Solid polyols properties

We were supported in our thesis by the work of Huddelston et al In order to achieve phase separation, they employed a salting out principle with good success. We employed a polyalcohol backbone and achieved phase separation by reacting the terminal alcohol groups with isocyanates. This was done after the addition of crosslinking chenficals yielded a solid polyol, which, as we will show in subsequent chapters, has the extractive properties we sought. Additional processing techniques allowed us to build an open-cell structure that permitted the flow of fluids and extracted the pollutants. 

Several solid polyols can be used as direct compression diluents, usually after some physical modification. Most such polyols can be obtained from natural sources, but are usually manufactured by hydrogenation of the parent sugar molecule. Some properties of polyols, together with comparative data for lactose and sucrose, are shown in Table 6. 

This area is expected to see further growth for RIM, part of which will come at the expense of cast systems (4). Many new formulations with inproved properties will become possible through the use of "HOT RIM" equipment which will allow low melting solid isocyanate MDI prepolymers to be used along with low melting solid polyols in the "B" side. 

Properties Pale yel. solid, polyol odor sol. in water, aliphatic ketones, alcohols, glycol ethers, esters, aromatic hydrocarbons si. sol. in aliphatic hydrocarbons sp.gr. 1.08 (70 C) vapor pressure < 0.1 mm Hg acid no. 0.1-0.3 hyd. no. 73.4-81.4 flash pt. (PMCC) > 300 F Toxicology Not expected to cause skin or eye irritation Precaution Incompat. with strong oxidizing materials Hazardous decomp, prods. Thermal decomp, may produce CO ... 

The specialty class of polyols includes poly(butadiene) and polycarbonate polyols. The poly(butadiene) polyols most commonly used in urethane adhesives have functionalities from 1.8 to 2.3 and contain the three isomers (x, y and z) shown in Table 2. Newer variants of poly(butadiene) polyols include a 90% 1,2 product, as well as hydrogenated versions, which produce a saturated hydrocarbon chain [28]. Poly(butadiene) polyols have an all-hydrocarbon backbone, producing a relatively low surface energy material, outstanding moisture resistance, and low vapor transmission values. Aromatic polycarbonate polyols are solids at room temperature. Aliphatic polycarbonate polyols are viscous liquids and are used to obtain adhesion to polar substrates, yet these polyols have better hydrolysis properties than do most polyesters. 

Thermal degradation of foams is not different from that of the solid polymer, except in that the foam structure imparts superior thermal insulation properties, so that the decomposition of the foam will be slower than that of the solid polymer. Almost every plastic can be produced with a foam structure, but only a few are commercially significant. Of these flexible and rigid polyurethane (PU) foams, those which have urethane links in the polymer chain are the most important. The thermal decomposition products of PU will depend on its composition that can be chemically complex due to the wide range of starting materials and combinations, which can be used to produce them and their required properties. Basically, these involve the reaction between isocyanates, such as toluene 2,4- and 2,6-diisocyanate (TDI) or diphenylmethane 4,3-diisocyanate (MDI), and polyols. If the requirement is for greater heat stability and reduced brittleness, then MDI is favored over TDI. 

Cervera ME, Heinamaki J, Krogars K, et al. Solid state and mechanical properties of aqueous chitosan-amylose starch films plasticized with polyols. AAPS Pharm Set Tech 2004 5(1) E15. 

A third process of solid bisphenol A alkoxylation is to use a suspension of solid bisphenol A in final polyether polyol (40-60% bisphenol A and 60-40% liquid polyether diol). This suspension, in the presence of a tertiary amine as catalyst, is ethoxylated at 80-95 °C, with 8-9 mols of EO/mol of bisphenol A. At the end of the reaction, all the solid bisphenol A was totally transformed into liquid polyether diols [30]. The resulting polyether diols are used successfully for production of urethane-isocyanuric foams with very good physico-mechanical properties and intrinsic fire resistance. 

Details on reinforced reaction injection molding (RRIM) using TS polyurethane (PUR). Two-component PUR mixtures, in which a polyol and isocyanate are brought together and a fast reaction takes place to produce a solid compound with useful properties lend themselves well to molding with reinforcement. This can be a flat or preformed mat placed in the mold, or a chopped reinforcement introduced into the stream of components in the mixing head. 

Uses Esterification catalyst for mfg. of unsaf. polyesters, esp. isophthalates, polyester polyols, phthalates, adipates, powd. coatings, coil coatings, specialty enamels at temps, of 200-230 C Properties Wh. solid sol. in most ester prods. insol. in most org. soivs. ... 

Chem. Descrip. Polyol resin in n-bulyl acetate Uses Resin for low odor, non-HAPs coatings Features Alternate solv. version of Joncryl 500 Properties Vise. 3800 cps VOC 2.8-3.1 Ib/gal 80% solids Joncryl 537 [S.C. Johnson Polymer]... 

Chem. Descrip. Acrylic polyol resin in butyl acetate Uses Acrylic for two-part urethane coatings Features Economical low VOC Properties Vise. 5500 cps VOC 2.6-3.0 Ib/gal 77% solids Joncryl 1532 [S.C. Johnson Polymer]... 

Features Sat., aliphatic polyester polyols with primary hydroxyl functionality produces urethanes with high tens, str., heat and solv. resist. Properties Gardner 1 solid m.w. 1020 dens. 10.0 Ib/gal vise. 400 cps (60 C) m.p. 55-65 C acid no. 0.5 hyd. no. 110. 

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