Amidic polyols

The reaction between dialkanolamines with organic acids or better still with their methyl esters gives the well known dialkanolamides. This reaction is used industrially for the synthesis of diethanolamides of fatty acids, which are well known nonionic surfactants (reaction 19.1) [1-10]  

With methyl esters of fatty acids, the reaction takes place at a higher yield (around 90-92%) as compared to the free fatty acids (the yield is 60-70%) [2, 7-9]. The catalysts of this amidation reaction are KOH, NaOH, CH3ONa, CH3OK, etc. (the most used catalyst is sodium methylate). The diethanolamides of fatty acids, as presented in Chapter 17, are used sometimes as copolyols in rigid polyurethane (PU) foams, to improve the compatibility of other rigid polyols with pentanes, used as blowing agents [4-8]. 

By using the principles of this classic reaction, new aromatic polyols were created, based on the reaction between dimethyl phthalate, dimethyl isophthalate and dimethylterephthalate with diethanolamine, using sodium or potassium methylate as catalyst (reactions 19.2, 19.3 and 19.4)  

A partial esterification reaction takes places (19.5). This side reaction does not have a negative effect on rigid PU foam fabrication because it gives a very convenient tetrafunctional compound, which participates, together with the amidic polyol, to build the crosslinked structure of polyurethane. These compounds containing ester groups are present in low concentrations, maximum 5-7% [1,2]. 

Except for the diamide derived from phthalic acid (19.2) which is a viscous liquid at room temperature, the diamides of isophthalic and terephthalic acids are solid, with convenient melting points. Because these diamides have a relatively high hydroxyl number of around 650 mg KOH/g, a propoxylation reaction (reaction 19.6) was developed. The 

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After the propoxylation step, the resulting amidic polyols are purified by classical methods (for example by the treatment with solid disodium acid pyrophosphate). The liquid bis (diethanolamide) of phthalic acid, without any propoxylation step, can be used as a crosslinker or as a copolyol for rigid PU foams. 

The amidic polyol obtained by the propoxylation of bis (diethanolamide) of phthalic acid, with an hydroxyl number in the range of 380-400 mg KOH/g, is an alternative for ortho-toluene diamine (o-TDA) based polyether polyols. The amidic polyols do not have the problems of a dark colour as the o-TDA polyols do and have lower viscosities than o-TDA polyols. 

The amidic polyols derived from bis (diethanolamide) of phthalic acid (structure 19.6) have the same functionality as o-TDA based polyols and have internal ethylene oxide (EO), similar to commercial o-TDA polyether polyols. The difference is that the labile amino groups are replaced with more stable amidic groups and the amidic polyol does not have a methyl group in the aromatic nucleus. The similarities between o-TDA based polyols and the amidic polyols derived from bis (diethanolamide) of phthalic acid are shown in the structures presented in Figure 19.1. 

The synthesised amidic polyols have an hydroxyl number between 350-500 mg KOH/g and viscosities between 7000-25000 mPa-s at 25 °C, the lowest viscosity being in the polyols derived from the bis (diethanolamide) of phthalic acid. The pH of amidic polyols is slightly basic, in the range of 8-9.5. 

Dimethyl phthalate, a very convenient liquid raw material, is a by-product in the fabrication of dimethylterephthalate. The amidic polyols can be used to replace the Mannich polyols. The self catalytic effect in PU formation is much less important in the case of amidic polyols, as compared with Mannich polyols. The rigid PU foams derived from amidic polyols are much more thermoresistant than the rigid PU foams derived from Mannich polyols [2]. 

The amidic polyols represent a new generation of aromatic polyols for rigid PU foams, with an high application potential, all the raw materials used, dimethyl esters, dialkanolamines and PO being produced in large quantities industrially. 

The reaction of polyethylene terephthalate) (PET) with diethanolamine, followed by propoxylation, gives liquid amidic polyols useful in rigid PU foam fabrication. This method is an efficient variant of PET waste chemical recovery (bottles, x-ray films, fibres and so on) [1]. 

Preparation of hybrid polyols with both ester glyceride and amide polyols. 

Mukherjee RN, Sanyal SN, Pal SK (1983) Studies on jute fibers composites with polyester-amide polyols as interfacial agent. J Appl Polym Sci 28 3029-3040... 

Polymerization Solvent. Sulfolane can be used alone or in combination with a cosolvent as a polymerization solvent for polyureas, polysulfones, polysUoxanes, polyether polyols, polybenzimidazoles, polyphenylene ethers, poly(l,4-benzamide) (poly(imino-l,4-phenylenecarbonyl)), sUylated poly(amides), poly(arylene ether ketones), polythioamides, and poly(vinylnaphthalene/fumaronitrile) initiated by laser (134—144). Advantages of using sulfolane as a polymerization solvent include increased polymerization rate, ease of polymer purification, better solubilizing characteristics, and improved thermal stabUity. The increased polymerization rate has been attributed not only to an increase in the reaction temperature because of the higher boiling point of sulfolane, but also to a decrease in the activation energy of polymerization as a result of the contribution from the sulfonic group of the solvent. 

H-Bonding, Strongly Associative (HBSA) Water Primary amides Secondary amides Polyacids Dicarboy lic acids Monohydro) acids Polyj)henols Oximes Hydroj laniines Amino alcohols Polyols... 

The synthesis of the polyol glycoside subunit 7 commences with an asymmetric aldol condensation between the boron enolate derived from imide 21 and a-(benzyloxy)acetaldehyde (24) to give syn adduct 39 in 87 % yield and in greater than 99 % diastereomeric purity (see Scheme 8a). Treatment of the Weinreb amide,20 derived in one step through transamination of 39, with 2-lithiopropene furnishes enone 23 in an overall yield of 92 %. To accomplish the formation of the syn 1,3-diol, enone 23 is reduced in a chemo- and... 

A new iterative strategy for enantio- and diastereoselective syntheses of all possible stereoisomers of 1,3-polyol arrays has been described by Shibasaki. This strategy relies on a highly catalyst-controlled epoxidation of a, 3-unsaturated morpholi-nyl amides promoted by the Sm-BIN0L-Ph3As=0 complex, followed by the con-... 

Isocyanates react with carboxylic acids to form amides, ureas, anhydrides, and carbon dioxide, depending on reaction conditions and the structure of the starting materials (Scheme 4.13). Aliphatic isocyanates more readily give amides. Aromatic isocyanates tend to react with carboxylic acids to first generate anhydrides and ureas, which at elevated temperatures (ca. 160°C) may further react to give amides. In practice, the isocyanate reaction with carboxylic acid is rarely utilized deliberately but can be an unwanted side reaction resulting from residual C02H functionality in polyester polyols. 

Commercially available hyperbranched polymers are Polyglycerol (aliphatic polyether polyol) and Polyethylenimine (aliphatic polyamine) both from Hyperpolymers, Boltom (aliphatic polyesters) from Perstorp and Hybrane (aromatic polyester amide) from DSM. 

The compositions consist of a heat-plastified mixture of an ethylene homopolymer or copolymer, about 3 to 30 pbw of an elastomer, a stability control agent, which is a partial ester of a long chain fatty acid with a polyol, higher allyl amine, fatty acid amide or olefinically unsaturated carboxylic acid copolymer, and a hydrocarbon blowing agent having from 1 to 6 carbon atoms and a boiling point between -175 and 50C. 

Detergent In relationship to fuel technology, a detergent is an oil-soluble surfactant added to fuel aiding in the prevention and removal of deposits. Examples include anionic alkyl aryl sulfonates, cationic fatty acid amides, or nonionic polyol condensates. 

The formation of isocyanurates in the presence of polyols occurs via intermediate allophanate formation, i.e, die urethane group acts as a cocatalyst in the dimerization reaction. By combining cyclotrimeiization with polyurethane formation, processibility is improved, and the friability of the derived foams is reduced. Modification of cellular polymers by incorporating amide, imide, oxazolidinone, or carbodiimide groups has been attempted but only the urethane-modified isocyanurate foams are produced in the 1990s. PUIR foams often do not require added fire retardants to meet most regulatory requirements. A typical PUIR foam formulation is shown in Table 2. 

In situ amine-impregnated silica gel Amine- or amide-bonded phases Diol- and polyol-bonded silica gel Anion exchangers Cation exchangers... 

Approximately six years after Denkewalter s patent, two new architectures were published in 1985. Newkome et al. 41 relied on triester amidation with tris for the construction of polyols (8) possessing maximal 1 — 3 C-based branching. Repetition of the sequence was precluded by surface steric inhibition towards nucleophilic substitution. Tomalia et al. 42a reported the preparation of an entire series of dendrimers (9, up to the 7th tier) possessing trigonal, l—>2 N- based, branching centers. To date, availability has... 

These stringent requirements are demonstrated by few chemicals other than water. It remains to be seen to what extent the limitations can be relaxed for a chemical promoter to be acceptable (to patients and to the regulatory authorities). Enhancers include a wide range of chemical entities that increase skin permeability (Figure 8.9), such as sulphoxides, alcohols, polyols, pyrrolidones, alkanes, fatty acids, esters, amines and amides, terpenes, surfactants, cyclodextrins, water, etc. 

TNT 7.5, Al dust 0.5, coal 3 and chalk 0.5%. The introduction of up to 10% of hydrazine nitrate in an AN expl markedly increases sensitivity and deton rate. AN and hydrazine nitrate are prefetbably mixed together prior to the addition of other ingredients, or they may be fused, solidified and subdivided prior to such addition (Ref 80) k)An expl obtai ned by neutralization of an acidic nitrated polyol such as NG by the addition of amines or amides such as urea, especially i n the form of a melt with AN i n a eutectic mixt. The expl is stable i n storage, especially when the amine or amide is present in excess(Ref 87)... 

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