Air-drying UP resins

Air-drying UP Resins. Air-drying UP resins, also known as gloss polyesters, are... 

Whereas fillers are applied using a roller machine, putties are usually applied by reverse roller, spray gun or curtain coater. Depending on the substrate, the application rate is between 50 and 200 g/m. Fillers are mainly formulated with paraffin-type UP resins or air-drying types which are UV-cured. For fillers cured with hy-droperoxide/cobalt, air-drying UP resins are normally used in combination with flexibilising resins. 

The maximum amount of toluene diisocyanate which could react without gelation varied according to the type of modification used e.g., up to 1.35 mole proportions with the mono-Miisocyanate route and somewhat lower (1.1 to 1.2 mole) proportions in the other cases. The mono-/diisocyanate approach, as expected, produced resins with the best alkali resistcuice, in some cases at least comparable to high quality, commercial, air-drying polyurethane resins and, therefore, was studied in more detail. 

The sample is loaded at a flow-rate of 1 ml/min onto the FPLC column equilibrated with the same MOPS buffer used to resuspend the RNA pellets. The free nucleotides are completely removed with a 5-ml wash with 350 mM NaCl and the RNA is eluted with a 20-ml (350—750 mM NaCl) linear gradient and analyzed by PAGE/urea gel electrophoresis (see later). Up to 2 mg of RNA can be loaded onto and eluted from a 1-ml (of resin) mono Q column without loss of resolution. The homogeneity of RNA in the fractions collected, as seen by gel electrophoresis, should be >90%. The appropriate fractions are pooled and the RNA collected by ethanol precipitation. The RNA pellet is washed twice with 70% ethanol, air-dried, and finally redissolved in DEPC-treated H20. The total recovery after the entire procedure of purification is = 90%. This protocol yields = 800 pmoles of purified 002 mRNA/pmole template DNA. 

Apart from air drying systems, P.R.14 is also used in baking enamels however, it blooms beyond certain concentration limits. In an alkyd-melamine resin system, for instance, the pigment shows resistance to blooming up to 160°C, independent of the concentration the concentration limit at 180°C is 0.2%, and at 200°C it is 1%. Blooming is accompanied by considerable bleeding. 

Zeolites are suitable for heavy-duty purifications of gas streams. Moreover, like resins, they can be manufactured with pore stincUires of the desired diameter in order to be used for the selective adsorption of specific contaminants based on their molecular size. They are resistant to temperature rise, being stable at temperatures up to 800 °C in dry air and up to 500 °C in humid air. Therefore, they can be treated at high temperature with air to avoid the... 

The wide range of UP resins on the market covers products which require the addition of paraffin wax through air-drying, UV-curing, amine-accelerated or flex-ibilising products to styrene-free and/or water-dispersible resins. 

UP Resins for Fillers. Tack-free films are also obtained if phthalic acid anhydride is substituted with tetrahydrophthalic acid anhydride [2.104]. The addition of en-domethyl tetrahydrophthalic acid anhydride (a cycloaddition product of maleic acid and cyclopentadiene) also has a positive effect on the air-drying properties [2.105]. Both product classes have become popular above all in the manufacture of binders for highly extended fillers for vehicle repair applications. 

To circumvent interference from the extending oil, no internal chromatographic standard was used to check response. Polymer standards were prepared. These were made by incorporating the oil and antioxidant into unstabilised polybutadiene or styrene-butadiene resin cement at typical levels of concentration. These preparations were then air-dried to a dry polymer condition. For analytical purposes, 10.0 0.01 gram of polymer were ethanol extracted in a Soxhlet apparatus using 165 ml of solvent for 16 hours. The extract solution was then concentrated to about 10 ml volume and taken up in the appropriate solvent to a 50 ml volume and used for chromatographic analysis of the antioxidant. 

Although in the dry state carbon tetrachloride may be stored indefinitely in contact with some metal surfaces, its decomposition upon contact with water or on heating in air makes it desirable, if not always necessary, to add a smaH quantity of stabHizer to the commercial product. A number of compounds have been claimed to be effective stabHizers for carbon tetrachloride, eg, alkyl cyanamides such as diethyl cyanamide (39), 0.34—1% diphenylamine (40), ethyl acetate to protect copper (41), up to 1% ethyl cyanide (42), fatty acid derivatives to protect aluminum (43), hexamethylenetetramine (44), resins and amines (45), thiocarbamide (46), and a ureide, ie, guanidine (47). 

For the preparation of the foam, a solution of 1 g technical sodium diisobutyl naphthalene sulfonate in 50 ml of 3% orthophosphoric acid is prepared. 20 ml of this solution are poured into a 11 beaker and air is stirred in with a fast running mixer until the cream-like dispersion has reached a volume of 300-400 ml.Then,20 ml of the prepared urea/formaldehyde resin are mixed in, whereby the resin must be evenly distributed. After 3-4 min the introduced resin gellifies into a molded article permeated with many water/air pores under the influence of the acidic catalyst. After 24 h,the crosslinking is completed. Drying for 12 h at 40 °C in a circulating air dryer yields a brittle thermoset foam.The foamed plastic obtained is hydrophobic and has a large internal surface. It can take up about 30 times its own weight of petroleum ether. 

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