was confirmed by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H NMR). The reaction of PPCAGE-PUB and GMA-PSA was monitored by FT-IR, companied by the titration of -NCO and epoxide. The molecular weight of PSA and GMA-PSA was determined by gel permeation chromatography (GPC). The surface morphology of the adhesive was observed by scanning electron microscopy (SEM). The viscoelasticity of adhesive was measured by real-time rheology. The 180° peel strength, micro-surface morphology, gel content, unsaturation conversion and glass transition temperature of UV-induced peelable adhesive were characterized. The results showed that the peel strength of adhesive was 17.82 N/25 mm before UV curing. After UV curing, the surface morphology changed from smooth to rough, the peel strength decreased to 0.08 N/25 mm and the modulus of the PSA increased due to the cross-linking. DSC results showed that the glass transition temperature increased after UV curing.

Microcrack self‐healing capability of waterborne polyurethane/polyacrylate composites with dynamic disulfide bond

AbstractIn this paper, a series of self‐healing waterborne polyurethane/polyacrylate composites (SWPUA) with different disulfide content on the main chain were synthesized. The SWPUAs were synthesized from isophorone diisocyanate, dimethylolpropionic acid, polyether diol and bis(2‐hydroxyethyl) disulfide (HEDS). The structure of the products was characterized by IR and Raman spectra. The effects of different content of HEDS on dispersion stability, mechanical property and self‐healing properties (including tensile strength and breaking elongation) of SWPUAs were studied. The results showed that all the prepared SWPUAs have excellent dispersion stability, thermal stability, self‐healing efficiency and certain hydrophobic capacity. Thereinto, SWPUA‐1 and SWPUA‐2 products with HEDS content of 0.0025 mol and 0.0050 mol have the best repair efficiency. They can recover 101.03% and 102.18%, respectively, after 3 h of repair at 75°C. In addition, SWPUA‐1 has the highest repeatedly repair efficiency of 91% for tensile strength but 75% for breaking elongation because of the influence of physical entanglement and chain link.

Synthesis and properties of biomass polyether diols based polyurethane dispersions by a solvent-free process

Synthesis and properties of biomass polyether diols based polyurethane dispersions by a solvent-free process

Effect of the symmetry of polyether glycols on structure-morphology-property behavior of polyurethane elastomers

The macroscopic properties of polymers could be significantly affected by subtle structural changes in the building blocks, either in a beneficial or detrimental manner. Therefore, it is of essential importance to investigate the structure−property relationships of polymeric materials and provide guiding principles for realizing the optimal thermal, mechanical, and optoelectrical characteristics. Polyurethane (PU) is a kind of widely applied functional polymers with alternating soft and hard segments. The structure-morphology-property behavior of PU is dictated by both segments. Herein, PU elastomers (PUEs) are synthesized with identical hard segment and four kinds of soft segments (polyether diols) with similar chain length but different chain symmetry. The chosen polyether diols either have symmetrical and linear structure like poly(trimethylene ether) glycol (PO3G) and poly(tetramethylene ether) glycol (PTMG), or have asymmetrical chain structure with side methyl groups like poly(propylene glycol) (PPG), and 3-methyltetrahydrofuran/tetrahydrofuran copolyether glycol (3MCPG). The effects of structural symmetry of polyether diols on the structure, morphology, and mechanical properties of the as-prepared PUEs are investigated. The results reveal that the PO3G based PUE exhibits the highest value of hydrogen bonding (74.7%) and the highest degree of microphase separation among four PUE samples, along with the highest Young's modulus (42.7 MPa), tear strength (112.8 kN/m), and the best elastic resiliency capability, thanks to the high structural regularity of the PO3G chains. On the contrary, PPG based PUE typically have the deteriorated thermal and mechanical performance due to the interfered microscopic packing. This work highlights how the small structural changes of building blocks in PU would manipulate its macroscopic feature and provide an additional structural handle for designing advanced PU materials.

Synthesis and Characterization of Biodegradable Polyester/Polyether WPU as the Environmental Protection Coating

Polyester diol PCL and PBA, polyether diol PTMG and polycarbonate diol PCDL were used as components of WPU soft segment, respectively. Polyether PTMG-WPU has the worst hydrolytic property and the highest thermal stability. The maximum degradation rate temperature Tmax is 407.8 °C, the water contact angle reaches 89.5 °. Traditional polyester PCL-WPU shows the strongest hydrolysis performance, the smallest water contact angle, only 71.7 °, the water absorption rate of 72 h at room temperature is as high as 26.7%. However, the thermal stability of PCL-WPU is lower, the soft segment Tg is −52.3 °C, and Tmax is only 333.7 °C, but the mechanical property of which is the best, the tensile strength is 58.3 MPa, and the elongation at break reaches 857.9%. The most important thing is that the structure of polyester PCL-WPU is more easily destroyed by lipase and water molecules. The acidic products produced after hydrolysis will further promote the degradation of polyester. Therefore, compared with other WPUs, PCL-WPU has the best biodegradability and the most obvious degradation effect under the same conditions. The degradation rate of PTMG-WPU after 30 days of degradation in 0.6% lipase PBS buffer solution and soil was only 4.2% and 2.3%, while the highest degradation rate of traditional polyester PCL-WPU reached 41.7% and 32.0%, respectively. In addition, polycarbonate PCDL-WPU has the highest hardness, reaching 95.5 HD. But its other performances are lower than PCL-WPU.

Effect of the particle sizes of silica on the properties of UV-curing matting coatings

UV-curable matting composites were prepared by micron silica matting agent, polyether diol (PPG), isophorone diisocyanate (IPDI), and 2-hydroxyethyl methacrylate (HEMA) via the in situ polymerization method. The structure, surface morphology, and thermal stability of the composites were characterized by FTIR, SEM, and TGA, respectively. As the main resin in the UV-curable coating, the effects of particle sizes of silica on the gloss, abrasion resistance, adhesion, and hydrophilic properties of coatings were measured. The results show that the agglomeration phenomenon of the modified silica in the composite coating was obviously improved. The smaller the particle size, the lower the gloss of coatings with the same content. The adhesion strength and abrasion resistance of the composites were superior to those of pure UV-curing coatings without silica. The greater the particle sizes of the added modified silica, the stronger the hydrophilicity of the composite.

Influence of the hard segments content on the structure, viscoelastic and adhesion properties of thermoplastic polyurethane pressure sensitive adhesives

New thermoplastic poly(ether-urethane)s (PUs) with different hard segments (HS) contents (13.9–24.4% by weight) intended for pressure-sensitive adhesives (PSAs) have been synthesized by reacting different blends of polyether diols of different molecular weights – poly(propyleneglycol) (PPG) of molecular weight 2000 Da and poly(tetrahydrofuran) (PTHF) of molecular weight 1000 Da – 4,4′-diphenylmethane diisocyanate, and 1,4-butanediol, the prepolymer method was used. The increase of the HS content increased the contribution of the associated by hydrogen bond urethane groups and decreased the degree of micro-phase separation in the PUs synthetized with PPG + PTHF blends, an increase of the thermal stability was also obtained. On the other hand, the PU made with NCO/OH ratio of 1.10 showed unexpected properties because the contribution of the free urethane groups, the storage modulus and the temperature at the cross-over between the storage and loss moduli were higher than in the rest of the PUs synthesized with different NCO/OH ratios. The PUs with HS contents of 14.0–16.7% by weight were typical general-purpose pressure-sensitive adhesives (PSAs), whereas the PUs with HS content of 19–22% by weight were typical high shear PSAs. All PU PSAs followed the Dahlquist criterion and the one synthesized with 50 wt% PPG + 50 wt% PTHF and an NCO/OH ratio of 1.10 showed an optimal balance between tack, shear resistance and 180° peel strength values.

Viscoelastic and Adhesion Properties of New Poly(Ether-Urethane) Pressure-Sensitive Adhesives

New thermoplastic poly(ether-urethane) (TPUs) pressure sensitive adhesives (PSAs) have been synthesized with the prepolymer method by reacting methylene diisocyanate, different blends of polyether diols  poly(propyleneglycol) (PPG) and poly(tetramethylene ether glycol (PTMEG) , and 1,4-butanediol chain extender; different NCO/OH ratios have been used. The properties of the TPU PSAs depended on both the NCO/OH ratio and the PTMEG content in the blend. The addition of PTMEG polyol produced semicrystalline regions of the soft segments of the TPUs and inhibited the mobility of the polymeric chains, this leaded to improved cohesion of the TPU pressure sensitive adhesives; however, similar degrees of phase separation were obtained in all TPUs synthesized with different PTMEG contents. The increase of the PTMEG content in the polyols blend improved both the cohesion and the adhesion but decreased the tack of the TPU pressure sensitive adhesives. The optimal balance between the adhesion and cohesion properties was found in the TPU pressure sensitive adhesive synthesized with 50 wt% PPG + 50 wt% PTMEG and an NCO/OH ratio of 1.20.

ОСОБЛИВОСТІ МОЛЕКУЛЯРНО-МАСОВОГО РОЗПОДІЛУ ФЛУОРЕСЦЕЇНВМІСНИХ КОПОЛІЕСТЕРІВ СИНТЕЗОВАНИХ ЗА РЕАКЦІЄЮ СТЕГЛІХА

The properties of polymers are substantially determined by their molecular mass and molecular mass distribution. At the same time, the average molecular mass of the polymers does not characterize them complete enough, particularly it does not describe the properties of the polymers of special purpose, which are produced for drug delivery and drug release. In this case the accurate assessment of the properties of polymers is especially needed. The article deals with the research of the composition of fractions and functional homogeneity of new amphiphilic copolyesters. Fluorescein-containing amphiphilic copolyesters of N-acyl derivatives of glutamic acid and polyether diols, which form self-stabilized dispersions in aqueous media can be considered as promising multifunctional polymers and may be used in biomedicine.The molecular mass fractionation of copolyesters was carried out with the use of dialysis. The obtained polymers and their fractions were analyzed by exclusion chromatography and functional analysis, the surface tension was determined.A detailed molecular mass distribution of copolyesters was obtained byusing the efficient exclusion chromatography, as well as due to the rather high mass of the monomers. The content of individual fractions, their functionality and colloid-chemical properties were quantitatively compared. It was shown that despite the different molecular mass the individual fractions of a copolyester were homogeneous with identical properties. This allowed us to describe such copolyesters as the good base for the creation of drug delivery systems and nanodiagnostics.

Self-photoinitiating water-diluted polyurethane acrylates and their UV-curing kinetics

In order to find a novel solution to eliminate the photolysis residues and migration problems of organic photoinitiators, a new kind of self-photoinitiating oligomers of water-diluted polyurethane acrylate (WPUA) was synthesized. The UV-curable WPUAs were synthesized with toluene diisocyanate, polyether diols, 2, 2-dimethylol propionic acid, hydroxyl propyl acrylate, pentaerythritol triacrylate, and triethylamine. The UV-curable WPUAs were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, thermogravimetry, differential scanning calorimeter, and UV-Vis spectroscopy, respectively. Effects of different neutralizers, neutralization degrees, hydroxyl acrylates, double bond contents, soft and hard segment ratios on UV-curing degrees and properties of UV-cured films were investigated. The real time UV-vis spectra during the UV-curing process were measured. The UV-curing kinetics of WPUA at low concentrations were conformed to be zero order reactions. The results showed that the UV-cured films had the best performance when triethylamine was used as the neutralizing agent, the neutralization degree was 100%, the initiation molar ratio of -OH and -NCO was 5, and the molar ratio of pentaerythritol triacrylate and 2-hydroxyethyl methacrylate was 3:2. A novel self-photoinitiating mechanism with neutralized triethylamine in WPUA was proposed. Thus, the novel self-photoinitiating WPUAs were proved to be effective and sufficient to use in UV-curing coatings.

Property Study of Polyurethane Template Materials for Molding Concrete

In this paper, polyether diol (CASPOL1861 (V)), liquefied diphenylmethane diisocyanate (103C) and small molecular diol (CASPOL1905) were used as the main reaction materials to synthesize polyurethane template materials for the molding concrete. According to the requirements of polyurethane template materials on high strength, high elongation at break, moderate hardness, low water absorption rate and high alkali resistance, the effect of the types of the soft segments and the types of isocyanate on the mechanical properties, alkali hydrolysis resistance, water absorption, thermal properties and aging properties of the prepared polyurethane template materials were studied by characterizing the properties of polyurethane template materials by mechanical tests, TG, DSC, and other methods.

Preparation of an ionic/nonionic polyurethane-silicone dispersion (PUSD) with a high solid content and low viscosity using complex soft segments

A series of ionic/nonionic polyurethane-silicone dispersions (PUSDs) with a high solid content and low viscosity were prepared using isophorone diisocyanate as the hard segment, polytetrahydrofuran polyether diol (PTMG) and polysiloxane diol (PESI) as the complex soft segments and an ionic/nonionic low molecular weight polyether diol (DPSA) as the hydrophilic, chain-extending agent. The morphologies and rheological properties of the ionic/nonionic PUSD were examined using particle-size, TEM, and viscosity analyses. The hydrophobic and mechanical properties of the dispersions were also tested. It was found that under the conditions of a constant NCO/OH ratio (2/1) and weight percentage of DPDA (6%), the PUSD dispersions with higher PESI contents possessed higher average particle diameters and wider particle-size distributions. Particles in the PUSD dispersions are generally spherical and have a typical core–shell structure due to the use of complex soft segments. However, the solid content of the ionic/nonionic PUSD increased first and then decreased as the weight ratio of PESI to PTMG increased. When the ratio ranged from 4/10 to 6/10, the max solid content of the ionic/nonionic PUSD reached up to 58%, but the viscosity of the PUSD was less than 400 mPa.s−1. Meanwhile, the water contact angle of the films increased due to the formation of a crosslinking structure on the side of the PUSD macromolecule, and when the weight ratio of PESI to PTMG varied from 3/10 to 7/10, the water contact angle of the films increased from 48.3° to 72.3°. In addition, both the freeze-thaw and thermal stabilities of the PUSD dispersions were enhanced as the weight ratio of PESI to PTMG increased. The PUSD coating had good mechanical properties as well.

Self-photoinitiated oligomers of water-diluted polyurethane acrylate grafted with zinc oxide of low concentrations

In order to eliminate some problems of organic photoinitiators, self-photoinitiated oligomers of water-diluted polyurethane acrylate grafted with 0.1–0.3 wt.% zinc oxide (ZnO) were prepared. ZnO was first facilely treated by vacuum dehydration and sonication, and then reacted into the oligomers by NCO and OH groups. The oligomers were synthesized using toluene diisocyanate, polyether diols, 2, 2-dimethylol propionic acid, hydroxyl propyl acrylate, pentaerythritol triacrylate, ZnO, and triethylamine. The prepared oligomers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, particle size analyzer, and UV–vis spectroscopy. The kinetics of the UV-curing process was investigated. We observed a maximum kinetic rate constant with ZnO content of 0.2%, and the best film performance with ZnO content around 0.25%. The photoinitiation efficiency of the oligomers was similar to the value of 2-hydroxyl-2-methyl-1-phenyl-1-propanone. In general, the physical properties of the films with physically mixed ZnO were worse than those of the films with chemically grafted ZnO. This investigation demonstrated novel oligomers grafted with a few ZnO can be self-photoinitiated and facilely prepared.

New polyether diols as flame retardants for polyurethane: Derivatives of epoxy‐functionalized phosphonates and phosphates

SummaryPhosphorus‐containing epoxides were used to generate several oligomeric polyether diols, which were in turn utilized in the preparation of model polyurethane (PU) samples, either as comonomers in the polymerization (Prep samples) or solvent blended into a priori prepared PU (Blend samples). The resultant samples were evaluated for heat release reduction potential using microcombustion calorimetry. Several variables were investigated in the oligomerization of the original epoxides, such as presence of initiator, epoxide comonomer, and solvent. The oligomer mixtures were thoroughly characterized, using NMR, mass spectrometry (MS), elemental analysis, and viscosity measurements. The final PU Prep samples were carefully analyzed to demonstrate and evaluate the degree of chemical incorporation of the polyether diols into the PU main chain. Results from the heat release studies demonstrated that incorporation of the phosphorus‐containing diol did lower flammability, but the structure of the original epoxide, as well as the oligoimerization conditions, had an effect on heat release reduction. The results are complex and require further study, but the phosphonate‐based materials showed greater heat release reduction potential, both in the form of Prep and Blend samples, especially in one case of a Blend sample, where a notable amount of intumescent char was formed.