Triol, 555 Table

Table 3. Charges for a 3000 Molecular Weight Glycerol-Initiated PPO Triol...

Starters. Nearly any compound having an active hydrogen can be used as starter (initiator) for the polymerization of PO. The common types are alcohols, amines, and thiols. Thus in Figure 2 ROH could be RNH2 or RSH. The fiinctionahty is derived from the starter, thus glycerol results in a triol. Some common starters are shown in Table 4. The term starter is preferred over the commonly used term initiator because the latter has a slightly different connotation in polymer chemistry. Table 5 Hsts some homopolymer and copolymer products from various starters. 

Crystalline polyesters are highly important as adhesive raw materials. They are normally crystalline waxes and are highly symmetrical in nature, which can aid the crystallization process [26]. Poly(hexamethylene adipate) and poly(caprolactone), shown in Table 2, are only two of the many crystallizable backbones. Poly(ethylene adipate) and poly(letramethylene adipate) are also commonly used in urethane adhesives. The crystalline polyesters are used in curing hot melts, waterborne polyurethanes, thermoplastic polyurethanes, and solvent-borne urethane adhesives. The adipates are available mostly as diols. The poly(caprolactones) are available as diols and triols. 

To overcome these problems with the first generation Brmsted acid-assisted chiral Lewis acid 7, Yamamoto and coworkers developed in 1996 a second-generation catalyst 8 containing the 3,5-bis-(trifluoromethyl)phenylboronic acid moiety [10b,d] (Scheme 1.15, 1.16, Table 1.4, 1.5). The catalyst was prepared from a chiral triol containing a chiral binaphthol moiety and 3,5-bis-(trifluoromethyl)phenylboronic acid, with removal of water. This is a practical Diels-Alder catalyst, effective in catalyzing the reaction not only of a-substituted a,/ -unsaturated aldehydes, but also of a-unsubstituted a,/ -unsaturated aldehydes. In each reaction, the adducts were formed in high yields and with excellent enantioselectivity. It also promotes the reaction with less reactive dienophiles such as crotonaldehyde. Less reactive dienes such as isoprene and cyclohexadiene can, moreover, also be successfully employed in reactions with bromoacrolein, methacrolein, and acrolein dienophiles. The chiral ligand was readily recovered (>90%). 

Boric acid esters provide for thermal stabilization of low-pressure polyethylene to a variable degree (Table 7). The difference in efficiency derives from the nature of polyester. Boric acid esters of aliphatic diols and triols are less efficient than the aromatic ones. Among polyesters of aromatic diols and triols, polyesters of boric acid and pyrocatechol exhibit the highest efficiency. Boric acid polyesters provide inhibition of polyethylene thermal destruction following the radical-chain mechanism, are unsuitable for inhibition of polystyrene depolymerization following the molecular pattern and have little effect as inhibitors of polypropylene thermal destruction following the hydrogen-transfer mechanism. 

The density tables are organized into 3 main classes of compounds as described in the Table of Contents monoalcohols, diols, and triols. Within each main class (except for the triols) there are several subclasses. They start with fully saturated compounds and proceed with increasing extents of unsaturation. Within each subclass the compounds are arranged in formula order. First with increasing number of carbon atoms in the empirical formula and then with increasing number of hydrogen atoms. Compounds with the same formula are sorted alphabetically by Table Name... 

One system studied by the authors(3) used LG56 triol which had been characterised by molar-mass as well as end-group determinations. The data for the samples used are given in Table III, indicating a true number-average functionality (fn) of between 2.95 and 2.99. The triol was reacted with HDI in bulk (see Figure 1) and at various dilutions in benzene, and values of Nr and ac determined. To estimate functionality from ac, equations... 

For networks prepared from MDI and a PPO triol whose molecular weight and functionality were 2630 and 2.89, respectively, Dusek and Ilavsky (27) found the moduli to be about twofold greater than those calculated from the sol fraction when h and TeG ax in eq 2 are equated to zero. Thus, vc/(vc + ve) is about 0.50 whereas the data in Table III give 0.62, approximately. 

The strain grew on various PPGs with Mns 670-4000 (diol and triol types), monomer and dipropylene glycol, but did not assimilate PEGS. The strain also grew on a few PEG-PPG copolymers which contained a larger amount of PPG than PEG (Table I). 

The gel point is usually determined experimentally as that point in the reaction at which the reacting mixture loses fluidity as indicated by the failure of bubbles to rise in it. Experimental observations of the gel point in a number of systems have confirmed the general utility of the Carothers and statistical approaches. Thus in the reactions of glycerol (a triol) with equivalent amounts of several diacids, the gel point was observed at an extent of reaction of 0.765 [Kienle and Petke, 1940, 1941], The predicted values of pc, are 0.709 and 0.833 from Eqs. 148 (statistical) and 2-139 (Carothers), respectively. Flory [1941] studied several systems composed of diethylene glycol (/ = 2), 1,2,3-propanetricarboxylic acid (/ = 3), and either succinic or adipic acid (/ = 2) with both stoichiometric and nonstoichiometric amounts of hydroxyl and carboxyl groups. Some of the experimentally observed pc values are shown in Table 2-9 along with the corresponding theoretical values calculated by both the Carothers and statistical equations. 

It was of obvious interest to prepare the inhibitors 60 as their pure dia-stereoisomers, 66 and 67. Following on from our successful treatment of alkenyl D-glucosides under Sharpless asymmetric dihydroxylation conditions [21], we treated the alkenes 64 with the a-AD - and AD -mLxes - the results are summarized in Table 2. In no case did we ever obtain a satisfactory diastereo-isomeric excess of the diol 68 over the diol 69, or vice versa. A similar lack of stereoselectivity was also obtained with the triol 70 and the amine 71 [48]. 

Diols and polyols can participate in equilibria with boric acid in aqueous solution. The stability of polyolborates is determined by the number of OH groups in cis positions. Complexes with polyols are more stable than with diols, and 1,2-diol complexes are more stable than their 1,3-diol counterparts (Table 10) since the resulting five-membered chelate ring is unstrained.75120 In the case of 1,3,5-triols stable cage-like structures (5) and (6) are favored. Open-chain or five-membered cyclic polyols form more stable chelate complexes than their six-membered counterparts.120 Thus, chelates from alditols and ketohexoses are more stable than the corresponding aldose chelates (Table 10). Many polyols allow quantitative titrimetric determination of boric acid. Of these, mannitol remains the most widely used reagent on the basis of availability, cost and ease of handling.75... 

Lipids are constituents of plants and animals that are characteristically insoluble in water. Fats and oils are lipids that are triesters formed by reaction of the triol glycerol with long-chain saturated or unsaturated acids called fatty acids. The common acids in fats and oils have an even number of carbons (for example, stearic acid has 18 carbons), and, if unsaturated (for example, oleic acid), they have the Z configuration (Table 15.1 lists the fatty acids, with their common names). Hydrogenation of oils, which have a high percentage of unsaturated acids, converts them to solid fats in a process called hardening. 

Figure 18.3. Scheme for the formation of cholesterol epoxides. Compounds are as follows (1) CHOL (2) a-epoxide (3) ft-epoxide (4) triol. For abbreviations, see Table 18.1. 

Both tributylstannyl ethers and dibutylstannylene acetals of terminal triols yield in most cases the product of reaction with 1,2-diols in preference to other hydroxyl groups, as shown in Figs. 47 and 48. Figure 47 also illustrates the tendency of t-butylchlorodimethylsilane to react with terminal 1,3-diols in preference to terminal 1,2-diols.87 Figure 48 shows that the preference for reaction at terminal oxygen atoms is considerably stronger than the preference for reaction next to unsubstituted centers, discussed in the previous section. As the numerous examples in Table IX demonstrate, this selectivity is maintained over a wide range of structural features. 

From these findings with triols, it follows that, apart from the expectation that formation of five- and six-membered rings would be favored (see, however, the exceptional compound 19), no general conclusions can be drawn regarding the structures of boronates derived from more-complex polyhydric alcohols. In Table V, alditol boronates are listed with structures when these can be concluded either from the method of synthesis, from physical studies, or by deduction (as with the 1,2 5,6-diesters formed from 3,4-di-O-substi-tuted mannitols). 

One-shot polyether foams were studied, using a variety of catalysts. The formula contained 100 parts by weight of poly(oxypropylene)triol of 3000 M.W., 38 parts of 80 20-TDI, 2.9 of water, 0.3 of 4-dimethyl-aminopyridine, 0.5 of lV,iV-dimethylbenzylamine, varying amounts of metal catalysts, and 0.1 part of X-520 siloxaneoxyalkylene copolymer. All of the gas was evolved from these systems within 60 sec after mixing. Viscosity measurements were not satisfactory due to fracture of the polymeric phase. Analysis of the reaction mixture at the end of 55 sec reaction time indicated the relative rate of formation of various products, as indicated in Table 22. The importance of selecting the proper catalyst to avoid undesirable side reactions is readily apparent. The results shown in Table 22 indicate that both tin catalysts promote the isocyanate/water reaction more than the isocyanate/hydroxyl reaction in the system studied. This is unusual, since other reports, though often of dilute solution studies, have shown the tin catalysts to promote the isocyanate/ hydroxyl reaction more [145,147,196]. 

Ligands with three different phosphine donors (39)-(47) (Table 2) are accessible on the routes shown in Scheme 1. The starting materials for routes A and B are generally obtained from the corresponding triol (see Equation (3)). 

The enthalpies of formation for a variety of arenediols and arenetriols (triols to be discussed in Section IV) appear in Table 7. 

All the allylic alcohols form the oxirane as the initial product, but as the conversion increases the ring opened products, the ether diols (formed by reaction with the alcohol solvent) and the triol (formed by reaction with water) are also observed. It is apparent that cis-crotyl alcohol reacts approximately three times more rapidly than the trans-crotyl even though it is present as the minor component. This was inve.stigated further using crotyl alcohols with a range of trans/cis ratios and the results are shown in Table 1. 

By utilizing the new findings mentioned above, PECHG and polyepichlorohydrin triol (PECHT), each with a molecular weight of approximately 1000, were prepared using ethylene glycol and glycerol, respectively. The results are summarized in Table III. 

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