Liquid polyol

Cai, W. and Wan, J.Q. (2007) Facile synthesis of superparamagnetic magnetite nanoparticles in liquid polyols. Journal of Colloid and Interface Science, 305 (2), 366-370. 

Nitro Nobel A process for making nitrate esters such as nitroglycerol. A special injector is used to mix the liquid polyol with the nitrating acid. 

General Principles for the Preparation of Metal Powders by Reduction in Liquid Polyols... 

Liquid polyols are interesting among nonaqueous solvents because, like water and monoalcohols, they are hydrogen-bonded liquids with a high value of relative permittivity (Table 9.2.1), and therefore they are able to dissolve to some extent ionic inorganic compounds. Moreover, reactions can be carried out in such solvents under atmospheric pressure up to 250°C, i.e., at a temperature range higher than in water or monoalcohols such as methanol or ethanol. 

If it is possible to control the morphological characteristics of the metal particles obtained by reduction in liquid polyols by following the guidelines described in the... 

Although the use of lignin as an additive to polyurethanes is not new (15-20), even the most judicious selection of lignin isolation or modification schemes has not allowed researchers to overcome the incorporation limit of 25 to 40 weight percent of lignin as an active component in polyurethanes. Solvent fractionation allows for the isolation of lignin fractions with well defined solubilities and functionalities (21,22). Both of these features are critical for the practical inclusion of lignin into liquid polyol systems. 

A popular method for the synthesis of metal nanowires is the use of the polyol process,lal wherein the metal salt Is reduced in the presence of PVP to yield nanowires of the desired metal. For example, Ag nanowires have been rapidly synthesized using a microwave-assisted polyol method.161 CoNi nanowires are obtained by heterogeneous nucleation in liquid polyol.162 While Bi nanowires have been prepared employing NaBiO, as the bismuth source.161 Pd nanobars are synthesized by varying the type and concentration of reducing agent as well as reaction temperature.1 ... 

Reaction injection molding (RIM) is a fast, low-pressure, low-temperature, low-cost process for one-step conversion of reactive liquids into large finished solid plastic products. Liquid polyol and liquid diisocyanate are mixed by impingement, pumped instantly to fill a large mold cavity, and polymerize/ cure rapidly to form a thermoset polyurethane product. The cured polymer may be a stiffly flexible product such as automotive bumper covers, front ends, and trim or a rigid foamed product such as furniture and housings (cabinets) for computers, business machines, TY and radio. 

The largest quantity of low-density foam is polyurethane, made by mixing liquid polyols... 

Liquid Polyols from Glucose Synthesis and Characterization. Liquid polyols were prepared from a-D-glucose (1) and the aglycon, a PTHF diol (2), by acid-catalyzed reactions under nitrogen at 130 °C in N-methyl pyrrolidone, NMP, solutions ( -0). 

Table I. Characterization Data of PTHF629m and PTHF629b Liquid Polyols...

NMP solvent and low acid contents. The liquid polyols thus prepared and characterized were then amenable for direct use in bulk polymerizations with MDI to form polyurethane materials. 

In order for such glycosides to be utilized for polyurethane formation, further chemical modification is required to reduce hydrogen-bonding interactions. Chain extension, often by alkoxylation at elevated temperature and under pressure, is used to obtain suitable liquid polyols. Otey (if), for example, has modified EGG in this manner in a bulk alkoxylation to yield polyols that could then be used to form polyurethane foams. 

In the present work, however, a more controlled oxypropylation process (12) carried out in solution and at atmospheric pressure was developed and used to convert EGG into a liquid polyol. This polyol, with the idealized structure (6) in which n = 3, had an equivalent weight toward MDI of 293 g-mol-1. 

Glucose can be reacted with an aglycon from a renewable resource in a one-stage synthesis to yield liquid polyols suitable for direct bulk polyurethane formation ... 

Soroushian B, Lampre 1, Bonin J, Pernot P, Pommeret S, Mostafavi M. (2006) Solvation dynamics of the electron produced by two-photon ionization of liquids polyols. I. Ethylene glycol. J Phys Chem A 110 1705-1717. 

First, the monomers found most useful for nylon RIM systems are E-caprolactam and lauryl lactam. Unlike the liquid polyol and isocyanate materials in common use in urethane RIM, these materials have melting points of 158°F and 320°F respectively, making them solids at room temperature. Thus, nylon RIM equipment must have heated tanks, pumps, lines and molds. In commercial practice, this is accomplished by jacketing the equipment with circulating hot oil or water systems, by enclosing the hardware in temperature-controlled ovens or by electrically tracing the equipment with resistance heating hands and tapes. The first two methods are preferred because of their uniformity of control and lack of hot spots. 

Soroushian B., Lampre I., Bonin J., Pernot R, Pommeret S., Mostafavi M., Solvation dynamics ofthe electron produced by two-photon ionisation of liquid polyols. 1. Ethylene glycol, J. Phys. Chem. A, 2006,110,1705-1717. 

Reacting melamine with ethylene carbonate or propylene carbonate, at 150-200 °C, in liquid medium (for example a Mannich polyol derived from phenol), 2-hydroxyalkyl carbamates of melamine are obtained [4] (reaction 15.42). The reaction developed in the absence of this liquid polyol takes place with difficulty and with decomposition. Ethylene carbonate is reactive, but propylene carbonate has a much lower reactivity. 

THEI, a solid substance, can be transformed into liquid polyol by reaction with 2-3 mols of PO/mol of THEI in the presence of a tertiary amine. The polyol with 3 mols of PO/mol of THEI has an hydroxyl number of around 375 mg KOH/g. 

By the reaction of alcohols (in excess) with epoxidised vegetable oils in the presence of acids as catalysts - liquid polyols are formed (reaction 17.22). For example by the alcoholysis of epoxidised soybean oil with methanol, at the reflux temperature of methanol (the boiling point of methanol is 64.7 °C), in the presence of an acidic catalyst (H2S04, p-toluene sulfonic acid, HBF4 [31, 34, 44, 45], solid acidic clays [39], supported acidic catalysts), liquid soybean oil based polyols are obtained, with an hydroxyl number of around 170-173 mg KOH/g, a functionality of about 3-4 OH groups/mol and a viscosity of around 4,000-7,000 mPa-s at 25 °C. After the neutralisation of the acidic catalyst or by the filtration of solid acid catalysts, the methanol is distilled under vacuum and recycled back into the process. 

These "polymer-polyols" are made by the in situ polymerization of vinyl monomers such as acrylonitrile (although grafting with other monomers has also been reported in a liquid polyol solution, e.g., polyether triol of molecular weight 3000) to give stable dispersions of the polymeric portion in the liquid polyol. Grafting is carried out with azobis(isobutyronitrile) or dibenzoyl peroxide as initiators at 80-90 °C. A polymer-polyol containing about 20% acrylonitrile appeared to be the best compromise between polyol viscosity and urethane foam properties (108). 

---