P. Ferruti

Fractionation techniques in a hydro-organic environment: II. Acryloyl-morpholine polymers as a matrix for electrophoresis in hydro-organic solvents☆

The properties of gels prepared either from acryloyl-morpholine (ACM) or from its mixtures with acrylamide and crosslinked either with bisacrylylpiperazine or with methylenebisacrylamide have been described. ACM-containing gels are compatible with organic solvents. If polymerized in water and dried, they are able to reswell, e.g., in dimethyl sulfoxide or dimethylformamide. If polymerized in presence of dimethylformamide, they form perfectly clear gels, whose mechanical properties are by far superior than those of similar plain polyacrylamide formulations.

Protonation studies of multifunctional polymers with a poly(amido-amine) structure

The protonation of some poly(amide-amines) has been studied in aqueous solution by both 13C n.m.r. and potentiometric methods. In particular 13C n.m.r. chemical shifts were plotted as a function of pH. In all cases the curves show points of inflexion at pH values which can be predicted from potentiometric pK values. 1,4-Diacyl piperazine groups are present in the main chain of the poly(amino-amine). We found that 50% cis and 50% trans isomers with respect to the carbonyls were present in aqueous solution; the cistrans ratio is independent of pH. Only ‘apparent’ constants were found in the previously described polymeric acids and bases; however, ‘real’ basicity constants could be determined for the poly(amido-amines) studied in the present work. Moreover, the protonated monomeric unit site could be determined exactly by both potentiometric and 13C n.m.r. methods.

Thermodynamic and 13C n.m.r. data on the protonation of polymeric bases whose repeating units behave independently towards protonation

Abstract The protonation of several poly(amido-amines) and their non-macromolecular model compounds has been studied in aqueous solution by 13 C n.m.r., potentiometric, and calorimetric techniques. Sharp basicity constants and thermodynamic functions have been obtained with poly(amido-amines), thus confirming the peculiar behaviour of this family of polymeric bases. The behaviour of the models is similar to that of the corresponding polymers. However, they are constantly slightly more basic. This difference is mainly due to the entropy term.

Macroinorganics: 8. Chelation of copper(II) ion with some new poly(amido-amines)☆

Abstract The effect on Cu(ll) complexing ability of the number (n) of methylenic groups between aminic nitrogens has been studied for two classes of poly (amido-amines). In order to better elucidate the mechanism of complex formation, low molecular weight models of the polymers have also been studied. The complexing abilities of polymers and models are very similar and decrease by increasing n. Indeed compounds with n = 4 fail to form complexes in aqueous solution. Some viscosimetric titrations have been performed in order to ascertain possible conformational transitions upon complexation.

Synthesis and characterization of piperazine-derived poly(amido-amine)s with different distributions of amido- and amino-groups along the macromolecular chain

Abstract Four poly(amido-amine)s based on piperazine have been synthesized by poly(acylation-addition) reaction of piperazind with various activated derivatives of acrylic acid. In these polymers, amido-, and amino groups are randomly arranged along the macromolecular chain. These polymers have been fully characterized by hydrolytic analysis, 13 C n.m.r., and potentiometric techniques.

Macro inorganics V. Basicity and complexing ability of a new class of poly(amido-amines) with tertiary amino groups present both in the main chain and as side substituent

Abstract The basicity and Cu(III) ion complexing ability of a poly(amido-amine) carrying two tertiary amino groups in its repeating unit, have been studied in aqueous solution by potentiometric, calorimetric and spectrophotometric techniques. Contrary to most polymeric acids and bases, but according to the previously studied poly(amido-amines), whose amino groups were all present in the main chain, the new polymer exhibits ‘sharp’ constants, i.e. its constants do not depend on the ionization degree of the whole macromolecule. This peculiar behaviour was found in both the protonation and in complex formation processes.

New Oligomers and Polymers as Drug Carriers

The preparation of polymeric derivatives of drugs, in which the drug molecules are linked to polymeric matrices by means of covalent bonds of limited stability to biological environments, is receiving increasing attention by several groups (1–16) as one of the most promising ways to modify the pharmacokinetic properties of the drugs themselves, and, possibly, to achieve a preferential localization in target cells or tissues. In many cases, the aim is to prolong the pharmacological activity of the drug, while minimizing unfavorable side effects due to hyperdosage.

Synthesis of tertiary poly(amido-amine)s with amido- and amino-groups randomly arranged along the macromolecular chain

Abstract A new synthesis of poly(amido-amine)s from bis (secondary amine)s and acryloyl chloride has been studied, leading to polymers in which the amido- and amino-groups are randomly arranged along the macromolecular chain. A poly(amido-amine) based on piperazine, chosen as the mother compound, has been fully characterized by 13 C n.m.r. as well as by identification and quantitative evaluation of its hydrolysis products.

Thermodynamic studies on the protonation and complex formation of new tertiary animo polymers in aqueous solution

Abstract In previous studies we have found that polymers having a poly(amido-amine) structure show interesting properties in aqueous solution as far as their protonation and complex formation are concerned [1–4]. We thought it interesting to study a second class of poly(amido-amines) with entirely linear marcomolecular chains. The structures of the polymers are reported in Fig. 1 together with the protonation and stability constants of the second class of poly(amido-amines). The new polymers have been synthesized by poly-addition of pyperazine and NN′-dimethylethylenediamine to NN′-diacriloyl NN′-diethylethylenediamine (polymers I and II) or divinylsulphone (polymer III). Also in the case of these new polymers on the contrary to most polyelectrolytes ‘sharp’ basicity constants have been obtained. The results for polymers I and II are very close to those of the corresponding polymers of the first class: this means that the presence of a ring structure in the main chain is irrelevant with respect to protonation. Also for despite the short distance between basic nitrogens of different monomeric units; these constants are very low. A close similarity exists also between the stability constants of both classes of polymers. A Cu2+ complex may be formed in aqueous solution also with polymer III. The stability constant of this complex, however, is much lower than that with polymer I.