Low molecular weight polyamine

The same kind of relationship of carboxylates was found for ammonia, amines, and low-molecular-weight polyamines (eq. 6). 

More interest has been shown in polymeric flexibilisers, particularly the low molecular weight polyamides from dimer acid (see Chapter 18), the low molecular weight poly sulphides (Chapter 19), polyamines and the polyglycol diepoxides. 

Polybutadienes, polycaprolactones, polycarbonates, and amine-terminated polyethers (ATPEs) are shown in Scheme 4.4 as examples of other commercially available polyols. They are all specialty materials, used in situations where specific property profiles are required. For example, ATPEs are utilized in spray-applied elastomers where fast-reacting, high-molecular-weight polyamines give quick gel times and rapid viscosity buildup. Polycarbonates are used for implantation devices because polyuredtanes based on them perform best in this very demanding environment. Polycaprolactones and polybutadienes may be chosen for applications which require exceptional light stability, hydrolysis resistance, and/or low-temperature flexibility. 

Polycondensation of aromatic primary diamines and aromatic dibromides gave high molecular weight polyamine (Mw > 15 000) irrespective of the m-and p-substituted positions of both monomers (Scheme 12). In this polycondensation, BINAP was effective as a ligand of the Pd(0) catalyst use of P(f-butyl)3, which was effective for the above polymerization using secondary diamines, afforded polymer in a low yield [65,66]. When BINAP was used... 

In an alternative route, starch is complexed with a polyamine, poly(vinyl amine), polyethylene imine) or chitosan to render it cationic. Although stronger, these complexes may also separate with time and lead to an undesirable accumulation of a low molecular weight, high-charge polyamine fraction and interference in the retention process. 

The p-DVB-piperazine adducts can also undergo self condensation whereby the macromonomers formed exhibit rather low molecular weights, and are insoluble in the reaction mixture (benzene or THF). They dissolve only upon the addition of an acid or in hot chloroform. Free-radical copolymerization of this macromonomer with styrene was carried out in benzene in the presence of some acetic acid (to obtain a homogeneous reaction mixture) to yields of about 20% M). Here again separation of the unreacted macromonomer is possible, and the polyamine content of the graft copolymer is very close to the amount contained in the reaction mixture. 

While they are called resins, they are really monomers to low-molecular-weight oligomers, liquids to soluble fusible solids, with high reactivity in the epoxy rings, and fair reactivity in the internal hydroxyl groups. They are cured most often by room-temperature reaction with polyamines or polyamide amines. 

Since this manuscript was prepared Volkova et al. ( ) have presented a structure for a 636 molecular weight toxin isolated from the venom of Argiope lobata. Also Aramaki et. al. ( ) have presented somewhat similar structures for low molecular weight toxins present in the venoms of Nephila clavata and Nephila maculata. These compounds share in common the presence of amino acids, a phenyl group (62) and a polyamine. 

Aminic polyols are low molecular weight adducts of propylene oxide (PO) [and/or ethylene oxide (EO)] made from aliphatic or aromatic polyamines such as ethylenediamine (EDA), diethylene triamine (DETA) [1, 2], ortho-toluene diamine (o-TDA) [3, 4] or diphenylmethanediamine (MDA) [2, 5, 6]. Because these starters are liquid at room temperature (EDA, DETA) or low melting point solids (o-TDA, MDA), they are alkoxylated in the absence of solvents. 

Polyamines are low-molecular-weight molecules which are found in both prokaryotes and eukaryotes, and which fulfil essential needs for growth, division and differentiation. The most common poly amines are putrescine (1,4-diaminobutane tetramethylene-diamine), spermidine (N-(3-aminopropyl)-l,4-butane diamine) and spermine (N,N -bis(3-aminopropyl)-1,4-butane diamine). Cadaverine (1,5-diaminopentane) is also found in some micro-organisms (1,2). Most prokaryotes do not contain spermine but all cells contain putrescine and spermidine, in most cases in millimolar concentrations. 

Reactive polyamides resins are produced by reacting dimer acid with a slight excess of polyamines (diethyl triamine and triethyl tetramine) to produce low-molecular-weight polyamide resins having free amino groups in the chain (Kale et al., 1994). 

Individual rat posterior pituitaries were homogenized in dilute acid. Proteins were precipitated with trichloroacetic acid, whereas a-amino acids, polyamines, and other low-molecular-weight amino compounds were... 

Stoichiometric ratios can be calculated similarly for hardeners. In principle, each active hydrogen will react with one epoxy group. Thus a low-molecular-weight aliphatic polyamine such as diethylene triamine (DETA) has a molecular weight of 103 and five active hydrogens. The hydrogen equivalent is thus 20.6. The stoichiometrically correct ratio with an epoxy resin of EEW 200 would thus be 100 parts resin to 10.3 parts of DETA. In practice there is always a percentage of homopolymerization, especially at the temperature... 

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